Resource Reservation for Sidelink Communication

Abstract

To provide resource reservation for suitable side-link communications.SOLUTION: A base station can communicate with a mixture of wireless devices. The wireless devices and / or base station can support multiple techniques and / or multiple releases of the same technique. A first wireless device determines a second reservation period in units of slots based on a first reservation period in milli-second (ms) and the number of side-link slots within a fixed period. The number of the side-link slots is based on a resource pool configuration. A transport block is transmitted via one or more transmission resources based on the second reservation period.SELECTED DRAWING: Figure 23

Description

Background Art

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 62 / 977,085, filed on February 14, 2020, which is hereby incorporated herein by reference in its entirety.

Summary of the Invention

Means for Solving the Problems

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

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

[0004] A base station can communicate with a mixture of wireless devices. A wireless device and / or a base station can support multiple technologies and / or multiple releases of the same technology. A wireless device can have some specific capabilities depending on the category and / or capabilities of the wireless device. When the present disclosure refers to a base station communicating with multiple wireless devices, the present disclosure can refer to a subset of all wireless devices within a coverage area. The present disclosure can refer to, for example, multiple wireless devices of a given LTE or 5G release that include a given capability and are in a given sector of a base station. The multiple wireless devices in the present disclosure can refer to a selected multiple wireless devices and / or a subset of all wireless devices within a coverage area that execute according to the disclosed method, etc. There may be multiple base stations or multiple wireless devices in a coverage area that do not conform to the disclosed method. For example, those wireless devices or base stations are executed based on an old release of LTE or 5G technology.

[0005] As used herein, the terms "a" and "an" and similar phrases are to be construed as "at least one" and "one or more". Similarly, any term ending with the suffix "(s)" should be construed as "at least one" and "one or more". As used herein, the term "may" is to be construed as "for example, may be". In other words, the term "may" indicates that the phrase following the term "may" is one example of a plurality of appropriate 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" enumerate one or more components of the recited element. The term "comprises" is interchangeable with "includes" and does not exclude unrecited components included in the recited element. In contrast, "consists of" provides a complete enumeration of one or more components of the recited element. As used herein, the term "based on" should be construed as "at least partially based on" rather than, for example, "based only on". As used herein, the term "and / or" represents any possible combination of the recited elements. For example, "A, B, and / or C" may represent A, B, C, A and B, A and C, B and C, or A, B, and C.

[0006] If A and B are a set and all elements of A are also elements of B, then A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, the possible subsets of B = {Cell 1, Cell 2} are {Cell 1}, {Cell 2}, and {Cell 1, Cell 2}. The phrase "based on" (or equivalently "at least based on") indicates an example of one of a number of suitable possibilities where the phrase following the term "based on" may or may not be used in one or more of various embodiments. The phrase "in response to" (or equivalently "at least in response to") indicates an example of one of a number of suitable possibilities where the phrase following the phrase "in response to" may or may not be used in one or more of various embodiments. The phrase "in accordance with" (or equivalently "at least in accordance with") indicates an example of one of a number of suitable possibilities where the phrase following the phrase "in accordance with" may or may not be used in one or more of various embodiments. The phrase "employed / used" (or equivalently "at least employed / used") indicates an example of one of a number of appropriate possibilities where the phrase following the phrase "employed / used" may or may not be used in one or more of various embodiments.

[0007] The term "configured" can relate to the capacity of a device regardless of whether the device is in an operating state or a non-operating state. "Configured" can also refer to specific settings of a device that affect the operating characteristics of the device regardless of whether the device is in an operating state or a non-operating state. In other words, hardware, software, firmware, registers, memory values, etc. can be "configured" within a device regardless of whether the device is in an operating state or a non-operating state in order for the device to provide certain characteristics. Terms such as "control messages generated in a device" can mean having parameters that can be used to configure certain characteristics in a device or to implement certain actions in a device regardless of whether the device is in an operating state or a non-operating state.

[0008] In the present disclosure, a parameter (or equivalently a field, or an information element: IE for short) can include one or more information objects, and an information object can include one or more other objects. For example, if parameter (IE) N includes parameter (IE) M, parameter (IE) M includes parameter (IE) K, and parameter (IE) K includes parameter (information element) J, then for example, N includes K and N includes J. In an exemplary embodiment, when one or more messages include a plurality of parameters, it means that among the plurality of parameters, the parameters are included in at least one of the one or more messages, but do not necessarily need to be included in each of the one or more messages.

[0009] Furthermore, many of the features presented above are described as being optional by the use of "may" or the use of parentheses. For the sake of brevity and readability, the present disclosure does not explicitly describe every possible variation that can be obtained by selecting from the set of optional features. The present disclosure should be construed as explicitly disclosing all such variations. For example, a system described as having three optional features can be implemented in seven ways, namely, only one of the three possible features, any two of the three features, or all three of the three features. The present invention provides, for example, the following. (Item 1) A method comprising: receiving, by a first wireless device, from a base station, one or more messages indicating a slot format configuration and a resource pool configuration; receiving, by the first wireless device, from a second wireless device, physical sidelink control information (SCI) indicating a first reservation period in milliseconds (ms); The first wireless device determines a second reservation period in slot units based on the number of sidelink slots within the first reservation period and the fixed period, where the number of the sidelink slots is determined based on the resource pool configuration and the slot format configuration, selecting one or more transmission resources based on the second reservation period, transmitting a transport block via the one or more transmission resources, the method comprising: (Item 2) The method according to item 1, wherein at least one of the one or more messages is a radio resource control message. (Item 3) The method according to any one of items 1 to 2, wherein at least one of the one or more messages is a system information block. (Item 4) A method comprising: receiving, by a first wireless device, sidelink control information indicating a first reservation period in milliseconds (ms) from a second wireless device; determining a second reservation period in slot units based on the first reservation period and the number of sidelink slots within the fixed period, where the number of the sidelink slots is determined based on the resource pool configuration and the slot format configuration; transmitting a transport block via one or more transmission resources based on the second reservation period, the method comprising: (Item 5) The method according to item 4, further comprising selecting the one or more transmission resources based on the second reservation period. (Item 6) A method comprising: receiving, by a first wireless device, sidelink control information indicating a first reservation period in milliseconds (ms) from a second wireless device; Determining a second reservation period in slot units based on the number of sidelink slots within the first reservation period and the fixed period, wherein the number of the sidelink slots is based on a slot format configuration; Transmitting a transport block via one or more transmission resources based on the second reservation period, the method comprising: (Item 7) The method according to item 6, wherein the number of the sidelink slots is further based on a resource pool configuration. (Item 8) A method comprising: Receiving, by a first wireless device, sidelink control information indicating a first reservation period in milliseconds (ms) from a second wireless device; Determining a second reservation period in slot units based on the number of sidelink slots within the first reservation period and the fixed period, wherein the number of the sidelink slots is based on a resource pool configuration; Transmitting a transport block via one or more transmission resources based on the second reservation period, the method comprising: (Item 9) The method according to item 8, wherein the number of the sidelink slots is further based on a slot format configuration. (Item 10) A method comprising: Determining, by a first wireless device, a second reservation period in slot units based on a first reservation period in milliseconds (ms) and the number of sidelink slots within a fixed period, wherein the number of the sidelink slots is based on a resource pool configuration; Transmitting a transport block via one or more transmission resources based on the second reservation period, the method comprising: (Item 11) The method according to item 10, wherein the first reservation period is received from an upper layer of the first wireless device. (Item 12) The method according to any one of items 10 to 11, wherein the first reservation period is received from a second wireless device via SCI. (Item 13) The method according to any one of items 10 to 12, wherein the number of the sidelink slots is further based on a slot format configuration. (Item 14) The method according to any one of items 10 to 13, wherein the resource pool configuration indicates one or more sidelink slots within the fixed period. (Item 15) A method, comprising: determining, by a first wireless device, a second reservation period in slot units based on a first reservation period in milliseconds (ms) and the number of sidelink slots within a fixed period, wherein the number of the sidelink slots is based on a slot format configuration; and transmitting a transport block via one or more transmission resources based on the second reservation period. (Item 16) The method according to item 15, wherein the first reservation period is received from an upper layer of the first wireless device. (Item 17) The method according to any one of items 15 to 16, wherein the first reservation period is received from a second wireless device via SCI. (Item 18) The method according to any one of items 15 to 17, wherein the number of the sidelink slots is further based on a resource pool configuration. (Item 19) The method according to any one of items 15 to 18, wherein the slot format configuration is a cell-specific time division duplex (TDD) uplink (UL) and downlink (DL) configuration. (Item 20) The method according to any one of items 15 to 19, wherein the slot format configuration indicates one or more sidelink slots within the fixed period. (Item 21) The method according to any one of items 15 to 20, wherein the fixed period is 20 ms. (Item 22) The method according to any one of items 15 to 21, further comprising converting the first reservation period in milliseconds into the second reservation period in slot units based on the number of the sidelink slots within the fixed period. (Item 23) The method according to any one of items 15 to 22, wherein the number of the sidelink slots within the fixed period is further based on the number of valid sidelink slots. (Item 24) The method according to item 23, wherein the valid sidelink slots among the valid sidelink slots have a number of uplink symbols greater than a threshold. (Item 25) The method according to item 24, wherein the threshold is indicated from a base station. (Item 26) The method according to any one of items 24 to 25, wherein the threshold is indicated via a system information block from a base station. (Item 27) The method according to any one of items 24 to 26, wherein the threshold is indicated via a radio resource control message from a base station. (Item 28) The method according to any one of items 24 to 27, wherein the threshold is preconfigured. (Item 29) The method according to any one of items 15 to 28, further comprising determining a third reservation period by applying a ceiling function to the second reservation period. (Item 30) The method according to item 29, further comprising transmitting the transport block via one or more transmission resources based on the third reservation period. (Item 31) The method according to any one of items 15 to 30, wherein the determining of the second reservation period further comprises scaling the first reservation period by a scalar value. (Item 32) The method according to item 31, wherein the scalar value is determined by a part of the number of the sidelink slots within the fixed period. (Item 33) The method according to item 32, wherein the part is obtained by dividing the number of the sidelink slots within the fixed period by the total number of slots within the fixed period. (Item 34) The method according to item 33, wherein the total number of the slots within the fixed period (X) is determined based on the subcarrier spacing (SCS) μ. (Item 35) The method according to item 34, wherein the SCS is indicated from a base station. (Item 36) The method according to any one of items 34 to 35, wherein the SCS is preconfigured. (Item 37) The total number of the slots within the fixed period (X) is X * 2 μ The method according to any one of items 33 to 36. (Item 38) The SCS of 15 kHz corresponds to μ = 0, The SCS of 30 kHz corresponds to μ = 1, The SCS of 60 kHz corresponds to μ = 2, The SCS of 120 kHz corresponds to μ = 4, and The SCS of 240 kHz corresponds to μ = 8. The method according to any one of items 33 to 37. (Item 39) A method, comprising: receiving, by a first wireless device, from a base station, one or more messages indicating a slot format configuration; receiving, by the first wireless device, from a second wireless device, sidelink control information indicating a first reservation period in milliseconds (ms); determining, by the first wireless device, a second reservation period in slot units based on the first reservation period and the number of slots for sidelink transmission within a fixed period, wherein the number of the slots is based on the slot format configuration. Determining a third reservation period by applying a ceiling function to the second reservation period; Selecting one or more transmission resources based on the third reservation period; Transmitting a transport block via the one or more transmission resources, the method comprising. (Item 40) The method according to item 39, wherein at least one of the one or more messages is a radio resource control message. (Item 41) The method according to any one of items 39 to 40, wherein at least one of the one or more messages is a system information block. (Item 42) A method, comprising: Receiving, by a first wireless device, from a second wireless device, sidelink control information indicating a first reservation period in milliseconds (ms); Determining a second reservation period in slot units based on the first reservation period and the number of slots for sidelink transmission within a fixed period, the determining being based on a slot format configuration; Determining a third reservation period by applying a ceiling function to the second reservation period; Transmitting a transport block via one or more transmission resources based on the third reservation period, the method comprising. (Item 43) The method according to item 42, further comprising receiving, by the first wireless device, from a base station, one or more messages indicating the slot format configuration. (Item 44) The method according to any one of items 42 to 43, further comprising selecting the one or more transmission resources based on the third reservation period. (Item 45) The method according to any one of items 42 to 44, wherein the number of slots is further based on a resource pool configuration. (Item 46) A method comprising: receiving, by a first wireless device, sidelink control information indicating a first reservation period in milliseconds (ms) from a second wireless device; determining, based on the first reservation period and the number of slots for sidelink transmission within a fixed period, a second reservation period in slot units, wherein the number of slots is based on a slot format configuration; transmitting a transport block via one or more transmission resources based on the second reservation period. (Item 47) The method according to item 46, further comprising determining a third reservation period by applying a ceiling function to the second reservation period. (Item 48) The method according to item 47, further comprising transmitting the transport block via the one or more transmission resources based on the third reservation period. (Item 49) A method comprising: determining, by a first wireless device, a second reservation period in slot units based on a first reservation period in milliseconds (ms) and the number of slots for sidelink transmission within a fixed period, wherein the number of slots is based on a slot format configuration; transmitting a transport block via one or more transmission resources based on the second reservation period. (Item 50) The method according to item 49, wherein the first reservation period is received from an upper layer of the first wireless device. (Item 51) The method according to any one of items 49 to 50, wherein the first reservation period is received from a second wireless device via an SCI. (Item 52) The method according to any one of items 49 to 51, wherein the slot format configuration indicates one or more slots for sidelink transmission within the fixed period. (Item 53) The method according to any one of items 49 to 52, wherein the slot format configuration is a cell-specific time division duplex (TDD) uplink (UL) and downlink (DL) configuration. (Item 54) The method according to any one of items 49 to 53, wherein the fixed period is 20 ms. (Item 55) The method according to any one of items 49 to 54, further comprising converting the first reservation period in milliseconds into the second reservation period in slot units based on the number of slots within the fixed period. (Item 56) The method according to item 55, wherein the number of slots within the fixed period is further based on the number of valid uplink slots. (Item 57) The method according to item 56, wherein the valid slots of the valid uplink slots have a number of uplink symbols greater than a threshold value. (Item 58) The method according to item 57, wherein the threshold value is indicated by a base station. (Item 59) The method according to any one of items 57 to 58, wherein the threshold value is indicated via a system information block from a base station. (Item 60) The method according to any one of items 57 to 59, wherein the threshold value is indicated via a radio resource control message from a base station. (Item 61) The method according to any one of items 57 to 60, wherein the threshold value is pre-configured. (Item 62) The method according to any one of items 49 to 61, wherein the determining of the second reservation period further comprises scaling the first reservation period by a scalar value. (Item 63) The method according to item 62, wherein the scalar value is determined by a part of the number of uplink slots within the fixed period. (Item 64) The method according to item 63, wherein a part of the above is the number of uplink slots within the fixed period divided by the total number of slots within the fixed period. (Item 65) The method according to item 64, wherein the total number of slots within the fixed period (X) is determined based on the subcarrier spacing (SCS) μ. (Item 66) The total number of slots within the fixed period (X) is X * 2 μ The method according to item 65, which is as follows. (Item 67) The SCS of 15 kHz corresponds to μ = 0, The SCS of 30 kHz corresponds to μ = 1, The SCS of 60 kHz corresponds to μ = 2, The SCS of 120 kHz corresponds to μ = 4, and The SCS of 240 kHz corresponds to μ = 8. The method according to item 66. (Item 68) The method according to any one of items 65 to 67, wherein the SCS is indicated from a base station. (Item 69) The method according to any one of items 65 to 68, wherein the SCS is preconfigured. (Item 70) A method comprising: receiving, by a wireless device, from a base station, one or more messages indicating a channel occupancy (CR) measurement window size; determining a range of values of a sidelink resource reselection counter based on the CR measurement window size; selecting a sidelink resource reselection counter value from the range of values; transmitting one or more transport blocks via a sidelink based on the sidelink resource reselection counter value. (Item 71) The method according to item 70, wherein at least one of the one or more messages is a radio resource control message. (Item 72) The method according to any one of items 70 to 71, wherein at least one of the one or more messages is a system information block. (Item 73) A method comprising: receiving, by a wireless device, from a base station, one or more messages indicating a channel occupancy (CR) measurement window size; selecting a sidelink resource reselection counter value from a range of values for the sidelink resource reselection counter based on the CR measurement window size; transmitting one or more transport blocks via a sidelink based on the sidelink resource reselection counter value. (Item 74) The method according to item 73, further comprising determining a range of values of a sidelink resource reselection counter based on the CR measurement window size. (Item 75) The method according to item 74, further comprising selecting a sidelink resource reselection counter value from the range of values. (Item 76) A method comprising: receiving, by a wireless device, from a base station, one or more messages indicating a channel occupancy (CR) measurement window size; determining a range of values of a sidelink resource reselection counter based on the CR measurement window size; transmitting one or more transport blocks via a sidelink based on the range of values. (Item 77) The method according to item 76, further comprising selecting a sidelink resource reselection counter value from the range of values. (Item 78) The method according to item 77, further comprising transmitting the one or more transport blocks via the sidelink based on the sidelink resource reselection counter value. (Item 79) A method comprising: determining a range of a sidelink resource reselection counter for transmitting one or more transport blocks via a sidelink based on a channel occupancy (CR) measurement window size; transmitting the one or more transport blocks via the sidelink based on the range. (Item 80) The method according to Item 79, further comprising receiving, from a base station, one or more messages indicating a channel occupancy (CR) measurement window size. (Item 81) The method according to Item 80, further comprising selecting a sidelink resource reselection counter value from the range. (Item 82) The method according to Item 81, further comprising transmitting the one or more transport blocks via the sidelink based on the sidelink resource reselection counter value. (Item 83) A method comprising transmitting one or more transport blocks via a sidelink based on a range of a sidelink resource reselection counter value, the range corresponding to a channel occupancy (CR) measurement window size. (Item 84) The method according to Item 83, further comprising receiving, from a base station, one or more messages indicating a channel occupancy (CR) measurement window size. (Item 85) The method according to any one of Items 83 to 84, further comprising selecting a sidelink resource reselection counter value from the range. (Item 86) The method according to Item 85, further comprising transmitting the one or more transport blocks via the sidelink based on the sidelink resource reselection counter value. (Item 87) The method according to any one of items 83 to 86, wherein the CR measurement window size is one of a plurality of values. (Item 88) The method according to item 87, wherein at least one of the plurality of values is 1000 ms. (Item 89) The method according to any one of items 87 to 88, wherein at least one of the plurality of values is 1000 slots. (Item 90) The method according to item 89, wherein the length of one of the 1000 slots is determined based on a subcarrier spacing (SCS). (Item 91) The method according to item 90, wherein the SCS is indicated from a base station. (Item 92) The method according to item 83, wherein when the CR measurement window size is 1000 ms, the range is 5 to 15. (Item 93) The method according to any one of items 83 to 92, wherein when the CR measurement window size is 500 ms, the range is 3 to 8. (Item 94) The method according to any one of items 83 to 93, wherein when the CR measurement window size is 250 ms, the range is 2 to 4. (Item 95) The method according to any one of items 83 to 94, wherein when the CR measurement window size is 125 ms, the range is 1 to 2. (Item 96) The method according to any one of items 83 to 95, wherein the range of the sidelink resource reselection counter value is determined based on the SCS. (Item 97) The method according to item 96, wherein when the SCS is 15 kHz, the range is 5 to 15. (Item 98) The method according to any one of items 96 to 97, wherein when the SCS is 30 kHz, the range is 10 to 30. (Item 99) The method according to any one of items 96 to 98, wherein when the SCS is 60 kHz, the range is 20 to 60. (Item 100) The method according to any one of items 96 to 99, wherein when the SCS is 120 kHz, the range is 40 to 120. (Item 101) The method according to any one of items 96 to 100, wherein when the SCS is 240 kHz, the range is 80 to 240. (Item 102) The method according to any one of items 96 to 101, wherein when the SCS is 480 kHz, the range is 160 to 480. (Item 103) A method comprising: determining, by a wireless device, transmission time resources reserved by the wireless device for transmitting a transport block via a sidelink; determining, based on the transmission time resources, one or more first resources to be excluded from candidate resources for the transmission of the transport block; selecting a second resource for the transmission from candidate resources other than the one or more first resources; and transmitting the transport block via the second resource. (Item 104) A method comprising: selecting, by a wireless device, a second resource from candidate resources other than one or more first resources based on transmission time resources reserved by the wireless device; and transmitting a transport block via the second resource of the sidelink. (Item 105) The method according to item 104, further comprising determining, by the wireless device, the transmission time resources reserved by the wireless device for transmitting a transport block via a sidelink. (Item 106) The method according to any one of items 104 to 105, wherein the wireless device indicates the transmission time resource via a sidelink control channel. (Item 107) The method according to item 106, further comprising transmitting, by the wireless device, the transmission time resource via the sidelink control channel. (Item 108) The method according to any one of items 104 to 107, further comprising triggering a resource (re)selection by the wireless device after identifying the transmission time resource. (Item 109) The method according to item 108, wherein the resource (re)selection is triggered by a new packet arrival or a preemption indication. (Item 110) The method according to any one of items 104 to 109, wherein the one or more first resources are any resources that temporally overlap with the transmission time resource. (Item 111) The method according to any one of items 104 to 110, wherein the candidate resource is determined based on a packet delay budget. (Item 112) A method comprising transmitting, by a wireless device, a transport block via a second resource of a sidelink, wherein the second resource is one of candidate resources other than one or more first resources based on a transmission time resource reserved by the wireless device. (Item 113) The method according to item 112, further comprising determining one or more first resources to be excluded from candidate resources for the transmission of the transport block based on the transmission time resource. (Item 114) The method according to any one of items 112 to 113, further comprising determining the transmission time resource reserved by the wireless device for transmitting the transport block via the sidelink. (Item 115) The method according to item 114, further comprising determining one or more first resources to be excluded from candidate resources for the transmission of the transport block based on the transmission time resource. (Item 116) The method according to item 115, further comprising selecting the second resource from candidate resources other than the one or more first resources based on the transmission time resource reserved by the wireless device. (Item 117) A wireless device, one or more processors, a memory storing instructions that, when executed by the one or more processors, cause the wireless device to execute the method according to any one of items 1 to 116. (Item 118) A non-transitory computer-readable medium including instructions that, when executed by one or more processors, cause the one or more processors to execute the method according to any one of items 1 to 116. (Item 119) A system, a base station, a wireless device, one or more processors, a memory that stores instructions that, when executed by the one or more processors, cause the wireless device to execute the method according to any one of items 1 to 116 together with the base station.

