Method and apparatus for small data transmission, sdt

Abstract

To provide a method and an apparatus for suitable small data transmission, SDT.SOLUTION: A wireless device receives, from a base station, radio resource control, RRC, and a RRC release message comprising a measurement configuration for one or more measurements by the wireless device while the wireless device is in an inactive state and small data transmission, SDT, a configuration of a SDT procedure for transmission by the wireless device while the wireless device is in a RRC inactive state. While the wireless device is, on the basis of the RRC release message, in the RRC inactive state, the wireless device initiates the SDT procedure on the basis of the SDT configuration and does not perform, during the SDT procedure, measurements associated with the measurement configuration.SELECTED DRAWING: Figure 22

Description

[Background technology]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 226,882, filed July 29, 2021, which is incorporated herein by reference in its entirety. Summary of the Invention [Means for solving the problem]

[0002] In this disclosure, various embodiments are presented as examples of how the disclosed technology may be implemented and / or how the disclosed technology may be practiced in environments and scenarios. It will be apparent to those skilled in the relevant art that various changes in form and details may be made without departing from the scope. Indeed, after reading the specification, it will be apparent to those skilled in the relevant art how to implement alternative embodiments. The present embodiments should not be limited by any of the exemplary embodiments. The embodiments of the present disclosure are described with reference to the accompanying drawings. Limitations, features, and / or elements from the disclosed exemplary embodiments may be combined to create further embodiments within the scope of the present disclosure. The figures that highlight features and advantages are shown by way of example only. The disclosed architecture is sufficiently flexible and configurable to be utilized in ways other than those shown. For example, the actions listed in any flowchart may be rearranged in some embodiments or used only optionally.

[0003] The embodiments may be configured to operate as desired. The disclosed mechanisms may be implemented when certain criteria are met, for example, in a wireless device, a base station, a wireless environment, a network, a combination of the above, etc. Exemplary criteria may be based at least in part, for example, on wireless device or network node configuration, traffic load, initial system setup, packet size, traffic characteristics, a combination of the above, etc. When one or more criteria are met, various exemplary embodiments may be applied. Thus, it may be possible to implement exemplary embodiments that selectively implement the disclosed protocols.

[0004] A base station may communicate with a mix of wireless devices. A wireless device and / or a base station may support multiple technologies and / or multiple releases of the same technology. A wireless device may have some specific capabilities depending on the category and / or capabilities of the wireless device. When this disclosure refers to a base station communicating with multiple wireless devices, this disclosure may refer to a subset of all wireless devices in the coverage area. This disclosure may refer to multiple wireless devices of a given LTE or 5G release, including a given capability, and in a given sector of the base station. Multiple wireless devices in this disclosure may refer to selected multiple wireless devices and / or a subset of all wireless devices in the coverage area that implement according to the disclosed methods, etc. There may be multiple base stations or multiple wireless devices in a coverage area that may not comply with the disclosed methods. For example, those wireless devices or base stations are implemented based on older releases of LTE or 5G technology.

[0005] As used herein, "a" and "an" and similar phrases are to be interpreted as "at least one" and "one or more". Similarly, any term ending with the suffix "(s)" should be interpreted as "at least one" and "one or more". As used herein, the term "may" should be interpreted as "may be, for example". In other words, the term "may" indicates that the phrase following the term "may" is an example of multiple preferred possibilities and may or may not be used by one or more of the various embodiments. As used herein, the terms "comprises" and "consists of" recite one or more components of a described element. The term "comprises" is interchangeable with "includes" and does not exclude unrecited components included in the described element. In contrast, "consists of" provides a complete recitation of one or more components of a described element. As used herein, the term "based on" should be interpreted as "based at least in part on" rather than, for example, "based only on". As used herein, the term "and / or" refers to any possible combination of the listed elements. For example, "A, B, and / or C" can refer to A, B, C, A and B, A and C, B and C, or A, B, and C.

[0006] If A and B are sets and every element of A is also an element of B, then A is said to be a subset of B. Only non-empty sets and subsets are considered herein. For example, possible subsets of B={cell1, cell2} are {cell1}, {cell2}, and {cell1, cell2}. The phrase "based on" (or equivalently "based at least on") indicates that the phrase following the term "based on" is an example of a number of suitable possibilities that may or may not be used in one or more of the various embodiments. The phrase "in response to" (or equivalently "at least in response to") indicates that the phrase following the phrase "in response to" is an example of a number of suitable possibilities that may or may not be used in one or more of the various embodiments. The phrase "in response to" (or equivalently "in response to") indicates that the phrase following the phrase "in response to" is an example of a number of suitable possibilities that may or may not be used in one or more of the various embodiments. The phrase "adopted / used" (or, equivalently, "adopted / used at least") indicates that the phrase following the phrase "adopted / used" is one example of many suitable possibilities that may or may not be used in one or more of the various embodiments.

[0007] The term configured may relate to the capacity of a device, whether the device is in an operational or non-operational state. Configured may refer to a particular setting of a device that affects the operational characteristics of the device, whether the device is in an operational or non-operational state. In other words, hardware, software, firmware, registers, memory values, etc. may be "configured" within a device, whether the device is in an operational or non-operational state, to provide the device with a particular characteristic. A term such as "a control message originating at a device" may mean that the control message has parameters that can be used to configure a particular characteristic in the device or to implement a particular action in the device, whether the device is in an operational or non-operational state.

[0008] In this disclosure, a parameter (or equivalently referred to as a field, or information element: IE) may contain one or more information objects, which may contain one or more other objects. For example, if parameter (IE) N contains parameter (IE) M, which contains parameter (IE) K, which contains parameter (IE) K, then N contains K and N contains J. In an example embodiment, when one or more messages contain multiple parameters, it means that a parameter of the multiple parameters is included in at least one of the one or more messages, but need not be included in each of the one or more messages.

[0009] Many of the presented features are described as optional through the use of "may" or through the use of parentheses. For the sake of brevity and readability, this disclosure does not explicitly describe each and every variation that may be obtained by selecting from a set of optional features. This disclosure should be construed as explicitly disclosing all such variations. For example, a system described as having three optional features may be embodied in seven ways, i.e., with only one of the three possible features, any two of the three features, or three of the three features.

[0010] Many of the elements described in the disclosed embodiments may be implemented as modules, where a module is defined as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g., hardware with biological components), or a combination thereof, which may be behaviorally equivalent. For example, a module may be implemented in software routines written in a computer language configured to run on a hardware machine (C, C++, Fortran, Java, Basic, Matlab, etc.) or Simulink, Stateflow, GNU Octave, or LabVIEW MathScript. It may also be possible to implement modules using physical hardware incorporating discrete or programmable analog, digital, and / or quantum hardware. Examples of programmable hardware include computers, microcontrollers, microprocessors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), and complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages ​​such as assembly, C, C++, etc. FPGAs, ASICs, and CPLDs are often programmed using Hardware Description Languages ​​(HDLs) such as Verilog or VHSIC Hardware Description Language (VHDL), which configure the connections between the less functional internal hardware modules of the programmable device. To achieve a functional modular result, the above techniques are often used in combination. The present invention provides, for example, the following: (Item 1) 1. A method comprising: From the base station by the wireless device, a measurement configuration for one or more measurements by the wireless device while the wireless device is in a radio resource control (RRC) inactive state; receiving an RRC release message including a small data transmission (SDT) configuration of an SDT procedure for transmission by the wireless device while the wireless device is in the RRC inactive state; Based on receiving the RRC release message, transitioning, by the wireless device, to the RRC inactive state; starting, by the wireless device, a timer T331 for measurements in the RRC inactive state; performing measurements associated with said measurement configuration while T331 is running; initiating the SDT procedure based on the SDT configuration while the wireless device is in the RRC inactive state; not performing the measurement associated with the measurement configuration during the SDT procedure. (Item 2) 2. The method of claim 1, wherein the measurement configuration includes a T331 value. (Item 3) 3. The method of claim 1 or 2, further comprising stopping and / or pausing T331 based on the starting of the SDT procedure, and wherein the not performing the measurement associated with the measurement configuration is based on the stopping and / or pausing of T331. (Item 4) by the wireless device based on a failure of the SDT procedure. T331, and / or 4. The method according to any one of claims 1 to 3, further comprising resuming, starting and / or restarting the measurement associated with the measurement configuration. (Item 5) 1. A method comprising: From the base station by the wireless device, a measurement configuration for one or more measurements by the wireless device while the wireless device is in a radio resource control (RRC) inactive state; receiving an RRC release message including a small data transmission (SDT) configuration of an SDT procedure for transmission by the wireless device while the wireless device is in the RRC inactive state; transitioning, by the wireless device, to the RRC inactive state and performing measurements associated with the measurement configuration based on receiving the RRC release message; While the wireless device is in the RRC inactive state, initiating the SDT procedure based on the SDT configuration; and not performing a measurement associated with the measurement configuration during the SDT procedure. (Item 6) 6. The method of claim 5, further comprising starting, by the wireless device, a timer T331 for measurements in the RRC inactive state based on receiving the RRC release message. (Item 7) 7. The method of claim 6, wherein the performing of the measurement associated with the measurement configuration is while T331 is running. (Item 8) 8. The method according to claim 6 or 7, wherein the measurement configuration comprises a T331 value. (Item 9) 9. The method according to any one of items 6 to 8, further comprising stopping and / or pausing a measurement timer based on starting the SDT procedure, and wherein not performing the measurement associated with the measurement configuration is based on stopping and / or pausing the measurement timer. (Item 10) by the wireless device based on a failure of the SDT procedure. said measurement timer, and / or 10. The method according to any one of claims 6 to 9, further comprising resuming, starting and / or restarting the measurement associated with the measurement configuration. (Item 11) 1. A method comprising: From the base station by the wireless device, a measurement configuration for one or more measurements by the wireless device while the wireless device is in a radio resource control (RRC) inactive state; receiving an RRC release message including a small data transmission (SDT) configuration of an SDT procedure for transmission by the wireless device while the wireless device is in the RRC inactive state; Based on the RRC release message, while the wireless device is in the RRC inactive state, initiating the SDT procedure based on the SDT configuration; and not performing a measurement associated with the measurement configuration during the SDT procedure. (Item 12) 12. The method of claim 11, further comprising: transitioning, by the wireless device, to the RRC inactive state based on the RRC release message. (Item 13) 13. The method according to item 11 or 12, wherein the measurement configuration comprises a carrier frequency list and / or a validity area list. (Item 14) 14. The method according to any one of claims 11 to 13, further comprising starting, by the wireless device, a measurement timer based on the RRC release message. (Item 15) The measurement timer, 15. The method of claim 14, wherein the timer for measurements in the RRC inactive state and / or T331 are one or more of: (Item 16) 16. The method of claim 14 or 15, wherein the measurement configuration includes a value for the measurement timer. (Item 17) 17. The method according to any one of claims 14 to 16, further comprising: performing, by the wireless device, the measurement associated with the measurement configuration while the measurement timer is running based on the RRC release message. (Item 18) 18. The method of any one of items 14 to 17, further comprising stopping and / or pausing the measurement timer based on the starting of the SDT procedure. (Item 19) 20. The method of claim 18, wherein the not performing the measurement associated with the measurement configuration is based on stopping and / or pausing the measurement timer. (Item 20) upon failure of the SDT procedure, by the wireless device, said measurement timer, and / or 20. The method of claim 19, further comprising resuming, starting and / or restarting the measurement associated with the measurement configuration. (Item 21) The failure of the SDT procedure, that the SDT procedure failure timer has expired; selecting a serving cell, the cell being different from a serving cell, through which the wireless device is performing the SDT procedure; receiving a fallback indication; receiving a rejection message; and / or 21. The method according to any one of claims 11 to 20, based on at least one of determining that an RRC message cannot be complied with. (Item 22) 22. The method according to any one of claims 11 to 21, further comprising: performing, by the wireless device, the measurements associated with the measurement configuration based on the RRC release message. (Item 23) 23. The method of claim 22, wherein not performing the measurement associated with the measurement configuration comprises stopping performing the measurement and / or pausing performing the measurement. (Item 24) The wireless device Initiating the SDT procedure; and / or 24. The method according to any one of items 11 to 23, further comprising transmitting one or more results of the one or more measurements associated with the measurement configuration based on not performing the measurement associated with the measurement configuration. (Item 25) The SDT configuration, Next Hop Chain Count (NCC), A resume identity of the wireless device; and 25. The method according to any one of claims 11 to 24, comprising at least one of indications of configured radio bearers to the SDT procedure. (Item 26) said initiating said SDT procedure, receiving, by the wireless device, a paging message indicating the SDT procedure; and / or 26. The method according to any one of items 11 to 25, based on one or more of the SDT procedure data being available to the wireless device. (Item 27) not performing the measurements associated with the measurement configuration during the SDT procedure; based on the determination of an initiation of the SDT procedure, not performing the measurement associated with the measurement configuration; not performing the measurements associated with the measurement configuration based on transmitting a first uplink message for the SDT procedure; and / or not performing the measurements associated with the measurement configuration upon receiving a message for the SDT procedure; and 28. The method of any one of claims 11 to 27, comprising: not performing the measurements associated with the measurement configuration based on determining that a cell in which the wireless device has initiated the SDT procedure is invalid for the measurements. (Item 28) the wireless device supports carrier aggregation and / or dual connectivity; and / or 28. The method according to any one of claims 11 to 27, wherein the measurement configuration is for carrier aggregation and / or dual connectivity of the wireless device. (Item 29) A wireless device comprising one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to implement a method according to any one of items 1 to 28. (Item 30) A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform a method according to any one of items 1 to 28. (Item 31) 1. A method comprising: From the base station by the wireless device, a measurement configuration for one or more measurements by the wireless device while the wireless device is in a radio resource control (RRC) inactive state; receiving an RRC release message including a small data transmission (SDT) configuration of an SDT procedure for transmission by the wireless device while the wireless device is in the RRC inactive state; Based on receiving the RRC release message, transitioning, by the wireless device, to the RRC inactive state; starting, by the wireless device, a timer T331 for measurements in the RRC inactive state; performing measurements associated with said measurement configuration while T331 is running; not performing the measurements associated with the measurement configuration during the SDT procedure; performing, by the wireless device, the measurements associated with the measurement configuration based on a failure of the SDT procedure. (Item 32) 32. The method of claim 31, further comprising stopping and / or pausing T331 based on starting the SDT procedure, and wherein not performing the measurement associated with the measurement configuration is based on the stopping and / or pausing T331. (Item 33) by the wireless device based on the failure of the SDT procedure. T331, and / or 33. The method of claim 31 or 32, further comprising resuming, starting and / or restarting the measurement associated with the measurement configuration. (Item 34) The failure of the SDT procedure, that the SDT procedure failure timer has expired; selecting a serving cell, the cell being different from a serving cell, through which the wireless device is performing the SDT procedure; receiving a fallback indication; receiving a rejection message; and / or 34. The method according to any one of claims 31 to 33, based on at least one of determining that an RRC message cannot be complied with. (Item 35) 1. A method comprising: From the base station by the wireless device, a measurement configuration for one or more measurements by the wireless device while the wireless device is in a radio resource control (RRC) inactive state; receiving an RRC release message including a small data transmission (SDT) configuration of an SDT procedure for transmission by the wireless device while the wireless device is in the RRC inactive state; transitioning, by the wireless device, to the RRC inactive state and performing measurements associated with the measurement configuration based on receiving the RRC release message; not performing the measurements associated with the measurement configuration during the SDT procedure; performing, by the wireless device, the measurements associated with the measurement configuration based on a failure of the SDT procedure. (Item 36) Item 36. The method of item 35, wherein the wireless device starts a timer T331 for measurements in the RRC inactive state based on receiving the RRC release message. (Item 37) Item 37. The method of item 36, wherein the performing of the measurement associated with the measurement configuration is while T331 is running. (Item 38) 38. The method of claim 36 or 37, further comprising stopping and / or pausing T331 based on starting the SDT procedure, and wherein not performing the measurement associated with the measurement configuration is based on the stopping and / or pausing T331. (Item 39) by the wireless device based on the failure of the SDT procedure. T331, and / or 39. The method of any one of claims 35 to 38, further comprising resuming, starting and / or restarting the measurement associated with the measurement configuration. (Item 40) The failure of the SDT procedure, that the SDT procedure failure timer has expired; selecting a serving cell, the cell being different from a serving cell, through which the wireless device is performing the SDT procedure; receiving a fallback indication; receiving a rejection message; and / or 40. The method according to any one of claims 35 to 39, based on at least one of determining that an RRC message cannot be complied with. (Item 41) 1. A method comprising: From the base station by the wireless device, a measurement configuration for one or more measurements by the wireless device while the wireless device is in a radio resource control (RRC) inactive state; receiving an RRC release message including a small data transmission (SDT) configuration of an SDT procedure for transmission by the wireless device while the wireless device is in the RRC inactive state; not performing measurements associated with said measurement configuration during said SDT procedure; performing, by the wireless device, the measurements associated with the measurement configuration based on a failure of the SDT procedure. (Item 42) 42. The method of claim 41, further comprising: transitioning, by the wireless device, to the RRC inactive state based on the RRC release message. (Item 43) Item 43. The method according to item 41 or 42, wherein the measurement configuration comprises a carrier frequency list and / or a validity area list. (Item 44) 44. The method according to any one of claims 41 to 43, further comprising starting, by the wireless device, a measurement timer based on the RRC release message. (Item 45) The measurement timer, 45. The method according to claim 44, wherein the timer for measurements in the RRC inactive state and / or T331 are one or more of: (Item 46) Item 46. The method of item 44 or 45, wherein the measurement configuration includes a value for the measurement timer. (Item 47) 47. The method according to any one of items 44 to 46, wherein the performing of the measurement associated with the measurement configuration is while the measurement timer is running. (Item 48) 48. The method of any one of claims 44 to 47, further comprising stopping and / or pausing the measurement timer based on starting the SDT procedure associated with the SDT configuration. (Item 49) Item 49. The method of item 48, wherein the not performing the measurement associated with the measurement configuration is based on the stopping and / or pausing of the measurement timer. (Item 50) by the wireless device based on the failure of the SDT procedure. said measurement timer, and / or 50. The method of any one of claims 41 to 49, further comprising resuming, starting and / or restarting the measurement associated with the measurement configuration. (Item 51) The failure of the SDT procedure, that the SDT procedure failure timer has expired; selecting a serving cell, the cell being different from a serving cell, through which the wireless device is performing the SDT procedure; receiving a fallback indication; receiving a rejection message; and / or 51. The method according to any one of items 41 to 50, based on at least one of determining that an RRC message cannot be complied with. (Item 52) 52. The method according to any one of claims 41 to 51, further comprising: performing, by the wireless device, the measurement associated with the measurement configuration based on the RRC release message. (Item 53) not performing the measurement associated with the measurement configuration; and / or stopping performing said measurements and / or pausing performing said measurements; and / or 53. The method according to any one of items 41 to 52, based on initiating the SDT procedure associated with the SDT configuration. (Item 54) The wireless device Initiating the SDT procedure associated with the SDT configuration; and / or 54. The method of any one of items 41 to 53, further comprising transmitting one or more results of the one or more measurements associated with the measurement configuration based on not performing the measurement associated with the measurement configuration. (Item 55) The SDT configuration, Next Hop Chain Count (NCC), A resume identity of the wireless device; and 55. A method according to any one of claims 41 to 54, comprising at least one indication of configured radio bearers to the SDT procedure. (Item 56) said initiating said SDT procedure, receiving, by the wireless device, a paging message indicating the SDT procedure; and / or 56. A method according to any one of items 41 to 55, based on one or more of the SDT procedure data being available to the wireless device. (Item 57) not performing the measurements associated with the measurement configuration during the SDT procedure; based on the determination to initiate the SDT procedure, not performing the measurement associated with the measurement configuration; not performing the measurements associated with the measurement configuration based on transmitting a first uplink message for the SDT procedure; and / or not performing the measurements associated with the measurement configuration upon receiving a message for the SDT procedure; and 57. The method of any one of claims 41 to 56, comprising: not performing the measurement associated with the measurement configuration based on determining that a cell in which the wireless device has initiated the SDT procedure is invalid for the measurement. (Item 58) the wireless device supports carrier aggregation and / or dual connectivity; and / or Item 58. The method according to any one of items 41 to 57, wherein the measurement configuration is for carrier aggregation and / or dual connectivity of the wireless device. (Item 59) A wireless device comprising one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to implement a method according to any one of items 1 to 58. (Item 60) A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method of any one of items 1 to 58. [Brief description of the drawings]

[0011] Some examples of various embodiments of the present disclosure are described herein with reference to the drawings.

[0012] [Figure 1A] 1 illustrates an exemplary mobile communication network in which embodiments of the present disclosure may be implemented. [Figure 1B] 1 illustrates an exemplary mobile communication network in which embodiments of the present disclosure may be implemented. [Figure 2A] The new wireless (NR) user plane and control plane protocol stacks are shown, respectively. [Figure 2B] The new wireless (NR) user plane and control plane protocol stacks are shown, respectively. [Diagram 3] 2B illustrates an example of a service provided between protocol layers of the NR user plane protocol stack of FIG. 2A. [Figure 4A] 2B illustrates an example downlink data flow through the NR user plane protocol stack of FIG. 2A. [Figure 4B] 1 illustrates an example format of a MAC subheader in a MAC PDU. [Figure 5A]1 shows the mapping between downlink and uplink logical, transport, and physical channels, respectively. [Figure 5B] 1 shows the mapping between downlink and uplink logical, transport, and physical channels, respectively. [Figure 6] FIG. 2 is an exemplary diagram illustrating RRC state transitions of a UE. [Figure 7] 1 illustrates an example structure of an NR frame in which OFDM symbols are grouped. [Figure 8] 1 illustrates an example configuration of slots in the time and frequency domain of an NR carrier. [Figure 9] An example of bandwidth adaptation using three configured BWPs for an NR carrier is shown. [Figure 10A] 1 shows three carrier aggregation configurations with two component carriers. [Figure 10B] 1 shows an example of how aggregation cells can be arranged into one or more PUCCH groups. [Figure 11A] 1 shows an example of an SS / PBCH block structure and location. [Figure 11B] 1 illustrates an example of a CSI-RS mapped to the time and frequency domain. [Figure 12A] Three examples of downlink and uplink beam management procedures are shown, respectively. [Figure 12B] Three examples of downlink and uplink beam management procedures are shown, respectively. [Figure 13A] A four-step contention-based random access procedure, a two-step contention-free random access procedure, and an alternative two-step random access procedure are shown, respectively. [Figure 13B] A four-step contention-based random access procedure, a two-step contention-free random access procedure, and an alternative two-step random access procedure are shown, respectively. [Figure 13C]A four-step contention-based random access procedure, a two-step contention-free random access procedure, and an alternative two-step random access procedure are shown, respectively. [Figure 14A] 1 shows an embodiment of a CORESET configuration for a bandwidth portion. [Figure 14B] 13 shows an embodiment of CCE to REG mapping for DCI transmission on CORESET and PDCCH processing. [Figure 15] 1 illustrates an embodiment of a wireless device in communication with a base station. [Figure 16A] 1 shows an example structure for uplink and downlink transmission. [Figure 16B] 1 shows an example structure for uplink and downlink transmission. [Figure 16C] 1 shows an example structure for uplink and downlink transmission. [Figure 16D] 1 shows an example structure for uplink and downlink transmission. [Figure 17] 1 illustrates an embodiment of an RRC connection re-establishment procedure. [Figure 18] 1 illustrates an embodiment of an RRC connection resumption procedure. [Figure 19] 13 shows an example of a subsequent small data transmission (SDT). [Figure 20A] 13 illustrates an embodiment of time window management for one or more subsequent transmissions of an SDT. [Figure 20B] 13 illustrates an embodiment of time window management for one or more subsequent transmissions of an SDT. [Figure 21] 13 shows an example of idle / inactivity measurement using the SDT procedure. [Figure 22] 1 illustrates an embodiment of managing idle / inactivity measurements using SDT procedures. [Figure 23] Based on the SDT procedure, an embodiment for managing idle / inactivity measurements using timers is presented. [Figure 24] 1 illustrates an embodiment of detecting failure of an SDT procedure using idle / inactivity measurements. [Diagram 25]1 illustrates an embodiment of managing idle / inactivity measurements using SDT procedures. [Figure 26] 1 illustrates an embodiment for managing idle / inactivity measurements using a timer with an SDT procedure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 1A illustrates an example of a mobile communication network 100 in which an embodiment of the present disclosure may be implemented. The mobile communication network 100 may be, for example, a public land mobile network (PLMN) launched by a network operator. As illustrated in FIG. 1A, the mobile communication network 100 includes a core network (CN) 102, a radio access network (RAN) 104, and a wireless device 106.

[0014] The CN 102 may provide the wireless device 106 with an interface to one or more data networks (DNs), such as a public DN (e.g., the Internet), a private DN, and / or an intra-operator DN. As part of its interfacing function, the CN 102 may set up an end-to-end connection between the wireless device 106 and one or more DNs, authenticate the wireless device 106, and provide charging functionality.

[0015] The RAN 104 may connect the CN 102 to the wireless devices 106 via wireless communication over the air interface. As part of the wireless communication, the RAN 104 may provide scheduling, radio resource management, and retransmission protocols. The communication direction over the air interface from the RAN 104 to the wireless devices 106 is known as the downlink, and the communication direction over the air interface from the wireless devices 106 to the RAN 104 is known as the uplink. The downlink transmission may be separated from the uplink transmission using frequency division duplexing (FDD), time division duplexing (TDD), and / or some combination of the two duplexing techniques.

[0016] The term wireless device may be used throughout this disclosure to refer to and encompass any mobile or fixed (non-portable) device for which wireless communication is required or available. For example, a wireless device may be a phone, a smartphone, a tablet, a computer, a laptop, a sensor, a meter, a wearable device, an Internet of Things (IoT) device, a vehicular roadside unit (RSU), a relay node, an automobile, and / or any combination thereof. The term wireless device encompasses other terms, including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transmit / receive unit (WTRU), and / or wireless communication device.

[0017] The RAN 104 may include one or more base stations (not shown). The term base station may be used throughout this disclosure to refer to and encompass a Node B (associated with UMTS and / or 3G standards), an evolved Node B (eNB, associated with E-UTRA and / or 4G standards), a remote radio head (RRH), a baseband processing unit coupled to one or more RRHs, a repeater or relay node used to extend the coverage area of ​​a donor node, a next generation evolved Node B (ng-eNB), a generation Node B (gNB, associated with NR and / or 5G standards), an access point (AP, e.g., associated with WiFi or other suitable wireless communication standards), and / or any combination thereof. A base station may include at least one gNB central unit (gNB-CU) and at least one gNB distributed unit (gNB-DU).

[0018] The base stations included in the RAN 104 may include one or more sets of antennas for communicating over the air interface with the wireless devices 106. For example, one or more of the base stations may include three sets of antennas for controlling three cells (or sectors) respectively. The size of a cell may be determined by the range over which a receiver (e.g., a base station receiver) can successfully receive a transmission from a transmitter (e.g., a wireless device transmitter) operating in the cell. Together, the cells of the base stations may provide wireless coverage to the wireless devices 106 over a wide geographic area to support wireless device mobility.

[0019] In addition to three sector sites, other implementations of base stations are possible. For example, one or more of the base stations of the RAN 104 may be implemented as a sector site having more or less than three sectors. One or more of the base stations of the RAN 104 may be implemented as an access point, as a baseband processing unit coupled to multiple remote radio heads (RRHs), and / or as a repeater or relay node used to extend the coverage area of ​​a donor node. The baseband processing unit coupled to the RRHs may be part of a centralized or cloud RAN architecture, where the baseband processing unit may be centralized or virtualized within a pool of baseband processing units. The repeater node may amplify and rebroadcast the wireless signal received from the donor node. The relay node may perform the same / similar functions as the repeater node, but may decode the wireless signal received from the donor node and remove noise before amplifying and rebroadcasting the wireless signal.

[0020] The RAN 104 may be deployed as a homogeneous network of macrocell base stations having similar antenna patterns and similar high-level transmit power. The RAN 104 may be deployed as a heterogeneous network. In a heterogeneous network, small cell base stations may be used to provide small coverage areas, such as coverage areas that overlap with the relatively large coverage areas provided by macrocell base stations. The small coverage areas may be provided in areas of high data traffic (or so-called "hot spots") or areas where macrocell coverage is weak. Examples of small cell base stations include, in order of decreasing coverage area, microcell base stations, picocell base stations, and femtocell or home base stations.

[0021] The 3rd Generation Partnership Project (3GPP®) was formed in 1998 to provide global standardization of specifications for mobile communication networks similar to the mobile communication network 100 of FIG. 1A. To date, 3GPP® has produced specifications for three generations of mobile networks: a third generation (3G) network known as Universal Mobile Telecommunications System (UMTS), a fourth generation (4G) network known as Long Term Evolution (LTE), and a fifth generation (5G) network known as 5G System (5GS). Embodiments of the present disclosure are described with reference to a RAN of a 3GPP 5G network, referred to as Next Generation RAN (NG-RAN). The embodiments may be applicable to the RAN of other mobile communication networks, such as the RAN 104 of FIG. 1A, RANs of earlier 3G and 4G networks, and future networks yet to be specified (e.g., a 3GPP 6G network). NG-RAN implements the 5G radio access technology known as New Radio (NR), and may be provisioned to implement other radio access technologies, including 4G radio access technologies or non-3GPP radio access technologies.

[0022] 1B illustrates another exemplary mobile communication network 150 in which embodiments of the present disclosure may be implemented. The mobile communication network 150 may be, for example, a PLMN launched by a network operator. As illustrated in FIG. 1B, the mobile communication network 150 includes a 5G core network (5G-CN) 152, an NG-RAN 154, and a UE 156A and a UE 156B (collectively, UE 156). These components may be implemented and operate in the same or similar manner as the corresponding components described with respect to FIG. 1A.