Brief Description of the Drawings

[0010] Some examples of various embodiments of the present disclosure are described herein with reference to the drawings.

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[0015] Figure 4B shows an example of the format of the MAC sub-header in the MAC PDU.

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[0022] Figure 10B shows an example of how an aggregation cell can be configured into one or more PUCCH groups.

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[0024] Figure 11B shows an example of CSI-RS mapped in the time and frequency domains.

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[0028] Figure 14B shows an example of CCE-to-REG mapping for DCI transmission on CORESET and PDCCH processing.

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DETAILED DESCRIPTION OF THE INVENTION

[0048] Many of the elements described in the disclosed embodiments can be implemented as modules. Here, 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 combined with hardware, firmware, wetware (e.g., hardware having biological elements), or combinations thereof, and they can be behaviorally equivalent. For example, a module can be implemented as a software routine described in a computer language configured to be executed on a hardware machine (such as C, C++, Fortran, Java®, Basic, Matlab®) or in Simulink, Stateflow, GNU Octave, or LabVIEW MathScript. It may also be possible to implement a module 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), complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages such as assembly, C, C++. FPGAs, ASICs, CPLDs are often programmed using hardware description languages (HDLs) such as VHSIC Hardware Description Language (VHDL) or Verilog, which configure connections between internal hardware modules with fewer programmable device functions. To achieve the results of functional modules, the above techniques are often used in combination.

[0049] Figure 1A shows an example of a mobile communication network 100 in which embodiments of the present disclosure may be implemented. The mobile communication network 100 may be, for example, a public land mobile network (PLMN) executed by a network operator. As shown in Figure 1A, the mobile communication network 100 includes a core network (CN) 102, a radio access network (RAN) 104, and a wireless device 106.

[0050] CN 102 may provide an interface for the wireless device 106 to one or more data networks (DNs) such as a public DN (e.g., the Internet), a private DN, and / or an operator-internal DN. As part of the interface function, 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 a charging function.

[0051] RAN 104 may connect CN 102 to the wireless device 106 via wireless communication on the air interface. As part of the wireless communication, RAN 104 may provide scheduling, radio resource management, and a retransmission protocol. The communication direction from RAN 104 to the wireless device 106 on the air interface is known as the downlink, and the communication direction from the wireless device 106 to RAN 104 on the air interface is known as the uplink. Downlink transmission may be separated from uplink transmission using frequency division duplexing (FDD), time division duplexing (TDD), and / or some combination of the two duplexing techniques.

[0052] The term "wireless device" is 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 can be a phone, smartphone, tablet, computer, laptop, sensor, meter, wearable device, Internet of Things (IoT) device, vehicle roadside unit (RSU), relay node, 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.

[0053] RAN104 may include one or more base stations (not shown). The term "base station" can be used throughout this disclosure to refer to and encompass Node B (associated with UMTS and / or 3G standards), evolved Node B (eNB, associated with E-UTRA and / or 4G standards), remote radio head (RRH), a baseband processing unit coupled to one or more RRHs, a repeater node or relay node used to extend the coverage area of a donor node, next generation evolved Node B (ng-eNB), gNode B (gNB, associated with NR and / or 5G standards), 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).

[0054] The base stations included in RAN104 may include a set of one or more antennas for communicating with the wireless device 106 over the air interface. For example, one or more 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 within which a receiver (e.g., a base station receiver) can successfully receive transmissions from a transmitter operating in the cell (e.g., a wireless device transmitter). Together, the cells of the base stations may provide wireless coverage to the wireless device 106 over a wide geographical area to support wireless device mobility.

[0055] In addition to three-sector sites, other implementations of base stations are possible. For example, one or more base stations of RAN104 may be implemented as sector sites having more than three or less than three sectors. One or more base stations of RAN104 may be implemented as an access point, as a baseband processing unit coupled to a plurality of 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 RRH may be part of a centralized or cloud RAN architecture, and the baseband processing unit may be centralized within a pool of baseband processing units or may be virtualized. A repeater node may amplify and rebroadcast a wireless signal received from a donor node. A relay node may perform the same / similar functions as a repeater node, but may decode a wireless signal received from a donor node and remove noise before amplifying and rebroadcasting the wireless signal.

[0056] RAN104 can be deployed as a homogeneous network of macrocell base stations having similar antenna patterns and similar high-level transmission powers. RAN104 can be deployed as a heterogeneous network. In a heterogeneous network, small cell base stations can be used to provide small coverage areas, for example, coverage areas that overlap with a relatively large coverage area provided by a macrocell base station. The small coverage areas can be provided in areas with high data traffic (or so-called hotspots), or in areas where macrocell coverage is weak. Examples of small cell base stations include microcell base stations, picocell base stations, and femtocell base stations or home base stations, in order of decreasing coverage area.

[0057] The Third Generation Partnership Project (3GPP™) was formed in 1998 to provide global standardization of the specifications of mobile communication networks similar to the mobile communication network 100 of FIG. 1A. To date, 3GPP™ has produced the specifications for three generations of mobile networks, a third generation (3G) network known as the Universal Mobile Telecommunications System (UMTS), a fourth generation (4G) network known as Long Term Evolution (LTE), and a fifth generation (5G) network known as the 5G System (5GS). Embodiments of the present disclosure are described with reference to the RAN of the 3GPP™ 5G network, referred to as the Next Generation RAN (NG-RAN). Embodiments may be applicable to the RANs of other mobile communication networks, such as the RAN104 of FIG. 1A, the RANs of previous 3G and 4G networks, and future networks that have not yet been specified (e.g., the 3GPP™ 6G network). The NG-RAN implements 5G radio access technology known as New Radio (NR) and can be provided to implement other radio access technologies, including 4G radio access technology or non-3GPP™ radio access technology.

[0058] Figure 1B shows a mobile communication network 150 of another example in which embodiments of the present disclosure may be implemented. The mobile communication network 150 can be, for example, a PLMN executed by a network operator. As shown in Figure 1B, the mobile communication network 150 includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and 156B (collectively UEs 156). These components can be implemented and operate in the same or similar manner as the corresponding components described with respect to Figure 1A.

[0059] The 5G-CN 152 provides an interface to one or more DNs, such as a public DN (e.g., the Internet), a private DN, and / or an operator-internal DN, to the UEs 156. As part of the interface function, the 5G-CN 152 can set up an end-to-end connection between the UEs 156 and one or more DNs, authenticate the UEs 156, and provide a charging function. Compared to the CN of a 3GPP (registered trademark) 4G network, the basis of the 5G-CN 152 can be a service-based architecture. This means that the architecture of the nodes that make up the 5G-CN 152 can be defined as network functions that provide services via interfaces to other network functions. The network functions of the 5G-CN 152 can be implemented in several ways, as network elements on dedicated or shared hardware, as software instances operating on dedicated or shared hardware, or as virtualized functions instantiated on a platform (e.g., a cloud-based platform).

[0060] As shown in FIG. 1B, 5G-CN152 includes an access and mobility management function (AMF) 158A and a user plane function (UPF) 158B, shown as a single component AMF / UPF158 in FIG. 1B for simplicity of explanation. UPF158B can function as a gateway between NG-RAN154 and one or more DNs. UPF158B can perform functions such as packet routing and forwarding, packet inspection and enforcement of user plane policy rules, reporting of traffic usage, uplink classification to support routing of traffic flows to one or more DNs, quality of service (QoS) handling for the user plane (e.g., packet filtering, gating, uplink / downlink rate enforcement, and uplink traffic verification), downlink packet buffering, and downlink data notification triggering. UPF158B can function 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-home PDU sessions. UE156 can be configured to receive services via a PDU session, which is a logical connection between the UE and a DN.

[0061] AMF158A can 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 (registered trademark) access networks, idle mode UE reachability (e.g., control and execution of paging retransmission), registration area management, in-system and inter-system mobility support, access authentication, access authorization including checking of 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 functions operating between the CN and the UE, and AS may refer to functions operating between the UE and the RAN.

[0062] 5G-CN152 may include one or more additional network functions not shown in FIG. 1B for clarity. For example, 5G-CN152 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).

[0063] NG-RAN154 may connect 5G-CN 152 to UE156 via wireless communication over the air interface. NG-RAN154 may include one or more gNBs (collectively gNB160) illustrated as gNB160A and gNB160B and / or one or more ng-eNBs (collectively ng-eNB162) illustrated as ng-eNB162A and ng-eNB162B. gNB160 and ng-eNB162 may more generally be referred to as base stations. gNB160 and ng-eNB162 may include a set of one or more antennas for communicating with UE156 over the air interface. For example, one or more of gNB160 and / or one or more of ng-eNB162 may include three sets of antennas for controlling three cells (or sectors) respectively. Collectively, the cells of gNB160 and ng-eNB162 may provide wireless coverage to UE156 over a wide geographic area to support UE mobility.

[0064] As shown in FIG. 1B, gNB 160 and / or ng-eNB 162 may be connected to 5G-CN 152 via the NG interface and may be connected to other base stations via the 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. gNB 160 and / or ng-eNB 162 may be connected to UE 156 via the Uu interface. For example, as shown in FIG. 1B, gNB 160A may be connected to UE 156A via the 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 in 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 the user. The control plane may process signaling messages of interest to the network elements.

[0065] gNB 160 and / or ng-eNB 162 may be connected to one or more AMF / UPF functions of 5G-CN 152, such as AMF / UPF 158, via one or more NG interfaces. For example, gNB 160A may be connected to UPF 158B of AMF / UPF 158 via the NG user plane (NG-U) interface. The NG-U interface may provide the supply of user plane PDUs between gNB 160A and UPF 158B (e.g., non-guaranteed delivery). gNB 160A may be connected to AMF 158A using the NG control plane (NG-C) interface. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, NAS message transfer, paging, PDU session management and configuration transfer and / or warning message transmission.