[0023] 5G-CN 152 provides UE 156 with an interface to one or more DNs, such as a public DN (e.g., Internet), a private DN, and / or an intra-operator DN. As part of the interface function, 5G-CN 152 may set up an end-to-end connection between UE 156 and one or more DNs, authenticate UE 156, and provide charging functions. Compared to the CN of the 3GPP 4G network, the base of 5G-CN 152 may be a service-based architecture. This means that the architecture of the nodes constituting 5G-CN 152 may be defined as a network function that provides services via interfaces to other network functions. The network functions of 5G-CN 152 may be implemented in several ways: as network elements on dedicated or shared hardware, as software instances running on dedicated or shared hardware, or as virtualized functions instantiated on a platform (e.g., a cloud-based platform).

[0024] As shown in FIG. 1B, the 5G-CN 152 includes an Access and Mobility Management Function (AMF) 158A and a User Plane Function (UPF) 158B, which are shown in FIG. 1B as one component AMF / UPF 158 for ease of explanation. The UPF 158B may act as a gateway between the NG-RAN 154 and one or more DNs. The UPF 158B may perform functions such as packet routing and forwarding, packet inspection and enforcement of user plane policy rules, traffic utilization reporting, uplink classification to support routing of traffic flows to one or more DNs, quality of service (QoS) processing for the user plane (e.g., packet filtering, gating, uplink / downlink rate enforcement, and uplink traffic validation), downlink packet buffering, and downlink data notification triggers. The UPF 158B may act as an anchor point for intra / inter radio access technology (RAT) mobility, an external protocol (or packet) data unit (PDU) session point interconnected to one or more DNs, and / or a branching point to support multi-homed PDU sessions. The UE 156 may be configured to receive services via a PDU session, which is a logical connection between the UE and the DN.

[0025] The AMF 158A may perform functions such as termination of Non-Access Stratum (NAS) signaling, NAS signaling security, Access Stratum (AS) security control, inter-CN node signaling for mobility between 3GPP® access networks, idle mode UE reachability (e.g., control and execution of paging retransmissions), registration area management, intra-system and inter-system mobility support, access authentication, access authorization including checking roaming rights, mobility management control (subscription and policy), support for network slicing, and / or selection of a Session Management Function (SMF). NAS may refer to a function operating between the CN and the UE, and AS may refer to a function operating between the UE and the RAN.

[0026] 5G-CN 152 may include one or more additional network functions not shown in FIG. 1B for clarity. For example, 5G-CN 152 may include one or more of a Session Management Function (SMF), an NR Repository Function (NRF), a Policy Control Function (PCF), a Network Exposure Function (NEF), a Unified Data Management (UDM), an Application Function (AF), and / or an Authentication Server Function (AUSF).

[0027] The NG-RAN 154 may connect the 5G-CN 152 to the UE 156 via wireless communication over the air interface. The NG-RAN 154 may include one or more gNBs (collectively gNB 160), illustrated as gNB 160A and gNB 160B, and / or one or more ng-eNBs (collectively ng-eNB 162), illustrated as ng-eNB 162A and ng-eNB 162B. The gNBs 160 and ng-eNB 162 may be more generally referred to as base stations. The gNBs 160 and ng-eNB 162 may include one or more sets of antennas for communicating with the UE 156 over the air interface. For example, one or more of the gNBs 160 and / or one or more of the ng-eNBs 162 may include three sets of antennas for controlling three cells (or sectors), respectively. Together, the gNB160 and ng-eNB162 cells may provide radio coverage to the UE156 over a wide geographic area to support UE mobility.

[0028] As shown in FIG. 1B, the gNB 160 and / or the ng-eNB 162 may be connected to the 5G-CN 152 by an NG interface and to other base stations by an Xn interface. The NG and Xn interfaces may be established using direct physical connections and / or indirect connections over an underlying transport network, such as an Internet Protocol (IP) transport network. The gNB 160 and / or the ng-eNB 162 may be connected to the UE 156 by a Uu interface. For example, as shown in FIG. 1B, the gNB 160A may be connected to the UE 156A by a Uu interface. The NG, Xn, and Uu interfaces are associated with protocol stacks. The protocol stacks associated with the interfaces may be used by the network elements of FIG. 1B to exchange data and signaling messages and may include two planes: a user plane and a control plane. The user plane may process data of interest to a user. The control plane may process signaling messages of interest to the network elements.

[0029] The gNB 160 and / or the ng-eNB 162 may be connected to one or more AMF / UPF functions of the 5G-CN 152, such as the AMF / UPF 158, by one or more NG interfaces. For example, the gNB 160A may be connected to the UPF 158B of the AMF / UPF 158 by an NG-User Plane (NG-U) interface. The NG-U interface may provide for the provision of user plane PDUs between the gNB 160A and the UPF 158B (e.g., non-guaranteed delivery). The gNB 160A may be connected to the AMF 158A using an NG Control Plane (NG-C) interface. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, transport of NAS messages, paging, PDU session management, and configuration transfer and / or alert message transmission.

[0030] The gNB 160 may provide NR user plane and control plane protocol termination towards the UE 156 on the Uu interface. For example, the gNB 160A may provide NR user plane and control plane protocol termination towards the UE 156A on the Uu interface associated with a first protocol stack. The ng-eNB 162 may provide Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol termination towards the UE 156 on the Uu interface, where E-UTRA refers to a 3GPP 4G radio access technology. For example, the ng-eNB 162B may provide E-UTRA user plane and control plane protocol termination towards the UE 156B on the Uu interface associated with a second protocol stack.

[0031] The 5G-CN 152 has been described as being configured to handle NR and 4G radio access. Those skilled in the art will appreciate that it may be possible for the NR to connect to a 4G core network in a mode known as "non-standalone operation." In non-standalone operation, the 4G core network is used to provide (or at least support) control plane functions (e.g., initial access, mobility, and paging). Although only one AMF / UPF 158 is shown in FIG. 1B, one gNB or ng-eNB may be connected to multiple AMF / UPF nodes to provide redundancy and / or load sharing across multiple AMF / UPF nodes.

[0032] As discussed in Figure 1B, interfaces between network elements (e.g., Uu, Xn, and NG interfaces) may be associated with protocol stacks that the network elements use to exchange data and signaling messages. The protocol stacks may include two planes: a user plane and a control plane. The user plane may handle data of interest to a user, and the control plane may handle signaling messages of interest to the network elements.

[0033] Figures 2A and 2B show examples of NR user plane and NR control plane protocol stacks, respectively, for the Uu interface between a UE 210 and a gNB 220. The protocol stacks shown in Figures 2A and 2B may be the same or similar to those used for the Uu interface between a UE 156A and a gNB 160A shown in Figure 1B, for example.

[0034] 2A shows an NR user plane protocol stack including five layers implemented in the UE 210 and the gNB 220. At the bottom of the protocol stack, the physical layer (PHY) 211 and 221 may provide transport services to the higher layers of the protocol stack and may correspond to layer 1 of the Open System Interconnection (OSI) model. The next four protocols above the PHY 211 and 221 include the media access control layer (MAC) 212 and 222, the radio link control layer (RLC) 213 and 223, the packet data convergence protocol layer (PDCP) 214 and 224, and the service data application protocol layer (SDAP) 215 and 225. Together, these four protocols may constitute layer 2 or the data link layer of the OSI model.

[0035] FIG. 3 shows an example of services provided between protocol layers of the NR user plane protocol stack. Starting from the top of FIG. 2A and FIG. 3, the SDAPs 215 and 225 may perform QoS flow processing. The UE 210 may receive services via a PDU session, which may be a logical connection between the UE 210 and the DN. The PDU session may have one or more QoS flows. The UPF (e.g., UPF 158B) of the CN may map IP packets to one or more QoS flows of the PDU session based on the QoS requirements (e.g., in terms of delay, data rate, and / or error rate). The SDAPs 215 and 225 may perform mapping / de-mapping between one or more QoS flows and one or more data radio bearers. The mapping / de-mapping between the QoS flows and the data radio bearers may be determined by the SDAP 225 at the gNB 220. The SDAP 215 at the UE 210 may be informed of the mapping between the QoS flows and the data radio bearers via reflected mapping or control signaling received from the gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 may mark the downlink packets with a QoS flow indicator (QFI) that may be observed by the SDAP 215 at the UE 210 to determine mapping / demapping between QoS flows and data radio bearers.

[0036] The PDCPs 214 and 224 may perform header compression / decompression to reduce the amount of data that needs to be transmitted over the air interface, encryption / decryption to prevent unauthorized decryption of data transmitted over the air interface, and integrity protection (to ensure that control messages originate from the intended source. The PDCPs 214 and 224 may perform retransmission of undelivered packets, in-sequence delivery and reordering of packets, and elimination of duplicate received packets for intra-gNB handover, for example. The PDCPs 214 and 224 may perform packet duplication to improve the likelihood of a packet being received and to eliminate any duplicate packets at the receiver. Packet duplication may be useful for services that require high reliability.

[0037] Although not shown in FIG. 3, the PDCPs 214 and 224 may perform mapping / demapping between split radio bearers and RLC channels in a dual connectivity scenario. Dual connectivity is a technique that allows a UE to connect to two cells, or more generally, two cell groups, a master cell group (MCG) and a secondary cell group (SCG). A split bearer is when a single radio bearer, such as one of the radio bearers provided by the PDCPs 214 and 224 as a service to the SDAPs 215 and 225, is handled by a cell group in dual connectivity. The PDCPs 214 and 224 may map / demap the split radio bearer between the RLC channels belonging to the cell group.

[0038] The RLCs 213 and 223 may perform segmentation, retransmission through automatic repeat request (ARQ), and removal of duplicate data units received from the MACs 212 and 222, respectively. The RLCs 213 and 223 may support three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). Based on the transmission mode in which the RLC is operating, the RLC may perform one or more of the indicated functions. This RLC configuration may be per logical channel independent of numerology and / or transmission time interval (TTI) duration. As shown in FIG. 3, the RLCs 213 and 223 may provide RLC channels as services to the PDCPs 214 and 224, respectively.

[0039] The MACs 212 and 222 may perform multiplexing / demultiplexing of logical channels and / or mapping between logical channels and transport channels. Multiplexing / demultiplexing may include multiplexing / demultiplexing of data units belonging to one or more logical channels to / from a transport block (TB) delivered to / from the PHYs 211 and 221. The MAC 222 may be configured to perform scheduling, scheduling information reporting, and prioritization between UEs by dynamic scheduling. Scheduling may be performed at the gNB 220 (at the MAC 222) for downlink and uplink. The MACs 212 and 222 may be configured to perform error correction, prioritization between logical channels of the UE 210 by logical channel prioritization, and / or padding through hybrid automatic repeat request (HARQ) (e.g., one HARQ entity per carrier in case of carrier aggregation (CA)). The MACs 212 and 222 may support one or more numerologies and / or transmission timings. In an embodiment, mapping restrictions on logical channel prioritization may control which numerology and / or transmission timing a logical channel may use. As shown in Figure 3, MACs 212 and 222 may offer logical channels as services to RLCs 213 and 223.

[0040] The PHYs 211 and 221 may perform mapping of transport channels to physical channels and digital and analog signal processing functions to transmit and receive information over the air interface. These digital and analog signal processing functions may include, for example, coding / decoding and modulation / demodulation. The PHYs 211 and 221 may perform multi-antenna mapping. As shown in FIG. 3, the PHYs 211 and 221 may provide one or more transport channels as services to the MACs 212 and 222.

[0041] 4A illustrates an exemplary downlink data flow through the NR user plane protocol stack. FIG. 4A illustrates a downlink data flow of three IP packets (n, n+1, and m) through the NR user plane protocol stack, generating two TBs at the gNB 220. The uplink data flow through the NR user plane protocol stack may be similar to the downlink data flow illustrated in FIG. 4A.

[0042] The downlink data flow in Figure 4A starts when the SDAP 225 receives three IP packets from one or more QoS flows and maps the three packets to radio bearers. In Figure 4A, the SDAP 225 maps IP packets n and n+1 to the first radio bearer 402 and maps IP packet m to the second radio bearer 404. An SDAP header (labeled "H" in Figure 4A) is added to the IP packets. Data units from / to the higher protocol layer are referred to as service data units (SDUs) of the lower protocol layer, and data units to / from the lower protocol layer are referred to as protocol data units (PDUs) of the higher protocol layer. As shown in Figure 4A, the data units from the SDAP 225 are the SDUs of the lower protocol layer PDCP 224 and the PDUs of the SDAP 225.

[0043] The remaining protocol layers in FIG. 4A may perform related functions (e.g., with respect to FIG. 3), add corresponding headers, and forward their respective outputs to the next lower layer. For example, PDCP 224 may perform IP header compression and encryption and forward its output to RLC 223. RLC 223 may optionally perform segmentation (e.g., as shown for IP packet m in FIG. 4A) and forward its output to MAC 222. MAC 222 may multiplex several RLC PDUs and attach MAC subheaders to the RLC PDUs to form a transport block. In NR, the MAC subheader may be distributed throughout the MAC PDU as shown in FIG. 4A. In LTE, the MAC subheader may be completely located at the beginning of the MAC PDU. The NR MAC PDU structure may reduce processing time and associated delays because the MAC PDU subheaders may be calculated before the complete MAC PDU is assembled.

[0044] 4B shows an example format of a MAC subheader in a MAC PDU. The MAC subheader includes an SDU length field to indicate the length (e.g., in bytes) of the MAC SDU it corresponds to, a logical channel identifier (LCID) field to identify the logical channel on which the MAC SDU started to aid in the demultiplexing process, a flag (F) to indicate the size of the SDU length field, and a reserved bit (R) field for future use.

[0045] FIG. 4B further illustrates MAC Control Elements (CEs) inserted into the MAC PDU by a MAC, such as MAC 223 or MAC 222. For example, FIG. 4B illustrates two MAC CEs inserted into the MAC PDU. MAC CEs may be inserted at the start of the MAC PDU for downlink transmission (as shown in FIG. 4B) and at the end of the MAC PDU for uplink transmission. MAC CEs may be used for in-band control signaling. Examples of MAC CEs include scheduling-related MAC CEs, such as buffer status reporting and power headroom reporting, activation / deactivation MAC CEs, such as for PDCP duplicate detection activation / deactivation, channel state information (CSI) reporting, sounding reference signal (SRS) transmission, and pre-configured components, discontinuous reception (DRX)-related MAC CEs, timing advancement MAC CEs, and random access-related MAC CEs. The CE may be preceded by a MAC subheader of a format similar to that described in the MAC SDU, and may be identified with a reserved value in the LCID field that indicates the type of control information contained in the MAC CE.

[0046] Before describing the NR control plane protocol stack, we first describe logical, transport, and physical channels and the mapping between channel types, one or more of which may be used to perform functions related to the NR control plane protocol stack, as described below.

[0047] 5A and 5B show the mapping between logical, transport, and physical channels for the downlink and uplink, respectively. Information is passed through channels between the RLC, MAC, and PHY of the NR protocol stack. Logical channels may be used between the RLC and MAC and may be classified as control channels, which carry control and configuration information in the NR control plane, or as traffic channels, which carry data in the NR user plane. Logical channels may be classified as dedicated logical channels, which are dedicated to a particular UE, or as common logical channels, which may be used by more than one UE. Logical channels may also be defined by the type of information they carry. The set of logical channels defined by NR includes, for example, - a paging control channel (PCCH) for carrying paging messages used to page UEs whose location is unknown to the network at the cell level; A Broadcast Control Channel (BCCH) for conveying system information messages in the form of a Master Information Block (MIB) and several System Information Blocks (SIBs), which may be used by UEs to obtain information about how the cell is configured and how to operate within the cell; and - a Common Control Channel (CCCH) for carrying control messages as well as random access; - a dedicated control channel (DCCH) for carrying control messages to and from a specific UE for configuring the UE; - Dedicated Traffic Channel (DTCH) for carrying user data to and from a specific UE.

[0048] Transport channels are used between the MAC and PHY layers and may be defined by how the information they carry is transmitted over the air interface. The set of transport channels defined by NR includes, for example: A paging channel (PCH) for carrying paging messages originating from the PCCH; - a Broadcast Channel (BCH) for carrying the MIB from the BCCH; -A downlink shared channel (DL-SCH) for carrying downlink data and signaling messages, including SIBs from the BCCH; - an uplink shared channel (UL-SCH) for carrying uplink data and signaling messages; A Random Access Channel (RACH) that allows a UE to contact the network without prior scheduling.

[0049] The PHY may pass information between processing levels of the PHY using physical channels. A physical channel may have an associated set of time-frequency resources for carrying information for one or more transport channels. The PHY may generate control information to support the lower level operation of the PHY and provide control information to the lower levels of the PHY via physical control channels known as L1 / L2 control channels. The set of physical channels and physical control channels defined by NR includes, for example: - a Physical Broadcast Channel (PBCH) for carrying the MIB from the BCH; A Physical Downlink Shared Channel (PDSCH) for carrying downlink data and signaling messages from the DL-SCH and paging messages from the PCH; A Physical Downlink Control Channel (PDCCH) for carrying downlink control information (DCI), which may include downlink scheduling commands, uplink scheduling grants, and uplink power control commands; A Physical Uplink Shared Channel (PUSCH) for carrying uplink data and signaling messages from the UL-SCH and, in some examples, uplink control information (UCI), as described below; A physical uplink control channel (PUCCH) for carrying UCI, which may include a HARQ acknowledgement, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and a scheduling request (SR); A Physical Random Access Channel (PRACH) for random access.

[0050] Similar to the physical control channel, the physical layer generates physical signals to support the low-level operations of the physical layer. As shown in Figures 5A and 5B, the physical layer signals defined by NR include the Primary Synchronization Signal (PSS), the Secondary Synchronization Signal (SSS), the Channel State Information Reference Signal (CSI-RS), the Demodulation Reference Signal (DMRS), the Sounding Reference Signal (SRS), and the Phase Tracking Reference Signal (PT-RS). These physical layer signals are described in more detail below.

[0051] FIG. 2B shows an example NR control plane protocol stack. In FIG. 2B, the NR control plane protocol stack may use the first four protocol layers that are the same / similar to the example NR user plane protocol stack. These four protocol layers include PHY 211 and 221, MAC 212 and 222, RLC 213 and 223, and PDCP 214 and 224. Instead of having SDAP 215 and 225 at the top of the stack like the NR user plane protocol stack, the NR control plane stack has radio resource control (RRC) 216 and 226, and NAS protocols 217 and 237 at the top of the NR control plane protocol stack.

[0052] The NAS protocols 217 and 237 may provide control plane functions between the UE 210 and the AMF 230 (e.g., AMF 158A), or more generally, between the UE 210 and the CN. The NAS protocols 217 and 237 may provide control plane functions between the UE 210 and the AMF 230 via signaling messages called NAS messages. There is no direct path between the UE 210 and the AMF 230 over which NAS messages can be transported. NAS messages can be transported using the AS of the Uu and NG interfaces. The NAS protocols 217 and 237 may provide control plane functions such as authentication, security, connection setup, mobility management, and session management.

[0053] The RRCs 216 and 226 may provide a control plane function between the UE 210 and the gNB 220, or more generally, between the UE 210 and the RAN. The RRCs 216 and 226 may provide a control plane function between the UE 210 and the gNB 220 via signaling messages, referred to as RRC messages. The RRC messages may be transmitted between the UE 210 and the RAN using signaling radio bearers and the same / similar PDCP, RLC, MAC, and PHY protocol layers. The MAC may multiplex the control plane and user plane data within the same transport block (TB). The RRCs 216 and 226 may provide control plane functions such as broadcasting of system information related to the AS and the NAS, paging initiated by the CN or the RAN, establishment, maintenance, and release of an RRC connection between the UE 210 and the RAN, security functions including key management, establishment, configuration, maintenance, and release of signaling and data radio bearers, mobility functions, QoS management functions, control of UE measurement reporting and reporting, detection and recovery of Radio Link Failure (RLF), and / or NAS message forwarding. As part of establishing an RRC connection, the RRCs 216 and 226 may establish an RRC context, which may involve setting parameters for communications between the UE 210 and the RAN.

[0054] FIG. 6 is an example diagram illustrating RRC state transitions of a UE. The UE may be the same as or similar to the wireless device 106 shown in FIG. 1A, the UE 210 shown in FIG. 2A and FIG. 2B, or any other wireless device described in this disclosure. As shown in FIG. 6, the UE may be in at least one of three RRC states: RRC connected 602 (e.g., RRC_CONNECTED), RRC idle 604 (e.g., RRC_IDLE), and RRC inactive 606 (e.g., RRC_INACTIVE).

[0055] In the RRC connection 602, the UE has an established RRC context and may have at least one RRC connection with a base station. The base station may be similar to one of the one or more base stations included in the RAN 104 shown in FIG. 1A, one of the gNB 160 or ng-eNB 162 shown in FIG. 1B, the gNB 220 shown in FIG. 2A and FIG. 2B, or any other base station described in this disclosure. The base station to which the UE is connected may have an RRC context for the UE. The RRC context, referred to as the UE context, may include parameters for communication between the UE and the base station. These parameters may include, for example, one or more AS contexts, one or more radio link configuration parameters, bearer configuration information (e.g., related to data radio bearers, signaling radio bearers, logical channels, QoS flows, and / or PDU sessions), security information, and / or PHY, MAC, RLC, PDCP, and / or SDAP layer configuration information. In the RRC connection 602, the mobility of the UE may be managed by the RAN (e.g., the RAN 104 or the NG-RAN 154). The UE may measure signal levels (e.g., reference signal levels) from the serving cell and neighboring cells and report these measurements to the base station currently serving the UE. The UE's serving base station may request a handover to a cell of one of the neighboring base stations based on the reported measurements. The RRC state may transition from RRC Connected 602 to RRC Idle 604 via a Connection Release procedure 608 or to RRC Inactive 606 via a Connection Deactivation procedure 610.

[0056] In RRC Idle 604, no RRC context may be established for the UE. In RRC Idle 604, the UE may not have an RRC connection with a base station. While in RRC Idle 604, the UE may be in a sleep state most of the time (e.g., to conserve battery power). The UE may wake up periodically (e.g., once every discontinuous reception cycle) to monitor for paging messages from the RAN. UE mobility may be managed by the UE through a procedure known as cell reselection. The RRC state may transition from RRC Idle 604 to RRC Connected 602 via a connection establishment procedure 612, which may involve a random access procedure as discussed in more detail below.

[0057] In RRC Inactive 606, previously established RRC context is maintained in the UE and base station. This reduces signaling overhead and allows for a fast transition to RRC Connected 602 compared to transitioning from RRC Idle 604 to RRC Connected 602. In RRC Inactive 606, the UE is in a sleep state and UE mobility may be managed by the UE through cell reselection. The RRC state may transition from RRC Inactive 606 to RRC Connected 602 by a Connection Resume procedure 614 or to RRC Idle 604 via a Connection Release procedure 616 that is the same as or similar to the Connection Release procedure 608.

[0058] The RRC states may be associated with mobility management mechanisms. In RRC IDLE 604 and RRC INACTIVE 606, mobility is managed by the UE through cell reselection. The purpose of mobility management in RRC IDLE 604 and RRC INACTIVE 606 is to allow the network to inform the UE of events via paging messages without broadcasting the paging messages throughout the entire mobile communication network. The mobility management mechanisms used in RRC IDLE 604 and RRC INACTIVE 606 may allow the network to track the UE on a cell group level, so that paging messages may be broadcast on cells of the cell group in which the UE is currently located instead of the entire mobile communication network. The mobility management mechanisms in RRC IDLE 604 and RRC INACTIVE 606 track the UE on a cell group level. They may do so using different granularity of grouping. For example, there may be three levels of granularity of cell grouping: individual cells, cells within a RAN area identified by a RAN Area Identifier (RAI), and cells within a group of RAN areas referred to as a tracking area and identified by a Tracking Area Identifier (TAI).

[0059] The tracking area may be used to track the UE at the CN level. The CN (e.g., CN 102 or 5G-CN 152) may provide the UE with a list of TAIs associated with UE registration areas. If the UE moves, through cell reselection, to a cell associated with a TAI that is not included in the list of TAIs associated with the UE registration area, the UE may perform a registration update with the CN to enable the CN to update the UE's location and provide the UE with a new UE registration area.

[0060] The RAN area may be used to track the UE at the RAN level. For a UE in RRC inactive 606 state, a RAN notification area may be assigned to the UE. The RAN notification area may include one or more cell identities, a list of RAIs, or a list of TAIs. In an embodiment, a base station may belong to one or more RAN notification areas. In an embodiment, a cell may belong to one or more RAN notification areas. If the UE moves through cell reselection to a cell that is not included in the RAN notification area assigned to the UE, the UE may perform a notification area update with the RAN to update the RAN notification area of ​​the UE.

[0061] A base station that stores the RRC context for a UE or the last serving base station for the UE may be referred to as an anchor base station. The anchor base station may maintain the RRC context for the UE at least for a period of time that the UE remains in the RAN notification area of ​​the anchor base station and / or for a period of time that the UE remains in RRC inactive 606.

[0062] A gNB, such as gNB 160 in FIG. 1B, may be divided into two parts: a central unit (gNB-CU) and one or more distributed units (gNB-DU). The gNB-CU may be coupled to one or more gNB-DUs using an F1 interface. The gNB-CU may include RRC, PDCP, and SDAP. The gNB-DU may include RLC, MAC, and PHY.

[0063] In NR, physical signals and physical channels (discussed with respect to FIG. 5A and FIG. 5B) may be mapped onto orthogonal frequency division multiplexing (OFDM) symbols. OFDM is a multicarrier communication scheme that transmits data on F orthogonal subcarriers (or tones). Before transmission, the data may be mapped to a series of complex symbols (e.g., M-quadrature amplitude modulation (M-QAM) or M-phase shift keying (M-PSK) symbols), referred to as source symbols, which are split into F parallel symbol streams. The F parallel symbol streams may be treated as if they were in the frequency domain and used as input to an inverse fast Fourier transform (IFFT) block that transforms them to the time domain. The IFFT block may take F source symbols, one from each of the F parallel symbol streams at a time, and use each source symbol to modulate the amplitude and phase of one of the F sinusoidal basis functions corresponding to the F orthogonal subcarriers. The output of the IFFT block may be F time domain samples that represent a sum of the F orthogonal subcarriers. The F time domain samples may form a single OFDM symbol. After some processing (e.g., adding a cyclic prefix) and upconversion, the OFDM symbols provided by the IFFT block may be transmitted over the air interface at a carrier frequency. The F parallel symbol streams may be mixed using an FFT block before being processed by the IFFT block. This processing produces a Discrete Fourier Transform (DFT) precoded OFDM symbol, which can be used by UEs in the uplink to reduce the peak-to-average power ratio (PAPR). Inverse processing may be performed on the OFDM symbols at the receiver using an FFT block to recover the data mapped to the source symbols.

[0064] FIG. 7 illustrates an example configuration of an NR frame in which OFDM symbols are grouped. An NR frame may be identified by a system frame number (SFN). The SFN may repeat at a period of 1024 frames. As illustrated, one NR frame may be 10 milliseconds (ms) in duration and may include 10 subframes that are 1 ms in duration. The subframes may be divided into slots that include, for example, 14 OFDM symbols per slot.

[0065] The duration of a slot may depend on the numerology used for the OFDM symbol of the slot. In NR, flexible numerology is supported to accommodate different cell deployments (e.g., cells with carrier frequencies less than 1 GHz up to cells with carrier frequencies in the mm-wave range). Numerology may be defined in terms of subcarrier spacing and cyclic prefix duration. For numerology in NR, subcarrier spacing may be scaled up by powers of 2 from a baseline subcarrier spacing of 15 kHz, and cyclic prefix duration may be scaled down by powers of 2 from a baseline cyclic prefix duration of 4.7 μs. For example, NR defines numerology with the following subcarrier spacing / cyclic prefix duration combinations: 15 kHz / 4.7 μs, 30 kHz / 2.3 μs, 60 kHz / 1.2 μs, 120 kHz / 0.59 μs, and 240 kHz / 0.29 μs.

[0066] A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols). Numerologies with higher subcarrier spacing have shorter slot durations and correspondingly more slots per subframe. Figure 7 illustrates this numerology-dependent slot duration and slot-per-subframe transmission structure (for ease of illustration, a numerology with 240 kHz subcarrier spacing is not shown in Figure 7). Subframes in NR may be used as a numerology-independent time reference, while slots may be used as the unit by which uplink and downlink transmissions are scheduled. To support low latency, scheduling in NR is decoupled from the slot duration and may start at any OFDM symbol and continue for as many symbols as necessary for transmission. These partial slot transmissions may be referred to as minislot or subslot transmissions.

[0067] FIG. 8 shows an example configuration of slots in the time and frequency domains of an NR carrier. A slot includes resource elements (REs) and resource blocks (RBs). An RE is the smallest physical resource in NR. An RE spans one OFDM symbol in the time domain by one subcarrier in the frequency domain as shown in FIG. 8. An RB spans 12 consecutive REs in the frequency domain as shown in FIG. 8. An NR carrier may be limited to a width of 275 RBs or 275×12=3300 subcarriers. Such limitations, if used, may limit an NR carrier to 50, 100, 200, and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz, respectively, and the 400 MHz bandwidth may be set based on the 400 MHz per carrier bandwidth limit.

[0068] Figure 8 shows a single numerology used across the entire bandwidth of an NR carrier. In other example configurations, multiple numerologies may be supported on the same carrier.

[0069] NR may support a wide range of carrier bandwidths (e.g., up to 400 MHz with 120 kHz subcarrier spacing). Not all UEs may be able to receive the full carrier bandwidth (e.g., hardware limitations, etc.). Also, receiving the full carrier bandwidth may be prohibitive from a UE power consumption perspective. In an embodiment, to reduce power consumption and / or for other purposes, the UE may adapt the size of its reception bandwidth based on the amount of traffic the UE is scheduled to receive. This is referred to as bandwidth adaptation.