[0066] gNB 160 may provide NR user plane and control plane protocol terminations towards UE 156 on the Uu interface. For example, gNB 160A may provide NR user plane and control plane protocol terminations towards UE 156A on the Uu interface associated with the first protocol stack. ng-eNB 162 may provide Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol terminations towards UE 156 on the Uu interface, where E-UTRA refers to the 3GPP (registered trademark) 4G radio access technology. For example, ng-eNB 162B may provide E-UTRA user plane and control plane protocol terminations towards UE 156B on the Uu interface associated with the second protocol stack.

[0067] 5G-CN 152 was described as being configured to handle both NR and 4G radio access. One of ordinary skill in the art will understand that NR may be able 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 such as initial access, mobility, and paging. Only one AMF / UPF 158 is shown in Figure 1B, but 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.

[0068] As discussed, in Figure 1B, interfaces between network elements (e.g., Uu, Xn, and NG interfaces) may be associated with protocol stacks that network elements use to exchange data and signaling messages. The protocol stack may include two planes, namely, a user plane and a control plane. The user plane may process data of interest to the user, and the control plane may process signaling messages of interest to the network element.

[0069] Figures 2A and 2B respectively show examples of NR user plane and NR control plane protocol stacks for the Uu interface between UE210 and gNB220. The protocol stacks shown in Figures 2A and 2B may be the same as or similar to those used for the Uu interface between UE156A and gNB160A shown in Figure 1B.

[0070] Figure 2A shows an NR user plane protocol stack including five layers implemented in UE210 and gNB220. At the bottom of the protocol stack, physical layers (PHYs) 211 and 221 may provide a transport service to the upper layers of the protocol stack and may correspond to layer 1 of the Open System Interconnection (OSI) model. The next four protocols above PHY211 and 221 include a media access control layer (MAC) 212 and 222, a radio link control layer (RLC) 213 and 223, a packet data convergence protocol layer (PDCP) 214 and 224, and a 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.

[0071] FIG. 3 shows an example of services provided between protocol layers of the NR user plane protocol stack. Starting from the top in FIGS. 2A and 3, SDAPs 215 and 225 may perform QoS flow processing. UE 210 may receive services via a PDU session, which may be a logical connection between UE 210 and the DN. The PDU session may have one or more QoS flows. The CN's UPF (e.g., UPF 158B) may map IP packets to one or more QoS flows of the PDU session based on QoS requirements (e.g., regarding latency, data rate, and / or error rate). SDAPs 215 and 225 may perform mapping / demapping between one or more QoS flows and one or more data radio bearers. The mapping / demapping between the QoS flow and the data radio bearer may be determined by SDAP 225 at gNB 220. SDAP 215 at UE 210 may be notified about the mapping between the QoS flow and the data radio bearer via reflected mapping or control signaling received from gNB 220. For reflected mapping, SDAP 225 at gNB 220 may mark downlink packets with a QoS flow indicator (QFI) that can be observed by SDAP 215 of UE 210 to determine the mapping / demapping between the QoS flow and the data radio bearer.

[0072] PDCP 214 and PDCP 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 the data transmitted over the air interface, and integrity protection (to ensure that control messages are sent from the intended source). PDCP 214 and 224 may perform, for example, retransmission of unsent packets, in-sequence delivery and re-sequencing of packets, and removal of duplicate packets received for gNB-internal handover. PDCP 214 and 224 may perform packet duplication to improve the likelihood of received packets and to remove any duplicate packets at the receiver. Packet duplication may be useful for services that require high reliability.

[0073] Although not shown in Figure 3, PDCP 214 and 224 may perform mapping / demapping between split radio bearers and RLC channels in a dual-connection scenario. Dual-connection is a technology that enables a UE to connect to two cells, or more generally, two cell groups of a master cell group (MCG) and a secondary cell group (SCG). A split bearer is when a single radio bearer, such as one provided by PDCP 214 and 224 as a service to SDAP 215 and 225, is processed by cell groups in a dual-connection. PDCP 214 and 224 may map / demap the split radio bearer between RLC channels belonging to the cell groups.

[0074] RLC 213 and 223 can each perform segmentation, retransmission through automatic repeat request (ARQ), and removal of duplicate data units received from MAC 212 and 222. RLC 213 and 223 can 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 can perform one or more of the indicated functions. This RLC configuration can be per logical channel regardless of numerology and / or transmission time interval (TTI) duration. As shown in Figure 3, RLC 213 and 223 can each provide an RLC channel as a service to PDCP 214 and 224.

[0075] MAC212 and MAC222 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 transport blocks (TBs) delivered to / from PHY211 and 221. MAC222 may be configured to perform scheduling, scheduling information reporting, and prioritization among UEs by dynamic scheduling. Scheduling may be performed at gNB220 (at MAC222) for downlink and uplink. MAC212 and 222 may be configured to perform error correction, prioritization among logical channels of UE210 by logical channel prioritization, and / or padding through hybrid automatic repeat request (HARQ) (e.g., one HARQ entity per carrier in the case of carrier aggregation (CA)). MAC212 and MAC222 may support one or more numerologies and / or transmission timings. In one embodiment, mapping restrictions in logical channel prioritization can control which numerology and / or transmission timing a logical channel can use. As shown in FIG. 3, MAC212 and 222 may provide logical channels to RLC213 and 223 as a service.

[0076] PHY211 and 221 may perform mapping of transport channels to physical channels and digital and analog signal processing functions for transmitting and receiving information on the air interface. These digital and analog signal processing functions may include, for example, encoding / decoding and modulation / demodulation. PHY211 and 221 may perform multi-antenna mapping. As shown in FIG. 3, PHY211 and 221 may provide one or more transport channels to MAC212 and 222 as a service.

[0077] Figure 4A shows an example of downlink data flow through the NR user plane protocol stack. Figure 4A shows the downlink data flow of three IP packets (n, n+1, and m) through the NR user plane protocol stack, generating two transport blocks at gNB 220. The uplink data flow through the NR user plane protocol stack may be similar to the downlink data flow shown in Figure 4A.

[0078] The downlink data flow in Figure 4A starts when SDAP 225 receives three IP packets from one or more QoS flows and maps the three packets to radio bearers. In Figure 4A, SDAP 225 maps IP packets n and n+1 to the first radio bearer 402 and 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 higher protocol layers are called service data units (SDUs) of lower protocol layers, and data units to / from lower protocol layers are called protocol data units (PDUs) of higher protocol layers. As shown in Figure 4A, the data unit from AP 225 is the SDU of the lower protocol layer PDCP 224 and the PDU of SDAP 225.

[0079] The remaining protocol layers of FIG. 4A may execute the associated functions (e.g., with respect to FIG. 3), add the corresponding headers, and transfer each output to the next lower layer. For example, PDCP 224 may perform IP header compression and encryption and transfer its output to RLC 223. RLC 223 may optionally perform segmentation (e.g., as shown for IP packet m in FIG. 4A) and transfer its output to MAC 222. MAC 222 may multiplex several RLC PDUs and may attach a MAC sub-header to the RLC PDU to form a transport block. In NR, as shown in FIG. 4A, the MAC sub-header may be distributed over the entire MAC PDU. In LTE, the MAC sub-header may be placed entirely at the beginning of the MAC PDU. The NR MAC PDU structure can reduce processing time and associated latency because the MAC PDU sub-header can be calculated before the complete MAC PDU is assembled.

[0080] FIG. 4B shows an example format of the MAC sub-header in the MAC PDU. The MAC sub-header includes an SDU length field for indicating the length (such as in bytes) of the MAC SDU corresponding to the MAC sub-header, a logical channel identifier (LCID) field for identifying the logical channel from which the MAC SDU started to assist in the demultiplexing process, a flag (F) for indicating the size of the SDU length field, and a reserved bit (R) field for future use.

[0081] Figure 4B further shows MAC control elements (CEs) inserted into the MAC PDU by a MAC such as MAC223 or MAC222. For example, Figure 4B shows two MAC CEs inserted into the MAC PDU. The MAC CE can be inserted at the start of the MAC PDU for downlink transmission (as shown in Figure 4B) and at the end of the MAC PDU for uplink transmission. The MAC CE can be used for in-band control signaling. Examples of MAC CEs include scheduling-related MAC CEs such as buffer status reports and power headroom reports, activation / deactivation MAC CEs for PDCP duplicate detection, channel state information (CSI) reports, sounding reference signal (SRS) transmission, and activation / deactivation for pre-configured components, discontinuous reception (DRX)-related MAC CEs, timing advance MAC CEs, and random access-related MAC CEs. The MAC CE may be preceded by a MAC sub-header in a format similar to that described for the MAC SDU and may be identified by a reserved value in an LCID field indicating the type of control information contained in the MAC CE.

[0082] Before describing the NR control plane protocol stack, the logical channels, transport channels, and physical channels, and the mapping between channel types are first described. One or more channels can be used to perform functions related to the NR control plane protocol stack described below.

[0083] Figures 5A and 5B show the mapping between logical channels, transport channels, and physical channels for the downlink and uplink, respectively. Information is transmitted through channels between the RLC, MAC, and PHY of the NR protocol stack. Logical channels can be used between the RLC and MAC and can be classified as control channels that carry control and configuration information within the NR control plane or as traffic channels that carry data within the NR user plane. Logical channels can be classified as dedicated logical channels specific to a particular UE or as common logical channels that can be used by multiple UEs. Logical channels can 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 displaying paging messages used to page UEs whose location is not known to the network at the cell level, and - A broadcast control channel (BCCH) for transmitting system information messages in the form of a master information block (MIB) and some system information blocks (SIBs), where the system information messages can be used by the UE to obtain information about how the cell is configured and how it operates within the cell. - A common control channel (CCCH) for transmitting control messages along with random access. - A dedicated control channel (DCCH) for transmitting control messages between a particular UE to configure the UE. - A dedicated traffic channel (DTCH) for transmitting user data between a particular UE.

[0084] Transport channels are used between the MAC layer and the PHY layer and can be defined by how the information they carry is transmitted on the air interface. The set of transport channels defined by NR includes, for example, - A paging channel (PCH) for transmitting paging messages sent from the PCCH, - A broadcast channel (BCH) for carrying the MIB from the BCCH, - A downlink shared channel (DL-SCH) for transmitting downlink data and signaling messages, including the SIB from the BCCH - An uplink shared channel (UL-SCH) for transmitting uplink data and signaling messages, - A random access channel (RACH) that enables the UE to connect to the network without prior scheduling.

[0085] The PHY can pass information between the processing levels of the PHY using physical channels. A physical channel may have an associated set of time-frequency resources for carrying the information of one or more transport channels. The PHY can generate control information to support the low-level operation of the PHY and provide the control information to the low level of the PHY via a physical control channel known as the L1 / L2 control channel. The set of physical channels and physical control channels defined by NR is, 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, as well as 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 HARQ acknowledgment responses, channel quality indicators (CQIs), precoding matrix indicators (PMIs), rank indicators (RIs), and scheduling requests (SRs), and - A physical random access channel (PRACH) for random access, are included.

[0086] Similar to physical control channels, the physical layer generates physical signals to support the low-level operations of the physical layer. As shown in FIGS. 5A and 5B, the physical layer signals defined by NR include primary synchronization signals (PSSs), secondary synchronization signals (SSSs), channel state information reference signals (CSI-RSs), demodulation reference signals (DMRSs), sounding reference signals (SRSs), and phase tracking reference signals (PT-RSs). These physical layer signals are described in more detail below.

[0087] FIG. 2B shows an example of the NR control plane protocol stack. In FIG. 2B, the NR control plane protocol stack may use the same / first four protocol layers similar to an example of the NR user plane protocol stack. These four protocol layers include PHY211 and 221, MAC212 and 222, RLC213 and 223, and PDCP214 and 224. Instead of having SDAP215 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 protocol 217 and 237 at the top of the NR control plane protocol stack.

[0088] The NAS protocols 217 and 237 can 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 can provide control plane functions between the UE 210 and the AMF 230 via signaling messages called NAS messages. There is no direct path for sending NAS messages between the UE 210 and the AMF 230. NAS messages can be sent using the AS of the Uu and NG interfaces. The NAS protocols 217 and 237 can provide control plane functions such as authentication, security, connection setup, mobility management, and session management.

[0089] The RRCs 216 and 226 can provide control plane functions between the UE 210 and the gNB 220, or more generally, between the UE 210 and the RAN. The RRCs 216 and 226 can provide control plane functions between the UE 210 and the gNB 220 via signaling messages called RRC messages. RRC messages can be sent between the UE 210 and the RAN using signaling radio bearers and the same / similar PDCP, RLC, MAC, and PHY protocol layers. The MAC can multiplex control plane and user plane data within the same transport block (TB). The RRCs 216 and 226 can provide control plane functions including broadcast of system information related to the AS and NAS, paging initiated by the CN or RAN, establishment, maintenance, and release of the 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, UE measurement report and report control, detection and recovery of radio link failure (RLF), and / or NAS message transfer. As part of the establishment of the RRC connection, the RRCs 216 and 226 can establish an RRC context, which may involve setting parameters for communication between the UE 210 and the RAN.

[0090] FIG. 6 is an exemplary diagram showing the RRC state transition of a UE. The UE can be the same as or similar to the wireless device 106 shown in FIG. 1A, the UE 210 shown in FIGS. 2A and 2B, or any other wireless device described in the present disclosure. As shown in FIG. 6, the UE can be in at least one of three RRC states. That is, RRC connection 602 (e.g., RRC_CONNECTED), RRC idle 604 (e.g., RRC_IDLE), and RRC inactive 606 (e.g., RRC_INACTIVE).

[0091] In RRC connection 602, the UE has an established RRC context and can have at least one RRC connection with a base station. The base station can be one of the one or more base stations included in RAN 104 shown in FIG. 1A, one of gNB 160 or ng-eNB 162 shown in FIG. 1B, gNB 220 shown in FIGS. 2A and 2B, or any other base station similar to those described in the present disclosure. There can be an RRC context of the UE in the base station to which the UE is connected. The RRC context, called 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 RRC connection 602, the mobility of the UE can be managed by the RAN (e.g., RAN 104 or NG-RAN 154). The UE can measure the signal levels (e.g., reference signal levels) from the serving cell and adjacent cells and report these measurements to the base station currently providing service to the UE. The serving base station of the UE can request a handover to a cell of one of the adjacent base stations based on the reported measurements. The RRC state may transition from RRC connection 602 to RRC idle 604 via connection release procedure 608 or to RRC inactive 606 via connection deactivation procedure 610.

[0092] In RRC idle 604, the RRC context cannot be established for the UE. In RRC idle 604, the UE cannot have an RRC connection with the base station. During RRC idle 604, the UE can be in a sleep state most of the time (e.g., to save battery power). The UE can wake up periodically (e.g., once per discontinuous reception cycle) to monitor paging messages from the RAN. The mobility of the UE can be managed by the UE through a procedure known as cell reselection. The RRC state can transition from RRC idle 604 to RRC connected 602 via a connection establishment procedure 612 that may involve a random access procedure as discussed in more detail below.

[0093] In RRC inactive 606, the previously established RRC context is maintained at the UE and the base station. This reduces the signaling overhead and enables a fast transition to RRC connected 602 compared to the transition from RRC idle 604 to RRC connected 602. In RRC inactive 606, the UE is in a sleep state and the mobility of the UE can be managed by the UE through cell reselection. The RRC state can 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.

[0094] The RRC state may be associated with a mobility management entity. 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 enable the network to notify the UE of events via paging messages without broadcasting the paging messages across the entire mobile communication network. The mobility management entity used in RRC idle 604 and RRC inactive 606 may enable the network to track the UE at the cell group level such that paging messages can be broadcast on the cells of the cell group in which the UE is currently present instead of across the entire mobile communication network. The mobility management entity for RRC idle 604 and RRC inactive 606 tracks the UE at the cell group level. They can do so using different granularities of grouping. For example, there can be three levels of granularity of cell grouping, namely, individual cells, cells within a RAN area identified by a RAN area identifier (RAI), and cells within a group of RAN areas called a tracking area and identified by a tracking area identifier (TAI).

[0095] The tracking area may be used to track the UE at the CN level. The CN (e.g., CN102 or 5G-CN152) may provide the UE with a list of TAIs associated with the UE registration area. If the UE moves to a cell associated with a TAI that is not included in the list of TAIs associated with the UE registration area through cell reselection, the UE may perform a registration update with the CN so that the CN can update the UE's location and may provide the UE with a new UE registration area.