[0070] NR defines a bandwidth portion (BWP) to support UEs that cannot receive the entire carrier bandwidth and to support bandwidth adaptation. In an embodiment, a BWP may be defined by a subset of contiguous RBs on a carrier. A UE may be configured (e.g., via the RRC layer) with one or more downlink BWPs and one or more uplink BWPs per serving cell (e.g., up to four downlink BWPs and up to four uplink BWPs per serving cell). At a given time, one or more of the BWPs configured for a serving cell may be active. These one or more BWPs may be referred to as the active BWPs of the serving cell. When a serving cell is configured with a secondary uplink carrier, the serving cell may have one or more first active BWPs on the uplink carrier and one or more second active BWPs on the secondary uplink carrier.

[0071] For an unpaired spectrum, a downlink BWP from a set of configured downlink BWPs may be linked with an uplink BWP from a set of configured uplink BWPs if the downlink BWP index of the downlink BWP and the uplink BWP index of the uplink BWP are the same. For an unpaired spectrum, the UE may expect the center frequency of the downlink BWP to be the same as the center frequency of the uplink BWP.

[0072] For a downlink BWP in a set of configured downlink BWPs on a primary cell (PCell), the base station may configure the UE with one or more control resource sets (CORESETs) for at least one search space. A search space is a set of locations in the time and frequency domain where the UE can find control information. The search space may be a UE-specific search space or a common search space (potentially usable by multiple UEs). For example, the base station may configure the UE with a common search space on a PCell or a primary secondary cell (PSCell) in an active downlink BWP.

[0073] For an uplink BWP in a set of configured uplink BWPs, the BS may configure the UE with one or more resource sets for one or more PUCCH transmissions. The UE may receive a downlink reception (e.g., PDCCH or PDSCH) in the downlink BWP according to the configured numerology (e.g., subcarrier spacing and cyclic prefix duration) for the downlink BWP. The UE may transmit an uplink transmission (e.g., PUCCH or PUSCH) in the uplink BWP according to the configured numerology (e.g., subcarrier spacing and cyclic prefix length for the uplink BWP).

[0074] One or more BWP indicator fields may be provided in the downlink control information (DCI). A value of the BWP indicator field may indicate which BWP of a set of configured BWPs is an active downlink BWP for one or more downlink receptions. A value of the one or more BWP indicator fields may indicate an active uplink BWP for one or more uplink transmissions.

[0075] The base station may semi-statically configure the UE with a default downlink BWP in a set of configured downlink BWPs associated with the PCell. If the base station does not provide a default downlink BWP for the UE, the default downlink BWP may be the initial active downlink BWP. The UE may determine which BWP is the initial active downlink BWP based on the CORESET configuration obtained using the PBCH.

[0076] The base station may configure the UE with a BWP inactivity timer value for the PCell. The UE may start or restart the BWP inactivity timer at any appropriate time. For example, the UE may start or restart the BWP inactivity timer when (a) the UE detects a DCI indicating an active downlink BWP other than a default downlink BWP for paired spectrum operation, or (b) the UE detects a DCI indicating an active downlink BWP or an active uplink BWP other than a default downlink BWP or an uplink BWP for unpaired spectrum operation. If the UE does not detect a DCI for a certain period of time (e.g., 1 ms or 0.5 ms), the UE may start the BWP inactivity timer towards expiration (e.g., increasing it from zero to the BWP inactivity timer value or decreasing it from the BWP inactivity timer value to zero). When the BWP inactivity timer expires, the UE may be switched from the active downlink BWP to the default downlink BWP.

[0077] In an embodiment, a base station may semi-statically configure a UE with one or more BWPs, and the UE may switch the active BWP from a first BWP to a second BWP in response to receiving a DCI indicating the second BWP as the active BWP and / or in response to expiration of a BWP inactivity timer (e.g., if the second BWP is a default BWP).

[0078] Downlink and uplink BWP switching (BWP switching refers to switching from a currently active BWP to a currently inactive BWP) may be performed independently in paired spectrum. In unpaired spectrum, downlink and uplink BWP switching may be performed simultaneously. Switching between configured BWPs may occur based on RRC signaling, DCI, expiration of a BWP inactivity timer, and / or initiation of random access.

[0079] FIG. 9 illustrates an example of bandwidth adaptation using three configured BWPs for an NR carrier. A UE configured with three BWPs may be switched from one BWP to another BWP at a switching point. In the example illustrated in FIG. 9, the BWPs include BWP 902 with a bandwidth of 40 MHz and a subcarrier spacing of 15 kHz, BWP 904 with a bandwidth of 10 MHz and a subcarrier spacing of 15 kHz, and BWP 906 with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. BWP 902 may be the initial active BWP, and BWP 904 may be the default BWP. The UE may switch between the BWPs at a switching point. In the example of FIG. 9, the UE may switch from BWP 902 to BWP 904 at switching point 908. Switching at switching point 908 may occur for any suitable reason, for example, in response to expiration of a BWP inactivity timer (indicating switching to the default BWP) and / or in response to receiving a DCI indicating BWP 904 as the active BWP. The UE may switch from the active BWP 904 to BWP 906 at switching point 910 in response to receiving a DCI indicating BWP 906 as the active BWP. The UE may switch from the active BWP 906 to BWP 904 at switching point 912 in response to expiration of a BWP inactivity timer and / or in response to receiving a DCI indicating BWP 904 as the active BWP. The UE may switch from the active BWP 904 to BWP 902 at switching point 914 in response to receiving a DCI indicating BWP 902 as the active BWP.

[0080] If the UE is configured for a secondary cell with a default downlink BWP in the configured set of downlink BWP and timer values, the UE procedure for switching the BWP on the secondary cell may be the same / similar to that on the primary cell, e.g., the UE may use timer values ​​and default downlink BWP for the secondary cell in the same / similar manner that the UE uses these values ​​for the primary cell.

[0081] To provide a larger data rate, carrier aggregation (CA) may be used to aggregate two or more carriers and transmit simultaneously to and from the same UE. The aggregated carriers of CA may be referred to as component carriers (CCs). When CA is used, there are many serving cells for the UE and one for the CC. The CC may have three configurations in the frequency domain.

[0082] 10A shows three CA configurations with two CCs. In an intra-band, contiguous configuration 1002, two CCs are aggregated in the same frequency band (frequency band A) and are located immediately adjacent to each other in the frequency band. In an intra-band, non-contiguous configuration 1004, two CCs are aggregated in the same frequency band (frequency band A) and are separated in frequency bands by a gap. In an intra-band configuration 1006, two CCs are located in frequency bands (frequency band A and frequency band B).

[0083] In an embodiment, up to 32 CCs may be aggregated. The aggregated CCs may have the same or different bandwidths, subcarrier spacing, and / or duplexing schemes (TDD or FDD). A serving cell of a UE using CA may have a downlink CC. In the case of FDD, one or more uplink CCs may optionally be configured for the serving cell. The ability to aggregate more downlink carriers than uplink carriers may be useful, for example, when a UE has more data traffic in the downlink than in the uplink.

[0084] When using CA, one of the aggregation cells of the UE may be referred to as a Primary Cell (PCell). The PCell may be a serving cell to which the UE initially connects in RRC connection establishment, re-establishment, and / or handover. The PCell may provide the UE with NAS mobility information and security inputs. The UE may have different PCells. In the downlink, the carrier corresponding to the PCell may be referred to as a Downlink Primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell may be referred to as an Uplink Primary CC (UL PCC). The other aggregation cell for the UE may be referred to as a Secondary Cell (SCell). In an embodiment, the SCell may be configured after the PCell is configured for the UE. For example, the SCell may be configured via an RRC connection reconfiguration procedure. In the downlink, the carrier corresponding to the SCell may be referred to as a Downlink Secondary CC (DL SCC). In the uplink, the carrier corresponding to the SCell may be referred to as an Uplink Secondary CC (UL SCC).

[0085] A configured SCell for a UE may be activated and deactivated based on, for example, traffic and channel conditions. Deactivation of a SCell may mean that PDCCH and PDSCH reception on the SCell is deactivated and PUSCH, SRS, and CQI transmission on the SCell is deactivated. A configured SCell may be activated and deactivated using a MAC CE with respect to FIG. 4B. For example, the MAC CE may use a bitmap (e.g., one bit per SCell) to indicate which SCell (e.g., among a subset of configured SCells) for a UE is activated or deactivated. A configured SCell may be deactivated in response to expiration of a SCell deactivation timer (e.g., one SCell deactivation timer per SCell).

[0086] Downlink control information such as scheduling assignments and scheduling grants for a cell may be transmitted on the cell corresponding to the assignments and grants, known as self-scheduling. DCI for a cell may be transmitted on another cell, known as cross-carrier scheduling. Uplink control information for aggregation cells (e.g., HARQ acknowledgements and channel state feedback such as CQI, PMI, and / or RI) may be transmitted on the PUCCH of the PCell. A large number of aggregated downlink CCs may overload the PUCCH of the PCell. A cell may be divided into multiple PUCCH groups.

[0087] FIG. 10B illustrates an example of how aggregation cells may be configured into one or more PUCCH groups. PUCCH group 1010 and PUCCH group 1050 may each include one or more downlink CCs. In the example of FIG. 10B, PUCCH group 1010 includes three downlink CCs: PCell 1011, SCell 1012, and SCell 1013. PUCCH group 1050 includes three downlink CCs: PCell 1051, SCell 1052, and SCell 1053 in this example. One or more uplink CCs may be configured as PCell 1021, SCell 1022, and SCell 1023. One or more other uplink CCs may be configured as Primary SCell (PSCell) 1061, SCell 1062, and SCell 1063. Uplink control information (UCI) related to downlink CCs of PUCCH group 1010, denoted as UCI 1031, UCI 1032, and UCI 1033, may be transmitted on the uplink of PCell 1021. Uplink control information (UCI) related to downlink CCs of PUCCH group 1050, denoted as UCI 1071, UCI 1072, and UCI 1073, may be transmitted on the uplink of PSCell 1061. In an embodiment, if the aggregation cells depicted in FIG. 10B are not divided into PUCCH group 1010 and PUCCH group 1050, a single uplink PCell and PCell for transmitting UCI related to downlink CCs may be overloaded. By dividing the transmission of UCI between PCell 1021 and PSCell 1061, the overload may be prevented.

[0088] A cell including a downlink carrier and optionally an uplink carrier may be assigned a physical cell ID and a cell index. The physical cell ID or cell index may identify the downlink carrier and / or the uplink carrier of the cell, for example, depending on the context in which the physical cell ID is used. The physical cell ID may be determined using a synchronization signal transmitted on a downlink component carrier. The cell index may be determined using an RRC message. In this disclosure, the physical cell ID may be referred to as a carrier ID, and the cell index may be referred to as a carrier index. For example, when this disclosure refers to a first physical cell ID for a first downlink carrier, this disclosure may mean that the first physical cell ID is for a cell including the first downlink carrier. The same / similar concept may be applied to, for example, carrier activation. When this disclosure indicates that a first carrier is activated, this specification may mean that a cell including the first carrier is activated.

[0089] In CA, the multi-carrier nature of the PHY may be exposed to the MAC. In an embodiment, a HARQ entity may operate on the serving cell. A transport block may be generated per assignment / grant per serving cell. The transport block and potential HARQ retransmissions of the transport block may be mapped to the serving cell.

[0090] In the downlink, a base station may transmit (e.g., unicast, multicast, and / or broadcast) one or more reference signals (RS) (e.g., PSS, SSS, CSI-RS, DMRS, and / or PT-RS as shown in FIG. 5A) to the UE. In the uplink, the UE may transmit one or more RS to the base station (e.g., DMRS, PT-RS, and / or SRS as shown in FIG. 5B). The PSS and SSS may be transmitted by the base station and used by the UE to synchronize the UE to the base station. The PSS and SSS may be provided in a synchronization signal (SS) / physical broadcast channel (PBCH) block that includes the PSS, SSS, and PBCH. The base station may periodically transmit bursts of the SS / PBCH block.

[0091] FIG. 11A illustrates an example of a structure and location of an SS / PBCH block. A burst of SS / PBCH blocks may include one or more SS / PBCH blocks (e.g., four SS / PBCH blocks as shown in FIG. 11A). A burst may be transmitted periodically (e.g., every two frames or every 20 ms). A burst may be limited to a half frame (e.g., the first half frame having a duration of 5 ms). It will be appreciated that FIG. 11A is an example, and these parameters (number of SS / PBCH blocks per burst, periodicity of the burst, location of the burst within a frame) may be configured based on, for example, the carrier frequency of the cell in which the SS / PBCH block is transmitted, the numerology or subcarrier spacing of the cell, configuration by the network (e.g., using RRC signaling), or any other suitable factor. In an example, the UE may assume a subcarrier spacing for the SS / PBCH block based on the monitored carrier frequency, unless the wireless network configures the UE to assume a different subcarrier spacing.

[0092] An SS / PBCH block may span one or more OFDM symbols in the time domain (e.g., four OFDM symbols as shown in the example of FIG. 11A) and one or more subcarriers in the frequency domain (e.g., 240 consecutive subcarriers). The PSS, SSS, and PBCH may have a common center frequency. The PSS may be transmitted first and may span, for example, one OFDM symbol and 127 subcarriers. The SSS may be transmitted after the PSS (e.g., the last two symbols) and may span one OFDM symbol and 127 subcarriers. The PBCH may be transmitted after the PSS (e.g., over the next three OFDM symbols) and may span 240 subcarriers.

[0093] The location of the SS / PBCH block in the time and frequency domain may be unknown to the UE (e.g., when the UE is searching for a cell). To find and select a cell, the UE may monitor the carrier for a PSS. For example, the UE may monitor a frequency location within the carrier. If the PSS is not found after a certain duration (e.g., 20 ms), the UE may search for a PSS at a different frequency location within the carrier as indicated by the synchronization raster. If the PSS is found at a location in the time and frequency domain, the UE may determine the location of the SSS and PBCH, respectively, based on the known structure of the SS / PBCH block. The SS / PBCH block may be a cell-defined SS block (CD-SSB). In an embodiment, a primary cell may be associated with the CD-SSB. The CD-SSB may be located on the synchronization raster. In an embodiment, cell selection / search and / or reselection may be based on the CD-SSB.

[0094] The SS / PBCH block may be used by the UE to determine one or more parameters of the cell. For example, the UE may determine a physical cell identifier (PCI) of the cell based on the PSS and SSS sequences, respectively. The UE may determine a location of a frame boundary of the cell based on the location of the SS / PBCH block. For example, the SS / PBCH block may indicate that it was transmitted according to a transmission pattern, where the SS / PBCH block is a known distance from a frame boundary.

[0095] The PBCH may use QPSK modulation and may use forward error correction (FEC). The FEC may use polar coding. One or more symbols spanned by the PBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCH may include an indication of the cell's current system frame number (SFN) and / or SS / PBCH block timing index. These parameters may facilitate time synchronization of the UE to the base station. The PBCH may include a Master Information Block (MIB) used to provide the UE with one or more parameters. The MIB is used for the UE to identify the remaining minimum system information (RMSI) associated with the cell. The RMSI may include a System Information Block Type 1 (SIB1). The SIB1 may include information necessary for the UE to access the cell. The UE may use one or more parameters of the MIB to monitor the PDCCH, which may be used to schedule the PDSCH. The PDSCH may include SIB1. The SIB1 may be decoded using parameters provided in the MIB. The PBCH may indicate the absence of SIB1. The UE may be pointed to a frequency based on the PBCH indicating that SIB1 is not present, and the UE may search for an SS / PBCH block on the frequency to which the UE is pointed.

[0096] The UE may assume that one or more SS / PBCH blocks transmitted with the same SS / PBCH block index are quasi-co-located (QCL'd) (e.g., have the same / similar Doppler spread, Doppler shift, average gain, average delay, and / or spatial Rx parameters). The UE may not assume that the QCL's for SS / PBCH block transmissions have different SS / PBCH block indices.

[0097] SS / PBCH blocks (e.g., blocks within a half frame) may be transmitted in spatial directions (e.g., using different beams across the coverage area of ​​a cell). In an embodiment, a first SS / PBCH block may be transmitted in a first spatial direction using a first beam and a second SS / PBCH block may be transmitted in a second spatial direction using a second beam.

[0098] In an embodiment, within the frequency span of a carrier, a base station may transmit multiple SS / PBCH blocks. In an embodiment, a first PCI of a first SS / PBCH block of the multiple SS / PBCH blocks may be different from a second PCI of a second SS / PBCH block of the multiple SS / PBCH blocks. The PCIs of SS / PBCH blocks transmitted at different frequency locations may be different or may be the same.

[0099] The CSI-RS may be transmitted by a base station and used by a UE to obtain channel state information (CSI). The base station may configure the UE with one or more CSI-RS for channel estimation or any other suitable purpose. The base station may configure the UE with one or more of the same / similar CSI-RS. The UE may measure one or more CSI-RS. The UE may estimate downlink channel conditions and / or generate a CSI report based on measurements of one or more downlink CSI-RS. The UE may provide the CSI report to the base station. The base station may perform link adaptation using feedback provided by the UE (e.g., estimated downlink channel conditions).

[0100] A base station may semi-statically configure a UE with one or more CSI-RS resource sets. The CSI-RS resources may be associated with a location and periodicity in the time and frequency domain. The base station may selectively activate and / or deactivate CSI-RS resources. The base station may indicate to the UE that CSI-RS resources in a CSI-RS resource set are activated and / or deactivated.

[0101] The base station may configure the UE to report CSI measurements. The base station may configure the UE to provide CSI reporting periodically, aperiodically, or semi-persistently. For periodic CSI reporting, the UE may be configured with the timing and / or periodicity of the CSI reports. For aperiodic CSI reporting, the base station may request the CSI reports. For example, the base station may instruct the UE to measure configured CSI-RS resources and provide a CSI report on the measurements. For semi-persistent CSI reporting, the base station may configure the UE to periodically transmit and selectively start or stop periodic reports. The base station may configure the UE with the CSI-RS resource set and CSI reports using RRC signaling.

[0102] The CSI-RS configuration may include, for example, one or more parameters indicating up to 32 antenna ports. The UE may be configured to use the same OFDM symbol for the downlink CSI-RS and a control resource set (CORESET) if the downlink CSI-RS and CORESET are spatially QCL'd and resource elements associated with the downlink CSI-RS are outside of a physical resource block (PRB) configured for the CORESET. The UE may be configured to use the same OFDM symbol for the downlink CSI-RS and SS / PBCH block if the downlink CSI-RS and SS / PBCH block are spatially QCL'd and resource elements associated with the downlink CSI-RS are outside of a PRB configured for the SS / PBCH block.

[0103] The downlink DMRS may be transmitted by a base station and used by a UE for channel estimation. For example, the downlink DMRS may be used for coherent demodulation of one or more downlink physical channels (e.g., PDSCH). An NR network may support one or more variable and / or configurable DMRS patterns for data demodulation. At least one downlink DMRS configuration may support a frontloaded DMRS pattern. The frontloaded DMRS may be mapped to one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). The base station may semi-statically configure the UE with the number (e.g., maximum number) of frontloaded DMRS symbols of the PDSCH. The DMRS configuration may support one or more DMRS ports. For example, in the case of single-user MIMO, the DMRS configuration may support up to eight orthogonal downlink DMRS ports per UE. In the case of multi-user MIMO, the DMRS configuration may support up to four orthogonal downlink DMRS ports per UE. The wireless network may support a common DMRS structure for downlink and uplink (e.g., at least for CP-OFDM). The DMRS position, DMRS pattern, and / or scrambling sequence may be the same or different. The base station may transmit the downlink DMRS and corresponding PDSCH using the same precoding matrix. The UE may use one or more downlink DMRS for coherent demodulation / channel estimation of the PDSCH.

[0104] In an embodiment, a transmitter (e.g., a base station) may use a precoder matrix for a portion of a transmission bandwidth. For example, the transmitter may use a first precoder matrix for a first bandwidth and a second precoder matrix for a second bandwidth. The first precoder matrix and the second precoder matrix may be different based on the first bandwidth being different from the second bandwidth. The UE may assume that the same precoding matrix is ​​used across a set of PRBs. The set of PRBs may be denoted as a precoding resource block group (PRG).

[0105] The PDSCH may include one or more layers. The UE may assume that at least one symbol with a DMRS is present on one or more layers of the PDSCH. Higher layers may configure up to three DMRS for the PDSCH.

[0106] The downlink PT-RS may be transmitted by the base station and may be used by the UE for phase noise compensation. Whether the downlink PT-RS is present depends on the RRC configuration. The presence and / or pattern of the downlink PT-RS may be configured on a UE-specific basis using a combination of RRC signaling and / or an association with one or more parameters used for other purposes (e.g., modulation and coding scheme (MCS)) that may be indicated by DCI. When configured, the dynamic presence of the downlink PT-RS may be associated with one or more DCI parameters including at least the MCS. The NR network may support multiple PT-RS densities defined in the time and / or frequency domain. The frequency domain density, if present, may be associated with at least one configuration of the scheduled bandwidth. The UE may assume the same precoding for the DMRS and PT-RS ports. The number of PT-RS ports may be less than the number of DMRS ports in the scheduled resources. The downlink PT-RS may be restricted to the scheduled time / frequency duration of the UE. The downlink PT-RS may be transmitted on symbols to facilitate phase tracking at the receiver.

[0107] The UE may transmit an uplink DMRS to a base station for channel estimation. For example, the base station may use the uplink DMRS for coherent demodulation of one or more uplink physical channels. For example, the UE may transmit the uplink DMRS on a PUSCH and / or a PUCCH. The uplink DM-RS may span a range of frequencies similar to the range of frequencies associated with the corresponding physical channel. The base station may configure the UE with one or more uplink DMRS configurations. At least one DMRS configuration may support a frontloaded DMRS pattern. The frontloaded DMRS may be mapped to one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). The one or more uplink DMRS may be configured to transmit on one or more symbols of the PUSCH and / or the PUCCH. The base station may semi-statically configure the UE with a number (e.g., a maximum number) of frontloaded DMRS symbols for the PUSCH and / or the PUCCH that the UE may use to schedule single-symbol DMRS and / or dual-symbol DMRS. An NR network may support a common DMRS structure for the downlink and uplink (e.g., for Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM)), where the DMRS location, DMRS pattern, and / or scrambling sequence for the DMRS may be the same or different.

[0108] The PUSCH may include one or more layers, and the UE may transmit at least one symbol having a DMRS present on one or more layers of the PUSCH. In an embodiment, higher layers may configure up to three DMRSs for the PUSCH.

[0109] An uplink PT-RS (which may be used by the base station for phase tracking and / or phase noise compensation) may be present or absent depending on the RRC configuration of the UE. The presence and / or pattern of the uplink PT-RS may be configured on a UE-specific basis by a combination of one or more parameters used for other purposes (e.g., modulation and coding scheme (MCS)) that may be indicated by RRC signaling and / or DCI. When configured, the dynamic presence of the uplink PT-RS may be associated with one or more DCI parameters including at least the MCS. The wireless network may support multiple uplink PT-RS densities defined in the time / frequency domain. The frequency domain density, if present, may be associated with at least one configuration of the scheduled bandwidth. The UE may assume the same precoding for the DMRS and PT-RS ports. The number of PT-RS ports may be less than the number of DMRS ports in the scheduled resources. For example, the uplink PT-RS may be limited to the scheduled time / frequency duration of the UE.

[0110] The SRS may be transmitted by the UE to the base station for channel condition estimation to support uplink channel-dependent scheduling and / or link adaptation. The SRS transmitted by the UE may enable the base station to estimate uplink channel conditions at one or more frequencies. The base station scheduler may use the estimated uplink channel conditions to allocate one or more resource blocks for uplink PUSCH transmission from the UE. The base station may semi-statically configure the UE with one or more SRS resource sets. For an SRS resource set, the base station may configure the UE with one or more SRS resources. The SRS resource set applicability may be configured by higher layer (e.g., RRC) parameters. For example, when higher layer parameters indicate beam management, SRS resources in one or more SRS resource sets (e.g., having the same / similar time domain behavior, periodic, aperiodic, and / or the like) may be transmitted instantaneously (e.g., simultaneously). The UE may transmit one or more SRS resources in an SRS resource set. An NR network may support aperiodic, periodic, and / or semi-persistent SRS transmission. The UE may transmit SRS resources based on one or more trigger types, which may include higher layer signaling (e.g., RRC) and / or one or more DCI formats. In an embodiment, at least one DCI format may be used for the UE to select at least one of the one or more configured SRS resource sets. SRS trigger type 0 may refer to SRS triggered based on higher layer signaling. SRS trigger type 1 may refer to SRS triggered based on one or more DCI formats. In an embodiment, if the PUSCH and SRS are transmitted in the same slot, the UE may be configured to transmit the SRS after the transmission of the PUSCH and the corresponding uplink DMRS.

[0111] The base station may quasi-statistically configure the UE with one or more SRS configuration parameters indicating at least one of an SRS resource configuration identifier, a number of SRS ports, a time domain behavior of the SRS resource configuration (e.g., an indication of periodic, semi-persistent, or aperiodic SRS), a slot, minislot, and / or subframe level periodicity, an offset for periodic and / or aperiodic SRS resources, a number of OFDM symbols in the SRS resource, a start OFDM symbol of the SRS resource, an SRS bandwidth, a frequency hopping bandwidth, a periodic shift, and / or an SRS sequence ID.

[0112] The antenna ports are defined such that a channel on which a symbol on an antenna port is carried can be inferred from a channel on which another symbol on the same antenna port is carried. When a first symbol and a second symbol are transmitted on the same antenna port, a receiver can infer a channel (e.g., fade gain, multipath delay, and / or the like) on which a second symbol on an antenna port is carried from a channel on which a first symbol on the antenna port is carried. A first antenna port and a second antenna port may be referred to as quasi-co-located (QCLed) if one or more large-scale characteristics of a channel on which a first symbol on the first antenna port is carried can be inferred from a channel on which a second symbol on the second antenna port is carried. The one or more large-scale characteristics may include at least one of delay spread, Doppler spread, Doppler shift, average gain, average delay, and / or spatial receive (Rx) parameters.

[0113] In a channel using beamforming, beam management is required. Beam management may include beam measurement, beam selection, and beam indication. A beam may be associated with one or more reference signals. For example, a beam may be identified by one or more beamforming reference signals. The UE may perform downlink beam measurement based on a downlink reference signal (e.g., a channel state information reference signal (CSI-RS)) and generate a beam measurement report. The UE may perform a downlink beam measurement procedure after an RRC connection is set up with the base station.

[0114] FIG. 11B illustrates an example of a channel state information reference signal (CSI-RS) mapped to the time and frequency domain. The squares illustrated in FIG. 11B may span resource blocks (RBs) within the bandwidth of a cell. The base station may transmit one or more RRC messages including CSI-RS resource configuration parameters indicating one or more CSI-RS. One or more of the following parameters may be set by higher layer signaling (e.g., RRC and / or MAC signaling) for the CSI-RS resource configuration: CSI-RS resource configuration identity, number of CSI-RS ports, CSI-RS configuration (e.g., symbol and resource element (RE) location within a subframe), CSI-RS subframe configuration (e.g., subframe position, offset, and radio frame periodicity), CSI-RS power parameters, CSI-RS sequence parameters, code division multiplexing (CDM) type parameters, frequency density, transmit comb, quasi-collocation (QCL) parameters (e.g., QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist, csi-rs-configZPid, qcl-csi-rs-configNZPid), and / or other radio resource parameters.

[0115] The three beams shown in FIG. 11B may be configured for a UE in a UE-specific configuration. Three beams are shown in FIG. 11B (Beam #1, Beam #2, and Beam #3), and more or less beams may be configured. Beam #1 may be assigned with CSI-RS 1101, which may be transmitted on one or more subcarriers in the RB of the first symbol. Beam #2 may be assigned with CSI-RS 1102, which may be transmitted on one or more subcarriers in the RB of the second symbol. Beam #3 may be assigned with CSI-RS 1103, which may be transmitted on one or more subcarriers in the RB of the third symbol. By using frequency division multiplexing (FDM), the base station may transmit another CSI-RS associated with another UE's beam using other subcarriers in the same RB (e.g., not used to transmit CSI-RS 1101). By using time domain multiplexing (TDM), the beam used for a UE may be configured such that the UE's beam uses symbols from the other UE's beam.

[0116] The CSI-RS (e.g., CSI-RS 1101, 1102, 1103) shown in FIG. 11B may be transmitted by a base station and used by a UE for one or more measurements. For example, the UE may measure the reference signal received power (RSRP) of configured CSI-RS resources. The base station may configure the UE with a reporting configuration, and the UE may report the RSRP measurements to the network (e.g., via one or more base stations) based on the reporting configuration. In an embodiment, the base station may determine one or more transmission configuration indication (TCI) states including some reference signals based on the reported measurement results. In an embodiment, the base station may indicate one or more TCI states to the UE (e.g., via RRC signaling, MAC CE, and / or DCI). The UE may receive a downlink transmission having a receive (Rx) beam determined based on one or more TCI states. In an embodiment, the UE may or may not have beam correspondence capability. If the UE has beam correspondence capability, the UE may determine a spatial domain filter of a transmit (Tx) beam based on the spatial domain filter of the corresponding Rx beam. If the UE does not have beam correspondence capability, the UE may perform an uplink beam selection procedure to determine a spatial domain filter of the Tx beam. The UE may perform an uplink beam selection procedure based on one or more sounding reference signal (SRS) resources configured in the UE by the base station. The base station may select and indicate an uplink beam for the UE based on measurements of one or more SRS resources transmitted by the UE.

[0117] In a beam management procedure, the UE may evaluate (e.g., measure) channel quality of one or more beam pair links, including a transmit beam transmitted by the base station and a receive beam received by the UE. Based on the evaluation, the UE may transmit a beam measurement report indicating one or more beam pair quality parameters including, for example, one or more beam identities (e.g., beam index, reference signal index, or the like), RSRP, a precoding matrix indicator (PMI), a channel quality indicator (CQI), and / or a rank indicator (RI).

[0118] FIG. 12A shows an example of three downlink beam management procedures, P1, P2, and P3. Procedure P1 may enable UE measurements at a transmit (Tx) beam of a transmit receive point (TRP) (or multiple TRPs) to support selection of, for example, one or more base station Tx beams and / or UE Rx beams (shown as ellipses in the top and bottom rows of P1, respectively). Beamforming at a TRP may include a Tx beam sweep for a set of beams (shown as an ellipse rotating in a counterclockwise direction as indicated by the dashed arrow in the top rows of P1 and P2). Beamforming at a UE may include a Rx beam sweep for a set of beams (shown as an ellipse rotating in a clockwise direction as indicated by the dashed arrow in the bottom rows of P1 and P3). Procedure P2 may be used to enable UE measurements at a Tx beam of a TRP (shown as an ellipse rotating in a counterclockwise direction as indicated by the dashed arrow in the top row of P2). The UE and / or base station may perform procedure P2 using a smaller set of beams than used in procedure P1, or using narrower beams than used in procedure P1. This may be referred to as beam refinement. The UE may perform procedure P3 for Rx beam determination by using the same Tx beam at the base station and sweeping the Rx beams at the UE.

[0119] FIG. 12B shows an example of three uplink beam management procedures, U1, U2, and U3. Procedure U1 may be used, for example, to enable the base station to perform measurements on the UE's Tx beams to support the selection of one or more UE Tx beams and / or base station Rx beams (shown as ellipses in the top and bottom rows of U1, respectively). Beamforming at the UE may include, for example, a Tx beam sweep from a set of beams (shown as an ellipse rotating in a clockwise direction as indicated by the dashed arrow in the bottom rows of U1 and U3). Beamforming at the base station may include, for example, a Rx beam sweep from a set of beams (shown as an ellipse rotating in a counterclockwise direction as indicated by the dashed arrow in the top rows of U1 and U2). Procedure U2 may be used to enable the base station to adjust its Rx beam when the UE uses a fixed Tx beam. The UE and / or base station may perform procedure U2 using a smaller set of beams than used in procedure P1, or using a narrower beam than used in procedure P1. This may be referred to as beam refinement. The UE may perform procedure U3 to adjust its Tx beam when the base station uses a fixed Rx beam.

[0120] The UE may initiate a beam failure recovery (BFR) procedure based on the detection of the beam failure. The UE may transmit a BFR request (e.g., a preamble, UCI, SR, MAC CE, and / or the like) based on the initiation of the BFR procedure. The UE may detect beam failure based on a determination that the quality of the beam pair link of the associated control channel is unsatisfactory (e.g., has an error rate higher than an error rate threshold, a received signal power lower than a received signal power threshold, a timer expires, and / or the like).

[0121] The UE may measure the quality of the beam pair link using one or more reference signals (RSs) including one or more SS / PBCH blocks, one or more CSI-RS resources, and / or one or more demodulation reference signals (DMRSs). The quality of the beam pair link may be based on one or more of a block error rate (BLER), an RSRP value, a signal-to-interference-plus-noise ratio (SINR) value, a reference signal received quality (RSRQ) value, and / or a CSI value measured on the RS resource. The base station may indicate that the RS resource is quasi-co-located (QCLed) with one or more DM-RSs of a channel (e.g., a control channel, a shared data channel, and / or the like). The RS resource and one or more DMRSs of the channel may be QCLed when the channel characteristics (e.g., Doppler shift, Doppler spread, average delay, delay spread, spatial Rx parameters, fade, and / or the like) from a transmission to the UE over the RS resource are similar or identical to the channel characteristics from a transmission to the UE over the channel.

[0122] The network (e.g., gNB and / or ng-eNB of the network) and / or the UE may initiate a random access procedure. A UE in RRC_IDLE state and / or a UE in RRC_INACTIVE state may initiate a random access procedure to request a connection setup to the network. The UE may initiate a random access procedure from the RRC_CONNECTED state. The UE may initiate a random access procedure to request uplink resources (e.g., for uplink transmission of SR when there are no PUCCH resources available) and / or to acquire uplink timing (e.g., when the uplink synchronization state is not synchronized). The UE may initiate a random access procedure to request one or more system information blocks (SIBs) (e.g., SIB2, SIB3, and / or other system information such as the like). The UE may initiate a random access procedure for a beam failure recovery request. The network may initiate a random access procedure to establish time alignment for handover and / or for SCell addition.

[0123] Figure 13A shows a four-step contention-based random access procedure. Before the procedure begins, the base station may transmit a configuration message 1310 to the UE. Figure 13A includes the transmission of four messages: Msg1 1311, Msg2 1312, Msg3 1313, and Msg4 1314. Msg1 1311 may include and / or be referred to as a preamble (or random access preamble). Msg2 1312 may include and / or be referred to as a random access response (RAR).

[0124] The configuration message 1310 may be transmitted, for example, using one or more RRC messages. The one or more RRC messages may indicate one or more Random Access Channel (RACH) parameters to the UE. The one or more RACH parameters may include at least one of general parameters (e.g., RACH-configGeneral), cell-specific parameters (e.g., RACH-ConfigCommon), and / or dedicated parameters (e.g., RACH-configDedicated) for one or more random access procedures. The base station may broadcast or multicast the one or more RRC messages to the one or more UEs. The one or more RRC messages may be UE-specific (e.g., dedicated RRC messages transmitted to the UE in RRC_CONNECTED and / or RRC_INACTIVE states). The UE may determine time-frequency resources and / or uplink transmit power for transmission of Msg1 1311 and / or Msg3 1313 based on the one or more RACH parameters. Based on the one or more RACH parameters, the UE may determine the receive timing and downlink channel for receiving Msg2 1312 and Msg4 1314.

[0125] The one or more RACH parameters provided in the configuration message 1310 may indicate one or more physical RACH (PRACH) opportunities available for transmission of Msg1 1311. The one or more PRACH opportunities may be predefined. The one or more RACH parameters may indicate one or more available sets of one or more PRACH opportunities (e.g., prach-ConfigIndex). The one or more RACH parameters may indicate an association between (a) one or more PRACH opportunities and (b) one or more reference signals. The one or more RACH parameters may indicate an association between (a) one or more preambles and (b) one or more reference signals. The one or more reference signals may be SS / PBCH blocks and / or CSI-RS. For example, the one or more RACH parameters may indicate a number of SS / PBCH blocks mapped to the PRACH opportunities and / or a number of preambles mapped to the SS / PBCH blocks.

[0126] The one or more RACH parameters provided in the configuration message 1310 may be used to determine the uplink transmission power of Msg1 1311 and / or Msg3 1313. For example, the one or more RACH parameters may indicate a reference power for the preamble transmission (e.g., a received target power and / or an initial power of the preamble transmission). There may be one or more power offsets indicated by the one or more RACH parameters. For example, the one or more RACH parameters may indicate a power ramping step, a power offset between SSB and CSI-RS, a power offset between the transmissions of Msg1 1311 and Msg3 1313, and / or a power offset value between the preamble groups. The one or more RACH parameters may indicate one or more thresholds for which the UE may determine at least one reference signal (e.g., SSB and / or CSI-RS) and / or uplink carrier (e.g., a normal uplink (NUL) carrier and / or a complementary uplink (SUL) carrier).

[0127] Msg1 1311 may include one or more preamble transmissions (e.g., a preamble transmission and one or more preamble retransmissions). The RRC message may be used to configure one or more preamble groups (e.g., Group A and / or Group B). The preamble group may include one or more preambles. The UE may determine the preamble group based on a path loss measurement and / or a size of Msg3 1313. The UE may measure the RSRP of one or more reference signals (e.g., SSB and / or CSI-RS) and determine at least one reference signal having an RSRP above an RSRP threshold (e.g., rsrp-ThresholdSSB and / or rsrp-ThresholdCSI-RS). The UE may select at least one preamble associated with the one or more reference signals and / or the selected preamble group, for example, if an association between the one or more preambles and the at least one reference signal is configured by the RRC message.

[0128] The UE may determine the preamble based on one or more RACH parameters provided in the configuration message 1310. For example, the UE may determine the preamble based on a path loss measurement, an RSRP measurement, and / or a size of Msg3 1313. As another example, the one or more RACH parameters may indicate one or more thresholds for determining a preamble format, a maximum number of preamble transmissions, and / or one or more preamble groups (e.g., Group A and Group B). The base station may configure the UE with an association between one or more preambles and one or more reference signals (e.g., SSB and / or CSI-RS) using the one or more RACH parameters. If an association is configured, the UE may determine a preamble to include in Msg1 1311 based on the association. Msg1 1311 may be transmitted to the base station via one or more PRACH opportunities. The UE may use one or more reference signals (e.g., SSB and / or CSI-RS) for preamble selection and PRACH opportunity determination. One or more RACH parameters (eg, ra-ssb-OccasionMskIndex and / or ra-OccasionList) may indicate an association between a PRACH opportunity and one or more reference signals.

[0129] The UE may perform a preamble retransmission if no response is received after the preamble transmission. The UE may increase the uplink transmit power for the preamble retransmission. The UE may select an initial preamble transmit power based on a path loss measurement and / or a target received preamble power configured by the network. The UE may determine to retransmit the preamble and may ramp up the uplink transmit power. The UE may receive one or more RACH parameters (e.g., PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step of the preamble retransmission. The ramping step may be the amount of incremental increase of the uplink transmit power for the retransmission. If the UE determines a reference signal (e.g., SSB and / or CSI-RS) that is the same as the previous preamble transmission, the UE may ramp up the uplink transmit power. The UE may count the number of preamble transmissions and / or retransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE may determine that the random access procedure has completed unsuccessfully, for example, if the number of preamble transmissions exceeds a threshold configured by one or more RACH parameters (eg, preambleTransMax).

[0130] The Msg2 1312 received by the UE may include an RAR. In some scenarios, Msg2 1312 may include multiple RARs corresponding to multiple UEs. Msg2 1312 may be received after or in response to the transmission of Msg1 1311. Msg2 1312 may be scheduled on the DL-SCH and indicated on the PDCCH using a Random Access RNTI (RA-RNTI). Msg2 1312 may indicate that Msg1 1311 was received by the base station. Msg2 1312 may include a time alignment command that the UE may use to adjust the UE's transmission timing, a scheduling grant for the transmission of Msg3 1313, and / or a Temporary Cell RNTI (TC-RNTI). After the UE transmits the preamble, the UE may start a time window (e.g., ra-ResponseWindow) in which it monitors the PDCCH for Msg2 1312. The UE may determine when to start the time window based on the PRACH opportunity that the UE uses to transmit the preamble. For example, the UE may start the time window one or more symbols after the last symbol of the preamble (e.g., on the first PDCCH opportunity from the end of the preamble transmission). The one or more symbols may be determined based on numerology. The PDCCH may be within a common search space (e.g., Type1-PDCCH common search space) configured by the RRC message. The UE may identify the RAR based on a Radio Network Temporary Identifier (RNTI). The RNTI may be used in response to one or more events that initiate the random access procedure. The UE may use a Random Access RNTI (RA-RNTI). The RA-RNTI may be associated with the PRACH opportunity on which the UE transmits the preamble. For example, the UE may determine the RA-RNTI based on an OFDM symbol index, a slot index, a frequency domain index, and / or a UL carrier indicator of the PRACH opportunity. Examples of the RA-RNTI may be as follows: RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id where s_id may be the index of the first OFDM symbol of the PRACH opportunity (e.g., 0≦s_id<14), t_id may be the index of the first slot of the PRACH opportunity in the system frame (e.g., 0≦t_id<80), f_id may be the index of the PRACH opportunity in the frequency domain (e.g., 0≦f_id<8), and ul_carrier_id may be the UL carrier used for preamble transmission (e.g., 0 for NUL carrier and 1 for SUL carrier).

[0131] The UE may transmit Msg3 1313 in response to successful reception of Msg2 1312 (e.g., using resources identified in Msg2 1312). Msg3 1313 may be used for contention resolution, for example, in the contention-based random access procedure shown in FIG. 13A. In some scenarios, multiple UEs may transmit the same preamble to the base station, and the base station may provide the UE with a corresponding RAR. If multiple UEs interpret the RAR as corresponding to themselves, a mismatch may occur. Contention resolution (e.g., use of Msg3 1313 and Msg4 1314) may be used to increase the likelihood that a UE does not mistakenly use the identity of another UE. To perform contention resolution, the UE may include a device identifier (e.g., C-RNTI, if assigned, TC-RNTI included in Msg2 1312, and / or any other suitable identifier) ​​in Msg3 1313.

[0132] Msg4 1314 may be received after or in response to the transmission of Msg3 1313. If a C-RNTI was included in Msg3 1313, the base station uses the C-RNTI to address the UE on the PDCCH. If the UE's unique C-RNTI is detected on the PDCCH, the random access procedure is determined to have been successfully completed. If a TC-RNTI is included in Msg3 1313 (e.g., the UE is in an RRC_IDLE state or is otherwise not connected to the base station), Msg4 1314 is received using the DL-SCH associated with the TC-RNTI. If the MAC PDU is successfully decoded and the MAC PDU matches the CCCH SDU sent (e.g., transmitted) in Msg3 1313 or otherwise includes a corresponding UE contention resolution identity MAC CE, the UE may determine that contention resolution has been successful and / or the UE may determine that the random access procedure has been successfully completed.

[0133] The UE may be configured with a complementary uplink (SUL) carrier and a normal uplink (NUL) carrier. Initial access (e.g., random access procedure) may be supported on the uplink carrier. For example, the base station may configure the UE with two separate RACH configurations, one for the SUL carrier and one for the NUL carrier. For random access in a cell configured with the SUL carrier, the network may indicate which carrier (NUL or SUL) to use. The UE may determine the SUL carrier, for example, if the measured quality of one or more reference signals is lower than a broadcast threshold. Uplink transmissions of the random access procedure (e.g., Msg1 1311 and / or Msg3 1313) may remain on the selected carrier. The UE may switch uplink carriers during the random access procedure (e.g., between Msg1 1311 and Msg3 1313) in one or more cases. For example, the UE may determine and / or switch the uplink carrier for Msg1 1311 and / or Msg3 1313 based on a channel clear assessment (eg, listen-before-talk).

[0134] Figure 13B illustrates a two-step contention-free random access procedure. Similar to the four-step contention-based random access procedure illustrated in Figure 13A, the base station may transmit a configuration message 1320 to the UE before the procedure begins. The configuration message 1320 may be similar in some respects to the configuration message 1310. Figure 13B includes the transmission of two messages, Msg1 1321 and Msg2 1322. Msg1 1321 and Msg2 1322 may be similar in some respects to Msg1 1311 and Msg2 1312, respectively, illustrated in Figure 13A. As can be seen from Figures 13A and 13B, the contention-free random access procedure may not include messages similar to Msg3 1313 and / or Msg4 1314.

[0135] The contention-free random access procedure shown in Figure 13B may be initiated for beam failure recovery, other SI requests, SCell addition, and / or handover. For example, the base station may indicate or assign to the UE the preamble to be used for Msg1 1321. The UE may receive an indication of the preamble (e.g., ra-PreambleIndex) from the base station via PDCCH and / or RRC.

[0136] After transmitting the preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor the PDCCH of the RAR. In case of a beam failure recovery request, the base station may configure the UE with a separate time window and / or separate PDCCH within the search space indicated by the RRC message (e.g., recoverySearchSpaceId). The UE may monitor for PDCCH transmissions addressed to the Cell RNTI (C-RNTI) on the search space. In the contention-free random access procedure shown in FIG. 13B, the UE may determine that the random access procedure is successfully completed after or in response to transmitting Msg1 1321 and receiving the corresponding Msg2 1322. The UE may determine that the random access procedure is successfully completed, for example, when the PDCCH transmission is addressed to the C-RNTI. The UE may determine that the random access procedure is successfully completed, for example, if the UE receives an RAR including a preamble identifier corresponding to a preamble transmitted by the UE and / or if the RAR includes a MAC sub-PDU including the preamble identifier. The UE may determine the response as an indication of a response acknowledgment to the SI request.

[0137] Figure 13C shows another two-step random access procedure. Similar to the random access procedure shown in Figures 13A and 13B, the base station may send a configuration message 1330 to the UE before the procedure begins. The configuration message 1330 may be similar in some respects to the configuration message 1310 and / or the configuration message 1320. Figure 13C includes the transmission of two messages, namely MsgA 1331 and MsgB 1332.

[0138] MsgA 1331 may be transmitted in an uplink transmission by the UE. MsgA 1331 may include one or more transmissions of a preamble 1341 and / or one or more transmissions of a transport block 1342. The transport block 1342 may include content similar and / or equivalent to the content of Msg3 1313 shown in FIG. 13A. The transport block 1342 may include UCI (e.g., SR, HARQ ACK / NACK, and / or the like). The UE may receive MsgB 1332 after or in response to the transmission of MsgA 1331. MsgB 1332 may include content similar and / or equivalent to the content of Msg2 1312 (e.g., RAR) shown in FIG. 13A and FIG. 13B and / or the content of Msg4 1314 shown in FIG. 13A.

[0139] The UE may initiate the two-step random access procedure of Figure 13C for licensed and / or unlicensed spectrum. The UE may determine whether to initiate the two-step random access procedure based on one or more factors. The one or more factors may be the radio access technology in use (e.g., LTE, NR, and / or similar), whether the UE has a valid TA, the cell size, the RRC state of the UE, the type of spectrum (e.g., licensed vs. unlicensed), and / or any other suitable factor.

[0140] The UE may determine radio resources and / or uplink transmit power for the preamble 1341 and / or the transport block 1342 included in the MsgA 1331 based on the two-step RACH parameters included in the configuration message 1330. The RACH parameters may indicate a modulation and coding scheme (MCS), time frequency resources, and / or power control for the preamble 1341 and / or the transport block 1342. The time frequency resources for the transmission of the preamble 1341 (e.g., PRACH) and the time frequency resources for the transmission of the transport block 1342 (e.g., PUSCH) may be multiplexed using FDM, TDM, and / or CDM. The RACH parameters may enable the UE to determine the receive timing and downlink channel for monitoring and / or receiving the MsgB 1332.

[0141] The transport block 1342 may include data (e.g., delay sensitive data), a UE identifier, security information, and / or device information (e.g., International Mobile Subscriber Identity (IMSI)). The base station may send MsgB 1332 in response to MsgA 1331. MsgB 1332 may include at least one of a preamble identifier, a timing advance command, a power control command, an uplink grant (e.g., radio resource allocation and / or MCS), a UE identifier for contention resolution, and / or an RNTI (e.g., C-RNTI or TC-RNTI). The UE may determine that the two-step random access procedure is successfully completed if the preamble identifier in MsgB 1332 matches the preamble transmitted by the UE and / or the UE identifier in MsgB 1332 matches the UE identifier (e.g., transport block 1342) in MsgA 1331.

[0142] The UE and the base station may exchange control signaling, which may be referred to as L1 / L2 control signaling, and may originate from the PHY layer (e.g., Layer 1) and / or the MAC layer (e.g., Layer 2). The control signaling may include downlink control signaling transmitted from the base station to the UE and / or uplink control signaling transmitted from the UE to the base station.

[0143] The downlink control signaling may include downlink scheduling assignments, uplink scheduling grants indicating uplink radio resources and / or transport formats, slot format information, preemption indications, power control commands, and / or any other suitable signaling. A UE may receive the downlink control signaling in a payload transmitted by a base station on a Physical Downlink Control Channel (PDCCH). The payload transmitted on the PDCCH may be referred to as Downlink Control Information (DCI). In some scenarios, the PDCCH may be a Group Common PDCCH (GC-PDCCH) that is common to a group of UEs.

[0144] The base station may attach one or more cyclic redundancy check (CRC) parity bits to the DCI to facilitate detection of transmission errors. When the DCI is intended for a UE (or a group of UEs), the base station may scramble the CRC parity bits with an identifier of the UE (or an identifier of the group of UEs). Scrambling the CRC parity bits with an identifier may include a modulo-2 addition (or exclusive OR) of the identifier value and the CRC parity bits. The identifier may include a Radio Network Temporary Identifier (RNTI), which is a 16-bit value.

[0145] DCIs may be used for different purposes. The purpose may be indicated by the type of RNTI used to scramble the CRC parity bits. For example, a DCI with CRC parity bits scrambled with a Paging RNTI (P-RNTI) may indicate paging information and / or system information change notification. The P-RNTI may be predefined as "FFFE" in hexadecimal. A DCI with CRC parity bits scrambled with a System Information RNTI (SI-RNTI) may indicate a broadcast transmission of system information. The SI-RNTI may be predefined as "FFFF" in hexadecimal. A DCI with CRC parity bits scrambled with a Random Access RNTI (RA-RNTI) may indicate a Random Access Response (RAR). A DCI with CRC parity bits scrambled with a Cell RNTI (C-RNTI) may indicate a unicast transmission of dynamic scheduling and / or a random access of PDCCH order trigger. A DCI with CRC parity bits scrambled with the Temporary Cell RNTI (TC-RNTI) may indicate contention resolution (e.g., Msg3 similar to Msg3 1313 shown in FIG. 13A). Encodings of other RNTIs configured by the base station in the UE include Configured Scheduling RNTI (CS-RNTI), Transmit Power Control-PUCCH RNTI (TPC-PUCCH-RNTI), Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI), Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), Interruption RNTI (INT-RNTI), Slot Format Indication RNTI (SFI-RNTI), Semi-Persistent CSI RNTI (SP-CSI-RNTI), Modulation and Coding Scheme Cell RNTI (MCS-C-RNTI), and / or the like.

[0146] Depending on the purpose and / or content of the DCI, the base station may transmit the DCI in one or more DCI formats. For example, DCI format 0_0 may be used for scheduling the PUSCH in the cell. DCI format 0_0 may be a fallback DCI format (e.g., has a compact DCI payload). DCI format 0_1 ​​may be used for scheduling the PUSCH in the cell (e.g., has a larger DCI payload than DCI format 0_0). DCI format 1_0 may be used for scheduling the PDSCH in the cell. DCI format 1_0 may be a fallback DCI format (e.g., has a compact DCI payload). DCI format 1_1 may be used for scheduling the PDSCH in the cell (e.g., has a larger DCI payload than DCI format 1_0). DCI format 2_0 may be used to provide a slot format indication to a group of UEs. DCI format 2_1 may be used to inform a group of UEs of physical resource blocks and / or OFDM symbols that the UE assumes are not intended for transmission to the UE. DCI format 2_2 may be used for transmission of transmit power control (TPC) commands for PUCCH or PUSCH. DCI format 2_3 may be used for transmission of a group of TPC commands for SRS transmission by one or more UEs. DCI formats for new features may be defined in future releases. DCI formats may have different DCI sizes or share the same DCI size.

[0147] After scrambling the DCI with the RNTI, the base station may process the DCI with channel coding (e.g., polar coding), rate matching, scrambling, and / or QPSK modulation. The base station may map the coded and modulated DCI onto resource elements used and / or configured for the PDCCH. Based on the payload size of the DCI and / or the coverage of the base station, the base station may transmit the DCI via the PDCCH occupying several consecutive control channel elements (CCEs). The number of consecutive CCEs (referred to as an aggregation level) may be 1, 2, 4, 8, 16, and / or any other suitable number. A CCE may include a number of resource element groups (REGs) (e.g., 6). A REG may include a resource block in an OFDM symbol. The mapping of the coded and modulated DCI onto resource elements may be based on a mapping of CCEs and REGs (e.g., CCE to REG mapping).

[0148] FIG. 14A illustrates an example of a CORESET configuration for a bandwidth portion. A base station may transmit DCI via a PDCCH on one or more control resource sets (CORESETs). A CORESET may include time-frequency resources on which a UE attempts to decode DCI using one or more search spaces. A base station may configure CORESETs in the time-frequency domain. In the example of FIG. 14A, a first CORESET 1401 and a second CORESET 1402 occur at a first symbol in a slot. The first CORESET 1401 overlaps with the second CORESET 1402 in the frequency domain. A third CORESET 1403 occurs at a third symbol in a slot. A fourth CORESET 1404 occurs at a seventh symbol of the slot. The CORESETs may have different numbers of resource blocks in the frequency domain.

[0149] FIG. 14B illustrates an example of CCE-to-REG mapping for DCI transmission on a CORESET and PDCCH processing. The CCE-to-REG mapping may be interleaved (e.g., to provide frequency diversity) or non-interleaved (e.g., to facilitate interference coordination and / or frequency selective transmission of control channels). A base station may implement different or the same CCE-to-REG mapping on different CORESETs. A CORESET may be associated with a CCE-to-REG mapping by RRC configuration. A CORESET may be configured with an antenna port quasi-co-location (QCL) parameter. The QCL parameter of an antenna port may indicate the QCL information of a demodulation reference signal (DMRS) for PDCCH reception in the CORESET.

[0150] The base station may send an RRC message to the UE including configuration parameters of one or more CORESETs and one or more search space sets. The configuration parameters may indicate an association between the search space set and the CORESET. The search space set may include a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters may indicate the number of PDCCH candidates monitored per aggregation level, a PDCCH monitoring periodicity and a PDCCH monitoring pattern, one or more DCI formats monitored by the UE, and / or whether the search space set is a common search space set or a UE-specific search space set. The set of CCEs in the common search space set may be predefined and known to the UE. The set of CCEs in the UE-specific search space set may be configured based on the UE's identity (e.g., C-RNTI).

[0151] As shown in FIG. 14B, the UE may determine time-frequency resources of the CORESET based on the RRC message. The UE may determine CCE-REG mapping (e.g., interleaved or non-interleaved, and / or mapping parameters) for the CORESET based on configuration parameters of the CORESET. The UE may determine the number of search space sets (e.g., up to 10) configured on the CORESET based on the RRC message. The UE may monitor a set of PDCCH candidates according to configuration parameters of the search space sets. The UE may monitor a set of PDCCH candidates in one or more CORESETs to detect one or more DCIs. The monitoring may include decoding one or more PDCCH candidates of the set of PDCCH candidates according to a monitored DCI format. The monitoring may include decoding DCI content of one or more PDCCH candidates having possible (or configured) PDCCH positions, possible (or configured) PDCCH formats (e.g., number of CCEs in a common search space, number of PDCCH candidates, and / or number of PDCCH candidates in a UE-specific search space), and possible (or configured) DCI formats. The decoding may be referred to as blind decoding. The UE may determine a valid DCI for the UE in response to a CRC check (e.g., scrambling bits to CRC parity bits of the DCI matching the RNTI value). The UE may process information included in the DCI (e.g., scheduling assignments, uplink grants, power control, slot format indication, downlink preemption, and / or the like).

[0152] The UE may transmit uplink control signaling (e.g., uplink control information (UCI)) to the base station. The uplink control signaling may include a hybrid automatic repeat request (HARQ) acknowledgement for a received DL-SCH transport block. The UE may transmit the HARQ acknowledgement after receiving the DL-SCH transport block. The uplink control signaling may include channel state information (CSI) indicating a channel quality of a physical downlink channel. The UE may transmit the CSI to the base station. The base station may determine transmission format parameters (e.g., including multiple antennas and beamforming schemes) for the downlink transmission based on the received CSI. The uplink control signaling may include a scheduling request (SR). The UE may transmit an SR indicating that uplink data is available for transmission to the base station. The UE may transmit the UCI (e.g., a HARQ acknowledgement (HARQ-ACK), a CSI report, an SR, etc.) via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). A UE may transmit uplink control signaling via the PUCCH using one of several PUCCH formats.

[0153] There may be five PUCCH formats, and the UE may determine the PUCCH format based on the size of the UCI (e.g., the number of uplink symbols of UCI transmission and the number of UCI bits). PUCCH format 0 may have a length of one or two OFDM symbols and may include two or less bits. The UE may transmit UCI in the PUCCH resource using PUCCH format 0 if the transmission is more than one or two symbols and the number of HARQ-ACK information bits with positive or negative SR (HARQ-ACK / SR bits) is one or two. PUCCH format 1 may occupy between four and fourteen OFDM symbols and may include two or less bits. The UE may use PUCCH format 1 if the transmission is four or more symbols and the number of HARQ-ACK / SR bits is one or two. PUCCH format 2 may occupy one or two OFDM symbols and may include more than two bits. The UE may use PUCCH format 2 if the transmission is more than one or two symbols and the number of UCI bits is two or more. PUCCH format 3 may occupy a number between 4 and 14 OFDM symbols and may include more than two bits. The UE may use PUCCH format 3 if the transmission is four or more symbols, the number of UCI bits is two or more, and the PUCCH resource does not include an orthogonal cover code. PUCCH format 4 may occupy a number between 4 and 14 OFDM symbols and may include more than two bits. The UE may use PUCCH format 4 if the transmission is four or more symbols, the number of UCI bits is two or more, and the PUCCH resource includes an orthogonal cover code.

[0154] The base station may transmit configuration parameters of multiple PUCCH resource sets to the UE, for example, using an RRC message. Multiple PUCCH resource sets (e.g., up to four sets) may be configured on the uplink BWP of the cell. A PUCCH resource set may be configured with a PUCCH resource set index, multiple PUCCH resources with PUCCH resources identified by a PUCCH resource identifier (e.g., pucch-Resourceid), and / or a number (e.g., a maximum number) of UCI information bits that the UE may transmit using one of the multiple PUCCH resources in the PUCCH resource set. When configured with multiple PUCCH resource sets, the UE may select one of the multiple PUCCH resource sets based on a total bit length of the UCI information bits (e.g., HARQ-ACK, SR, and / or CSI). If the total bit length of the UCI information bits is less than or equal to two, the UE may select a first PUCCH resource set with a PUCCH resource set index equal to "0". If the total bit length of the UCI information bits is greater than 2 and less than or equal to the first configuration value, the UE may select a second PUCCH resource set having a PUCCH resource set index equal to "1". If the total bit length of the UCI information bits is greater than the first configuration value and less than or equal to the second configuration value, the UE may select a third PUCCH resource set having a PUCCH resource set index equal to "2". If the total bit length of the UCI information bits is greater than the second configuration value and less than or equal to a third value (e.g., 1406), the UE may select a fourth PUCCH resource set having a PUCCH resource set index equal to "3".