[0096] The RAN area can be used to track the UE at the RAN level. For a UE in the RRC inactive 606 state, a RAN notification area can be assigned to the UE. The RAN notification area may include one or more cell identities, a list of RAI, or a list of TAI. In one embodiment, a base station may belong to one or more RAN notification areas. In one embodiment, a cell can belong to one or more RAN notification areas. When the UE moves to a cell not included in the RAN notification area assigned to the UE through cell reselection, the UE can perform an update of the notification area in the RAN and update the RAN notification area of the UE.

[0097] The base station storing the RRC context for the UE, or the last serving base station of the UE, may be referred to as the anchor base station. The anchor base station can maintain the RRC context for the UE at least during the time the UE stays in the RAN notification area of the anchor base station and / or during the time the UE stays in RRRC inactive 606.

[0098] A gNB, such as gNB160 in FIG. 1B, can be divided into two parts, namely a central unit (gNB-CU), and one or more distributed units (gNB-DU). The gNB-CU can be coupled to one or more gNB-DUs using the F1 interface. The gNB-CU may include RRC, PDCP, and SDAP. The gNB-DU may include RLC, MAC, and PHY.

[0099] In NR, physical signals and physical channels (Figs. 5A and 5B) can be mapped onto orthogonal frequency division multiplexing (OFDM) symbols. OFDM is a multi-carrier communication scheme that transmits data over F orthogonal sub-carriers (or tones). Before transmission, the data can be mapped to a series of complex symbols (e.g., M quadrature amplitude modulation (M-QAM) or M phase shift keying (M-PSK) symbols), which are called source symbols and are split into F parallel symbol streams. The F parallel symbol streams are treated as if they were in the frequency domain and can be used as inputs to an inverse fast Fourier transform (IFFT) block that converts them to the time domain. The IFFT block can take one from each of the F parallel symbol streams at a time into F source symbols and use each source symbol to modulate the amplitude and phase of one of the F sine wave basis functions corresponding to the F orthogonal sub-carriers. The output of the IFFT block can be F time domain samples representing the sum of the F orthogonal sub-carriers. The F time domain samples can form a single OFDM symbol. After some processing (e.g., addition of a cyclic prefix) and up-conversion, the OFDM symbol provided by the IFFT block can be transmitted over the air interface at the carrier frequency. The F parallel symbol streams can be scrambled using an FFT block before being processed by the IFFT block. This process can generate pre-coded OFDM symbols with discrete Fourier transform (DFT) and be used by the UE in the uplink to reduce the peak-to-average power ratio (PAPR). The reverse process can be performed on the OFDM symbol at the receiver using an FFT block to recover the data mapped to the source symbols.

[0100] Figure 7 shows a configuration example of an NR frame in which OFDM symbols are grouped. The NR frame can be identified by a system frame number (SFN). The SFN can be repeated over a period of 1024 frames. As shown in the figure, one NR frame may have a duration of 10 milliseconds (ms) or may include 10 subframes each having a duration of 1 ms. A subframe can be divided, for example, into slots each including 14 OFDM symbols per slot.

[0101] The duration of a slot can depend on the numerology used for the OFDM symbols 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 maximum mmWave range). Numerology can be defined with respect to the subcarrier spacing and the cyclic prefix duration. For numerology in NR, the subcarrier spacing may be scaled up by a power of 2 from a baseline subcarrier spacing of 15 kHz, and the cyclic prefix duration may be scaled down by a power of 2 from a baseline cyclic prefix duration of 4.7 μs. For example, NR defines numerology using the following combinations of subcarrier spacing / cyclic prefix duration: 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.

[0102] A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols). A numerology with a higher subcarrier spacing has a shorter slot duration, and accordingly, a larger number of slots per subframe. FIG. 7 shows this numerology-dependent slot duration and slot transmission structure per subframe (for ease of illustration, the numerology with a 240 kHz subcarrier spacing is not shown in FIG. 7). A subframe in NR can be used as a numerology-independent time reference, while a slot can be used as a unit in which uplink and downlink transmissions are scheduled. For low-latency support, scheduling in NR is separated from the slot duration and may start at any OFDM symbol and end with as many symbols as necessary for transmission. These partial slot transmissions may be referred to as mini-slot transmissions or sub-slot transmissions.

[0103] FIG. 8 shows an example configuration of a slot 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 a limitation, if used, may limit the NR carrier to 50, 100, 200, and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz, respectively, and a 400 MHz bandwidth may be set based on 400 MHz per carrier bandwidth limitation.

[0104] FIG. 8 shows a single numerology used across the full bandwidth of an NR carrier. In other exemplary configurations, multiple numerologies may be supported on the same carrier.

[0105] NR can support a wide carrier bandwidth (e.g., up to 400 MHz for a 120 kHz sub - carrier spacing). Not all UEs can receive the full carrier bandwidth (e.g., due to hardware limitations, etc.). Also, receiving the full carrier bandwidth may be prohibited from the perspective of the UE's power consumption. In one embodiment, to reduce power consumption and / or for other purposes, the UE can adapt the size of its receive bandwidth based on the amount of traffic the UE expects to receive. This is called bandwidth adaptation.

[0106] NR supports UEs that cannot receive the full carrier bandwidth and defines a bandwidth part (BWP) that supports bandwidth adaptation. In one embodiment, a BWP can be defined by a subset of consecutive RBs on a carrier. A UE can 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 can be active. These one or more BWPs may be referred to as the active BWPs of the serving cell. When the serving cell is composed of a secondary uplink carrier, the serving cell can have one or more first active BWPs on the uplink carrier and one or more second active BWPs on the secondary uplink carrier.

[0107] For unpaired spectrum, when the downlink BWP index of the downlink BWP is the same as the uplink BWP index of the uplink BWP, the downlink BWP from the set of configured downlink BWPs can be linked to the uplink BWP from the set of configured uplink BWPs. For unpaired spectrum, the UE can expect that the center frequency of the downlink BWP is the same as the center frequency of the uplink BWP.

[0108] For a downlink BWP within a set of downlink BWPs configured on a primary cell (PCell), the base station may configure the UE for at least one search space with one or more control resource sets (CORESETs). A search space is a set of positions in the time and frequency domains where the UE can find control information. The search space can be a UE-specific search space or a common search space (potentially usable by multiple UEs). For example, the base station can configure the UE with a common search space on the PCell or on a primary secondary cell (PSCell) in an active downlink BWP.

[0109] In the case of an uplink BWP within a set of configured uplink BWPs, the BS can configure the UE with one or more resource sets for one or more PUCCH transmissions. The UE can receive downlink receptions (e.g., PDCCH or PDSCH) within the downlink BWP according to the configured numerology (e.g., subcarrier spacing and cyclic prefix duration) for the downlink BWP. The UE can transmit uplink transmissions (e.g., PUCCH or PUSCH) within the uplink BWP according to the configured numerology (e.g., subcarrier spacing and cyclic prefix length) of the uplink BWP.

[0110] One or more BWP indicator fields may be provided in the downlink control information (DCI). The value of the BWP indicator field may indicate which BWP in the set of configured BWPs is the active downlink BWP for one or more downlink receptions. The value of one or more BWP indicator fields may indicate the active uplink BWP for one or more uplink transmissions.

[0111] The base station may semi-statically configure the UE with the default downlink BWP within the 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 can 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.

[0112] The base station can configure the UE with the BWP Inactive timer value. The UE can start or restart the BWP Inactive timer at any appropriate time. For example, (a) when the UE detects DCI indicating an active downlink BWP other than the default downlink BWP for paired spectrum operation, or (b) when the UE detects DCI indicating an active downlink BWP or active uplink BWP other than the default downlink BWP or uplink BWP for unpaired spectrum operation, the UE can start or restart the BWP Inactive timer. If the UE does not detect DCI for a certain period (e.g., 1 millisecond or 0.5 millisecond), the UE can run the BWP Inactive timer towards expiration (e.g., increase from zero to the BWP Inactive timer value or decrease from the BWP Inactive timer value to zero). When the BWP Inactive timer expires, the UE may be switched from the active downlink BWP to the default downlink BWP.

[0113] In one embodiment, the base station can semi-statically configure a UE having one or more BWPs. The UE can switch the active BWP from the first BWP to the second BWP in response to receiving DCI indicating the second BWP as the active BWP and / or in response to the expiration of the BWP Inactive timer (e.g., when the second BWP is the default BWP).

[0114] Downlink and uplink BWP switching (where BWP switching refers to switching from the currently active BWP to a non-currently active BWP) may be performed independently in a pair of spectrums. In non-pair spectrums, downlink and uplink BWP switching may be performed simultaneously. The switching between configured BWPs may occur based on RRC signaling, DCI, expiration of the BWP inactive timer, and / or the start of random access.

[0115] Figure 9 shows an example of bandwidth adaptation using three configured BWPs for an NR carrier. A UE configured with three BWPs may switch from one BWP to another at a switching point. In the example shown in Figure 9, the BWPs include BWP902 with a bandwidth of 40 MHz and a subcarrier spacing of 15 kHz, BWP904 with a bandwidth of 10 MHz and a subcarrier spacing of 15 kHz, and BWP906 with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. BWP902 may be the initial active BWP, and BWP904 may be the default BWP. The UE can switch between BWPs at the switching point. In the example of Figure 9, the UE may switch from BWP902 to BWP904 at switching point 908. The switching at switching point 908 may occur for any suitable reason, for example, in response to the expiration of a BWP inactive timer (indicating switching to the default BWP) and / or in response to receiving DCI indicating BWP904 as the active BWP. The UE may switch from active BWP904 to BWP906 at switching point 910 in response to receiving DCI indicating BWP906 as the active BWP. The UE may switch from active BWP906 to BWP904 at switching point 912 in response to the expiration of the BWP inactive timer and / or in response to receiving DCI indicating BWP904 as the active BWP. The UE may switch from active BWP904 to BWP902 at switching point 914 in response to receiving DCI indicating BWP902 as the active BWP.

[0116] If the UE is configured with a set of downlink BWPs and a default downlink BWP in timer values for a secondary cell, the UE procedure for switching the BWP on the secondary cell can be the same / similar to that on the primary cell. For example, the UE can use the timer values and the default downlink BWP for the secondary cell in the same / similar manner as it uses these values for the primary cell.

[0117] To provide a larger data rate, carrier aggregation (CA) can be used to aggregate two or more carriers and transmit simultaneously between the same UEs. The aggregated carriers of CA may also be called component carriers (CCs). When using CA, there are multiple serving cells for the UE and one cell for the CC. The CC can have three configurations within the frequency domain.

[0118] Figure 10A shows three CA configurations with two CCs. In the in-band, contiguous configuration 1002, the two CCs are aggregated in the same frequency band (frequency band A) and are placed directly adjacent to each other within the frequency band. In the in-band, non-contiguous configuration 1004, the two CCs are aggregated in the same frequency band (frequency band A) and are separated within the frequency band by a gap. In the in-band configuration 1006, the two CCs are located in frequency bands (frequency band A and frequency band B).

[0119] In one embodiment, up to 32 CCs can be aggregated. The aggregated CCs can have the same or different bandwidths, subcarrier spacings, and / or duplexing schemes (TDD or FDD). The serving cell of a UE using CA can have a downlink CC. For FDD, one or more uplink CCs can optionally be configured for the serving cell. The ability to aggregate more downlink carriers than uplink carriers can be useful, for example, when the UE has more data traffic in the downlink than in the uplink.

[0120] When using CA, one of the UE's aggregated cells may be referred to as the primary cell (PCell). The PCell can be the serving cell to which the UE first connects in RRC connection establishment, re - establishment, and / or handover. The PCell can provide the UE with NAS mobility information and security inputs. The UE can have different PCells. In the downlink, the carrier corresponding to the PCell may be referred to as the downlink primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell may be referred to as the uplink primary CC (UL PCC). The UE's other aggregated cells may be referred to as secondary cells (SCells). In one embodiment, an SCell can be configured after the PCell is configured for the UE. For example, an SCell can be configured via the RRC connection re - configuration procedure. In the downlink, the carrier corresponding to the SCell may be referred to as the downlink secondary CC (DL SCC). In the uplink, the carrier corresponding to the SCell may be referred to as the uplink secondary CC (UL SCC).

[0121] The SCell configured for the UE can be activated and deactivated, for example, based on traffic and channel conditions. The deactivation of an SCell can mean that PDCCH and PDSCH reception on the SCell is stopped, and PUSCH, SRS, and CQI transmissions on the SCell are stopped. The configured SCell can be activated and deactivated using MAC CE with respect to Figure 4B. For example, the MAC CE can use a bitmap (e.g., 1 bit per SCell) to indicate which SCell (e.g., among a subset of the configured SCells) for the UE is to be activated or deactivated. The configured SCell can be deactivated in response to the expiration of an SCell deactivation timer (e.g., one SCell deactivation timer per SCell).

[0122] Downlink control information such as cell scheduling assignment and scheduling grant can be transmitted on the cell corresponding to the assignment and grant, known as self-scheduling. DCI for a cell can be transmitted on another cell known as cross-carrier scheduling. Uplink control information for an aggregation cell (e.g., HARQ acknowledgement responses and channel state feedback such as CQI, PMI, and / or RI) can be transmitted on the PUCCH of the PCell. If the number of aggregated downlink CCs is large, the PUCCH of the PCell may become overloaded. The cell may be divided into a plurality of PUCCH groups.

[0123] FIG. 10B shows an example of how an aggregation cell can be configured into one or more PUCCH groups. PUCCH group 1010 and PUCCH group 1050 can each include one or more downlink CCs. In the example of FIG. 10B, PUCCH group 1010 includes three downlink CCs of PCell 1011, SCell 1012, and SCell 1013. PUCCH group 1050 includes three downlink CCs of PCell 1051, SCell 1052, and SCell 1053 in this example. One or more uplink CCs can be configured as PCell 1021, SCell 1022, and SCell 1023. One or more other uplink CCs can be configured as a primary S cell (PSCell) 1061, SCell 1062, and SCell 1063. Uplink control information (UCI) related to the downlink CCs of PUCCH group 1010 shown as UCI 1031, UCI 1032, and UCI 1033 can be transmitted on the uplink of PCell 1021. Uplink control information (UCI) related to the downlink CCs of PUCCH group 1050 shown as UCI 1071, UCI 1072, and UCI 1073 can be transmitted on the uplink of PSCell 1061. In one example, if the aggregation cell depicted in FIG. 10B is not split into PUCCH group 1010 and PUCCH group 1050, a single uplink PCell and PCell for transmitting UCI related to the downlink CCs can be in an overloaded state. By splitting the transmission of UCI between PCell 1021 and PSCell 1061, overload can be prevented.

[0124] A cell including a downlink carrier and an optional uplink carrier can be assigned a physical cell ID and a cell index. The physical cell ID or the cell index can identify the downlink carrier and / or the uplink carrier of the cell, depending on the context, for example, where the physical cell ID is used. The physical cell ID can be determined using the synchronization signal transmitted on the downlink component carrier. The cell index can be determined using the RRC message. In the present disclosure, the physical cell ID may be referred to as a carrier ID. The cell index may be referred to as a carrier index. For example, when the present disclosure refers to a first physical cell ID for a first downlink carrier, the present disclosure can mean that the first physical cell ID is for the cell including the first downlink carrier. The same concept can apply, for example, to the activation of a carrier. When the present disclosure indicates that a first carrier is activated, this specification can mean that the cell including the first carrier is activated.

[0125] In CA, the multi-carrier nature of the PHY can be exposed to the MAC. In one embodiment, the HARQ entity can operate on the serving cell. The transport block can be generated per allocation / grant per serving cell. The transport block and the potential HARQ retransmission of the transport block can be mapped to the serving cell.

[0126] In the downlink, the base station may transmit (e.g., unicast, multicast, and / or broadcast) one or more reference signals (RSs) to the UE (e.g., PSS, SSS, CSI-RS, DMRS, and / or PT-RS as shown in FIG. 5A). In the uplink, the UE may transmit one or more RSs to the base station (e.g., DMRS, PT-RS, and / or SRS as shown in FIG. 5B). The PSS and SSS are 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 within a synchronization signal (SS) / physical broadcast channel (PBCH) block including the PSS, SSS, and PBCH. The base station may periodically transmit bursts of SS / PBCH blocks.