[0155] After determining a PUCCH resource set from the multiple PUCCH resource sets, the UE may determine a PUCCH resource from the PUCCH resource set for UCI (HARQ-ACK, CSI, and / or SR) transmission. The UE may determine the PUCCH resource based on a PUCCH resource indicator in a DCI (e.g., DCI format 1_0 or DCI format 1_1) received on the PDCCH. The 3-bit PUCCH resource indicator of the DCI may indicate one of the eight PUCCH resources in the PUCCH resource set. Based on the PUCCH resource indicator, the UE may transmit the UCI (HARQ-ACK, CSI, and / or SR) using the PUCCH resource indicated by the PUCCH resource indicator in the DCI.

[0156] FIG. 15 illustrates an example of a wireless device 1502 communicating with a base station 1504 according to an embodiment of the disclosure. The wireless device 1502 and base station 1504 may be part of a mobile communication network, such as the mobile communication network 100 shown in FIG. 1A, the mobile communication network 150 shown in FIG. 1B, or other communication network. Although only one wireless device 1502 and one base station 1504 are shown in FIG. 15, it will be understood that a mobile communication network may include more than one UE and / or more than one base station having the same or similar configuration as shown in FIG. 15.

[0157] The base station 1504 may connect the wireless device 1502 to a core network (not shown) via wireless communication over an air interface (or radio interface) 1506. The direction of communication from the base station 1504 to the wireless device 1502 over the air interface 1506 is known as the downlink, and the direction of communication from the wireless device 1502 to the base station 1504 over the air interface is known as the uplink. The downlink transmission may be separated from the uplink transmission using FDD, TDD, and / or some combination of the two duplexing techniques.

[0158] In the downlink, data transmitted from the base station 1504 to the wireless device 1502 may be provided to a processing system 1508 of the base station 1504. The data may be provided to the processing system 1508 by, for example, a core network. In the uplink, data transmitted from the wireless device 1502 to the base station 1504 may be provided to a processing system 1518 of the wireless device 1502. The processing system 1508 and the processing system 1518 may implement Layer 3 and Layer 2 OSI functions to process the data for transmission. Layer 2 may include, for example, the SDAP layer, the PDCP layer, the RLC layer, and the MAC layer with respect to Figures 2A, 2B, 3, and 4A. Layer 3 may include the RRC layer with respect to Figure 2B.

[0159] After processing by the processing system 1508, data to be transmitted to the wireless device 1502 may be provided to a transmit processing system 1510 of the base station 1504. Similarly, after processing by the processing system 1518, data to be transmitted to the base station 1504 may be provided to a transmit processing system 1520 of the wireless device 1502. The transmit processing system 1510 and the transmit processing system 1520 may implement Layer 1 OSI functions. Layer 1 may include the PHY layer with respect to FIGS. 2A, 2B, 3, and 4A. For transmit processing, the PHY layer may perform, for example, forward error correction coding of transport channels, interleaving, rate matching, mapping of transport channels to physical channels, modulation of physical channels, multiple input multiple output (MIMO) or multi-antenna processing, and / or the like.

[0160] At the base station 1504, a receive processing system 1512 may receive uplink transmissions from the wireless device 1502. At the wireless device 1502, a receive processing system 1522 may receive downlink transmissions from the base station 1504. The receive processing system 1512 and the receive processing system 1522 may implement the OSI functions of Layer 1. Layer 1 may include the PHY layer with respect to Figures 2A, 2B, 3, and 4A. For receive processing, the PHY layer may perform, for example, error detection, forward error correction decoding, deinterleaving, demapping of transport channels to physical channels, demodulation of the physical channels, MIMO or multi-antenna processing, and / or the like.

[0161] 15, the wireless device 1502 and the base station 1504 may include multiple antennas. The multiple antennas may be used to implement one or more MIMO or multi-antenna techniques, such as spatial multiplexing (e.g., single-user MIMO or multi-user MIMO), transmit / receive diversity, and / or beamforming. In other embodiments, the wireless device 1502 and / or the base station 1504 may have a single antenna.

[0162] Processing system 1508 and processing system 1518 may be associated with memory 1514 and memory 1524, respectively. Memory 1514 and memory 1524 (e.g., one or more non-transitory computer readable media) may store computer program instructions or code that may be executed by processing system 1508 and / or processing system 1518 to perform one or more functions discussed in the present application. Although not shown in FIG. 15, transmit processing system 1510, transmit processing system 1520, receive processing system 1512, and / or receive processing system 1522 may be coupled to memory (e.g., one or more non-transitory computer readable media) that stores computer program instructions or code that may be executed to perform one or more of their respective functions.

[0163] The processing system 1508 and / or the processing system 1518 may include one or more controllers and / or one or more processors. The one or more controllers and / or the one or more processors may include, for example, a general purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and / or other programmable logic devices, discrete gate and / or transistor logic, discrete hardware components, on-board units, or any combination thereof. The processing system 1508 and / or the processing system 1518 may perform at least one of signal coding / processing, data processing, power control, input / output processing, and / or any other functionality that may enable the wireless device 1502 and the base station 1504 to operate in a wireless environment.

[0164] The processing system 1508 and / or the processing system 1518 may be connected to one or more peripheral devices 1516 and one or more peripheral devices 1526, respectively. The one or more peripheral devices 1516 and one or more peripheral devices 1526 may include software and / or hardware that provide features and / or functionality, such as a speaker, a microphone, a keypad, a display, a touchpad, a power source, a satellite transceiver, a universal serial bus (USB) port, a hands-free headset, a frequency modulation (FM) radio unit, a media player, an Internet browser, an electronic control unit (e.g., for a vehicle), and / or one or more sensors (e.g., an accelerometer, a gyroscope, a temperature sensor, a radar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, a camera, and / or the like). The processing system 1508 and / or the processing system 1518 may receive user input data and / or provide user output data from the one or more peripheral devices 1516 and / or one or more peripheral devices 1526. The processing system 1518 in the wireless device 1502 can receive power from a power source and / or can be configured to distribute power to other components in the wireless device 1502. The power source can include one or more power sources, such as a battery, a solar cell, a fuel cell, or any combination thereof. The processing system 1508 and / or the processing system 1518 can be connected to a GPS chipset 1517 and a GPS chipset 1527, respectively. The GPS chipset 1517 and the GPS chipset 1527 can be configured to provide geographic location information of the wireless device 1502 and the base station 1504, respectively.

[0165] FIG. 16A illustrates an example structure for uplink transmission. The baseband signal representing the physical uplink shared channel may perform one or more functions. The one or more functions may include at least one of scrambling, modulation of scramble bits to generate complex-valued symbols, mapping of complex-valued modulation symbols onto one or several transmission layers, transform precoding to generate complex-valued symbols, precoding of the complex-valued symbols, mapping of the precoded complex-valued symbols onto resource elements, generating complex-valued time-domain single carrier frequency division multiple access (SC-FDMA) or CP-OFDM signals to antenna ports, and / or the like. In an embodiment, if transform precoding is enabled, an SC-FDMA signal for uplink transmission may be generated. In an embodiment, if transform precoding is not enabled, a CP-OFDM signal for uplink transmission may be generated according to FIG. 16A. These functions are illustrated as examples, and it is anticipated that other mechanisms may be implemented in various embodiments.

[0166] 16B shows an example structure for modulation and upconversion of a baseband signal to a carrier frequency. The baseband signal may be a complex-valued SC-FDMA or CP-OFDM baseband signal and / or a complex-valued Physical Random Access Channel (PRACH) baseband signal for an antenna port. Filtering may be used before transmission.

[0167] 16C shows an example structure of a downlink transmission. The baseband signal representing the physical downlink channel can perform one or more functions. The one or more functions may include scrambling of coded bits in a codeword to be transmitted on the physical channel, modulation of the scrambled bits to generate complex-valued modulation symbols, mapping of the complex-valued modulation symbols onto one or several transmission layers, precoding of the complex-valued modulation symbols on the layers for transmission on the antenna ports, mapping of the complex-valued modulation symbols of the antenna ports to resource elements, generation of a complex-valued time-domain OFDM signal per antenna port, and / or the like. These functions are shown as examples, and it is expected that other mechanisms may be implemented in various embodiments.

[0168] 16D shows another exemplary structure for modulation and upconversion of a baseband signal to a carrier frequency. The baseband signal may be a complex-valued OFDM baseband signal for an antenna port. Filtering may be used before transmission.

[0169] The wireless device may receive one or more messages (e.g., RRC messages) from a base station including configuration parameters for multiple cells (e.g., primary cell, secondary cell). The wireless device may communicate with at least one base station (e.g., two or more base stations for dual connectivity) via the multiple cells. The one or more messages (e.g., as part of the configuration parameters) may include physical, MAC, RLC, PCDP, SDAP, RRC layer parameters for configuring the wireless device. For example, the configuration parameters may include parameters for configuring physical and MAC layer channels, bearers, etc. For example, the configuration parameters may include parameters indicating values ​​of timers for the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, RRC layer, and / or communication channels.

[0170] When a timer is started, it may start running and continue running until it is stopped or expires. A timer may be started if it is not running or restarted if it is running. A timer may be associated with a value (e.g., a timer may be started or restarted from a value, or may be started from zero and expire when the value is reached). A timer's duration may not be updated until the timer is stopped or expires (e.g., by BWP switching). A timer may be used to measure a time period / window of a process. When this specification refers to implementations and procedures related to one or more timers, it will be understood that there are multiple ways to implement one or more timers. For example, it will be understood that one or more of multiple ways to implement a timer may be used to measure a time period / window for a procedure. For example, a random access response window timer may be used to measure a window time for receiving a random access response. In an embodiment, the time difference between two timestamps may be used instead of the start and expiration of the random access response window timer. When the timer is restarted, the process for measuring the time window may be restarted. Another example implementation may be provided for restarting the measurement of the time window.

[0171] The UE may be in either an RRC connected state or an RRC inactive state when an RRC connection is established. If an RRC connection is not established, the UE is in an RRC idle state.

[0172] When the UE is in RRC idle state, the UE (RRC layer) or base station supports PLMN selection, system information broadcast, cell reselection mobility, paging of mobile terminated data initiated by 5GC, and DRX for core network (CN) paging configured by non-access stratum (NAS). When the UE is in RRC idle state, UE-specific DRX may be configured by higher layers and / or UE controlled mobility based on network configuration. When the UE is in RRC idle state, the UE (RRC layer) may monitor short messages sent on P-RNTI over DCI, monitor paging channel for core network (CN) paging using Serving Temporary Mobile Subscriber Identity (S-TMSI) (e.g., 5G-S-TMSI), perform neighbor cell measurements and cell (re)selection, obtain system information, send SI requests, and perform logging of available measurements along with logged measurement configuration UE location and time.

[0173] When the UE is in RRC inactive state, the UE (RRC layer) or base station may support PLMN selection, system information broadcast, cell reselection mobility, paging initiated by NG-RAN (RAN paging), RAN-based notification area (RNA) managed by NG-RAN, DRX for RAN paging configured by NG-RAN, core network (e.g., 5G Core, 5GC)-RAN (e.g., base station) connection (both control and / or user plane) established for the UE, UE AS context stored in RAN and UE, RAN knows the RNA to which the UE belongs. For example, when the UE (RRC layer) is in RRC inactive state, UE-specific DRX may be configured by higher layers or by the RRC layer, the UE may implement / support UE controlled mobility based on network configuration, the UE may store UE inactive AS context, and RAN-based notification area (RNA) may be configured by the RRC layer. When the UE is in an RRC inactive state, the UE (RRC layer) may monitor short messages sent on the P-RNTI via DCI, monitor the paging channel for CN paging using the S-TMSI and RAN paging using the Fully Inactive RNTI (I-RNTI) (or Fully Resume Identity), perform neighboring cell measurements and cell (re)selection, perform RAN based Notification Area (RNA) updates periodically and when moving outside a configured RAN based Notification Area, obtain system information, send SI requests, and perform logging of available measurements along with the logged measurement configured UE's location and time.

[0174] When the UE is in the RRC connected state, the UE (RRC layer) or the base station may support: 5GC-NG-RAN connection (both C / U plane) being established for the UE; UE AS context being stored in the RAN (e.g., base station) and the UE; the RAN knowing the cell the UE belongs to; forwarding of unicast data to / from the UE; network controlled mobility including measurements. For example, when the UE is in RRC connected state, the UE (RRC layer) may store AS context, forward / receive unicast data, be configured at lower layers with UE-specific DRX, use one or more SCells for UEs supporting CA, aggregated with SpCells for increased bandwidth, and use one SCG for UEs supporting DC, aggregated with MCG for increased bandwidth, and perform / support network controlled mobility within NR and between E-UTRA. When the UE is in RRC connected state, the UE may monitor short messages sent on the P-RNTI over DCI, monitor the control channel associated with the shared data channel to determine if data is scheduled for it, provide channel quality and feedback information, perform neighboring cell measurements and measurement reporting, obtain system information, and perform on-the-fly minimization of driving test (MDT) measurements along with available location reporting.

[0175] Radio bearers can be classified into two groups: Data Radio Bearers (DRBs) for user plane data and Signaling Radio Bearers (SRBs) for control plane data.

[0176] A signaling radio bearer (SRB) may be defined as a radio bearer (RB) that is used only for transmission of RRC and NAS messages. The following SRBs may be defined: SRB0 may be for RRC messages using the Common Control Channel (CCCH) logical channel, SRB1 may be for RRC messages (which may include piggybacked NAS messages) as well as NAS messages before the establishment of SRB2, all using the Dedicated Control Channel (DCCH) logical channel, SRB2 may be for NAS messages and RRC messages, which may include logged measurement information, all using the DCCH logical channel. SRB2 may have a lower priority than SRB1 and may be configured by the network after Access Stratum (AS) security activation, and SRB3 may be for certain RRC messages when the UE is in dual connectivity (e.g., (NG)EN-DC or NR-DC), all using the DCCH logical channel. In the downlink, piggybacking of NAS messages may be used for one dependent (e.g., with joint success / failure) procedure, i.e., bearer establishment / modification / release. In the uplink piggybacking of NAS messages, it may be used to transport initial NAS messages during (RRC) connection setup and (RRC) connection resumption. NAS messages transported over SRB2 may be included in RRC messages that may not contain RRC protocol control information. When AS security is activated, all RRC messages on SRB1, SRB2, and SRB3, including those containing NAS messages, may be integrity protected and encrypted by PDCP. The NAS may apply integrity protection and encryption to NAS messages independently. Split SRBs may be supported for dual connectivity (e.g., multi-radio (MR)-DC option) on both SRB1 and SRB2. Split SRBs may not be supported for SRB0 and SRB3. For operation with shared spectrum channel access, SRB0, SRB1, and SRB3 may be assigned with the highest channel access priority class (CAPC) (eg, CAPC=1), while the CAPC of SRB2 is configurable.

[0177] The MAC layer of the UE or base station may provide different kinds of data transfer services. Each logical channel type may be defined by what type of information is transferred. The logical channels may be classified into two groups: control channels and traffic channels. The control channels may be used for the transfer of control plane information: Broadcast Control Channel (BCCH), a downlink channel for broadcasting system control information; Paging Control Channel (PCCH), a downlink channel carrying paging messages; Common Control Channel (CCCH), a channel for transmitting control information between the UE and the network. This channel is used for UEs that do not have an RRC connection with the network, and Dedicated Control Channel (DCCH), a point-to-point bidirectional channel that transmits dedicated control information between the UE and the network. UEs that have an RRC connection are used. The traffic channels, i.e. Dedicated Traffic Channel (DTCH), a point-to-point channel dedicated to one UE for the transfer of user information, may be used for the transfer of user plane information. DTCH may exist in both uplink and downlink.

[0178] The UE may transition to the RRC connected state when the RRC connection is established or resumed. The UE may transition to the RRC idle state when the RRC connection is released or suspended. The UE may transition to the RRC inactive state when the RRC connection is suspended. When the UE is in the RRC idle state, the UE may have a suspended RRC connection. Based on the suspended RRC connection in the RRC idle state, the UE is in the RRC idle state with a suspended RRC connection.

[0179] The RRC connection establishment may include the establishment of SRB1. The base station may complete the RRC connection establishment before completing the establishment of a connection (e.g., N2 / N3 connection) with the core network (e.g., before receiving UE context information from a core network entity (e.g., AMF)). Access Stratum (AS) security may not be activated in the early stage of the RRC connection. During the early stage of the RRC connection, the base station may configure the UE to perform measurement reporting. The UE may send a corresponding measurement report upon successful AS security activation. The UE may receive or accept a handover message (e.g., handover command) when AS security is activated.

[0180] Upon receiving the UE context from the core network (e.g., AMF), the RAN (base station) can activate AS security (both ciphering and integrity protection) using an initial AS security activation procedure. The RRC messages for initiating AS security (command and success response) can be integrity protected, during which ciphering is started after completion of the procedure. The response to the RRC message used to activate AS security may not be ciphered, while subsequent messages (e.g., used to establish SRB2 and DRB) may be integrity protected and ciphered. After starting the initial AS security activation procedure, the network (e.g., base station) can start establishing SRB2 and DRB, e.g., the network can do this before receiving a confirmation of the initial AS security activation from the UE. The network can apply both ciphering and integrity protection to the RRC reconfiguration messages used to establish SRB2 and DRB. If the initial AS security activation and / or radio bearer establishment fails, the network needs to release the RRC connection. A configuration with SRB2 without a DRB or a configuration with DRB without SRB2 may not be supported (i.e., SRB2 and at least one DRB must be configured in the same RRC reconfiguration message, and releasing all DRBs without releasing the RRC connection may not be allowed). For an integrated access and backhaul mobile termination (IAB-MT), a configuration with SRB2 without a DRB may be supported.

[0181] The release of the RRC connection may be initiated by the network, and the release procedure may be redirected to redirect the UE to an NR frequency or an E-UTRA carrier frequency.

[0182] Suspension of the RRC connection may be initiated by the network. When the RRC connection is suspended, the UE may store the UE inactive AS context and any configuration received from the network and transition to an RRC inactive state. The RRC message to suspend the RRC connection may be integrity protected and encrypted.

[0183] The resumption of a suspended RRC connection may be initiated by higher layers when the UE needs to transition from an RRC inactive state to an RRC connected state, or by the RRC layer to perform an RNA update, or by RAN paging from the RAN (e.g., a base station). When the RRC connection is resumed, the network may configure the UE according to an RRC connection resume procedure based on the stored UE inactive AS context and any RRC configuration received from the network. The RRC connection resume procedure reactivates AS security and reestablishes SRBs and DRBs.

[0184] In response to the request to resume the RRC connection, the network may resume the suspended RRC connection, send / transition the UE to the RRC connected state, or reject the request to resume and send the UE to the RRC inactive state (with a waiting timer), or directly resuspend the RRC connection, send the UE to RRC_INACTIVE, or directly release the RRC connection, send / transition the UE to the RRC idle state, or command the UE to initiate NAS level recovery (in this case the network sends an RRC SETUP message). For user data (DRB), ciphering may provide confidentiality of user data, and integrity protection provides integrity of user data. For RRC signaling (SRB), ciphering may provide confidentiality of signaling data and integrity protection signaling data integrity. Ciphering and integrity protection may be optionally configured except for RRC signaling, where integrity protection may always be configured. Ciphering and integrity protection may be configured per DRB.

[0185] For key management and data handling, network entities or UEs processing cleartext may be protected from physical attacks and placed in a secure environment. Base station (e.g., gNB or eNB) (AS) keys may be cryptographically separated from (NAS) keys. Separate AS and NAS level Security Mode Command (SMC) procedures may be used. A sequence number (COUNT) may be used as input to ciphering and integrity protection, and a given sequence number may be used once for a given key (except for identical retransmissions) on the same radio bearer in the same direction.

[0186] The security keys are organized and derived as follows: Core network entity keys (e.g., AMF or Mobility Management Entity (MME) keys) may include KAMF (or KMME). Core network entity keys may be keys derived by the Security Anchor Function (SEAF) from the UE's Mobile Equipment (ME) and SEAF (KSEAF) keys. NAS signaling keys may include: KNASint is a key derived by the UE and core network Mobile Equipment (ME) from the core network entity keys that may be used for protection of NAS signaling with a specific integrity algorithm, and KNASenc is a key derived by the ME and core network entities from the core network entity (e.g., KAMF / KMME) keys that may be used for protection of NAS signaling with a specific encoding algorithm. The base station (e.g., gNB or eNB) key may include that KgNB (or KeNB) is a key derived by a core network entity (e.g., AMF / MME) from the ME and core network entity (e.g., KAMF / KMME) keys. The base station key may be further derived by the ME and source base station when performing horizontal or vertical key derivation. The UP traffic key may include that KUPenc is a key derived by the ME and base station from the base station key that may be used for protection of UP traffic between the ME and base station with a specific encoding algorithm, and KUPint may be a key derived by the ME and base station from the base station key that may be used for protection of UP traffic between the ME and base station with a specific integrity algorithm. The RRC signaling keys may include: KRRCint is a key derived by the ME and base station from the base station's key that may be used to protect RRC signaling with a particular encoding algorithm; and KRRCenc is a key derived by the ME and base station from the base station's key that may be used to protect RRC signaling with a particular encryption algorithm.The intermediate keys may include that the next hop parameter (NH) is a key derived by the ME and a core network entity (e.g., AMF / MME) to provide forward security, and that KgNB* (or KeNB*) is a key derived by the ME and base station when performing horizontal or vertical key derivation.

[0187] The primary authentication enables mutual authentication between the UE and the network and may provide an anchor key called KSEAF. From KSEAF, keys of core network entities (e.g., KAMF / KMME) may be created, for example, during the primary authentication or NAS rekeying and rekeying events. Based on the keys of core network entities, KNASint and KNASenc may be derived upon initiating a successful NAS SMC procedure.

[0188] When an initial AS security context needs to be established between a UE and a base station, a core network entity (e.g., AMF / MME) and the UE can derive a base station (e.g., KgNB / KeNB) key and a next hop parameter (NH). The base station and NH keys may be derived from the core network entity keys. A next hop chaining counter (NCC) may be associated with each base station and NH parameter key. The base station key may be associated with the NCC corresponding to the NH value from which it is derived. In an initial setup, the base station key may be derived directly from the core network entity keys and then considered to be associated with a virtual NH parameter with an NCC value equal to 0. In an initial setup, the derived NH value may be associated with an NCC value of 1. In a handover, the base station key base used between the UE and the target base station, called KgNB* (or KeNB*), may be derived from either the base station's current active key or the NH parameter. If KgNB* (or KeNB*) can be derived from the base station's currently active key, this is called horizontal key derivation and is indicated to the UE with a non-incrementing NCC. If KgNB* (or KeNB*) is derived from the NH parameters, the derivation is called vertical key derivation and is indicated to the UE with an NCC increment. KRRCint, KRRCenc, KUPint, and KUPenc can be derived based on the base station's key after the base station's new key is derived.

[0189] Based on the key derivation, a base station having knowledge of the base station's key shared with the UE (e.g., KgNB / KeNB) cannot calculate any previous KgNB used between the same UE and a previous base station, thus providing backward security. A base station having knowledge of the base station's key shared with the UE may not be able to predict any future base station's key used between the same UE and another base station after n or more handovers (because the NH parameter is only computable by the UE and a core network entity (e.g., AMF / MME)).

[0190] The AS SMC procedure may be for RRC and UP security algorithm negotiation and RRC security activation. When the AS security context is established in the base station, the AMF (or MME) may send the security capabilities of the UE to the base station. The base station may select an encryption algorithm. The selected encryption algorithm may have the highest priority from its configured list and may also be present in the security capabilities. The base station may select an integrity algorithm. The selected integrity algorithm may have the highest priority from its configured list and may also be present in the security capabilities. The selected algorithm may be indicated to the UE in the AS SMC, and this message may be integrity protected. RRC downlink encryption (encoding) at the base station may start after sending the AS SMC message. RRC uplink decoding (decryption) at the base station may start after receiving and successfully verifying an integrity protected AS security mode complete message from the UE. The UE may verify the validity of the AS SMC message from the base station by verifying the integrity of the received message. RRC uplink encryption (encoding) at the UE may start after sending the AS security mode complete message. RRC downlink decoding at the UE may be started after successful reception and validation of the AS SMC message. The RRC Connection Reconfiguration procedure used to add DRBs may only be performed after RRC security has been activated as part of the AS SMC procedure.

[0191] The UE may support integrity protected DRB. If the integrity check fails (e.g., a defective or missing Message Authentication Code for Integrity (MAC-I)), the associated Packet Data Unit (PDU) may be discarded by the receiving PDCP entity. Rekeying is performed by the base station (K gNB / K eNB ), K RRC-enc , K RRC-int , K UP-enc , and K UP-intFor example, if the PDCP COUNT is performed for the same radio bearer identity and the same K gNB Re-keying can be initiated by the base station when a key is to be reused in the base station (K gNB / K eNB ), K RRC-enc , K RRC-int , K UP-enc , and K UP-int This may be possible for the key and may be initiated by a core network entity (e.g., AMF / MME) when a different AS security context than the one currently active may be activated.

[0192] When a UE transitions from RRC Idle to RRC Connected, RRC protection keys and UP protection keys may be generated, but NAS protection keys as well as higher layer keys are assumed to be already available. These higher layer keys may be established as a result of Authentication and Key Agreement (AKA) activation, or as a result of a transfer from another AMF during handover or idle mode mobility. When a UE transitions from RRC Connected to RRC Idle, the base station may delete the keys stored for that UE, so that state information of the idle mode UE needs to be maintained only in the core network entity (e.g., AMF / MME). The base station may no longer store state information regarding the corresponding UE and may delete the current keys from memory (e.g., when transitioning the RRC connected state to an RRC idle state), the base station and UE may delete the NH, the base station's keys, KgNB, KRRCint, KRRCenc, KUPint, and KUPenc, and the associated NCC, and the core network entity (e.g., AMF / MME) and the UE may continue to store the keys of the core network entity (e.g., KAMF / KMME), KNASint, and KNASenc.

[0193] In mobility with vertical key derivation, the NH may be further bound to the target physical cell identifier (PCI) and its frequency absolute radio frequency channel number downlink (ARFCN-DL) before being used as the key for the base station in the target base station. In mobility with horizontal key derivation, the currently active key of the base station may be further bound to the target PCI (PCI of the target cell) and its frequency ARFCN-DL before being used as the key for the base station in the target gNB. In either case, the ARFCN-DL may be the absolute frequency of the SSB of the target primary cell (PCell). It may not be necessary to change the AS security algorithm during a gNB-Central Unit (CU) handover. If the UE does not receive an indication of a new AS security algorithm during an intra-gNB-CU handover, the UE may continue to use the same algorithm as before the handover.

[0194] AS security may include integrity protection and ciphering of RRC signaling (SRB) and user data (DRB). The AS may apply four different security keys: one integrity protection of RRC signaling (KRRCint), one ciphering of RRC signaling (KRRCenc), one integrity protection of user data (KUPint), and one ciphering of user data (KUPenc). The four AS keys may be derived from the base station's (e.g., KgNB / KgNB) keys. The base station's keys may be based on the core network entity's (KAMF / KMME) keys, which may be processed by higher layers (e.g., NAS layer). The integrity protection and ciphering algorithms may be changed upon synchronous reconfiguration (e.g., handover command). The AS keys (KgNB, KRRCint, KRRCenc, KUPint, and KUPenc) may be changed upon synchronous reconfiguration and upon connection re-establishment and resumption. For each radio bearer, a separate counter (count) may be maintained for each direction. For each radio bearer, the count may be used as input for ciphering and integrity protection.

[0195] Paging may allow base stations to reach UEs in RRC idle and RRC inactive states via paging messages, and to inform UEs in RRC idle, RRC inactive, and RRC connected states of system information changes of Earthquake Tsunami Warning System (ETWS) or Commercial Mobile Alert Service (CMAS) indications via short messages. Both paging and short messages may be addressed with the P-RNTI on the PDCCH. Paging messages may be transmitted on the PCCH, and short messages may be transmitted directly via the PDCCH.

[0196] While the UE is in RRC idle state, the UE may monitor a paging channel for core network (CN) initiated paging. While the UE is in RRC inactive state, the UE may monitor a paging channel for RAN initiated paging. The UE may not need to continuously monitor the paging channel. Paging DRX is defined where a UE in RRC idle state or RRC inactive state may only need to monitor the paging channel during one paging occasion (PO) per DRX cycle. The paging DRX cycle may be configured by the network (e.g., a base station or a core network entity (e.g., AMF / MME)), and for CN initiated paging, a default cycle may be broadcast in the system information, for CN initiated paging, a UE specific cycle may be configured via NAS signaling, and for RAN initiated paging, a UE specific cycle may be configured via RRC signaling, and the UE may use the shortest of the applicable DRX cycles. For example, a UE in RRC idle state may use the shortest of the first two cycles above. A UE in RRC_INACTIVE may use the shortest of the three cycles above.

[0197] The UE's POs for CN-initiated paging and RAN-initiated paging may be based on the same UE identity (ID), resulting in both POs overlapping. The number of different POs in a DRX cycle may be configurable via system information, and the network may distribute UEs to those POs based on their IDs.

[0198] When in RRC_CONNECTED, the UE may monitor the paging channel in any PO that is signaled in the system information for SI change indication and PWS notification. A UE in RRC connected state may only monitor the paging channel on active BWPs for which a common search space is configured. To operate with shared spectrum channel access, the UE may be configured for an additional number of PDCCH monitoring opportunities in its PO to monitor paging. If the UE detects a PDCCH transmission in the PO of the UE addressed in the P-RNTI, the UE may not need to monitor subsequent PDCCH monitoring opportunities in this PO.

[0199] A network (e.g., a base station) may initiate a paging procedure by sending a paging message at a paging occasion of the UE. The network may address multiple UEs in the paging message by including one paging record for each UE. The paging message may include a paging record list. The paging record list may include one or more paging records. Each paging record may include at least one of a UE identity (ID) and an access type. The UE identity may include an S-TMSI or an I-RNTI (resuming identity). The access type may indicate whether the paging message originates from a PDU session from a non-3GPP access.

[0200] Cell selection may be required at the transition from Registration Management (RM)-DEREGISTERED to RM-REGISTERED, from CM-IDLE to CM-CONNECTED, and from CM-CONNECTED to CM-IDLE. In RM-DEREGISTERED, the UE may not be registered with the network. The UE context in the core network entity (e.g., AMF / MME) may not hold valid location or routing information for the UE. The UE may not be reachable by the AMF. In the RM-REGISTERED state, the UE may be registered in the network. In the RM-REGISTERED state, the UE may receive services that require registration with the network. A UE in CM-IDLE may not have an established NAS signaling connection (e.g., via the N1 / S1 interface) with a core network entity (e.g., AMF / MME). The UE may perform cell selection / cell reselection and PLMN selection. A UE in CM-CONNECTED state may have a NAS signaling connection (e.g., over an N1 / S1 interface) with a core network entity. The NAS signaling connection may use an RRC connection between the UE and a base station (e.g., a RAN) and a Next Generation Application Protocol (NGAP) / S1AP UE association between an access network (AN) (e.g., a base station's AN) and a core network entity (e.g., an AMF / MME).

[0201] The cell selection may be based on the following principles: The UE NAS layer may identify the selected PLMN and equivalent PLMNs. The cell selection may be based on the cells defining SSB (CD-SSB) located on the synchronization raster. The UE may search the frequency (NR) bands and may identify the strongest cell according to the CD-SSB for each carrier frequency. The UE may then read the cell system information broadcast to identify its PLMN. The UE may search each carrier in turn ("initial cell selection") or may utilize stored information to shorten the search ("stored information cell selection"). The UE may attempt to identify a suitable cell if it is unable to identify a suitable cell, in which case the UE attempts to identify an acceptable cell. If a suitable cell is found or only acceptable cells are found, the UE may camp on that cell and initiate a cell reselection procedure. A suitable cell is one whose measured cell attributes meet the cell selection criteria, the cell PLMN is a selected PLMN, registered or equivalent PLMN, the cell is not barred or reserved, and the cell is not part of a tracking area in the list of "Forbidden Tracking Areas for Roaming", and an acceptable cell is one whose measured cell attributes meet the cell selection criteria and the cell is not barred.

[0202] Upon transition from RRC connected or RRC inactive to RRC idle state, the UE may camp on a cell as a result of cell selection according to the frequency assigned by RRC in the state transition message. The UE may attempt to find a suitable cell with the stored information above or in the manner described for initial cell selection. If no suitable cell is found for any frequency or RAT, the UE may attempt to find an acceptable cell. In multi-beam operation, cell quality may be derived among beams corresponding to the same cell.

[0203] A UE in RRC idle may perform cell reselection. The principle of the procedure is as follows: Cell reselection may be based on CD-SSB located on the synchronization raster. The UE may perform measurements of the attributes of the serving cell and neighboring cells to enable the reselection process. For the search and measurements of inter-frequency neighboring cells, the carrier frequency needs to be indicated. Cell reselection may identify the cell on which the UE should camp. Cell reselection may be based on cell reselection criteria that involve measurements of the serving and neighboring cells. Intra-frequency reselection is based on cell ranking. Inter-frequency reselection is based on absolute priority where the UE tries to camp on the highest priority frequency available. A neighboring cell list (NCL) may be provided by the serving cell to handle specific cases for intra-frequency and inter-frequency neighboring cells. A blacklist may be provided to prevent the UE from reselecting to certain intra-frequency and inter-frequency neighboring cells. A whitelist may be provided to request the UE to reselect only to certain intra-frequency and inter-frequency neighboring cells. Cell reselection may be speed dependent and service specific prioritization. In multi-beam operation, cell quality may be derived between beams corresponding to the same cell.

[0204] The UE may perform one of two procedures, such as initial cell selection and cell selection, by utilizing the stored information. If the UE does not have cell information stored for the selected PLMN, the UE may perform initial cell selection. Otherwise, the UE may perform cell selection by utilizing the stored information. For initial cell selection, the UE may scan all RF channels in the (NR) frequency band according to its capabilities to find a suitable cell. Based on the results of the scan, the UE may search for the strongest cell on each frequency. The UE may select a cell that is a suitable cell. For cell selection by utilizing the stored information, the UE may request information of the stored frequencies and, optionally, information about cell parameters from previously received measurement control information elements or previously detected cells. Based on the stored information, the UE may search for a suitable cell and select the suitable cell if the UE finds a suitable cell. If the UE does not find a suitable cell, the UE may perform initial cell selection.

[0205] The base station may configure cell selection criteria for cell selection. The UE may attempt to identify a suitable cell for cell selection. A suitable cell is a cell that satisfies the following conditions: (1) the measured cell attributes meet the cell selection criteria, (2) the cell PLMN is the selected PLMN, registered or equivalent PLMN, (3) the cell is not forbidden or reserved, and (4) the cell is not part of a tracking area that is in the list of "Forbidden Tracking Areas for Roaming". The RRC layer in the UE may inform the NAS layer in the UE of the cell selection and reselection results based on changes in the received system information related to the NAS. For example, the cell selection and reselection results may be the cell identity, the tracking area code, and the PLMN identity.

[0206] The UE-RRC layer may initiate an RRC connection establishment procedure, an RRC connection resumption procedure, or an RRC connection re-establishment procedure. Based on the initiation of the RRC connection establishment procedure or the RRC connection resumption procedure, the UE may perform one or more procedures, where the one or more procedures include performing a unified access control procedure (e.g., access barring check) for the access attempt of the RRC establishment / resumption procedure at the serving cell, applying default configuration parameters and configurations / parameters provided by SIB1 (e.g., applying default configurations and configurations / parameters provided by SIB1 based on the access attempt being allowed), performing transmission of a random access preamble to the serving cell based on the access attempt being allowed, sending an RRC request message to the serving cell, and performing a RRC connection establishment procedure (e.g., access barring check) for the access attempt of the RRC establishment / resumption procedure at the serving cell. The RRC connection re-establishment procedure may include at least one of: receiving an RRC request message to serving cell 0 based on determining that the random access response is successfully received (e.g., sending an RRC request message to serving cell 0 based on determining that the random access response is successfully received; starting a timer based on the sending of the RRC request message; receiving an RRC response message or an RRC reject message from the serving cell (e.g., in response to the RRC request message); or sending an RRC completion message (e.g., in response to receiving the RRC response message). For the RRC connection re-establishment procedure, the UE may not need to perform a unified access procedure (e.g., access barring check) for an access attempt of the RRC re-establishment procedure.

[0207] A base station (e.g., NG-RAN) may support overload and access control functions such as RACH backoff, RRC connection rejection, RRC connection release, and UE-based access barring mechanisms. A unified access control framework applies to all UE states (e.g., RRC idle, inactive, and connected). A base station may broadcast barring control information associated with an access category and an access identity (in case of network sharing, the barring control information may be set individually for each PLMN). A UE may determine whether an access attempt is authorized based on the barring information broadcast for a selected PLMN, the selected access category, and the access identity for the access attempt. For a NAS triggered request, the UE-NAS layer may determine the access category and access identity. For an AS triggered request, the UE-RRC layer determines the access category while the NAS determines the access identity. The base station may treat access attempts with establishment causes "emergency", "mps priority access" and "mcs priority access" (i.e. emergency call, MPS, MCS subscriber) with high priority and may respond to these access attempts with RRC Reject only under extreme network load conditions that may threaten the stability of the base station.

[0208] Based on the initiation of the RRC connection establishment procedure or the RRC connection resumption procedure, the UE in the RRC inactive or idle state may perform or initiate an access barring check (or a unified access control procedure) for the access attempt of the RRC connection establishment procedure or the RRC connection resumption procedure. Based on the initiation of the access barring check, the UE may determine an access category and an access identity for the access attempt. The UE may determine that the access attempt is barred based on at least one of: timer T309 is started for the access category for the access attempt, timer T302 is started, and the access category is neither "2" nor "0". The UE may determine that the access attempt is allowed based on at least one of: the access category is "0" and a system information block (system information block type 25) including unified access control (UAC) barring parameters is not broadcast by the serving cell. The UE may determine whether the access attempt is prohibited based on at least one of: the establishment cause (e.g., an access attempt) being other than an emergency; an access prohibition per RSRP parameter of the system information block that includes (or is set to) threshold 0; and, if the wireless device is in extended coverage, an access prohibition per RSRP parameter of the system information block that includes (or is set to) threshold 1 and the measured RSRP is less than a first entry of the RSRP threshold PRACH information list; a threshold 2 and the measured RSRP is less than a second entry of the RSRP threshold PRACH information list; and a threshold 3 and the measured RSRP is less than a third entry of the RSRP threshold PRACH information list.

[0209] The UE may determine that the access attempt is allowed based on the system information block not including a UAC barring parameter for the access attempt. For example, the UE may determine that the access attempt is allowed based on the system information block not including a UAC barring parameter for a UE selected PLMN and a UAC barring parameter for common. The UE may determine that the access attempt is allowed based on a UAC barring parameter for common that does not include an access category of the access attempt. The UAC barring parameters may include at least one of the following: a UAC barring parameter per PLMN and a UAC barring parameter for common. The UE may perform an access barring check for an access category of the access attempt based on the UAC barring parameters in the system information block. The UE may determine that the access attempt is allowed based on a corresponding bit of at least one of the access identities in the UAC barring parameter being zero. The UE may draw a first random number uniformly distributed in a range greater than or equal to 0 and less than 1.

[0210] The UE may determine that the access attempt is permitted based on the first random number being lower than a UAC prohibition factor of the UAC prohibition parameters. The UE may determine that the access attempt is barred based on the first random number being greater than a UAC prohibition factor of the UAC prohibition parameters. In response to determining that the access attempt is barred, the UE may draw a second random number uniformly distributed in a range greater than or equal to 0 and less than 1. The UE may start a bar timer T309 for the access category based on the second random number. When the bar timer T309 is running, an access attempt associated with the access category is barred (e.g., not permitted to transmit). Based on expiration of the bar timer T309, the UE may consider a bar for the access category to be relaxed. Based on the bar for the access category being relaxed, the UE may perform an access bar check for the access category if the UE has an access attempt for the access category.

[0211] Based on the initiation of the RRC connection re-establishment procedure, the UE may stop one or more prohibition timers T309 for all access categories if the one or more prohibition timers T309 are running. Based on the stopping of the one or more prohibition timers T309, the UE may determine to prohibit all access categories from being relaxed. The UE may perform an RRC connection re-establishment procedure based on prohibiting all access categories from being relaxed. For example, the UE may send an RRC establishment request without prohibition based on prohibiting all access categories from being relaxed.

[0212] To initiate an RRC connection establishment / resumption / re-establishment procedure, the UE-RRC layer may use the parameters in the received SIB1. The UE-RRC layer may use the L1 parameter values ​​and the time alignment timer in SIB1. The UE-RRC layer may implement a unified access control procedure using the UAC barring information in SIB1. Based on the unified access control procedure, the UE-RRC layer may determine whether the access attempts of those RRC procedures are barred or allowed. Based on determining that the access attempts are allowed, the UE-RRC layer may determine to send an RRC request message to the base station, where the RRC request message may be an RRC setup request message, an RRC restart request message, or an RRC re-establishment message. The UE-NAS layer may or may not provide the S-TMSI as the UE identity. The UE-RRC layer may set the UE identity in the RRC request message.

[0213] For an RRC SETUP REQUEST message, a UE in RRC idle state may initiate an RRC connection establishment procedure. Based on the initiation of the RRC connection establishment procedure, the UE-RRC layer in RRC idle state may set the UE identity to the S-TMSI if the UE-NAS layer provides S-TMSI. Otherwise, the UE-RRC layer in RRC idle state may draw a 39-bit random value and set the UE identity to the random value. For an RRC RESUME REQUEST message, the UE-RRC layer in RRC INACTIVE or IDLE state may set the UE identity to the stored resume identity. For an RRC RE-ESTABLISH REQUEST message, the UE-RRC layer in RRC CONNECTED state may set the UE identity to the C-RNTI used in the source PCell. The UE-NAS layer may provide an establishment cause (e.g., the UE-NAS layer). The UE-RRC layer sets the establishment cause of the RRC REQUEST message.

[0214] In the RRC Resume Request message, a UE in RRC inactive may initiate an RRC connection resume procedure. A UE in RRC with a suspended RRC connection may initiate an RRC connection resume procedure. The UE may be in an RRC inactive state or an RRC idle state and may initiate an RRC connection procedure based on at least one of resuming (suspending) an RRC connection and performing / starting a UP small data transmission. Based on the initiation of the RRC connection resume procedure, the UE-RRC layer may restore the stored configuration parameters and the stored security keys from the stored UE inactive AS context. Based on the security keys / parameters, the UE-RRC layer in an RRC inactive or idle state may set the resume MAC-I value to the 16 least significant bits of the MAC-I calculated based on the variable resume MAC input, the security key of the integrity protection for the RRC layer in the UE inactive AS context, the previously configured integrity protection algorithm, and other security parameters (e.g., count, bearer, and direction). The variable resume MAC input may include at least one of the physical cell identity of the source cell, the C-RNTI of the source cell, and the cell identity of the target cell (e.g., selected cell), where the cell identity is the cell identity in the system information block (e.g., SIB1) of the target cell (e.g., selected cell). Based on the security key and the number of next hop chains (NCC) value, the UE-RRC layer in the RRC inactive or idle state derives new security keys for integrity protection and ciphering and configures the lower layer (e.g., UE-PDCP layer) to apply them. The UE may have a stored NCC value and resume identity. The UE may receive an RRC release message with a suspend indication (or suspend configuration parameter), where the RRC release message includes at least one of the resume identity and the NCC value. The UE-RRC layer in the RRC inactive or idle state may re-establish a PDCP entity for one or more bearers. The UE-RRC layer may resume one or more bearers.For example, based on the resumption of the RRC connection, the UE-RRC layer may resume SRB1. Based on the implementation of UP small data transmission, the UE-RRC layer may resume one or more SRBs and DRBs. The UE-RRC layer in an RRC inactive or idle state may send an RRC resume request message to the base station, where the RRC resume request message may include at least one of a resume identity, a resume MAC-I, and a resume cause.

[0215] For the RRC re-establishment request message, the UE in the RRC connected state may initiate an RRC connection re-establishment procedure. Based on the initiation of the RRC connection re-establishment procedure, the UE-RRC layer in the RRC connected state may include the physical cell identity and short MAC-I of the source PCell in the RRC re-establishment message. The UE-RRC layer in the RRC connected state may set the short MAC-I to the 16 least significant bits of the MAC-I calculated based on a variable short MAC input, a security key of the integrity protection for the RRC layer, and the integrity protection algorithm used on the source PCell or PCell where the re-establishment trigger occurred, and other security parameters (e.g., count, bearer, and direction). The variable short MAC input may include at least one of the physical cell identity of the source cell, the C-RNTI of the source cell, and the cell identity of the target cell (e.g., selected cell), where the cell identity is the cell identity in the system information block (e.g., SIB1) of the target cell (e.g., selected cell). The UE-RRC layer in the RRC connected state can re-establish the PDCP and RLC entities for SRB1 and apply default SRB1 configuration parameters for SRB1. The UE-RRC layer in the RRC connected state can suspend integrity protection and ciphering for SRB1 and configure lower layers (e.g., the PDCP layer) to resume SRB1.

[0216] The UE-RRC layer may send an RRC request message to a lower layer (e.g., a PDCP layer, an RLC layer, a MAC layer, and / or a PHY layer) for transmission, where the RRC request message may be an RRC setup request message, an RRC resume request message, or an RRC re-establishment message.

[0217] The UE-RRC layer may receive an RRC SETUP message in response to an RRC RESUME REQUEST message or an RRC RE-ESTABLISH REQUEST message. Based on the RRC SETUP message, the UE-RRC layer may discard the stored AS context, the suspended configuration parameters, and the current AS security context. The UE-RRC layer may release radio resources for all established RBs except SRB0, including the release of the RLC entity, the associated PDCP entity, and the SDAP. The UE-RRC layer may release the RRC configurations except the default L1 parameter values, the default MAC cell group configuration, and the CCCH configuration. The UE-RRC layer may indicate a fallback of the RRC connection to the upper layer (e.g., the NAS layer). If timer T380 is running, where the periodic RAN-based notification area (RNA) update timer, the UE-RRC layer may stop timer T380.

[0218] The UE-RRC layer may receive an RRC Setup message in response to an RRC Setup Request message, an RRC Resume Request message, or an RRC Re-establishment Request message. The RRC Setup message may include cell group configuration parameters and radio bearer configuration parameters. The radio bearer configuration parameters may include at least one of signaling bearer configuration parameters, data radio bearer configuration parameters, and / or security configuration parameters. The security configuration parameters may include security algorithm configuration parameters and a key with an indication of whether the radio bearer configuration parameters use a master key or a secondary key. The signaling radio bearer configuration parameters may include one or more signaling radio bearer configuration parameters. Each signaling radio configuration parameter may include at least one of an SRB identity, a PDCP configuration parameter, a re-establish PDCP indication, and / or a discard PDCP indication. The data radio bearer configuration parameters may include one or more data radio bearer configuration parameters. Each data radio configuration parameter may include at least one of a DRB identity, a PDCP configuration parameter, an SDAP configuration parameter, a re-establishment PDCP indication, and / or a recovery PDCP indication. The radio bearer configuration in the RRC setup message may include the signaling radio configuration parameters of SIB1. Based on the RRC setup message, the UE-RRC layer may establish SRB1. Based on the RRC setup message, the UE-RRC layer may perform cell group configuration or radio bearer configuration. The UE-RRC layer may stop inhibit timers and wait timers for the cell that transmits the RRC setup message. Based on receiving the RRC setup message, the UE-RRC layer may perform one or more of transitioning to an RRC connected state, stopping a cell reselection procedure, considering the current cell that transmitted the RRC setup message to be a PCell, or / and transmitting an RRC setup complete message by configuring the content of the RRC setup complete message.

[0219] The UE-RRC layer may receive an RRC Resume message in response to the RRC Resume Request message. Based on the RRC Resume message, the UE-RRC layer may destroy the UE inactive AS context and release the suspension configuration parameters, except for the RNA notification area information. The RRC Resume message may include at least one of radio bearer configuration parameters, cell group configuration parameters, measurement configuration parameters, sk counters for AS security, a first indication for requesting idle / inactive measurement results, a second indication for restoring a secondary cell (SCell) of a master cell group (MCG), a third indication for restoring a secondary cell group (SCG), and SCG configuration parameters. Based on the RRC Resume message, the UE-RRC layer may perform procedures for configuring or restoring configuration parameters (e.g., cell group configuration, radio bearer configuration, and / or SCG configuration), a security key update procedure, and / or a measurement (configuration) procedure. Based on receiving the RRC Resume message, the UE-RRC layer may perform one or more of the following: indicate to upper layers (e.g., the NAS layer) that the suspended RRC connection has been resumed; resume SRB2, all DRBs and measurements; enter the RRC Connected state; stop the cell reselection procedure; consider the current cell sending the RRC Resume message to be the PCell; and / or send an RRC Resume Complete message by setting the content of the RRC Resume Complete message.

[0220] The cell group configuration parameters may be used to configure a master cell group (MCG) or a secondary cell group (SCG). When the cell group configuration parameters are used to configure an MCG, the cell group configuration parameters are master cell group configuration parameters. When the cell group configuration parameters are used to configure an SCG, the cell group configuration parameters are secondary cell group configuration parameters. A cell group includes one MAC entity, a set of logical channels with associated RLC entities, and a set of a primary cell (SpCell) and one or more secondary cells (SCells). The cell group configuration parameters (e.g., master cell group configuration parameters or secondary cell group configuration parameters) may include at least one of an RLC bearer configuration parameter for the cell group, a MAC cell group configuration parameter for the cell group, a physical cell group configuration parameter for the cell group, a SpCell configuration parameter for the cell group, or a SCell configuration parameter for the cell group. The MAC cell group configuration parameters may include MAC parameters for the cell group, and the MAC parameters may include at least DRX parameters. The physical cell group configuration parameters may include cell group specific L1 (Layer 1) parameters.

[0221] The special cell (SpCell) may include a primary cell (PCell) of an MCG or a primary SCG cell (PSCell) of an SCG. The SpCell configuration parameters may include serving cell specific MAC and PHY parameters of the SpCell. The MR-DC configuration parameters may include at least one of SRB3 configuration parameters, measurement configuration parameters for the SCG, and SCG configuration parameters.

[0222] The cell group configuration parameters may include at least one of RLC bearer configuration parameters, MAC cell group configuration parameters, physical cell group configuration parameters, SpCell configuration parameters for the first cell group, or SCell configuration parameters for other cells of the second base station. The SpCell configuration parameters may include at least one of radio link failure timers and constraints, out-of-sync radio link monitoring thresholds, and / or serving cell configuration parameters of the first cell. The serving cell configuration parameters may include at least one of: downlink BWP configuration parameters, uplink configuration parameters, uplink configuration parameters for a complementary uplink carrier (SUL), PDCCH parameters applicable to all BWPs of the serving cell, PDSCH parameters applicable to all BWPs of the serving cell, CSI measurement configuration parameters, an SCell deactivation timer, cross-carrier scheduling configuration parameters of the serving cell, a Timing Advance Group (TAG) Identity (ID) of the serving cell, a path loss reference link indicating whether the UE applies either the SpCell or the SCell's downlink for this uplink as a path loss reference, a serving cell measurement configuration parameter, and a channel access configuration parameter for access procedures for operation with shared spectrum channel access.

[0223] The CSI measurement configuration parameters may be for configuring a CSI-RS (Reference Signal) belonging to the serving cell, a channel state information report configuring the CSI-RS (Reference Signal) belonging to the serving cell, and a channel state information report on the PUSCH triggered by the DCI received on the serving cell.

[0224] In an embodiment, the downlink BWP configuration parameters may be used to configure dedicated (UE-specific) parameters of one or more downlink BWPs. The one or more downlink BWPs may include at least one of an initial downlink BWP, a default downlink BWP, and a first active downlink BWP. The downlink BWP configuration parameters may include at least one of configuration parameters for the one or more downlink BWPs, one or more downlink BWP IDs for the one or more downlink BWPs, and a BWP inactivity timer. The configuration parameters of the downlink BWPs may include at least one of the following: PDCCH configuration parameters for the downlink BWPs, PDSCH configuration parameters for the downlink BWPs, Semi-Persistent Scheduling (SPS) configuration parameters for the downlink BWPs, beam failure recovery SCell configuration parameters for candidate RSs, and / or radio link monitoring configuration parameters for detecting cell and beam radio link failure opportunities for the downlink BWPs. One or more downlink BWPs The ID may include at least one of an initial downlink BWP ID, a default downlink BWP identity (ID), and a first active downlink BWP ID.

[0225] In an embodiment, the uplink configuration parameters may be uplink configuration parameters for a normal uplink carrier (a non-complementary uplink carrier). The uplink configuration parameters (or the uplink configuration parameters of the SUL) may be used to configure dedicated (UE-specific) parameters for one or more uplink BWPs. The one or more uplink BWPs may include at least one of an initial uplink BWP and a first active uplink BWP. The uplink BWP configuration parameters may include at least one of configuration parameters for one or more uplink BWPs, one or more uplink BWP IDs for one or more uplink BWPs, PUSCH parameters common across BWPs of UEs of a serving cell, SRS carrier switching information, and power control configuration parameters. The configuration parameters for the uplink BWP may include at least one of one or more PUCCH configuration parameters for the uplink BWP, a PUSCH configuration parameter for the uplink BWP, one or more configured uplink grant configuration parameters for the uplink BWP, an SRS configuration parameter for the uplink BWP, a beam failure recovery configuration parameter for the uplink BWP, and / or a cyclic prefix (CP) extension parameter for the uplink BWP.

[0226] The one or more uplink BWP IDs may include at least one of an initial uplink BWP ID (e.g., initial uplink BWP ID=0) and / or a first active uplink BWP ID. The SRS carrier switching information may be used to configure for SRS carrier switching when PUSCH is not configured and for SRS power control independent of that of PUSCH. The power control configuration parameters may include at least one of a power control configuration parameter for PUSCH, a power configuration control parameter for PUCCH, and a power control parameter for SRS.

[0227] A UE-RRC layer in an RRC inactive or idle state may receive an RRC reject message in response to an RRC setup request message or an RRC resume request message. The RRC reject message may include a wait timer. Based on the wait timer, the UE-RRC layer may set a timer value to the wait timer and start timer T302. Based on the RRC reject message, the UE-RRC layer may inform upper layers (e.g., the UE-NAS layer) about the failure of the RRC connection setup or RRC connection resume. The UE-RRC layer may reset the MAC and release the default MAC cell group configuration. Based on the RRC reject received in response to a request from the upper layer, the UE-RRC layer may inform upper layers (e.g., the NAS layer) that the access barring is applicable to all access categories except categories "0" and "2".

[0228] A UE-RRC layer in an RRC inactive or idle state may receive an RRC reject message in response to an RRC resume resumption request message. Based on the RRC reject message, the UE-RRC layer may discard current security keys. The UE-RRC layer may resuspend the RRC connection. The UE-RRC layer may set the pending rna update value to true if the resume was triggered by an RNA update.

[0229] A UE-RRC layer in an RRC inactive or idle state may perform a cell (re)selection procedure while performing an RRC procedure to establish an RRC connection. Based on the cell selection or cell reselection, the UE-RRC layer may change the cell on the camped UE and stop the RRC procedure. The UE-RRC layer may inform upper layers (e.g., NAS layer) about the failure of the RRC procedure.

[0230] A UE in an RRC connected state may detect a failure of connection with a base station. A UE in an RRC connected state may activate AS security with the base station before detecting the failure. The failure includes at least one of the following: Radio Link Failure (RLF), reconfiguration with synchronization failure, mobility failure from new radio (NR), integrity check failure indication from lower layers (e.g., PDCP layer) for signaling radio bearer 1 (SRB1) or signaling radio bearer 2 (SRB2), or RRC connection reconfiguration failure.

[0231] The radio link failure may be a radio link failure of the base station's primary cell. The base station may send a reconfiguration with synchronization in an RRC message to the UE in the RRC connected state. The reconfiguration with synchronization may include a reconfiguration timer (e.g., T304). Based on receiving the reconfiguration synchronization, the UE may start a reconfiguration timer and perform a reconfiguration with synchronization (e.g., handover). Based on the expiration of the reconfiguration timer, the UE determines a reconfiguration synchronization failure. The base station may send a mobility from NR command message to the UE in the RRC connected state. Based on receiving the mobility from the NR command message, the UE may perform a handover from NR to a cell using another RAT (e.g., E-UTRA). The UE may determine a mobility from NR failure based on at least one of the following conditions being met: If the UE cannot establish a connection to the target radio access technology, or if the UE cannot comply with any part of the configuration included in the mobility from NR command message, or if there is a protocol error in the inter-RAT information included in the mobility from NR message.

[0232] Upon detection of the failure, the UE in the RRC connected state may initiate an RRC connection re-establishment procedure. Upon initiation of the RRC connection re-establishment procedure, the UE may start timer T311, stop all radio bearers except SRB0, and reset the MAC (layer). Upon initiation of the RRC connection re-establishment procedure, the UE in the RRC connected state may release the MCG SCell, and release the special cell (SpCell) configuration parameters and the multi-radio dual connectivity (MR-DC) related configuration parameters. For example, upon initiation of the RRC connection re-establishment procedure, the UE may release the master cell group configuration parameters.

[0233] Based on the initiation of the RRC connection re-establishment procedure, the UE in the RRC connected state may perform a cell selection procedure. Based on the cell selection procedure, the UE may select a cell based on the signal quality of the cell exceeding a threshold. The UE in the RRC connected state may select a cell based on the signal quality of the cell exceeding a threshold. The UE may determine the selected cell exceeding the threshold based on the cell selection procedure. The signal quality includes at least one of a reference signal received power, a received signal strength indicator, a reference signal received quality, or a signal to interference plus noise ratio.

[0234] Based on the selection of the preferred cell, the RRC connected UE may stop timer 311 and start timer T301. Based on the selection of the preferred cell, the RRC connected UE may stop the prohibition timer T390 for all access categories. Based on the stop of the prohibition timer T390, the RRC connected UE may consider that the prohibition for all access categories is relaxed for the cell. Based on the selection of the cell, the RRC connected UE may apply default L1 parameter values ​​except for the parameters provided in SIB1, apply the default MAC cell group configuration, apply the CCCH configuration, apply the timer alignment timer in SIB1, and start transmitting an RRC re-establishment request message.

[0235] The UE in the RRC connected state may stop the timer T301 based on receiving an RRC response message in response to the RRC re-establishment request message. The RRC response message may include at least one of an RRC re-establishment message, an RRC setup message, or an RRC re-establishment rejection message. The UE in the RRC connected state may stop the timer T301 when the selected cell becomes unsuitable.

[0236] Based on the cell selection procedure triggered by initiating the RRC connection re-establishment procedure, the UE in the RRC connected state can select an inter-RAT cell. Based on the selection of the inter-RAT cell, the UE in the RRC connected state (UE-AS layer) can transition to the RRC IDLE state and provide a release cause "RRC connection failure" to the upper layers of the UE (UE-NAS layer).

[0237] Based on the initiation of transmission of the RRC re-establishment request message, the UE in the RRC connected state may transmit an RRC re-establishment request message. The RRC re-establishment request message may include at least one of a C-RNTI used in the source PCell, a physical cell identity (PCI) of the source PCell, a short MAC-I, or a re-establishment cause. The re-establishment cause may include at least one of a reconfiguration failure, a handover failure, or another failure.

[0238] Based on initiating the transmission of the RRC re-establishment request message, the RRC connected UE (RRC layer) may re-establish PDCP for SRB1, re-establish RLC for SRB1, apply a default SRB configuration for SRB1, configure the lower layer (PDCP layer) to stop integrity protection and ciphering for SRB1, resume SRB1, and send an RRC re-establishment request message to the lower layer (PDCP layer) for transmission. Based on sending the RRC re-establishment request message to the lower layer, the RRC connected UE may send an RRC re-establishment request message to a target base station via a cell selected based on a cell selection procedure, where the target base station may or may not be the source base station.

[0239] Based on expiration of T311 or T301, the UE (UE-AS layer) may transition to an RRC idle state and may provide a release cause "RRC connection failure" to upper layers of the UE (UE-NAS layer).