[0127] FIG. 11A shows an example of the structure and position 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). The burst may be transmitted periodically (e.g., every 2 frames or every 20 milliseconds). The burst may be restricted to a half-frame (e.g., a first half-frame having a duration of 5 milliseconds). FIG. 11A is an example, and it will be understood that these parameters (the number of SS / PBCH blocks per burst, the periodicity of the burst, the position of the burst within the frame) may be configured based on, for example, the carrier frequency of the cell in which the SS / PBCH block is transmitted, the numerology of the cell or the subcarrier spacing, network configuration (e.g., using RRC signaling), or any other appropriate factor. In one embodiment, the UE may assume a subcarrier spacing for the SS / PBCH block based on the carrier frequency being monitored, except when the radio network configures the UE to assume a different subcarrier spacing.

[0128] The SS / PBCH block may span one or more OFDM symbols within the time domain (e.g., four OFDM symbols as shown in the example of FIG. 11A), and may also span 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, e.g., over one OFDM symbol and 127 subcarriers. The SSS may be transmitted after the PSS (e.g., in the next two symbols), and may span 1 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.

[0129] The position of the SS / PBCH block in the time and frequency domains may not be known 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 of the PSS. For example, the UE may monitor the frequency position within the carrier. If the PSS is not found after a certain period (e.g., 20 milliseconds), the UE may search for the PSS at different frequency positions within the carrier as indicated by the synchronization raster. When the PSS is found at its position in the time and frequency domains, the UE may determine the positions 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 one embodiment, the primary cell may be associated with the CD-SSB. The CD-SSB may be placed on the synchronization raster. In one embodiment, cell selection / search and / or reselection may be based on the CD-SSB.

[0130] The SS / PBCH block can be used by a UE to determine one or more parameters of a cell. For example, the UE may determine the physical cell identifier (PCI) of a cell based on each of the sequences of the PSS and SSS. The UE may determine the position of the cell's frame boundary based on the position of the SS / PBCH block. For example, the SS / PBCH block may indicate that it was transmitted according to a transmission pattern, and the SS / PBCH block in the transmission pattern is a known distance from the frame boundary.

[0131] PBCH may use QPSK modulation and may use forward error correction (FEC). FEC may use polar coding. One or more symbols spanned by PBCH may carry one or more DMRSs for demodulation of PBCH. PBCH may include an indication of the current system frame number (SFN) of the cell and / or the SS / PBCH block timing index. These parameters may facilitate time synchronization of the UE to the base station. PBCH may include the master information block (MIB) used to provide one or more parameters to the UE. The MIB can be used by the UE to find the remaining minimum system information (RSSI) associated with the cell. RMSI may include the system information block type 1 (SIB1). SIB1 may include the 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 can be used to schedule the PDSCH. The PDSCH may include SIB1. SIB1 may be decoded using the parameters provided by the MIB. PBCH may indicate the absence of SIB1. Based on the PBCH indicating the absence of SIB1, the UE may indicate a frequency. The UE may search for the SS / PBCH block at the frequency indicated by the UE.

[0132] The UE can assume that one or more SS / PBCH blocks transmitted with the same SS / PBCH block index are quasi-co-located (QCL) (e.g., having the same / similar Doppler spread, Doppler shift, average gain, average delay, and / or spatial Rx parameters). The UE cannot assume that SS / PBCH blocks having different SS / PBCH block indices are QCL for SS / PBCH block transmissions.

[0133] SS / PBCH blocks (e.g., blocks within a half-frame) can be transmitted in a spatial direction (e.g., using different beams across the cell coverage area). In one example, 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.

[0134] In one example, within the frequency span of a carrier, the base station can transmit multiple SS / PBCH blocks. In one example, the first PCI of the first SS / PBCH block of the multiple SS / PBCH blocks may be different from the second PCI of the second SS / PBCH block of the multiple SS / PBCH blocks. The PCI of SS / PBCH blocks transmitted at different frequency positions may be different or the same.

[0135] CSI-RS can be transmitted by a base station and used by a UE to obtain channel state information (CSI). The base station can configure the UE with one or more CSI-RSs for channel estimation or any other suitable purpose. The base station can configure the UE with one or more of the same / similar CSI-RSs. The UE can measure one or more CSI-RSs. The UE can estimate the downlink channel state and / or generate a CSI report based on the measurement of one or more downlink CSI-RSs. The UE can provide the CSI report to the base station. The base station can perform link adaptation using the feedback (e.g., the estimated downlink channel state) provided by the UE.

[0136] The base station can semi-statically configure the UE with one or more CSI-RS resource sets. The CSI-RS resources may be associated with positions and periodicities within the time and frequency domains. The base station can selectively activate and / or deactivate the CSI-RS resources. The base station can indicate to the UE that the CSI-RS resources within the CSI-RS resource set are activated and / or deactivated.

[0137] The base station can configure the UE to report CSI measurement values. The base station can configure the UE to provide CSI reports periodically, aperiodically, or semi-persistently. For periodic CSI reports, the UE can be configured with the timing and / or periodicity of multiple CSI reports. For aperiodic CSI reports, the base station can request a CSI report. For example, the base station can instruct the UE to measure the configured CSI-RS resources and provide a CSI report regarding the measurement values. For semi-persistent CSI reports, the base station can transmit periodic reports regularly and configure the UE to selectively activate or deactivate. The base station can configure the UE with CSI-RS resource sets and CSI reports using RRC signaling.

[0138] The CSI-RS configuration may include one or more parameters indicating, for example, up to 32 antenna ports. The UE may be configured to use the same OFDM symbol for the downlink CSI-RS and the control resource set (CORESET) when the downlink CSI-RS and the CORESET are spatially QCL and the resource elements associated with the downlink CSI-RS are outside the physical resource blocks (PRBs) configured for the CORESET. The UE may be configured to use the same OFDM symbol for the downlink CSI-RS and the SS / PBCH block when the downlink CSI-RS and the SS / PBCH block are spatially QCL and the resource elements associated with the downlink CSI-RS are outside the PRBs configured for the SS / PBCH block.

[0139] The downlink DMRS may be transmitted by the base station and can be used by the UE for channel estimation. For example, the downlink DMRS can be used for coherent demodulation of one or more downlink physical channels (e.g., PDSCH). The NR network may support one or more variable and / or configurable DMRS patterns for data demodulation. At least one downlink DMRS configuration can support a front-loaded DMRS pattern. The front-loaded DMRS can be mapped to one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). The base station can semi-statically configure the UE using the number (e.g., the maximum number) of front-loaded 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 can support up to eight orthogonal downlink DMRS ports per UE. In the case of multi-user MIMO, the DMRS configuration can support up to four orthogonal downlink DMRS ports per UE. The radio network can support a common DMRS structure for the downlink and uplink (e.g., for at least CP-OFDM). The DMRS position, DMRS pattern, and / or scrambling sequence may be the same or different. The base station can transmit the downlink DMRS and the corresponding PDSCH using the same precoding matrix. The UE can use one or more downlink DMRSs for coherent demodulation / channel estimation of the PDSCH.

[0140] In one embodiment, a transmitter (e.g., a base station) may use a precoder matrix for a part of the 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 indicated as a precoding resource block group (PRG).

[0141] The PDSCH may include one or more layers. The UE may assume that at least one symbol with DMRS exists on one or more layers of the PDSCH. The upper layer may configure up to three DMRSs for the PDSCH.

[0142] Downlink PT-RS may be transmitted by the base station and can be used by the UE for phase noise compensation. Whether downlink PT-RS exists depends on the RRC configuration. The presence and / or pattern of downlink PT-RS can be configured on a UE-specific basis using a combination of RRC signaling and / or association with one or more parameters used for other purposes (e.g., modulation and coding scheme (MCS)) indicated by DCI. When configured, the dynamic presence of downlink PT-RS can be associated with one or more DCI parameters including at least MCS. The NR network can support multiple PT-RS densities defined in the time and / or frequency domain. The frequency domain density, if it exists, can be associated with at least one configuration of the scheduled bandwidth. The UE may assume the same precoding for DMRS ports and PT-RS ports. The number of PT-RS ports may be less than the number of DMRS ports within the scheduled resources. Downlink PT-RS can be restricted to the UE's scheduled time / frequency period. Downlink PT-RS can be transmitted on symbols to facilitate phase tracking at the receiver.

[0143] The UE can transmit uplink DMRS to the base station for channel estimation. For example, the base station may use uplink DMRS for coherent demodulation of one or more uplink physical channels. For example, the UE may transmit uplink DMRS on PUSCH and / or PUCCH. The uplink DM-RS may span a frequency range similar to the frequency range associated with the corresponding physical channel. The base station can configure the UE with one or more uplink DMRS configurations. At least one DMRS configuration may support a front-loaded DMRS pattern. The front-loaded DMRS can be mapped to one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). One or more uplink DMRS may be configured to be transmitted in one or more symbols of PUSCH and / or PUCCH. The base station can semi-statically configure the UE using the number (e.g., maximum number) of front-loaded DMRS symbols for PUSCH and / or PUCCH that the UE can use to schedule single-symbol DMRS and / or double-symbol DMRS. The NR network may support a common DMRS structure for downlink and uplink (e.g., for cyclic prefix orthogonal frequency division multiplexing (CP-OFDM)), where the DMRS position, DMRS pattern, and / or DMRS scrambling sequence may be the same or different.

[0144] PUSCH may include one or more layers, and the UE may transmit at least one symbol having DMRS existing on one or more layers of PUSCH. In one embodiment, the upper layer may configure up to three DMRS for PUSCH.

[0145] The uplink PT-RS (which can be used by the base station for phase tracking and / or phase noise compensation) may or may not exist depending on the UE's RRC configuration. The presence and / or pattern of the uplink PT-RS can 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)), indicated by RRC signaling and / or DCI. When configured, the dynamic presence of the uplink PT-RS can be associated with one or more DCI parameters including at least the MCS. The radio network can support multiple uplink PT-RS densities defined in the time / frequency domain. The frequency domain density, if it exists, can be associated with at least one configuration of the scheduled bandwidth. The UE may assume the same precoding for the DMRS ports and the PT-RS ports. The number of PT-RS ports may be less than the number of DMRS ports within the scheduled resources. For example, the uplink PT-RS can be restricted to the UE's scheduled time / frequency period.

[0146] The SRS can be transmitted by the UE to the base station for channel state estimation to support uplink channel dependent scheduling and / or link adaptation. The SRS transmitted by the UE can enable the base station to estimate the uplink channel state at one or more frequencies. The base station scheduler can use the estimated uplink channel state to allocate one or more resource blocks for uplink PUSCH transmission from the UE. The base station can semi-statically configure the UE using one or more SRS resource sets. In the case of an SRS resource set, the base station can configure the UE using one or more SRS resources. The SRS resource set applicability can be configured by parameters of a higher layer (e.g., RRC). For example, when the higher layer parameter indicates beam management, the SRS resources within an SRS resource set (e.g., having the same / similar time domain behavior, periodicity, aperiodicity, and / or of the same kind) can be transmitted instantaneously (e.g., simultaneously). The UE can transmit one or more SRS resources within the SRS resource set. The NR network can support aperiodic, periodic, and / or semi-persistent SRS transmissions. The UE may transmit SRS resources based on one or more trigger types, and the one or more trigger types may include higher layer signaling (e.g., RRC) and / or one or more DCI formats. In one embodiment, at least one DCI format can be used for the UE to select at least one of one or more configured SRS resource sets. SRS trigger type 0 can refer to SRS triggered based on higher layer signaling. SRS trigger type 1 can refer to SRS triggered based on one or more DCI formats. In one embodiment, when the PUSCH and SRS are transmitted in the same slot, the UE can be configured to transmit the SRS after the transmission of the PUSCH and the corresponding uplink DMRS.

[0147] The base station can semi-statically configure the UE using one or more SRS configuration parameters indicating at least one of the SRS resource configuration identifier, the number of SRS ports, the time-domain behavior of the SRS resource configuration (e.g., indication of periodic, semi-persistent, or aperiodic SRS), slot, mini-slot, and / or sub-frame level periodicity, offset for periodic and / or aperiodic SRS resources, the number of OFDM symbols in the SRS resource, the starting OFDM symbol of the SRS resource, the SRS bandwidth, the frequency hopping bandwidth, the periodic shift, and / or the SRS sequence ID.

[0148] An antenna port is defined such that a channel on which a symbol on the antenna port is transmitted can be inferred from a channel on which another symbol on the same antenna port is transmitted. When a first symbol and a second symbol are transmitted on the same antenna port, the receiver can infer a channel (e.g., fade gain, multipath delay, and / or the like) for carrying the second symbol on the antenna port from the channel for carrying the first symbol on the antenna port. The first antenna port and the second antenna port may be called quasi-co-located (QCL) if one or more large-scale characteristics of a channel on which a first symbol on the first antenna port is transmitted can be inferred from a channel on which a second symbol of the second antenna port is transmitted. 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.

[0149] In channels that use 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 measurements based on downlink reference signals (e.g., Channel State Information Reference Signals (CSI-RS)) and generate a beam measurement report. The UE may perform the downlink beam measurement procedure after the RRC connection is set up at the base station.

[0150] Figure 11B shows an example of a Channel State Information Reference Signal (CSI-RS) mapped in the time and frequency domains. The squares shown in Figure 11B may span resource blocks (RBs) within the cell bandwidth. The base station can transmit one or more RRC messages containing CSI-RS resource configuration parameters indicating one or more CSI-RSs. One or more of the following parameters can be set by upper 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) positions within a subframe), CSI-RS subframe configuration (e.g., subframe position, offset, and periodicity of radio frames), CSI-RS power parameters, CSI-RS sequence parameters, code division multiplexing (CDM) type parameters, frequency density, transmission 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.

[0151] The three beams shown in FIG. 11B can be configured for a UE with a UE-specific configuration. The three beams are shown in FIG. 11B (Beam #1, Beam #2, and Beam #3), and more or fewer beams can be configured. Beam #1 can be allocated by CSI-RS1101 that can be transmitted on one or more subcarriers within the RB of the first symbol. Beam #2 can be allocated by CSI-RS1102 that can be transmitted on one or more subcarriers within the RB of the second symbol. Beam #3 can be allocated by CSI-RS1103 that can be transmitted on one or more subcarriers within the RB of the third symbol. By using frequency division multiplexing (FDM), the base station can use other subcarriers within the same RB (e.g., those not used for transmitting CSI-RS1101) to transmit another CSI-RS associated with the beam of another UE. By using time domain multiplexing (TDM), the beams used by the UE can be configured such that the symbols from the beams of other UEs are used by the beams of the UE.

[0152] The CSI-RS shown in FIG. 11B (e.g., CSI-RS 1101, 1102, 1103) is transmitted by a base station and can be used by a UE for one or more measurements. For example, the UE can measure the reference signal received power (RSRP) of the configured CSI-RS resources. The base station may configure the UE using a reporting configuration, and the UE may report the RSRP measurement value to the network (e.g., via one or more base stations) based on the reporting configuration. In one 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 one 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 downlink transmissions having a receive (Rx) beam determined based on one or more TCI states. In one embodiment, the UE may or may not have beam correspondence capabilities. If the UE has beam correspondence capabilities, the UE may determine the spatial domain filter of the transmit (Tx) beam based on the spatial domain filter of the corresponding Rx beam. If the UE does not have beam correspondence capabilities, the UE may perform an uplink beam selection procedure to determine the 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 for the UE by the base station. The base station may select and indicate an uplink beam for the UE based on the measurement values of one or more SRS resources transmitted by the UE.

[0153] In the beam management procedure, the UE may evaluate (e.g., measure) the channel quality of one or more beam pair links, the transmission beam transmitted by the base station, and the reception 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 identifications (e.g., beam index, reference signal index, or the like), RSRP, precoding matrix indicator (PMI), channel quality indicator (CQI), and / or rank indicator (RI).

[0154] Figure 12A shows examples of three downlink beam management procedures, P1, P2, and P3. Procedure P1 may enable UE measurements at the transmission (Tx) beam of a transmission reception point (TRP) (or multiple TRPs) to support the selection of, for example, one or more base station Tx beams and / or UE Rx beams (displayed as ellipses in the top and bottom rows of P1, respectively). Beamforming at the TRP may include a Tx beam sweep of a set of beams (as shown by the dashed arrows in the top row of P1 and P2, where the ellipse is shown rotating counterclockwise). Beamforming at the UE may include an Rx beam sweep for a set of beams (as shown in the lower rows of P1 and P3, where the ellipse rotates in a clockwise direction when indicated by the dashed arrows). Using procedure P2, UE measurements at the Tx beam of the TRP can be enabled. (As shown by the dashed arrows in the top row of P2, the ellipse is shown rotating counterclockwise). The UE and / or the base station may perform procedure P2 using a set of beams smaller than those used in procedure P1 or using beams narrower than the beams 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 beam at the UE.

[0155] FIG. 12B shows examples of three uplink beam management procedures, U1, U2, and U3. Using procedure U1, for example, the base station may be enabled to perform measurements on the UE's Tx beam to support the selection of, for example, one or more UE Tx beams and / or base station Rx beams (shown as ellipses at the top and bottom of U1, respectively). Beamforming at the UE may include, for example, a Tx beam sweep from a set of beams. (Shown as ellipses rotated clockwise when indicated by dashed arrows below U1 and U3). Beamforming at the base station may include, for example, an Rx beam sweep from a set of beams. (Shown as ellipses rotated counterclockwise as indicated by dashed arrows at the top of U1 and U2). Using procedure U2, the base station may be enabled to adjust its Rx beam when the UE uses a fixed Tx beam. The UE and / or the base station may perform procedure U2 using a set of beams smaller than those used in procedure P1 or using beams narrower than the beams 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.

[0156] The UE may initiate a beam failure recovery (BFR) procedure based on the detection of a 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 a beam failure based on a determination that the quality of the beam pair link of the associated control channel is unsatisfactory (e.g., having an error rate higher than an error rate threshold, a received signal power lower than a received signal power threshold, expiration of a timer, and / or the like).

[0157] 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 (DMRS). The quality of the beam pair link may be based on one or more of the block error rate (BLER), RSRP value, signal-to-interference plus noise ratio (SINR) value, reference signal received quality (RSRQ) value, and / or CSI value measured on the RS resource. The base station may indicate that the RS resource is quasi-co-located (QCL) with one or more DM-RSs of a channel (e.g., control channel, shared data channel, and / or the like). The RS resource of the channel and the one or more DMRSs may be QCL 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 via the RS resource are similar or identical to the channel characteristics from a transmission to the UE via the channel.

[0158] A network (e.g., a gNB and / or ng-eNB of the network) and / or a UE may initiate a random access procedure. A UE in the RRC_IDLE state and / or a UE in the RRC_INACTIVE state may initiate a random access procedure to request connection setup to the network. A UE may initiate a random access procedure from the RRC_CONNECTED state. A UE may initiate a random access procedure to request uplink resources (e.g., for SR uplink transmission when there are no available PUCCH resources) and / or to obtain uplink timing (e.g., when the uplink synchronization state is not synchronized). A UE may initiate a random access procedure to request one or more system information blocks (SIBs) (e.g., other system information such as SIB2, SIB3, and / or the like). A UE may initiate a random access procedure for beam failure recovery request. The network may initiate a random access procedure for handover and / or for establishing time alignment for SCell addition.

[0159] Figure 13A shows a 4-step contention-based random access procedure. Before the start of the procedure, the base station may send 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 a preamble (or a random access preamble) and / or may be referred to as a preamble. Msg2 1312 may include a random access response (RAR) and / or may be referred to as a random access response (RAR).

[0160] The constituent message 1310 can 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 for one or more random access procedures (e.g., RACH-configGeneral), cell-specific parameters (e.g., RACH-ConfigCommon), and / or dedicated parameters (e.g., RACH-configDedicated). The base station can broadcast or multicast the one or more RRC messages to one or more UEs. The one or more RRC messages can be UE-specific (e.g., dedicated RRC messages transmitted to the UE in the RRC_CONNECTED state and / or the RRC_INACTIVE state). The UE can determine the time-frequency resources and / or uplink transmission power for the 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 can determine the reception timing and downlink channel for receiving Msg2 1312 and Msg4 1314.

[0161] One or more RACH parameters provided in the configuration message 1310 may indicate one or more physical RACH (PRACH) opportunities available for the transmission of Msg1 1311. The one or more PRACH opportunities may be pre-defined. One or more RACH parameters may indicate one or more available sets of one or more PRACH opportunities (e.g., prach-ConfigIndex). One or more RACH parameters may indicate the association between (a) one or more PRACH opportunities and (b) one or more reference signals. One or more RACH parameters may indicate the 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, one or more RACH parameters may indicate the number of SS / PBCH blocks mapped to a PRACH opportunity and / or the number of preambles mapped to an SS / PBCH block.

[0162] The uplink transmission power of Msg1 1311 and / or Msg3 1313 may be determined using one or more RACH parameters provided in the configuration message 1310. For example, one or more RACH parameters may indicate a reference power for preamble transmission (e.g., the received target power and / or the initial power of preamble transmission). There may be one or more power offsets indicated by one or more RACH parameters. For example, one or more RACH parameters may indicate a power ramping step, a power offset between an SSB and a CSI-RS, a power offset between the transmissions of Msg1 1311 and Msg3 1313, and / or a power offset value between preamble groups. One or more RACH parameters may indicate one or more thresholds for the UE to determine at least one reference signal (e.g., an SSB and / or a CSI-RS) and / or an uplink carrier (e.g., a normal uplink (NUL) carrier and / or a supplementary uplink (SUL) carrier).

[0163] 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). A preamble group may include one or more preambles. The UE may determine a preamble group based on path loss measurements and / or the 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 exceeding an RSRP threshold (e.g., rsrp-ThresholdSSB and / or rsrp-ThresholdCSI-RS). The UE may select at least one preamble associated with one or more reference signals and / or a selected preamble group if, for example, an association between one or more preambles and at least one reference signal is configured by the RRC message.

[0164] The UE may determine a preamble based on one or more RACH parameters provided in the configuration message 1310. For example, the UE may determine a preamble based on path loss measurement, RSRP measurement, and / or the size of Msg3 1313. As another example, one or more RACH parameters may indicate a preamble format, a maximum number of preamble transmissions, and / or one or more thresholds for determining one or more preamble groups (e.g., group A and group B). The base station may use one or more RACH parameters to configure the UE in an association between one or more preambles and one or more reference signals (e.g., SSB and / or CSI-RS). When the 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 (e.g., ra-ssb-OccasionMskIndex and / or ra-OccasionList) may indicate an association between a PRACH opportunity and one or more reference signals.

[0165] If the UE does not receive a response after transmitting the preamble, the UE may perform a preamble retransmission. The UE may increase the uplink transmission power for the preamble retransmission. The UE may select the initial preamble transmission power based on path loss measurements and / or target received preamble power configured by the network. The UE may decide to retransmit the preamble and may ramp up the uplink transmission power. The UE may receive one or more RACH parameters (e.g., PREAMBLE_POWER_RAMPING_STEP) indicating the ramping steps for the preamble retransmission. The ramping step may be the amount of incremental increase in the uplink transmission power for retransmission. If the UE determines the same reference signal (e.g., SSB and / or CSI-RS) as the previous preamble transmission, the UE may ramp up the uplink transmission power. The UE can count the number of preamble transmissions and / or retransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE may determine that the random access procedure has failed and completed if, for example, the number of preamble transmissions exceeds a threshold configured by one or more RACH parameters (e.g., preambleTransMax).

[0166] The Msg2 1312 received by the UE may include an RAR. In some scenarios, the Msg2 1312 may include multiple RARs corresponding to multiple UEs. The Msg2 1312 may be received after or in response to the transmission of the Msg1 1311. The Msg2 1312 may be scheduled on the DL-SCH and indicated on the PDCCH using a random access RNTI (RA-RNTI). The Msg2 1312 may indicate that the Msg1 1311 has been received by the base station. The Msg2 1312 may include a timing alignment command that the UE may use to adjust the UE's transmission timing, Msg3 It may include scheduling permission for the transmission of 1313, and / or a temporary cell RNTI (TC-RNTI). After transmitting the preamble, the UE may start a time window (e.g., ra-ResponseWindow) for monitoring the PDCCH of Msg2 1312. The UE may determine when to start the time window based on the PRACH opportunity used by the UE to transmit the preamble. For example, the UE may start the time window after one or more symbols of the last symbol of the preamble (e.g., at the first PDCCH opportunity after the end of the preamble transmission). One or more symbols may be determined based on numerology. The PDCCH may be in a common search space (e.g., Type1-PDCCH common search space) configured by an 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 a random access procedure. The UE may use a random access RNTI (RA-RNTI). The RA-RNTI may be associated with the PRACH opportunity used by the UE to transmit the preamble. For example, the UE may determine the RA-RNTI based on the OFDM symbol index, slot index, frequency domain index, and / or UL carrier indicator of the PRACH opportunity. Examples of RA-RNTI may be as follows. RA-RNTI = 1 + s_id + 14×t_id + 14×80×f_id + 14×80×8×ul_carrier_id Here, 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 within 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 the NUL carrier, 1 for the SUL carrier). In response to successful reception of Msg2 1312 (e.g., using the resources identified in Msg2 1312), the UE may transmit Msg3 1313. Msg3 1313 may be used, for example, for contention resolution in the contention-based random access procedure shown in Figure 13A. In some scenarios, multiple UEs may transmit the same preamble to the base station, and the base station may provide the RAR corresponding to the UE. If multiple UEs interpret the RAR as corresponding to themselves, a mismatch may occur. Contention resolution (e.g., the use of Msg3 1313 and Msg4 1314) may be used to increase the likelihood that a UE does not incorrectly use the identity of another UE. To perform contention resolution, the UE may include a device identifier (e.g., if assigned, the C-RNTI, the TC-RNTI included in Msg2 1312, and / or any other appropriate identifier) in Msg3 1313.

[0167] Msg4 1314 may be received after or in response to the transmission of Msg3 1313. If the C-RNTI is included in Msg3 1313, the base station uses the C-RNTI to handle the UE on the PDCCH. If the UE's unique C-RNTI is detected on the PDCCH, it is determined that the random access procedure has been successfully completed. If the TC-RNTI is included in Msg3 1313 (e.g., if the UE is in the RRC_IDLE state or 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 transmitted (e.g., sent) in Msg3 1313 or otherwise contains the corresponding UE contention resolution identity EtOAc 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.

[0168] The UE may be composed of a supplementary 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, i.e., one for the SUL carrier and the other for the NUL carrier. For random access within the cell composed of the SUL carrier, the network may indicate which carrier (NUL or SUL) to use. The UE may determine the SUL carrier, for example, when the measurement quality of one or more reference signals is lower than the broadcast threshold. The uplink transmission of the random access procedure (e.g., Msg1 1311 and / or Msg3 1313) can stay on the selected carrier. The UE may switch the uplink carrier 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 of Msg1 1311 and / or Msg3 1313 based on the channel clear access assessment (e.g., listen before talk).

[0169] Figure 13B shows a two-step contention-free random access procedure. Similar to the four-step contention-based random access procedure shown in Figure 13A, the base station may send a configuration message 1320 to the UE before the start of the procedure. The configuration message 1320 may be similar to the configuration message 1310 in some respects. Figure 13B includes the transmission of two messages, Msg1 1321 and Msg2 1322. Msg1 1321 and Msg2 1322 may be similar to Msg1 1311 and Msg2 1312 shown in Figure 13A respectively in some respects. As understood from Figures 13A and 13B, the contention-free random access procedure may not include messages similar to Msg3 1313 and / or Msg4 1314.

[0170] The random access procedure without contention shown in FIG. 13B can be initiated for beam failure recovery, other SI requirements, SCell addition, and / or handover. For example, the base station may indicate or allocate to the UE the preamble 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.

[0171] After transmitting the preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor the PDCCH of the RAR. In the case of a beam failure recovery request, the base station may configure the UE with a separate time window and / or a 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 random access procedure without contention shown in FIG. 13B, the UE may determine that the random access procedure has completed successfully after or in response to the transmission of Msg1 1321 and the reception of the corresponding Msg2 1322. The UE may determine that the random access procedure has completed successfully, for example, if the PDCCH transmission is addressed to the C-RNTI. The UE may determine that the random access procedure has completed successfully if, for example, the UE receives an RAR that includes a preamble identifier corresponding to the preamble transmitted by the UE, and / or if the RAR includes a MAC sub-PDU that includes the preamble identifier. The UE may determine the response as an indicator of confirmation for the SI requirement.

[0172] FIG. 13C shows another two-step random access procedure. Similar to the random access procedures shown in FIGS. 13A and 13B, the base station may be able to transmit a configuration message 1330 to the UE before the start of the procedure. The configuration message 1330 may be similar to the configuration message 1310 and / or the configuration message 1320 in some respects. FIG. 13C includes the transmission of two messages, namely, Msg A 1331 and Msg B 1332.

[0173] Msg A 1331 can be transmitted by the UE in an uplink transmission. Msg A 1331 can include one or more transmissions of the preamble 1341 and / or one or more transmissions of the transport block 1342. The transport block 1342 can 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). After or in response to the transmission of Msg A 1331, the UE can receive Msg B 1332. Msg B 1332 can include content similar and / or equivalent to the content of Msg 2 1312 (e.g., RAR) shown in FIGS. 13A and 13B, and / or the content of Msg4 1314 shown in FIG. 13A.

[0174] The UE can initiate the two-step random access procedure of FIG. 13C for licensed spectrum and / or unlicensed spectrum. The UE can determine whether to initiate the two-step random access procedure based on one or more factors. The one or more factors can be the radio access technology in use (e.g., LTE, NR, and / or the like), whether the UE has a valid TA, cell size, the RRC state of the UE, the type of spectrum (e.g., licensed versus unlicensed), and / or any other suitable factor.

[0175] The UE may determine radio resources and / or uplink transmission power for the transport block 1342 included in the preamble 1341 and / or Msg A 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 reception timing and downlink channel for the monitoring and / or reception of Msg B 1332.

[0176] 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 transmit Msg B 1332 as a response to Msg A 1331. Msg B 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 when the preamble identifier of Msg B 1332 matches the preamble transmitted by the UE and / or the UE identifier of Msg B 1332 matches the UE identifier of Msg A 1331 (e.g., the transport block 1342).

[0177] The UE and the base station can exchange control signaling. The control signaling 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.

[0178] The downlink control signaling may include downlink scheduling assignments, uplink scheduling grants indicating uplink radio resources and / or transport formats, slot format information, preemption indication, power control commands, and / or any other suitable signaling. The UE may receive the downlink control signaling in the payload transmitted by the base station on the 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) common to a group of UEs.

[0179] The base station may attach one or more cyclic redundancy check (CRC) parity bits to the DCI to facilitate detection of transmission errors. If the DCI is intended for a UE (or a group of UEs), the base station may scramble the CRC parity bits with the identifier of the UE (or the identifier of the group of UEs). Scrambling the CRC parity bits with the identifier may include modulo-2 addition (or exclusive OR operation) of the identifier value and the CRC parity bits. The identifier may include a 16-bit value of a radio network temporary identifier (RNTI).

[0180] The DCI can be used for different purposes. The purpose can be indicated by the type of RNTI used to scramble the CRC parity bits. For example, DCI with CRC parity bits scrambled by a paging RNTI (P-RNTI) can indicate paging information and / or a system information change notification. The P-RNTI can be pre-defined as "FFFE" in hexadecimal. DCI with CRC parity bits scrambled by a system information RNTI (SI-RNTI) can indicate the broadcast transmission of system information. The SI-RNTI can be pre-defined as "FFFE" in hexadecimal. DCI with CRC parity bits scrambled by a random access RNTI (RA-RNTI) can indicate a random access response (RAR). DCI with CRC parity bits scrambled by a cell RNTI (C-RNTI) can indicate the unicast transmission of a dynamic schedule and / or a trigger for random access of the PDCCH order. DCI with CRC parity bits scrambled by a temporary cell RNTI (TC-RNTI) can indicate contention resolution (e.g., Msg3 similar to Msg3 1313 shown in FIG. 13A). The encoding of other RNTIs configured by the base station for the UE includes 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.