[0240] Based on receiving the release cause "RRC connection failure", if the UE in the RRC idle state is not in signaling pending and user data pending, the UE (UE-NAS layer) may perform a NAS signaling connection restoration procedure. Based on the performance of the NAS signaling connection restoration procedure, the UE in the RRC idle state may initiate a registration procedure by sending a registration request message to the AMF.

[0241] Based on receiving the release cause "RRC connection failure", a UE in RRC idle state (UE-NAS layer) can perform a service request procedure by sending a service request message to the AMF when the UE is on signaling hold or user data hold.

[0242] Based on receiving the RRC re-establishment request message, the target base station may check whether the UE context of the UE is available locally. Based on the UE context not being available locally, the target base station may perform an acquire UE context procedure by sending an acquire UE context request message to the source base station (last serving base station) of the UE.

[0243] In the RRC connection re-establishment procedure, the acquire UE context request message may include at least one of a UE context ID, an integrity protection parameter, or a new cell identifier. The UE context ID may include at least one of a C-RNTI that includes the RRC re-establishment request message and a PCI of the source PCell (last serving PCell). The integrity protection parameter of the RRC re-establishment procedure may be a short MAC-I. The new cell identifier may be an identifier of the target cell, where the target cell is the cell for which the RRC connection is requested to be re-established. The new cell identifier is a cell identity in a system information block (e.g., SIB1) of the target cell (e.g., the selected cell).

[0244] In the RRC connection re-establishment procedure, based on receiving the acquire UE context request message, the source base station can check the acquire UE context request message. If the source base station can identify the UE context by the UE context ID and successfully verify the UE by the integrity protection included in the UE context acquire request message, and determine to provide the UE context to the target base station, the source base station can respond to the target base station with a UE context acquire response message. If the source base station cannot identify the UE context by the UE context ID or the integrity protection included in the UE context acquire request message is not valid, the source base station can respond to the target base station with a UE context acquire failure message.

[0245] In the RRC connection re-establishment procedure, the UE context acquisition response message may include at least one of the following: Xn Application Protocol (XnAP) ID of the target base station, XnAP ID of the source base station, Global Unique AMF Identifier (GUAMI), or UE context information (e.g., UE context information UE context acquisition response). The UE context information may include at least one of the following: NG-C UE-related signaling criteria, UE security capability, AS security information, UE aggregated maximum bit rate, PDU sessions to be set up list, RRC context, mobility constraint list, or RAT / mobility selection priority index. The NG-C UE-related signaling criteria may be an NG application protocol ID assigned in the AMF of the UE on the NG-C connection with the source base station. The AS security information may be the ... gNB) and a security key and a number of next hop chains (NCC) value. The PDU session set up in the list may include PDU session resource related information used in the UE context of the source base station. The PDU session resource related information may include a PDU session ID, a PDU session resource aggregation maximum bit rate, a security indication, a PDU session type, or a QoS flow set up in the list. The security indication may include a user plane integrity protection indication and a confidentiality protection indication, which indicate the requirements of user plane (UP) integrity protection and encryption for the corresponding PDU session, respectively. The security indication may also include at least one of an indication of whether UP integrity protection is applied to the PDU session, an indication of whether UP encryption is applied to the PDU session, and a maximum integrity protection data rate value per UE for the integrity protected DRB (uplink and downlink). The PDU session type may indicate at least one of Internet Protocol version 4 (IPv4), IPv6, IPv4v6, Ethernet, or unstructured. The QoS flows set up in the list may include at least one of a QoS flow identifier, QoS flow level QoS parameters (QoS parameters that apply to the QoS flow), or a bearer identity.

[0246] In the RRC connection re-establishment procedure, the UE context acquisition failure message may include at least the XnAP ID and a cause value of the target base station.

[0247] In the RRC connection re-establishment procedure, based on receiving the UE context acquisition response message, the target base station may send an RRC re-establishment message to the UE. The RRC re-establishment message may include at least a network hop chain number (NCC) value.

[0248] Upon receiving the RRC re-establishment message, the UE determines the current K associated with the NCC value. gNB or based on at least one of the next hop (NH) parameters, the base station (KgNB Based on the base station's new security key and the previously configured integrity protection algorithm, the UE may derive a new security key for the RRC signaling (K RRCint ) and the security key for protecting the integrity of the user plane (UP) data (K UPint Based on the base station's new security key and the previously configured encryption algorithm, the UE can derive a security key for integrity protection of the RRC signaling (K RRCenc ) and the security key for encryption of the user plane (UP) data (K UPenc ) can be used to derive a security key for encrypting K RRCint Based on the previously configured integrity protection algorithm and K, the UE may verify the integrity protection of the RRC re-establishment message. Based on the verification failure, the UE (UE-AS layer) may transition to the RRC IDLE state and provide a release cause of "RRC connection failure" to the upper layer of the UE (UE-NAS layer). Based on the success of the verification, the UE may verify the integrity protection of the RRC re-establishment message based on the previously configured integrity protection algorithm and K. RRCint , and configures the previously configured encryption algorithm and K RRCenc The UE may be configured to resume ciphering of SRB1 based on the received SRB_RESET_CONFIGURATION_TIME. The UE may send an RRC re-establishment complete message to the target base station.

[0249] Based on receiving the UE context acquisition failure message, the target base station may send an RRC release message to the UE. For example, based on the UE context acquisition failure message including the RRC release message, the target base station may send an RRC release message to the UE. Based on receiving the UE context acquisition failure message, the target base station may send an RRC setup message or an RRC reject message. Based on receiving the UE context acquisition failure message, the target base station may not send a response message to the UE.

[0250] FIG. 17 illustrates an example of an RRC connection re-establishment procedure. A UE in an RRC connected state may transmit and receive data to a first base station (e.g., a source base station) through a cell, which includes a primary cell (PCell) of the first base station. The UE may detect a failure of a connection with the first base station. Based on the failure, the UE may initiate an RRC re-establishment procedure.

[0251] In the embodiment of FIG. 17, based on the start of the RRC connection re-establishment procedure, the UE may start timer T311, suspend all radio bearers except SRB0, and / or reset MAC (layer). Based on the start of the RRC connection re-establishment procedure, the UE may release the MCG SCell, release the special cell (SpCell) configuration parameters and the multi-radio dual connectivity (MR-DC) related configuration parameters. Based on the start of the RRC connection re-establishment procedure, the UE may perform a cell selection procedure. Based on the cell selection procedure, the UE may select cell 2 of a second base station (e.g., a target base station), where cell 2 is a preferred cell. Based on the selection of the preferred cell, the UE may stop timer T311 and start timer T301. Based on the selection of the preferred cell, the UE may stop one or more prohibition timers T309 for all access categories if one or more prohibition timers T309 are started. Based on the stopping of one or more prohibition timers T309, the UE may consider that the prohibition for all access categories is relaxed for the cell. Based on the cell selection, the UE may apply default L1 parameter values ​​except for the parameters provided in SIB1, apply the default MAC cell group configuration, apply the CCCH configuration, apply the timer alignment timer in SIB1, and start transmitting an RRC re-establishment request message.

[0252] In the embodiment of Figure 17, the RRC re-establishment message may include at least one of a C-RNTI used in the source PCell (e.g., cell 1), a physical cell identity (PCI) of the source PCell, a short MAC-I, or a re-establishment cause. Based on the initiation of transmission of the RRC re-establishment request message, the UE (RRC layer) may re-establish PDCP for SRB1, re-establish RLC for SRB1, apply a default SRB configuration for SRB1, configure the lower layer (PDCP layer) to suspend integrity protection and ciphering for SRB1, resume SRB1, and send an RRC re-establishment request message to the lower layer (PDCP layer) for transmission. Based on the initiation of transmission of the RRC re-establishment request message, the UE may send an RRC re-establishment request message to the second base station via cell 2.

[0253] In the embodiment of FIG. 17, based on receiving the RRC re-establishment request message, the second base station may check whether the UE context of the UE is locally available. Based on the UE context not being locally available, the second base station may perform an acquire UE context procedure by sending an acquire UE context request message to the source base station of the UE. The acquire UE context request message may include at least one of a UE context ID, an integrity protection parameter, or a new cell identifier. The UE context ID may include at least one of a C-RNTI that includes the RRC re-establishment request message and a PCI (last serving PCell) of the source PCell. The integrity protection parameter of the RRC re-establishment procedure may be a short MAC-I. The new cell identifier may be an identifier of a target cell, where the target cell is a cell for which an RRC connection is requested to be re-established. The new cell identifier is a cell identity in a system information block (e.g., SIB1) of the target cell (e.g., the selected cell).

[0254] In the embodiment of Figure 17, the source base station can check the acquire UE context request message based on receiving the acquire UE context request message. If the source base station successfully identifies the UE context by the C-RNTI, successfully verifies the UE by the short MAC-I, and can determine to provide the UE context to the second base station, the source base station can respond to the second base station with a UE context acquire response message. The UE context acquire response message can include at least GUAMI or UE context information. Based on receiving the UE context acquire response message, the second base station can send an RRC re-establishment message to the UE. The RRC re-establishment message can include a network hop chain number (NCC) value.

[0255] In the embodiment of FIG. 17, upon receipt of the RRC re-establishment message, the UE determines the current K gNB or based on at least one of the next hop (NH) parameters, the base station (K gNB ) can derive a new security key for the base station (K gNB ) and the previously configured security algorithm, the UE may then use RRC signaling (e.g., K RRCint , and K RRCenc ), and user plane (UP) data (e.g., K UPint , and K UPenc ) can be used to derive security keys for integrity protection and encryption of RRC signaling (K RRCint Based on the security key for integrity protection of K), the UE may verify the integrity protection of the RRC re-establishment message. Based on the successful verification, the UE may verify the integrity protection of the RRC re-establishment message based on the previously configured integrity protection algorithm and K RRCint and re-configuring integrity protection for one or more bearers (e.g., signaling radio bearers or RRC messages) based on a previously configured encryption algorithm and K RRCenc Based on the received ciphertext, the device may be configured to resume encryption of one or more bearers.

[0256] In the embodiment of FIG. 17, the second base station may transmit a first RRC reconfiguration message. The RRC first reconfiguration message may include SpCell configuration parameters. Based on receiving the SpCell configuration parameters, the UE may start transmitting and receiving data with the second base station. The UE may transmit an RRC reestablishment complete message to the second base station. The RRC reestablishment complete message may include a measurement report. Based on receiving the measurement report, the second base station may determine to configure a SCell and / or a secondary cell group (e.g., an SCG or a PSCell). Based on the determination, the second base station may transmit a second RRC reconfiguration message including the SCell configuration parameters and / or the MR-DC related configuration parameters. Based on receiving the second RRC reconfiguration message, the UE may transmit and receive data via the SCell and / or the SCG.

[0257] In the embodiment of FIG. 17, the RRC reconfiguration message may include at least one of cell group configuration parameters of the MCG and / or SCG, radio bearer configuration parameters, or AS security key parameters.

[0258] The base station may initiate an RRC connection release procedure to transition the RRC state of the UE from an RRC connected state to an RRC idle state, from an RRC connected state to an RRC inactive state, from an RRC inactive state to an RRC inactive state when the UE attempts to resume, or from an RRC inactive state to an RRC idle state when the UE attempts to resume. The RRC connection procedure may also be used to release the RRC connection of the UE and redirect the UE to another frequency. The base station may send an RRC release message including a suspension configuration parameter to the UE. Based on the RRC release message, the UE may stop the RRC connection. The UE may transition the RRC state of the UE to an RRC inactive state or an RRC idle state. The suspension configuration parameters may include at least one of a resume identity, an RNA configuration, a RAN paging cycle, or a network hop chain number (NCC) value, and the RNA configuration may include RNA notification area information or a periodic RNA update timer value (e.g., a T380 value). The base station may use a resumption identity (eg, an inactive-RNTI (I-RNTI)) to identify the UE context when the UE is in an RRC inactive state.

[0259] If the base station has a fresh, unused pair of {NCC, next hop (NH)}, the base station may include the NCC in the suspension configuration parameters. Otherwise, the base station may include the current K gNB The same NCC associated with the AS key (e.g., K) may be included in the suspension configuration parameter. The NCC is used for AS security. After the base station sends an RRC release message including the suspension configuration parameter to the UE, the base station may release the current AS key (e.g., K RRCenc , K UPenc ), and K UPint However, the current AS key K RRCint If the transmitted NCC value is fresh and belongs to an unused {NCC, NH} pair, the base station stores the {NCC, NH} pair in the current UE AS security context and retains the current AS key K gNB The transmitted NCC value can be deleted if the current KgNB If the NCC value associated with the current AS key K gNB and the NCC. The base station may store the transmitted resumption identity together with the current UE context, including the remaining parts of the AS security context.

[0260] Upon receiving the RRC release message including the suspension configuration parameters from the base station, the UE may verify that the integrity of the received RRC release message including the suspension configuration parameters is correct by checking the PDCP MAC-I. If this verification is successful, the UE obtains the received NCC value and stores it as the NCC stored with the current UE context. The UE may also verify that the current AS key K RRCenc , K UPenc , and K UPint However, the current AS key K RRCint The stored NCC value can hold the current K gNB If the NCC value associated with the current AS key K differs from the NCC value associated with the current AS key K, the UE gNB The stored NCC can be deleted from the current gNB If the received resumption identity is equal to the NCC value associated with the AS, the UE shall retain the current AS key KgNB. The UE may store the received resumption identity together with the current UE context, including the remaining part of the AS security context, for the next state transition.

[0261] Upon receiving an RRC release message including the suspension configuration parameters, the UE may reset the MAC, release the default MAC cell group configuration, and re-establish an RLC entity for one or more bearers. Upon receiving an RRC release message including the suspension configuration parameters, the UE may store the current configuration parameters and the current security keys in the UE inactive AS context. For example, the UE may store some of the current configuration parameters. The stored current configuration parameters may include the Robust Header Compression (ROHC) state, the Quality of Service (QoS) flow to DRB mapping rule, the C-RNTI used in the source PCell, the global cell identity and physical cell identity of the source PCell, and all other parameters configured except those in the reconfiguration with synchronization and the serving cell configuration common parameters of the SIB. The stored security keys are K gNB and K RRCint The UE may include at least one of the following: The serving cell configuration common parameters in the SIB may be used to configure cell-specific parameters of the UE's serving cell in SIB1. Upon receiving an RRC release message including the suspension configuration parameters, the UE may suspend all SRBs and DRBs except SRB0. Upon receiving an RRC release message including the suspension configuration parameters, the UE may start timer T380, enter an RRC inactive state, and perform a cell selection procedure.

[0262] A UE in an RRC inactive state may initiate an RRC connection resumption procedure. For example, based on having data or signaling to transmit or receiving a RAN paging message, a UE in an RRC inactive state may initiate an RRC connection resumption procedure. Based on the initiation of the RRC connection resumption procedure, the UE may select an access category based on a trigger condition of the RRC connection resumption procedure and perform a unified access control procedure based on the access category. Based on the unified access control procedure, the UE may consider an access attempt of the RRC connection resumption procedure as authorized. Based on considering the access attempt as authorized, the UE may apply default L1 parameter values ​​specified in the corresponding physical layer specification, except for parameters whose values ​​are provided in SIB1, apply a default SRB1 configuration, apply a CCCH configuration, apply a common time alignment timer included in SIB1, apply a default MAC cell group configuration, start timer T319, and start transmitting an RRC resumption request message.

[0263] Based on the initiation of transmission of the RRC resume request message, the UE may set a context for the RRC resume request message. The RRC resume request message may include at least one of a resume identity, a resume MAC-I, or a resume cause. The resume cause may include at least one of an emergency, high priority access, mt access, mo signaling, mo data, mo voice call, mo sms, ran update, mps priority access, mcs priority access.

[0264] Based on the initiation of the transmission of the RRC Resume Request message, the UE may restore the stored configuration parameters and the stored security keys from the (stored) UE inactive AS context, except for the master cell group configuration parameters, the MR-DC related configuration parameters (e.g., secondary cell group configuration parameters), and the PDCP configuration parameters. The configuration parameters may include at least one of the C-RNTI used in the source PCell, the global cell identity and the physical cell identity of the source PCell, and all other configured parameters, except for those in the reconfiguration with synchronization and the serving cell configuration common parameters in the SIB. The current (restored) K associated with the stored NCC value. gNB Or based on the next hop (NH) parameter, the UE may select the base station (K gNB Based on the base station's new key, the UE may derive new keys for security keys (e.g., K and K , respectively) for integrity protection and ciphering of the RRC signaling. RRCenc and K RRCint ), and security keys for integrity protection and encryption of user plane data (e.g., K UPint and K UPenc ) can be derived. The constructed algorithm and K RRCint and K UPint Based on the configured algorithm and K, the UE may configure the lower layers (e.g., the PDCP layer) to apply integrity protection to all radio bearers except SRB0. RRCenc and K UPenc Based on this, the UE may configure the lower layers (e.g., the PDCP layer) to apply ciphering to all radio bearers except SRB0.

[0265] Based on the start of transmission of the RRC Resume Request message, the UE may re-establish a PDCP entity for one or more bearers, resume the one or more bearers, and send an RRC Resume Request message to lower layers, which may include at least one of a PDCP layer, an RLC layer, a MAC layer, or a physical (PHY) layer.

[0266] The target base station may receive an RRC Resume Request message. Based on receiving the RRC Resume Request message, the target base station may check whether the UE context of the UE is locally available. Based on the UE context not being locally available, the target base station may perform a UE context procedure by sending a UE context acquisition request message to the source base station (last serving base station) of the UE. The UE context acquisition request message may include at least one of a UE context ID, an integrity protection parameter, a new cell identifier, or a resume cause, where the resume cause is in the RRC Resume Request message.

[0267] In the RRC connection resumption procedure, based on receiving the UE context acquisition request message, the source base station can check the UE context acquisition request message. If the source base station can identify the UE context by the UE context ID and successfully verify the UE by the integrity protection included in the UE context acquisition request message, and can determine to provide the UE context to the target base station, the source base station can respond to the target base station with a UE context acquisition response message. If the source base station cannot identify the UE context by the UE context ID, or if the integrity protection included in the UE context acquisition request message is not valid, or if the source base station determines not to provide the UE context to the target base station, the source base station can respond to the target base station with a UE context acquisition failure message.

[0268] In the RRC connection resumption procedure, the UE context acquisition failure message may include at least the XnAP ID of the target base station, an RRC release message, or a cause value.

[0269] In the RRC connection resumption procedure, based on receiving the UE context acquisition response message, the target base station may send an RRC resume message to the UE. The RRC resume message may include at least one of radio bearer configuration parameters, cell group configuration parameters of the MCG and / or SCG, measurement configuration parameters, or an sk counter, where the sk counter is a count of K gNB The secondary base station may then be configured to derive a security key for the secondary base station based on the received signal.

[0270] Based on receiving the UE context acquisition failure message, the target base station may send an RRC release message to the UE. For example, based on the UE context acquisition failure message including the RRC release message, the target base station may send an RRC release message to the UE. Based on receiving the UE context acquisition failure message, the target base station may send an RRC setup message or an RRC reject message. Based on receiving the UE context acquisition failure message, the target base station may not send a response message to the UE.

[0271] Based on receiving the RRC Resume message, the UE may stop timers T319 and T380. Based on receiving the RRC Resume message, the UE may restore the master cell group configuration parameters, secondary cell group configuration parameters, and PDCP configuration parameters to the UE inactive AS context. Based on restoring the master cell group configuration parameters and / or secondary cell group configuration parameters, the UE may configure the MCG and / or SCG SCells by configuring lower layers to consider the restored MCG and / or SCG SCells to be in a deactivated state, tear down the UE inactive AS context, and release the suspension configuration parameters.

[0272] Based on receiving the cell group configuration parameter in the RRC Resume message, the UE may perform cell group configuration of the MCG and / or SCG. Based on receiving the radio bearer configuration parameter in the RRC Resume message, the UE may perform radio bearer configuration. Based on the sk counter in the RRC Resume message, the UE may perform to update the security key of the secondary base station.

[0273] The UE can stay in CM-CONNECTED and move within the area configured by the base station without notifying the base station when the UE is in the RRC inactive state where the area is RNA. In the RRC inactive state, the last serving base station may hold the UE context and the UE-related NG connection with the serving AMF and UPF. While the UE is in the RRC inactive state, based on the received downlink data from the UPF or the downlink UE-related signaling from the AMF, the last serving base station can page in the cell corresponding to the RNA if the RNA contains the cell of the neighbor base station, and can send RAN paging to the neighbor base station via the Xn interface.

[0274] The AMF may provide core network assistance information to the base station to assist the base station in determining whether the UE can be sent to an RRC inactive state. The core network assistance information may include a registration area configured for the UE, a periodic registration update timer, a UE identity index value, a UE-specific DRX, an indication of whether the UE is configured with the AMF in a Mobile Initiated Connection Dedicated (MICO) mode, or expected UE behavior, etc. The base station may use the UE-specific DRX and the UE identity index value to determine a paging occasion for RAN paging. The base station may use the periodic registration update timer to configure a periodic RNA update timer (e.g., timer T380). The base station may use the expected UE behavior to assist the UE RRC state transition determination.

[0275] 18 illustrates an example of an RRC connection resumption procedure. A UE in an RRC connected state may transmit and receive data to and from a first base station (a source base station) through cell 1. The first base station may determine to transition the UE in an RRC connected state to an RRC inactive state. Based on the determination, the base station may send an RRC release message including a suspension configuration parameter.

[0276] In the embodiment of FIG. 18, based on receiving the RRC release message including the suspension configuration parameters, the UE may store the current security keys (e.g., KgNB and KRRCint keys) and the current configuration parameters in the UE inactive AS context. For example, the UE may store a part of the current configuration parameters. The stored (current) configuration parameters are at least one of the following: Robust Header Compression (ROHC) state, QoS flow to DRB mapping rule, C-RNTI used in the source PCell, global cell identity and physical cell identity of the source PCell, and all other parameters configured except those in the reconfiguration with synchronization and serving cell configuration common parameters of SIB. The Robust Header Compression (ROHC) state may include ROHC state for all PDCP entities (or all bearers), where each PDCP entity per bearer (or each bearer) may have one ROHC state. The QoS flow to DRB mapping rule may be the QoS flow to DRB mapping rule for all data radio bearers (DRBs), and each DRB may have one QoS according to the DRB mapping rule.

[0277] In the embodiment of FIG. 18, based on receiving an RRC release message including the suspension configuration parameter, the UE may stop all SRBs and DRBs except SRB0. Based on receiving an RRC release message including the suspension configuration parameter, the UE may start timer T380, enter an RRC inactive state, and perform a cell selection procedure. Based on the cell selection procedure, the UE may select cell 2 of a second base station (target base station). The UE in the RRC inactive state may initiate an RRC connection resumption procedure. The UE may perform a unified access control procedure. Based on the unified access control procedure, the UE may consider an access attempt of the RRC connection resumption procedure as authorized. The UE may apply default L1 parameter values ​​specified in the corresponding physical layer specification, except for parameters whose values ​​are provided in SIB1, apply a default SRB1 configuration, apply a CCCH configuration, apply a common time alignment timer included in SIB1, apply a default MAC cell group configuration, start timer T319, and start transmitting an RRC resume request message.

[0278] In the embodiment of FIG. 18, based on the initiation of the transmission of the RRC resume request message, the UE may restore the stored configuration parameters and the stored security keys from the (stored) UE inactive AS context. For example, the UE may restore the stored configuration parameters and the stored security keys (e.g., K gNB and K RRCint ) can be restored. The current (restored) K associated with the stored NCC value can be gNB Or based on the next hop (NH) parameter, the UE may select the base station (K gNB Based on the base station's new key, the UE may derive new keys for security keys (e.g., K and K , respectively) for integrity protection and ciphering of the RRC signaling. RRCenc and K RRCint), and security keys for integrity protection and encryption of user plane data (e.g., K UPint and K UPenc ) can be derived. RRCint and K UPint Based on the configured algorithm, and K, the UE (RRC layer) can configure the lower layer (e.g., the PDCP layer) to apply integrity protection to all radio bearers except SRB0. RRCenc and K UPenc Based on the configuration parameters, the UE may configure lower layers (e.g., the PDCP layer) to apply ciphering to all radio bearers except SRB0. Integrity protection and / or ciphering may be required for communications between the UE and the base station. Based on the integrity protection and / or ciphering, the UE may transmit data to and receive data from the second base station. The UE may transmit data to and receive data from the second base station using the restored configuration parameters.

[0279] In the embodiment of Figure 18, based on initiating the transmission of the RRC Resume Request message, the UE may re-establish a PDCP entity for one or more bearers, resume the one or more bearers, and send an RRC Resume Request message to lower layers. Based on receiving the RRC Resume Request message, the second base station may check whether the UE context of the UE is locally available. Based on the UE context not being locally available, the second base station may perform a UE context procedure by sending a Get UE Context Request message to the first base station (last serving base station) of the UE. The Get UE Context Request message may include at least one of a Resume Identity, a Resume MAC-I, or a Resume Cause.

[0280] In the embodiment of FIG. 18, the first base station may check the acquire UE context request message based on receiving the acquire UE context request message. If the first base station can identify the UE context by the UE context ID, successfully verify the UE by the resume MAC-I, and determine to provide the UE context to the second base station, the first base station may respond with a UE context acquire response message to the second base station. Based on receiving the UE context acquire response message, the second base station may send an RRC resume message to the UE. Based on receiving the RRC resume message, the UE may restore the master cell group configuration parameters, the secondary cell group configuration parameters, and the PDCP configuration parameters to the UE inactive AS context. Based on restoring the master cell group configuration parameters and / or the secondary cell group configuration parameters, the UE may configure the SCells of the MCG and / or SCG by configuring the lower layers to consider the restored MCG and / or SCG SCells to be in a deactivated state, tear down the UE inactive AS context, and release the suspension configuration parameters. The UE may transmit and receive data via the SCell and / or the SCG.

[0281] The base station may send an RRC release message to the UE to release the UE's RRC connection. Based on the RRC release message, the UE may release the established radio bearers as well as all radio resources.

[0282] The base station may send an RRC release message to the UE to suspend the RRC connection. Based on the RRC release message, the UE may suspend all radio bearers except for signaling radio bearer 0 (SRB0). The RRC release message may include suspension configuration parameters. The suspension configuration parameters may include a next hop chain number (NCC) and a resume identity (e.g., ID or identifier).

[0283] The base station may send an RRC release message to transition an RRC connected UE to an RRC idle state, or transition an RRC connected UE to an RRC inactive state, or transition an RRC inactive UE back to an RRC inactive state when the UE attempts to resume, or transition an RRC inactive UE to an RRC idle state when the UE attempts to resume.

[0284] The base station may send an RRC release message to redirect the UE to another frequency.

[0285] The UE may receive an RRC release message from a base station of a serving cell (or PCell). Based on the RRC release message, the UE may perform a UE action for the RRC release message from the base station. The UE may delay the UE action for the RRC release message for a certain time (e.g., 60 ms) from the time of receiving the RRC release message or from the time of successfully acknowledging the reception of the RRC release message. The UE may send a HARQ acknowledgement to the base station for acknowledging the RRC release message. Based on the RLC protocol data unit (PDU) including the RRC release message and the RLC PDU including a polling bit, the UE may send an RLC message (e.g., a status report) to the base station for acknowledging the RRC release message.

[0286] The UE action in response to an RRC release message from the base station may include at least one of suspending the RRC connection, releasing the RRC connection, a cell (re)selection procedure, and / or idle / inactive measurements.

[0287] The RRC release message from the base station may include a suspension configuration parameter. Based on the suspension configuration parameter, the UE may perform a suspension of the RRC connection. The suspension of the RRC connection may include at least one of a media access control (MAC) reset (or MAC reset), a release of a default MAC cell group configuration, a re-establishment of an RLC entity for one or more radio bearers, storing current configuration parameters and current security keys, a suspension of one or more bearers, where the bearers include a signaling radio bearer and a data radio bearer, and / or a transition to an RRC idle state or an RRC inactive state.

[0288] For example, the suspension configuration parameter may further include an RNA configuration parameter. Based on the RNA configuration parameter, the UE may transition to an RRC inactive state. For example, based on the suspension configuration parameter not including the RNA configuration parameter, the UE may transition to an RRC idle state. For example, an RRC release message including the suspension configuration parameter may include an indication of transition to an RRC inactive state. Based on the indication, the UE may transition to an RRC inactive state. For example, based on the RRC release message not including the indication, the UE may transition to an RRC idle state.

[0289] Based on the MAC reset, the UE may perform at least one of: stopping all timers started at the UE-MAC layer, considering all time alignment timers as expired, setting new data indicators (NDIs) for all uplink HARQ processes to value 0, stopping ongoing RACH procedures, discarding explicitly signaled contention-free random access resources if any, flushing the Msg3 buffer, canceling triggered scheduling request procedures, canceling triggered buffer status reporting procedures, canceling triggered power headroom reporting procedures, flushing soft buffers for all DL HARQ processes, considering the next received transmission for TB as the first transmission for each DL HARQ process, and / or releasing the temporary C-RNTI.

[0290] Based on deeming the time alignment timer to have expired, the UE may perform at least one of: flushing all HARQ buffers for all serving cells, notifying RRC to release PUCCH for all serving cells (if configured), notifying RRC to release SRS for all serving cells (if configured), clearing any configured downlink assignments and configured uplink grants, clearing any PUSCH resources for semi-persistent CSI reporting, and / or deeming all running time alignment timers to have expired.

[0291] The default MAC cell group configuration parameters may include buffer status reporting (BSR) configuration parameters for the base station's cell group (e.g., BSR timers) and power headroom reporting (PHR) configuration parameters for the base station's cell group (e.g., PHR timers or PHR transmit power factor change parameters).

[0292] Re-establishing the RLC entity may include at least one of discarding all RLC SDUs, RLC SDU segments, and RLC PDUs (if present), stopping and resetting all timers of the RLC entity, and resetting all state variables of the RLC entity to their initial values.