[0181] Depending on the purpose and / or content of the DCI, the base station may transmit DCI in one or more DCI formats. For example, DCI format 0_0 can be used for scheduling PUSCH within a cell. DCI format 0_0 can be a fallback DCI format (e.g., having a compact DCI payload). DCI format 0_1 can be used for scheduling PUSCH within a cell (e.g., having more DCI payload than DCI format 0_0). DCI format 1_0 can be used for scheduling PDSCH within a cell. DCI format 1_0 can be a fallback DCI format (e.g., having a compact DCI payload). DCI format 1_1 can be used for scheduling PDSCH within a cell (e.g., having more DCI payload than DCI format 1_0). DCI format 2_0 can be used to provide slot format indication to a group of UEs. DCI format 2_1 can be used to notify a group of UEs of physical resource blocks and / or OFDM symbols that are assumed not to be intended for transmission to the UEs. DCI format 2_2 can be used for transmitting transmission power control (TPC) commands for PUCCH or PUSCH. DCI format 2_3 can be used for transmitting a group of TPC commands for SRS transmission by one or more UEs. New feature DCI formats may be defined in future releases. DCI formats may have different DCI sizes or share the same DCI size.

[0182] After scrambling the DCI with the RNTI, the base station may process the DCI using channel coding (e.g., polar coding), rate matching, scrambling and / or QPSK modulation. The base station may map the encoded 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 a PDCCH that occupies several consecutive control channel elements (CCEs). The number of consecutive CCEs (referred to as the 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 resource blocks within an OFDM symbol. The mapping of the encoded and modulated DCI onto the resource elements may be based on the mapping of the CCEs and REGs (e.g., CCE~REG mapping).

[0183] FIG. 14A shows an example of a CORESET configuration for a bandwidth part. The base station may transmit the DCI via a PDCCH on one or more control resource sets (CORESETs). A CORESET may include time-frequency resources for which the UE attempts to decode the DCI using one or more search spaces. The base station may configure the CORESET within the time-frequency domain. In the example of FIG. 14A, a first CORESET 1401 and a second CORESET 1402 occur in the first symbol within a slot. The first CORESET 1401 overlaps with the second CORESET 1402 in the frequency domain. A third CORESET 1403 occurs in the third symbol within the slot. A fourth CORESET 1404 occurs in the seventh symbol of the slot. The CORESET may have a different number of resource blocks in the frequency domain.

[0184] FIG. 14B shows an example of CCE-to-REG mapping for DCI transmission on CORESET and PDCCH processing. The CCE-to-REG mapping can be an interleaved mapping (e.g., for the purpose of providing frequency diversity) or a non-interleaved mapping (e.g., for the purpose of facilitating interference coordination and / or frequency selective transmission of control channels). The base station may perform different or the same CCE-to-REG mapping on different CORESETs. The CORESET may be associated with the CCE-to-REG mapping by RRC configuration. The CORESET may be configured with antenna port quasi-collocation (QCL) parameters. The QCL parameters of the antenna port may indicate the QCL information of the demodulation reference signal (DMRS) for PDCCH reception within the CORESET.

[0185] The base station can transmit an RRC message to the UE that includes configuration parameters of one or more CORESETs and one or more search space sets. The configuration parameters may indicate the 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 for each aggregation level, the PDCCH monitoring periodicity and 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 within the common search space set may be predefined and known to the UE. The set of CCEs within the UE-specific search space set may be configured based on the identity of the UE (e.g., C-RNTI).

[0186] As shown in FIG. 14B, the UE may determine the time-frequency resources of the CORESET based on the RRC message. The UE may determine the CCE-to-REG mapping (e.g., interleaved or non-interleaved, and / or mapping parameters) for the CORESET based on the 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 the configuration parameters of the search space set. The UE may monitor a set of PDCCH candidates within 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 the monitored DCI format. The monitoring may include decoding the DCI content of one or more PDCCH candidates having possible (or configured) PDCCH positions, possible (or configured) PDCCH formats (e.g., the number of CCEs in the common search space, the number of PDCCH candidates, and / or the number of PDCCH candidates in the 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., the scrambling bits for the CRC parity bits of the DCI that match the RNTI value). The UE may process the information included in the DCI (e.g., scheduling assignment, uplink grant, power control, slot format indication, downlink preemption, and / or the like).

[0187] 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 response for the received DL-SCH transport block. The UE may transmit the HARQ acknowledgement response after receiving the DL-SCH transport block. The uplink control signaling may include channel state information (CSI) indicating the channel quality of the physical downlink channel. The UE may transmit the CSI to the base station. The base station may determine transmission format parameters (e.g., including multi-antenna and beamforming schemes) for 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 UCI (e.g., HARQ acknowledgement (HARQ-ACK), CSI report, SR, etc.) via the physical uplink control channel (PUCCH) or the physical uplink shared channel (PUSCH). The UE may transmit uplink control signaling via the PUCCH using one of several PUCCH formats.

[0188] There can be five PUCCH formats, and the UE can determine the PUCCH format based on the size of the UCI (e.g., the number of uplink symbols for UCI transmission and the number of UCI bits). PUCCH format 0 may have a length of one or two OFDM symbols and may contain 2 bits or less. The UE can use PUCCH format 0 to transmit UCI on a PUCCH resource when the transmission exceeds one or two symbols and the number of HARQ-ACK information bits (HARQ-ACK / SR bits) with positive or negative SR is one or two. PUCCH format 1 may occupy a number between 4 and 14 OFDM symbols and may contain 2 bits or less. The UE can use PUCCH format 1 when 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 contain more than 2 bits. The UE can use PUCCH format 2 when the transmission exceeds 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 contain more than 2 bits. The UE can use PUCCH format 3 when 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 contain more than 2 bits. The UE can use PUCCH format 4 when 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.

[0189] The base station may transmit the configuration parameters of a plurality of PUCCH resource sets to the UE using, for example, RRC messages. A plurality of 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 composed of a PUCCH resource set index, a plurality of PUCCH resources identified by a PUCCH resource identifier (e.g., pucch-Resourceid), and / or the number (e.g., the maximum number) of UCI information bits that the UE can transmit using one of the plurality of PUCCH resources within the PUCCH resource set. When composed of a plurality of PUCCH resource sets, the UE may select one of the plurality of PUCCH resource sets based on the 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 2 or less, the UE may select the first PUCCH resource set whose PUCCH resource set index is equal to "0". If the total bit length of the UCI information bits is greater than 2 and less than or equal to a first configured 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 configured value and less than or equal to a second configured 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 configured 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".

[0190] After determining a PUCCH resource set from a plurality of PUCCH resource sets, the UE may determine a PUCCH resource from the PUCCH resource set for transmitting UCI (HARQ-ACK, CSI, and / or SR). The UE may determine the PUCCH resource based on a PUCCH resource indicator in DCI received on the PDCCH (e.g., DCI format 1_0 or DCI format 1_1). The 3-bit PUCCH resource indicator of the DCI may indicate one of eight PUCCH resources within the PUCCH resource set. Based on the PUCCH resource indicator, the UE may transmit UCI (HARQ-ACK, CSI, and / or SR) using the PUCCH resource indicated by the PUCCH resource indicator in the DCI.

[0191] FIG. 15 shows an example of a wireless device 1502 communicating with a base station 1504 according to an embodiment of the present disclosure. The wireless device 1502 and the 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 networks. Only one wireless device 1502 and one base station 1504 are shown in FIG. 15. However, it will be understood that the mobile communication network may include a plurality of UEs and / or a plurality of base stations having the same or similar configuration as that shown in FIG. 15.

[0192] The base station 1504 may connect the wireless device 1502 to a core network (not shown) via wireless communication on an air interface (or wireless interface) 1506. The communication direction from the base station 1504 to the wireless device 1502 on the air interface 1506 is known as the downlink, and the communication direction from the wireless device 1502 to the base station 1504 on the air interface is known as the uplink. Downlink transmission may be separated from uplink transmission using FDD, TDD, and / or some combination of two duplexing techniques.

[0193] On the downlink, data transmitted from the base station 1504 to the wireless device 1502 can be provided to the processing system 1508 of the base station 1504. The data can be provided to the processing system 1508, for example, by a core network. On the uplink, data transmitted from the wireless device 1502 to the base station 1504 can be provided to the processing system 1518 of the wireless device 1502. The processing system 1508 and the processing system 1518 can implement layer 3 and layer 2 OSI functions to process data for transmission. Layer 2 can include, for example, an SDAP layer, a PDCP layer, an RLC layer, and a MAC layer with respect to FIGS. 2A, 2B, 3, and 4A. Layer 3 can include an RRC layer with respect to FIG. 2B.

[0194] After being processed by the processing system 1508, the data transmitted to the wireless device 1502 can be provided to the transmission processing system 1510 of the base station 1504. Similarly, after being processed by the processing system 1518, the data transmitted to the base station 1504 can be provided to the transmission processing system 1520 of the wireless device 1502. The transmission processing system 1510 and the transmission processing system 1520 can implement layer 1 OSI functions. Layer 1 can include a PHY layer with respect to FIGS. 2A, 2B, 3, and 4A. For transmission processing, the PHY layer can perform, for example, forward error correction coding of a transport channel, interleaving, rate matching, mapping of a transport channel to a physical channel, modulation of the physical channel, multiple-input multiple-output (MIMO) or multi-antenna processing, and / or the like.

[0195] At base station 1504, the reception processing system 1512 can receive uplink transmissions from wireless device 1502. At wireless device 1502, the reception processing system 1522 can receive downlink transmissions from base station 1504. The reception processing system 1512 and the reception processing system 1522 can implement the OSI functions of layer 1. Layer 1 can include the PHY layer with respect to FIGS. 2A, 2B, 3, and 4A. For reception processing, the PHY layer can perform, for example, error detection, forward error correction decoding, deinterleaving, demapping of transport channels to physical channels, demodulation of physical channels, MIMO or multi-antenna processing, and / or the like.

[0196] As shown in FIG. 15, wireless device 1502 and base station 1504 can include a plurality of antennas. The plurality of antennas can be used to implement one or more MIMO or multi-antenna technologies such as spatial multiplexing (e.g., single-user MIMO or multi-user MIMO), transmit / receive diversity, and / or beamforming. In other embodiments, wireless device 1502 and / or base station 1504 can have a single antenna.

[0197] 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) can store computer program instructions or code that can be executed by processing system 1508 and / or processing system 1518 to perform one or more of the functions discussed in this application. Although not shown in FIG. 15, transmission processing system 1510, transmission processing system 1520, reception processing system 1512, and / or reception processing system 1522 can be coupled to a memory (e.g., one or more non-transitory computer-readable media) that stores computer program instructions or code that can be executed to perform one or more of their respective functions.

[0198] Processing system 1508 and / or processing system 1518 may include one or more controllers and / or one or more processors. The one or more controllers and / or one or more processors may include, for example, general purpose processors, digital signal processors (DSPs), microcontrollers, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) and / or other programmable logic devices, discrete gates and / or transistor logic, discrete hardware components, on-board units, or any combination thereof. Processing system 1508 and / or processing system 1518 may perform at least one of signal encoding / processing, data processing, power control, input / output processing, and / or any other function that may enable wireless device 1502 and base station 1504 to operate in a wireless environment.

[0199] Processing system 1508 and / or processing system 1518 can each be connected to one or more peripheral devices 1516 and one or more peripheral devices 1526. The one or more peripheral devices 1516 and the one or more peripheral devices 1526 can include software and / or hardware that provide features and / or functions, such as speakers, microphones, keypads, display devices, touch pads, power supplies, satellite transceivers, universal serial bus (USB) ports, hands-free headsets, frequency modulation (FM) radio units, media players, Internet browsers, electronic control units (e.g., for vehicles), and / or one or more sensors (e.g., accelerometers, gyroscopes, temperature sensors, radar sensors, lidar sensors, ultrasonic sensors, optical sensors, cameras, and / or the like). Processing system 1508 and / or processing system 1518 can receive user input data from the one or more peripheral devices 1516 and / or the one or more peripheral devices 1526 and / or provide user output data. The processing system 1518 within the wireless device 1502 can receive power from a power source and / or be configured to distribute power to other components within the wireless device 1502. The power source can include one or more power sources, such as batteries, solar cells, fuel cells, or any combination thereof. Processing system 1508 and / or processing system 1518 can each be connected to a GPS chipset 1517 and a GPS chipset 1527. The GPS chipset 1517 and the GPS chipset 1527 can each be configured to provide geographical location information of the wireless device 1502 and the base station 1504.

[0200] FIG. 16A shows an exemplary structure for uplink transmission. The baseband signal representing the physical uplink shared channel can perform one or more functions. These one or more functions can include at least one of scrambling, modulation of scrambling bits to generate complex-valued symbols, mapping of the complex-valued modulated 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 to resource elements, generation of a complex-valued time-domain single-carrier frequency-division multiple access (SC-FDMA) or CP-OFDM signal to an antenna port, and / or the like. In one embodiment, when transform precoding is enabled, an SC-FDMA signal for uplink transmission can be generated. In one embodiment, when transform precoding is not enabled, a CP-OFDM signal for uplink transmission can be generated according to FIG. 16A. These functions are shown by way of example, and it is expected that other mechanisms can be implemented in various embodiments.

[0201] FIG. 16B shows an exemplary structure for modulation and upconversion of the baseband signal to a carrier frequency. The baseband signal can 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 can be used before transmission.

[0202] FIG. 16C shows an exemplary structure of downlink transmission. The baseband signal representing the physical downlink channel can perform one or more functions. These one or more functions include scrambling of the encoded bits in the 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 layer for transmission on the antenna port, mapping of the complex-valued modulation symbols of the antenna port onto resource elements, generation of the complex-valued time-domain OFDM signal for each antenna port, and / or the like. These functions are shown by way of example, and it is expected that other mechanisms can be implemented in various embodiments.

[0203] FIG. 16D shows another exemplary structure for modulation and upconversion of the baseband signal to the carrier frequency. The baseband signal can be a complex-valued OFDM baseband signal for the antenna port. Filtering can be used before transmission.

[0204] The wireless device can receive from the base station one or more messages (e.g., RRC messages) including configuration parameters of a plurality of cells (e.g., primary cell, secondary cell). The wireless device can communicate with at least one base station (e.g., two or more base stations in dual connectivity) via a plurality of cells. One or more messages (e.g., as part of the configuration parameters) may include parameters of the physical, MAC, RLC, PCDP, SDAP, RRC layers for configuring the wireless device. For example, the configuration parameters may include parameters for configuring physical layer and MAC layer channels, bearers, etc. For example, the configuration parameters may include parameters indicating the values of timers for the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, RRC layer, and / or communication channels.

[0205] When the timer is started, execution begins and can continue until stopped or until expiration. The timer can be started when not running or restarted when running. The timer may be associated with a value (e.g., the timer may start or resume from a certain value, or may start from zero and expire when the value is reached). The duration of the timer cannot be updated (e.g., by BWP switching) until the timer stops or expires. Timers can be used to measure the duration / 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 the multiple ways to implement a timer can be used to measure the duration / window of a procedure. For example, a random access response window timer can be used to measure the window time for receiving a random access response. In one embodiment, instead of starting and expiring a random access response window timer, the time difference between two timestamps can be used. When the timer is resumed, the process for measuring the time window can be resumed. Other exemplary implementations can be provided to resume the measurement of the time window.

[0206] Figure 17 shows an example of device - to - device (D2D) communication where there is direct communication between wireless devices. In one embodiment, D2D communication may be performed via a side - link (SL). Wireless devices can exchange side - link communication via a side - link interface (e.g., a PC5 interface). The side - link is different from the uplink (where a wireless device communicates with a base station) and the downlink (where a base station communicates with a wireless device). Wireless devices and base stations can exchange uplink and / or downlink communication via a user - plane interface (e.g., a Uu interface).

[0207] As shown in the figure, wireless device #1 and wireless device #2 can be within the coverage area of base station #1. For example, both wireless device #1 and wireless device #2 can communicate with base station #1 via the Uu interface. Wireless device #3 can be within the coverage area of base station #2. Base station #1 and base station #2 may share a network and jointly provide a network coverage area. Wireless device #4 and wireless device #5 can be outside the network coverage area.

[0208] In-coverage D2D communication may be performed when two wireless devices share a network coverage area. Both wireless device #1 and wireless device #2 are within the coverage area of base station #1. Therefore, they can perform in-coverage in-cell D2D communication labeled as sidelink A. Wireless device #2 and wireless device #3 are within the coverage areas of different base stations but share the same network coverage area. Therefore, they can perform in-coverage in-cell D2D communication labeled as sidelink B. Partial-coverage D2D communication can be performed when one wireless device is within the network coverage area and the other wireless device is outside the network coverage area. Wireless device #3 and wireless device #4 can perform partial-coverage D2D communication labeled as sidelink C. Out-of-coverage D2D communication can be performed when both wireless devices are outside the network coverage area. Wireless device #4 and wireless device #5 can perform out-of-coverage D2D communication labeled as sidelink D.