[0293] The RRC release message from the base station may not include the suspension configuration parameter. Based on the RRC message not including the suspension configuration parameter, the UE may perform a release of the RRC connection. The release of the RRC connection may include at least one of a MAC reset (or a MAC reset), a discard of stored configuration parameters and stored security keys (or a discard of stored UE inactive AS contexts), a release of the suspension configuration parameters, a release of all radio resources including the RLC entity, the MAC configuration, and associated PDCP entities, a release of SDAPs for all established radio bearers, and / or a transition to an RRC idle state.

[0294] The RRC release message may include an RRC Early Data Complete message.

[0295] Small Data Transmission (SDT) is a procedure that enables data transmission / reception while a wireless device remains in an RRC inactive state or an RRC idle state (eg, without transitioning to an RRC connected state).

[0296] In an embodiment, a small data transmission (SDT) procedure may include an exchange of user data between a wireless device and a base station while the wireless device is in a non-connected state (e.g., a radio resource control (RRC) non-connected state) (e.g., an idle state, an inactive state, etc.). The amount of data exchanged in an SDT transmission of an SDT procedure may be less than a threshold amount of data. The SDT procedure may include a small amount of data and / or one SDT transmission of a series of SDT transmissions. For example, using an SDT procedure, the wireless device and / or the base station may transmit and / or receive data via a user plane (UP) or a control plane (CP) while the wireless device remains in a non-connected state (e.g., idle, inactive, etc.). For example, using an SDT procedure, the wireless device may transmit and / or receive data without completing a connection setup or resumption procedure (and without control plane signaling related to setup and / or resumption). The data may include user data and signaling.

[0297] In an embodiment, a wireless device may require a permission to transmit data (e.g., uplink data) associated with an SDT procedure. The wireless device may receive the permission from / through a base station. The permission may be an uplink grant for one or more uplink resources, and the wireless device may transmit the data (e.g., uplink data) using the one or more uplink resources. The permission may be a dynamic uplink grant or a configured uplink grant for one or more uplink resources. A dynamic uplink grant may indicate one or more specific uplink resources to be used for uplink transmission at a particular time. A configured uplink grant may indicate resources that are recurring, intermittent, and / or periodic. For example, a configured uplink grant configuration may indicate a periodicity of the configured uplink grant, and one or more uplink resources of the configured uplink grant configuration may be reused periodically. For example, a configured uplink grant may be configured / activated, and resources associated with the configured uplink grant may be used until the configured uplink grant is released / deactivated. As an illustration, a dynamic uplink grant may indicate resources at time k, while a configured uplink grant may grant resources at time k+nT, where T is the duration of the configured uplink grant and n is an integer [0, 1, 2, ...].

[0298] In an embodiment, the wireless device may obtain an uplink grant via a physical or MAC signal (e.g., a DCI or a random access (RA) response) indicating an uplink grant. For example, in a random access (RA)-based procedure (e.g., an early data transmission (EDT) procedure), the wireless device may transmit an RA preamble requesting one or more uplink resources. Based on the RA preamble, the wireless device may receive an uplink grant indicating one or more uplink resources for transmitting small data.

[0299] In an embodiment, the wireless device may obtain an uplink grant based on a configured uplink grant (CG). The configured uplink grant may be associated with a configured uplink grant configuration (e.g., a preconfigured uplink resource (PUR) configuration). The wireless device may receive the configured uplink grant configuration via an RRC message (e.g., an RRC release message). The configured uplink grant configuration may indicate grant of one or more uplink resources, and the wireless device may use and / or reuse the one or more uplink resources (e.g., the preconfigured uplink resources) to transmit small data.

[0300] SDT may be configured to take place on either the RACH or configured uplink grant (CG) resources (e.g., type 1 CG resources). SDT configured to take place on the RACH may be referred to as a RACH-based SDT (or EDT). SDT configured to take place on CG resources may be referred to as a CG-based SDT (or uplink transmission using PUR). For example, the wireless device may transmit a first uplink message for an SDT procedure based on an uplink grant from the RACH-based SDT or the CG-based SDT. For example, the wireless device may transmit a first uplink message for an SDT procedure based on an RA response indicating an uplink grant for an SDT procedure or a configured uplink grant for an SDT procedure. For example, for subsequent transmissions, the wireless device may transmit data / signals using a dynamic uplink grant or a configured uplink grant. The base station may transmit the dynamic uplink grant or the configured uplink grant to the wireless device.

[0301] The configured uplink grant for the SDT (e.g., SDT resource) may be configured with either an initial BWP or a dedicated BWP. The configured uplink grant for the SDT may be configured with a normal uplink (NUL) carrier and / or a supplemental uplink (SUL) carrier. The configured uplink grant for the SDT may be provided to the wireless device in an RRC connected state via / within an RRC release message. In case of RACH, the base station may configure to the wireless device whether 2-step and 4-step RA types may be used for the SDT. If both can be used, the UE may select one of the RA types.

[0302] The wireless device may select a RACH resource for the SDT. The RACH resource may be different from the RACH resource for the RRC connection. The RACH resource may include at least one of an RA preamble and a RACH opportunity (RO). The wireless device may perform a RACH procedure for the SDT using the RACH resource. The wireless device may receive a Random Access Response (RAR) via a serving cell of the base station. The RAR may include / indicate an uplink grant for the SDT. Based on the RAR, the wireless device in an RRC inactive state or an RRC idle state may transmit a first (uplink) message for the SDT to the base station.

[0303] The SDT may include user plane (UP) small data transmission and control plane (CP) small data transmission. Based on the UP small data transmission, a UE in an RRC idle state or an RRC inactive state may transmit / receive data via the user plane (e.g., via a DTCH). Based on the CP small data transmission, a UE in an RRC idle state or an RRC inactive state may transmit / receive data via the control plane (e.g., a CCCH). Based on the UP small data transmission, a base station of the UE may receive downlink data via the user plane from the UPF of the UE. Based on the CP small data transmission, a base station of the UE may receive downlink data via the control plane from the AMF / non-SDT of the UE.

[0304] The base station may configure / indicate a first radio bearer to the wireless device. The first radio bearer may be configured for SDT. For example, the base station may send an RRC release message to the wireless device to configure / indicate the first radio bearer. The base station may send a configuration for SDT procedure (SDT configuration) to the wireless device. The SDT configuration may include parameters of the first radio bearer. The RRC release message may include the SDT configuration. The wireless device may send SDT data of the first radio bearer during the SDT procedure.

[0305] The SDT data may be data of a first logical channel of a first radio bearer. The data may include user data and signaling. The first radio bearer may include a data radio bearer (DRB) and a signaling radio bearer (SRB). The SRB may include SRB1 and SRB2. The base station may enable the wireless device to transmit the SDT data during the SDT procedure.

[0306] The user data may be user data of a DRB. The signal may be a signal of an SRB. The wireless device may transmit user data via a DRB. The wireless device may transmit a signal via an SRB. For example, the signal may be an RRC message or a NAS message.

[0307] The second radio bearer may not be configured in the SDT procedure. The second radio bearer may not be the first radio bearer. The base station may not allow the wireless device to transmit data of the second radio bearer during the SDT procedure. The non-SDT data may be data of a second logical channel of the second radio bearer. The data may include user data and signaling. The second radio bearer may include a data radio bearer (DRB) and a signaling radio bearer (SRB). The SRB may include SRB1 and SRB2. The user data may be user data of the DRB. The base station may not allow the wireless device to transmit non-SDT data during the SDT procedure.

[0308] The wireless device may determine to initiate an SDT procedure based on at least one of: less than a configured amount of uplink (UL) data awaits transmission over a radio bearer for which SDT is enabled; and a measured signal strength (e.g., RSRP) in a cell exceeds a configured threshold.

[0309] Based on the initiation of the SDT procedure, the wireless device may (re)activate AS security. For example, the wireless device may have a sold value of Next Hop Chaining Number (NCC) provided in the RRC Release message during a previous RRC Connection Release procedure. For example, the RRC Release message may include a suspension configuration parameter. Based on the initiation of the SDT procedure, the wireless device may derive a key for the base station (e.g., KgNB / KeNB) using the NCC. Based on the key for the base station, the wireless device may derive an integrity protection key and an encryption key. The integrity protection key may include an integrity protection key for RRC messages, KRRCint, and an integrity protection key for the user plane (data), KUPint. The encryption keys may include an encryption key for RRC messages, KRRCenc, and an encryption key for the user plane (data), KUPenc. The wireless device may be configured to resume integrity protection using the integrity protection key for data / signals received and transmitted by the wireless device during the SDT procedure. The wireless device may be configured to resume encryption using a key for encrypting data / signals received and transmitted by the wireless device during the SDT procedure.

[0310] Once initiated, the SDT procedure may continue unless the wireless device is explicitly directed to RRC idle or RRC inactive (via RRC release), or RRC connected (via RRC resume).

[0311] The SDT (procedure) may include at least one of an initial SDT transmission and a subsequent transmission. Based on the initiation of the SDT procedure, the wireless device may transmit a first (uplink) message for the SDT procedure. The wireless device may transmit the first message via an SDT resource. The SDT resource may be an uplink grant or a CG resource in response to a RACH preamble for the SDT procedure.

[0312] The first message may be Msg3 or MsgA. The first message may include at least one of an RRC request message, the first uplink data, an assistance parameter for an SDT procedure (or assistance information for an SDT procedure), and a request for uplink grant of the second uplink data. The RRC request message may be transmitted via a common control channel (CCCH). The CCCH message may include an RRC request message. The first uplink data may include user data and a signal (e.g., an RRC message). The user data of the first uplink data may be transmitted via a dedicated traffic channel (DTCH). The signal of the first uplink data may be transmitted via a dedicated control channel (DCCH). The DTCH message may include the user data of the first uplink data. The DCCH message may include the signal of the first uplink data. The CCCH message and the DTCH / DCCH message may be multiplexed into the first message. The first message may include at least one of a CCCH message, a DTCH message, and a DCCH message. The aiding parameters (or aiding information) may include (expected) traffic information of the wireless device. The traffic information may indicate at least one of whether a subsequent transmission for the uplink and / or downlink is expected and the amount of data of the subsequent transmission. For example, the aiding parameters may include Release Assistance Information (RAI). The request for an uplink grant of the second uplink data may be a Buffer Status Report (BSR).

[0313] The wireless device may receive a response to the first message from the base station. The response may include an RRC response message to the RRC request message of the first uplink message. Based on the response including the RRC response message, the wireless device may complete the SDT procedure. The RRC response message may be an RRC release message, or an RRC resume message, or an RRC setup message. Based on the RRC response message being an RRC release message, the wireless device may transition back to an RRC idle state or an RRC inactive state. Based on the RRC message being an RRC resume / setup message, the wireless device may transition to an RRC connected state.

[0314] The wireless device may receive a response to the first message from the base station. The response may not include an RRC response message. The base station may determine that the wireless device is allowed to perform a subsequent transmission in an RRC inactive or RRC idle state. The response may indicate an uplink grant for the subsequent transmission. The response may indicate the subsequent transmission. Based on the response, the wireless device may perform the subsequent transmission while remaining in an RRC inactive or RRC idle state. For example, the response may be Msg4 or MsgB.

[0315] After the initial SDT transmission, subsequent transmissions may be handled differently depending on the type of resources configured: if CG resources are used, the network may schedule subsequent UL transmissions using dynamic grants or may take place at the next CG resource opportunity; if RACH resources are used, the network may schedule subsequent UL and downlink DL transmissions using dynamic grants and allocations after the RA procedure is completed.

[0316] During the subsequent transmission, the wireless device may receive an RRC response message to the RRC request message of the first uplink message. Based on the RRC response message, the wireless device may complete the SDT procedure. The RRC response message may be an RRC release message, or an RRC resume message, or an RRC setup message. Based on the RRC response message being an RRC release message, the wireless device may transition back to an RRC idle state or an RRC inactive state. Based on the RRC response message being an RRC resume / setup message, the wireless device may transition to an RRC connected state.

[0317] Based on receiving the paging message indicating the SDT (procedure), the wireless device may determine to initiate the SDT procedure. The wireless device may transmit a first uplink message for the SDT procedure, where the first uplink message may include an RRC request message. The RRC request message may indicate the SDT (procedure).

[0318] The UE may determine to start the SDT using the configured uplink grant (CG-based SDT) based on the configured uplink grant condition being satisfied. The configured uplink grant condition may include at least one of: the UE has a valid configured uplink grant configuration parameter, the UE has a valid Timing Alignment (TA) value, the system information of the serving cell indicates the configured uplink grant support, the establishment or resumption request is for a call from the mobile phone and the establishment cause is mo data or mo exception data or delay tolerant access, the UE supports the configured uplink grant, the size of the resulting MAC PDU including the total uplink data is expected to be equal to or smaller than the TBS configured for the configured uplink grant, and the UE has a stored NCC value provided in an RRC release message including the suspension configuration parameter during the aforementioned suspension procedure.

[0319] The UE may determine a small data transmission timing alignment value for a configured uplink grant that is valid based on a TA verification condition for the configured uplink grant being satisfied. The TA verification condition for the configured uplink grant may include at least one of: a time alignment timer for the configured uplink grant is running, or the serving cell RSRP has not increased beyond an RSRP increase threshold and has not decreased beyond an RSRP increase threshold.

[0320] For CG-based SDT (or uplink transmission using PUR), a UE in an RRC connected state may send a CG (or PUR) configuration request message (or assistance information message) to the base station, where the CG configuration request message may include at least one of a requested number of CG opportunities, which may be one or infinite in number, a requested CG periodicity, a requested transport block size (TBS) for CG, and / or a requested time offset for the first CG opportunity.

[0321] The base station may transmit a set uplink grant configuration (parameters) including the (pre)configured uplink grant (resources) to the wireless device. For example, in response to a configured uplink grant configuration request message, the base station may transmit the configured uplink grant configuration parameters including the preconfigured uplink resources to the UE. For example, the base station may transmit an RRC release message including the configured uplink grant configuration parameters to the UE.

[0322] The configured uplink grant configuration parameters may include at least one of an indication to set up or release the configured uplink grant configuration parameters, a number of configured uplink grant opportunities, a configured uplink grant resource identifier (configured uplink grant RNTI), a configured uplink grant configuration identity (configured uplink grant configID), a value of a time offset for the first configured uplink grant opportunity (configured uplink grant start time), a configured uplink grant resource periodicity (configured uplink grant periodicity), a configured uplink grant response window duration (configured uplink grant response window time), a serving cell RSRP change threshold in dB for TA validation (configured uplink grant change threshold) (thresholds include RSRP increase threshold and RSRP decrease threshold), a value of a time alignment timer for the configured uplink grant, and / or physical configuration parameters of the configured uplink grant. The physical configuration parameters of the configured uplink grant may include at least one of the following: PUSCH configuration parameters of the configured uplink grant, PDCCH configuration parameters of the configured uplink grant, PUCCH configuration parameters of the configured uplink grant, downlink carrier configuration parameters used for the configured uplink grant, and / or uplink carrier frequency of the uplink carrier used for the configured uplink grant. The configured uplink grant RNTI can be assigned to two or more wireless devices. The configured uplink grant configID can be unique in one base station.

[0323] Based on the configured uplink grant configuration parameters, the UE may store or replace the configured uplink grant configuration parameters provided by the configured uplink grant configuration parameters based on an indication requesting to set up the configured uplink grant configuration parameters. In response to receiving the configured uplink grant configuration parameters, the UE may start a time alignment timer for the configured uplink grant with a value of the time alignment timer for the configured uplink grant and configure the configured uplink grant configuration parameters. For example, based on the indication requesting to set up the configured uplink grant configuration parameters, the UE may start a time alignment timer for the configured uplink grant with a value of the time alignment timer for the configured uplink grant and configure the configured uplink grant configuration parameters. In response to receiving the configured uplink grant configuration parameters, the UE may discard the configured uplink grant configuration parameters based on an indication requesting to release the configured uplink grant configuration parameters. In response to configuring the configured uplink grant configuration parameters, the UE may generate the configured uplink grant based on the configured uplink grant configuration parameters. For example, based on the configured uplink grant configuration parameters, the UE may determine when to generate the configured uplink grant. For example, based on a configured uplink grant start time and a configured uplink grant periodicity, the UE may determine when to generate a configured uplink grant. For example, based on a PUSCH configuration parameter, the UE may determine a configured uplink grant (transmit a block). For example, based on a PUSCH configuration parameter, the UE may determine a configured uplink grant (transmit a block).

[0324] Based on the CG configuration parameter, the UE in RRC idle or RRC inactive state may start a CG time alignment timer with the value of the CG time alignment timer and configure the CG configuration parameter. In response to the configuration of the CG configuration parameter, the UE in RRC idle or RRC inactive state may generate pre-configured uplink resources / grant for the CG based on the CG configuration parameter. Based on the first RRC release message, the UE may perform a cell (re)selection procedure. Based on the cell (re)selection procedure, the UE in RRC idle or RRC inactive state may select cell 2 of the second base station (target base station). The UE in RRC idle or RRC inactive state may have the first uplink data in the uplink buffer. The UE in RRC idle or RRC inactive state may determine to start the CG-based SDT based on one or more conditions being met.

[0325] The wireless device may transmit a message (e.g., a first uplink message for an SDT procedure) using a CG (or an uplink resource / grant for a CG), and the UE (UE-MAC entity) may start a CG response window timer with a CG response window time. Based on the start, the UE may monitor a PDCCH identified by the CG RNTI until the CG response window timer expires. The UE (UE-MAC entity) may receive a downlink message (e.g., a DCI) identified by the CG RNTI on the PDCCH. Based on the reception of a downlink message indicating an uplink grant for a retransmission, the UE may restart the configured CG response window timer in the last subframe (e.g., 4 subframes) of a PUSCH transmission indicating an uplink grant pulse time gap. Based on the restart, a UE in an RRC idle state or an RRC inactive state may monitor a PDCCH identified by the CG RNTI until the CG response window timer expires. Based on receiving a downlink message indicating an L1 (Layer 1) ack for CG, the UE in RRC idle or RRC inactive state may stop the CG response window timer and consider the CG-based SDT to be successful. Based on receiving a downlink message indicating a fallback of PUR, the UE in RRC idle or RRC inactive state may stop the CG response window timer and consider the CG-based SDT to be failed. Based on receiving a downlink message indicating a PDCCH transmission (downlink grant or downlink assignment) for the CG RNTI and / or MAC PDU including successfully decoded uplink data, the UE in RRC idle or RRC inactive state may stop the CG response window timer and consider the CG-based SDT to be successful. Based on the PDCCH transmission, the UE in RRC idle or RRC inactive state may receive at least one of an RRC response message and downlink data. The RRC response message may include at least one of an RRC release message or an RRC early data complete message.Based on not receiving any downlink messages until the CG response window timer expires, the UE in the RRC idle or RRC inactive state may consider the CG-based SDT to have failed. Based on considering the CG-based SDT to have failed, the UE may perform a random access procedure. For example, the random access procedure may include a RACH procedure for a RACH-based SDT.

[0326] CG resources for SDT procedures may be configured on the NUL and / or SUL. The wireless device may start a (response) window after a CG transmission or a dynamic grant (DG) transmission for a CG-based SDT. The wireless device may start a timer for the window based on the start of the window.

[0327] The wireless device may start a timer alignment timer (TAT) associated with a CG-SDT resource (TAT-SDT) upon receiving a TAT-SDT configuration from a base station (e.g., via an RRC release message). The wireless device may restart the TAT-SDT upon receiving a TA command. The wireless device may determine that a CG resource for an SDT procedure is valid based on a TA verification mechanism. For example, the wireless device may determine that a CG resource for an SDT procedure is valid based on an RSRP associated with the CG resource and an RSRP threshold associated with the CG resource.

[0328] For CG-based SDT, subsequent data transmissions may use CG resources or DGs (e.g., dynamic grants addressed to the UE's C-RNTI). The C-RNTI may be a C-RNTI explicitly assigned or configured by the base station. The base station may send multiple CG-SDT configurations per carrier in RRC idle or RRC inactive state. The CG-SDT resource may be valid in one cell. The wireless device may release the CG-SDT resource when the TAT-SDT expires in RRC idle or RRC inactive state.

[0329] The base station may send a configuration of the SDT procedure to the wireless device via an RRC release message. The configuration may indicate the configured radio bearers for the SDT procedure (e.g., SDT bearers). Based on receiving the RRC release message, the wireless device may suspend one or more radio bearers. The wireless device may suspend the RRC connection. Based on initiating the SDT procedure while leaving non-SDT bearers suspended, the wireless device may resume the SDT bearers. During the SDT procedure, the wireless device may transmit / receive data / signals associated with the SDT bearers.

[0330] During the SDT procedure, the wireless device may receive an RRC message (e.g., an RRC RESUME message) to transition to an RRC CONNECTED state. Based on receipt of the RRC RESUME message, the wireless device may resume non-SDT bearers. The wireless device may transition to an RRC CONNECTED state.

[0331] During the SDT procedure, the wireless device may send a message based on having data / signals associated with a non-SDT bearer. The message may indicate the arrival of data / signals associated with the non-SDT bearer. The message may request a transition to an RRC connected state. The message may be a Common Control Channel (CCCH) message or a Dedicated Control Channel (DCCH) message. For example, the CCCH message may include an RRC (Resume) Request message. The DCCH message may include an Assistance Information message. Based on receiving the message, the base station may send an RRC message (e.g., an RRC Resume message) to transition to an RRC connected state.

[0332] A wireless device performing an SDT procedure may detect a failure of the SDT procedure, including at least one of the following: an SDT failure detection timer expiring, cell (re)selection / change, inability to comply with an RRC message, a radio link failure (RLF), an RLC (PDU) maximum retransmission failure, receiving a rejection / fallback indication from a base station, or a CG response window timer expiring.

[0333] The wireless device may start the SDT failure detection timer based on the initiation of an SDT procedure. The wireless device may not start T319 or T300, which are configured to start based on an RRC resume request message.

[0334] Based on the detection of the failure of the SDT procedure, the wireless device may release the RRC connection. For example, the wireless device may transition to an RRC idle state by releasing the RRC connection. The wireless device may perform high layer (e.g., application layer) retransmission.

[0335] Based on the detection of the failure of the SDT procedure, the wireless device may continue to suspend the RRC connection. For example, the wireless device may remain in an RRC inactive state. The wireless device may remain in an RRC idle state with the RRC connection suspended. The wireless device may send an RRC resume request to a new cell. For example, the wireless device may select a new cell based on a cell (re)selection procedure in response to the detection of the failure.

[0336] FIG. 19 illustrates an example of small data transmission (SDT). The wireless device may be in an unconnected state (e.g., an RRC idle state, an RRC inactive state, etc.). For example, the wireless device may receive a release message. The release message may be an RRC release message. The wireless device may transition to the unconnected state based on the release message. The wireless device may determine to initiate an SDT procedure. The determination may occur while the wireless device is in the unconnected state. The determination may be based on the wireless device being in the unconnected state.

[0337] In the example of FIG. 19, the wireless device may determine to initiate an SDT procedure (e.g., based on one or more SDT conditions being satisfied). The determination may occur while the UE is in an unconnected state. The determination may be based on the UE being in an unconnected state. Initiating an SDT may include at least one of activating / deriving security keys for integrity protection and / or ciphering, configuring to resume integrity protection, applying security keys for ciphering to data / signals, configuring to use SDT, and generating an RRC request message.

[0338] In the embodiment of FIG. 19, based on the start of the SDT, the wireless device may transmit a first (uplink) message (for the initial SDT). The first message may be transmitted while in a disconnected state. The first message may be transmitted to the base station (via the serving cell of the base station). The first message may be Msg3 and / or MsgA. The first message may include at least one of an RRC request message for the SDT, first uplink data, and assistance parameters for the SDT (or assistance information for the SDT procedure). The first message may indicate that a subsequent transmission (and reception) is expected / required. For example, the assistance parameters may indicate the (expected) traffic pattern / size for the subsequent transmission. Msg3 and / or MsgA may be transmitted on an uplink shared channel (UL-SCH). Msg3 and / or MsgA may include a C-RNTI MAC CE and / or CCCH SDU as part of a random access procedure, and may be associated with a UE contention resolution identity. The wireless device may perform a RACH procedure for the SDT. For example, the wireless device may perform a RACH procedure using RACH resources configured for the SDT. The RACH resources may include at least one of an RA preamble for the SDT and a RACH opportunity (RO).

[0339] In the embodiment of FIG. 19, the SDT (procedure) may include an initial small data transmission (or an initial small data transmission phase) and a subsequent transmission (or a subsequent transmission phase or a subsequent SDT (phase)). For example, the wireless device may initiate an SDT procedure. The wireless device may determine to initiate an SDT procedure based on receiving a paging message indicating an SDT or based on having a packet associated with an SDT. For example, the packet may be a packet of a configured radio bearer for an SDT. The wireless device may initiate an SDT based on an SDT condition being satisfied, where the SDT condition includes at least one of a first condition for an RA-based SDT or a second condition for a CG-based SDT. Based on the initiation of the SDT, the wireless device may transmit a first (uplink) message for the initial SDT. The initial SDT may include transmitting the first message and receiving a response to the first message. The initial SDT phase may be a duration from a time of transmitting the first message to a time for determining whether the transmission is completed successfully. The time may be a time of receipt of a response to the first message. The wireless device may start a subsequent SDT (phase) after the initial (SDT) transmission is successfully completed. The wireless device may complete the (subsequent) SDT procedure based on receiving a message indicating completion of the SDT procedure or detecting a failure of the SDT procedure. The message may be an RRC release message.

[0340] In the embodiment of FIG. 19, based on the second condition being satisfied, the wireless device may transmit the first message using a CG configured in the SDT. The wireless device may start a CG (or PUR) response window timer and monitor the cell's PDCCH for a response to the first message. Based on receiving the response, the wireless device may determine that the initial SDT (or transmission of the first message) has completed successfully. Based on not receiving a response (e.g., until the CG response window timer expires), the wireless device may determine that the initial SDT (or transmission of the first message) has not c...

Claims

1. An apparatus for a wireless device, the apparatus comprising: one or more processors; A memory that stores instructions the instructions, when executed by the one or more processors, cause the wireless device to: Processing a radio resource control (RRC) message received by the wireless device from a base station, the RRC message comprising: a measurement configuration for one or more measurements by the wireless device while the wireless device is in an RRC inactive state; a small data transmission (SDT) configuration of an SDT procedure for transmission by the wireless device while the wireless device is in the RRC inactive state; and While the wireless device is in the RRC inactive state, initiating the SDT procedure based on the SDT configuration; and not performing measurements associated with said measurement configuration during said SDT procedure; To carry out A device that performs the above function.

2. The instructions, when executed by the one or more processors, further cause the wireless device to: After the wireless device is in the RRC inactive state, and Before the wireless device initiates the SDT procedure, The apparatus of claim 1 , configured to perform the measurement associated with the measurement configuration.

3. The RRC message includes an RRC release message, Conducting the measurement includes: the wireless device receiving the RRC release message; or the wireless device is in the RRC inactive state The apparatus of claim 2 , based on one or more of:

4. The instructions, when executed by the one or more processors, further cause the wireless device to: The apparatus of claim 3 , further comprising: a step of: transitioning to the RRC inactive state based on the RRC release message.

5. The instructions, when executed by the one or more processors, further cause the wireless device to: The apparatus of claim 3 , further comprising: starting a measurement timer based on the RRC release message.

6. The apparatus of claim 5 , wherein the measurement timer is one or more of a timer for measurements in the RRC inactive state or T331.

7. The instructions, when executed by the one or more processors, further cause the wireless device to: The apparatus of claim 6 , further comprising: causing the measurement associated with the measurement configuration to be performed while the measurement timer is running.

8. The SDT configuration includes: Next Hop Chain Count (NCC), A resume identity of the wireless device; and Indication of configured radio bearers for the SDT procedure The apparatus of claim 1 , comprising at least one of:

9. Initiating the SDT procedure comprises: receiving a paging message indicating the SDT procedure, and / or that data of the SDT procedure is available to the wireless device; The apparatus of claim 1 , based on one or more of:

10. the wireless device supports carrier aggregation and / or dual connectivity; and / or The apparatus of claim 1 , wherein the measurement configuration is for the carrier aggregation and / or dual connectivity of the wireless device.

11. A method, comprising:

13. A method for receiving, from a base station, a radio resource control (RRC) message, comprising: a measurement configuration for one or more measurements by the wireless device while the wireless device is in an RRC inactive state; a small data transmission (SDT) configuration of an SDT procedure for transmission by the wireless device while the wireless device is in the RRC inactive state; and While the wireless device is in the RRC inactive state, initiating the SDT procedure based on the SDT configuration; and not performing measurements associated with said measurement configuration during said SDT procedure; To carry out A method comprising:

12. The wireless device, After the wireless device is in the RRC inactive state, and Before the wireless device initiates the SDT procedure, The method of claim 11 , further comprising causing the measurement associated with the measurement configuration to be performed.

13. The RRC message includes an RRC release message, Conducting the measurement includes: the wireless device receiving the RRC release message; or the wireless device is in the RRC inactive state The method of claim 12, based on one or more of:

14. The method of claim 13, further comprising causing the wireless device to transition to the RRC inactive state based on the RRC release message.

15. The method of claim 13, further comprising the wireless device starting a measurement timer based on the RRC release message.

16. The method of claim 15, wherein the measurement timer is one or more of a timer for measurements in the RRC inactive state or T331.

17. The method of claim 16, further comprising causing the wireless device to perform the measurement associated with the measurement configuration while the measurement timer is running.

18. The SDT configuration, Next Hop Chain Count (NCC), A resume identity of the wireless device; and Indication of configured radio bearers for the SDT procedure The method of claim 11 , comprising at least one of:

19. Initiating the SDT procedure comprises: receiving a paging message indicating the SDT procedure, and / or that data of the SDT procedure is available to the wireless device; The method of claim 11 , based on one or more of:

20. The wireless device supports carrier aggregation and / or dual connectivity, and / or The method of claim 11 , wherein the measurement configuration is for the carrier aggregation and / or dual connectivity of the wireless device.

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