[0209] Side-link communication can be configured using physical channels, such as a Physical Side-link Broadcast Channel (PSBCH), a Physical Side-link Feedback Channel (PSFCH), a Physical Side-link Discovery Channel (PSDCH), a Physical Side-link Control Channel (PSCCH), and / or a Physical Side-link Shared Channel (PSSCH). The PSBCH can be used by a first wireless device to transmit broadcast information to a second wireless device. The PSBCH may be similar to the PBCH in some respects. The broadcast information may include, for example, slot format indication, resource pool information, side-link system frame number, or any other suitable broadcast information. The PSFCH can be used by a first wireless device to transmit feedback information to a second wireless device. The feedback information may include, for example, HARQ feedback information. The PSDCH can be used by a first wireless device to transmit discovery information to a second wireless device. The discovery information can be used by a wireless device to signal its presence and / or service availability to other wireless devices within its area. The PSCCH can be used by a first wireless device to transmit side-link control information (SCI) to a second wireless device. The PSCCH may be similar to the PDCCH and / or PUCCH in some respects. The control information may include, for example, time / frequency resource allocation information (RB size, number of retransmissions, etc.), demodulation-related information (DMRS, MCS, RV, etc.), identification information of the transmitting and / or receiving wireless device, process identifier (HARQ, etc.), or any other suitable control information. The PSCCH can be used to allocate, prioritize, and / or reserve side-link resources for side-link transmission. The PSSCH can be used by a first wireless device to transmit and / or relay data and / or network information to a second wireless device. The PSSCH may be similar to the PDSCH and / or PUSCH in some respects. Each of the side-link channels may be associated with one or more demodulation reference signals.The sidelink operation can establish the timing of the sidelink operation by using sidelink synchronization signals. A wireless device configured for sidelink operation may transmit sidelink synchronization signals, for example, by using PSBCH. The sidelink synchronization signals may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS).

[0210] The sidelink resources can be configured for the wireless device in any suitable manner. The wireless device may be preconfigured for sidelink, for example, it may be preconfigured with sidelink resource information. Additionally or alternatively, the network may broadcast system information related to a resource pool for sidelink. Additionally or alternatively, the network may configure a specific wireless device with a dedicated sidelink configuration. The configuration may identify sidelink resources used for sidelink operation (for example, configuring a combination of sidelink bands).

[0211] The wireless device may operate in different modes, for example, a support mode (which may be called mode 1) or an autonomous mode (which may be called mode 2). The mode selection may be based on the coverage status of the wireless device, the radio resource control status of the wireless device, information and / or commands from the network, and / or any other suitable factors. For example, if the wireless device is idle or inactive, or if the wireless device is outside the network coverage area, the wireless device may select to operate in the autonomous mode. For example, if the wireless device is in a connected mode (for example, connected to a base station), the wireless device may select to operate in the support mode (or be instructed to operate by the base station). For example, the network (for example, the base station) may instruct a connected wireless device to operate in a specific mode.

[0212] In the support mode, a wireless device may request scheduling from the network. For example, the wireless device may send a scheduling request to the network, and the network may allocate sidelink resources to the wireless device. The support mode may be referred to as a network support mode, a gNB support mode, or a base station support mode. In the autonomous mode, the wireless device may select sidelink resources based on measurements within one or more resource pools (e.g., pre-configured or network-allocated resource pools), and the sidelink resource selection may be made by other wireless devices and / or the use of sidelink resources by other wireless devices may be selected.

[0213] To select sidelink resources, the wireless device may observe a sensing window and a selection window. During the sensing window, the wireless device may use the sidelink resource pool to observe the SCI transmitted by other wireless devices. The SCI may identify resources that may be used and / or reserved for sidelink transmissions. Based on the resources identified by the SCI, the wireless device may select resources within the selection window (e.g., resources different from the resources identified by the SCI). The wireless device may transmit using the selected sidelink resources.

[0214] FIG. 18 shows an example of a resource pool for sidelink operation. A wireless device may operate using one or more sidelink cells. A sidelink cell may include one or more resource pools. Each resource pool may be configured to operate according to a specific mode (e.g., assisted or autonomous). The resource pool may be divided into resource units. In the frequency domain, each resource unit may include one or more resource blocks, which may be referred to as subchannels, for example. In the time domain, each resource unit may include, for example, one or more slots, one or more subframes, and / or one or more OFDM symbols. The resource pool may be continuous or discontinuous in the frequency domain and / or the time domain (e.g., including continuous resource units or discontinuous resource units). The resource pool may be divided into repeating resource pool portions. The resource pool may be shared among one or more wireless devices. Each wireless device may attempt to transmit using different resource units, for example, to avoid collisions.

[0215] The sidelink resource pool may be arranged in any suitable manner. In the figure, an exemplary resource pool is discontinuous in the time domain and limited to a single sidelink BWP. In an example of a resource pool, the frequency resources are divided into Nf resource units per unit time and numbered from zero to Nf - 1. An exemplary resource pool may include a plurality of portions (discontinuous in this example) that are repeated every k units of time. In this figure, the time resources are numbered n, n + 1,..., n + k, n + k + 1,....

[0216] A wireless device may select one or more resource units from a resource pool for transmission. In an exemplary resource pool, the wireless device selects a resource unit (n,0) for sidelink transmission. The wireless device may further select periodic resource units in a later portion of the resource pool, such as resource unit (n + k,0), resource unit (n + 2k,0), resource unit (n + 3k,0), etc. The selection may be based on a determination, for example, that communication using resource unit (n,0) does not (or is unlikely to) collide with sidelink transmissions of wireless devices sharing the sidelink resource pool. The determination may be based on, for example, the behavior of other wireless devices sharing the resource pool. For example, if no sidelink transmission is detected at resource unit (n - k,0), the wireless device may select resource unit (n,0), resource (n + k,0), etc. For example, if a sidelink transmission from another wireless device is detected at resource unit (n - k,1), the wireless device may avoid selecting resource unit (n,1), resource (n + k,1), etc.

[0217] For different sidelink physical channels, different resource pools may be used. For example, PSCCH may use the first resource pool, and PSSCH may use the second resource pool. Different resource priorities may be associated with different resource pools. For example, data associated with the first QoS, service, priority, and / or other characteristics may use the first resource pool, and data associated with the second QoS, service, priority, and / or other characteristics may use the second resource pool. For example, the network (e.g., base station) may configure the priority level of each resource pool, the services supported for each resource pool, etc. For example, the network (e.g., base station) may configure the first resource pool for use by unicast UEs, the second resource pool for use by groupcast UEs, etc. For example, the network (e.g., base station) may configure the first resource pool for transmitting sidelink data, the second resource pool for transmitting discovery messages, etc.

[0218] In the existing technology, a wireless device may be composed of a first reservation period in milliseconds indicated by the upper layer or another wireless device. The first reservation period may need to be converted into a logical unit capable of performing sidelink operations. In a cellular network, some wireless resources may be allocated for cellular Uu operations. For example, in a TDD configuration, multiple time resources may be allocated for downlink operations. A wireless device may determine a second reservation period based on the TDD configuration and the number of uplink unit resources (e.g., subframes or slots) within the first reservation period. For example, if the TDD configuration includes 6 uplink subframes every 10 subframes, the wireless device may obtain a second reservation period of 60 subframes based on the first reservation period of 100 milliseconds and the number of uplink unit resources in the TDD configuration.

[0219] If not all of the uplink resources are configured for sidelink resources, the existing technology cannot be accurate. For example, if 50% of the UL resources are configured for SL resources with the same TDD configuration, the first reservation of 100 milliseconds can be converted into a second reservation period of 120 subframes. The second reservation period of 120 subframes may extend to 200 milliseconds, which is a double delay.

[0220] When the TDD configuration period is not fixed, the existing technology can determine an inaccurate second reservation period. The existing technology can determine the second reservation period based on the number of uplink unit resources (e.g., slots) in the TDD configuration. For example, the first TDD configuration has a 10-millisecond periodicity, and in the first TDD configuration, the number of uplink slots is 5. The second TDD configuration has a 0.5-millisecond periodicity, and the number of uplink slots in the second TDD configuration is 1. The second TDD configuration may have 20 uplink slots with a 10-millisecond periodicity, but the existing technology can determine the second reservation period based on the number of uplink slots within the second TDD configuration.

[0221] Exemplary embodiments of the present disclosure define a method for determining a second reservation period in units of basic time resources (e.g., slots) based on a resource pool configuration and / or a TDD (or slot format) configuration. In an exemplary embodiment, a wireless device can determine the second reservation period in slot units based on the first reservation period and the number of sidelink slots within a fixed period. The number of sidelink slots can be determined using a resource pool configuration. The number of sidelink slots can be determined using a slot format configuration. For example, a resource pool configuration can indicate a resource pool bitmap. One of the bitmaps can indicate the position of the sidelink slots. The wireless device can count the number of sidelink slots within a fixed period. Exemplary embodiments can result in an accurate determination of the second reservation period in slot units when some uplink resources are not configured for sidelink resources.

[0222] In an exemplary embodiment, the wireless device may determine a second reservation period in slot units based on the number of sidelink slots within a first reservation period and a fixed period. The number of sidelink slots may be determined using a slot format configuration. For example, the slot format configuration may indicate the number of sidelink slots. For example, sidelink resources may be allocated to uplink slots within the slot format configuration. The exemplary embodiment may result in an accurate determination of the second reservation period in slot units when some uplink resources are not configured for sidelink resources.

[0223] In an exemplary embodiment, the wireless device may determine the number of sidelink slots within a fixed period. The fixed number of sidelink slot periods may be based on a TDD configuration. For example, assuming there are two different TDD configuration periodicities, when the wireless device determines a second reservation period based on the number of sidelink slots within a fixed period that is generally used for the two different TDD configuration periodicities, the wireless device may determine an accurate second reservation periodicity even with different TDD configurations. The fixed duration may be 20 milliseconds regardless of the TDD configuration.

[0224] Based on the exemplary embodiments of the present disclosure, the wireless device may determine a second reservation period for a resource pool configuration, a slot format configuration, and a numerology without additional delay.

[0225] In an existing system, the sidelink resource pool is configured only as part of the uplink resources. In one embodiment, in an FDD cell, the sidelink resource pool may be configured with an uplink band, and in a TDD cell, the sidelink resources may be configured with uplink subframes. The sidelink resource pool may be configured for one or more UL resources from the available UL resources, and the one or more UL resources may be a subset of the available UL resources. For example, a part of the available UL resources may be configured for the sidelink resource pool, and the remaining part of the available UL resources may be used for Uu operations (e.g., communication between a base station and a wireless device, uplink control information transmission, or UL shared channel transmission).

[0226] In an existing sidelink operation, a first reservation period indicated in units of milliseconds (ms) by a higher layer or by another wireless device via a sidelink control channel can be converted into a second reservation period in units of subframes (or a basic time resource unit, e.g., a slot or a subframe) by multiplying the first reservation period by an expansion / contraction rate. The expansion / contraction rate can be a one-to-one association with a TDD configuration. FIG. 19A shows a TDD configuration, and FIG. 19B shows a table for determining Pstep. Divide Pstep by 100 to derive the expansion / contraction rate, and multiply the first reservation period indicated in ms by this expansion / contraction rate to obtain the second reservation period in subframe units. This method can be to convert an absolute time period into a logical unit where the actual sidelink operation is performed. A transmitter wireless device can indicate a resource reservation period via a sidelink control channel or sidelink control information. The resource reservation period may be indicated in milliseconds, and a receiver wireless device that receives the sidelink control channel or sidelink control information can convert the first reservation period into a second reservation period in subframe units.

[0227] In the existing sidelink operation, in a TDD cell, since sidelink resources may not exist for each time resource (e.g., subframe), excessive delay may occur in the resource reservation operation where some future resources are reserved for transmitting another transport block. To reduce the excessive delay, an expansion / contraction value for the reservation period is introduced according to the TDD configuration. For example, as shown in FIGS. 20A and 20B, different expansion / contraction values may be used according to the TDD configuration. In one embodiment, in TDD configuration 0, there are six time resources (e.g., subframes) within a radio frame (e.g., 10 milliseconds). This means that a resource 100 milliseconds later in milliseconds represents a resource that appears after 60 subframes. Therefore, even if a future resource is indicated as 100 milliseconds, this means that the actual transmission occurs after 60 UL subframes. However, this solution cannot solve the problem of excessive delay when not all UL subframes are configured for sidelink subframes. For example, as shown in FIG. 21, assuming that only 50% of the UL subframes are configured as SL resources in TDD configuration 0, the existing method of using different expansion / contraction values according to the TDD configuration causes double delay. In this figure, the radio device may indicate a reservation period of 50 milliseconds, but since only 50% of the resources are configured for sidelink resources, the actual delay may be 100 milliseconds.

[0228] Furthermore, the method of converting the reservation period into logical units may not be applicable when the subcarrier spacing is changed. For example, at a subcarrier spacing of 30 kHz, one logical unit (subframe or slot) decreases to 0.5 milliseconds instead of 1 millisecond. If the reservation period value is directly converted into the same number of logical units, there may be a reservation occurring at an unexpected time for the wireless device, or the reservation may be too early. Figures 22A and 22B show different behaviors for different subcarrier spacings. In the case of 15 kHz, a 10-slot reservation is equal to a 10-millisecond reservation shown in Figure 22A, but in the case of 30 kHz, a 10-slot reservation decreases to 5 milliseconds shown in Figure 22B. Therefore, the existing method may not have accurate resource reservation behavior when the SCS is changed.

[0229] Furthermore, when the TDD configuration or resource pool is dynamically changed in the existing sidelink operation, the method of determining the reservation period based only on the TDD configuration may cause inaccurate resource reservation behavior. For example, in a TDD cell, when the base station dynamically changes the TDD configuration, the existing technology may result in inaccurate resource reservation behavior.

[0230] In existing technologies for sidelink operations, a wireless device may utilize a resource reservation function, and the wireless device may reserve one or more periodic resources based on a reservation period. Resource reservation can be beneficial for sidelink applications such as cooperative awareness enhancement messages. Regarding resource reservation, the wireless device may receive a reservation period from its application layer or upper layer, and the reservation period may be indicated in units of time (e.g., milliseconds, seconds). Based on the reservation period in units of time, the wireless device needs to derive a resource reservation period, and the resource reservation period may be based on time domain units of physical resources (e.g., subframes and / or slots and / or frames and / or X slots and / or X OFDM symbols). In existing technologies, a unit of time (e.g., 1 millisecond) is mapped to a unit of time domain of a physical resource (e.g., a subframe). Since sidelink resources can be configured in one or more uplink subframes, existing technologies can derive a resource reservation period based on TDD configuration and mapping. For example, the TDD configuration includes 6 uplink subframes every 10 subframes, and 60 expansion / contraction rates are used in 100 milliseconds. A reservation period of 100 milliseconds can be derived into 60 resource reservation periods.

[0231] Existing mechanisms may, in some cases, have drawbacks. For example, when a resource pool includes sidelink resources with a large gap (e.g., >2 milliseconds) between two consecutive sidelink resources, existing operations may cause excessive delay. For example, existing operations may not effectively operate with one or more subcarrier spacings, and a slot (e.g., the basic time unit of a physical resource) may not correspond to a unit of time (e.g., 1 millisecond). For example, existing operations may not be able to handle the case when uplink resources are dynamically adapted (e.g., via slot format) or when the resource pool configuration is changed. Considering various numerologies and dynamic resource adaptation mechanisms, enhancement of existing technologies is required.

[0232] Embodiments of the present disclosure define a method of converting a first reservation period in milliseconds into a second reservation period in units of a basic time unit (e.g., a slot or a subframe) based on subcarrier spacing and / or resource pool configuration and / or TDD (or slot formation) configuration and / or base station indication parameters.

[0233] Embodiments of the present disclosure do not cause excessive delay by adaptively adjusting the reservation period even when there is a change in the TDD configuration or slot format or resource pool or numerology. Further, accurate resource reservation can be performed even when the resource pool, TDD configuration, or slot format configuration is changed.

[0234] In some aspects of the embodiments, the slot format configuration or TDD configuration or TDD The UL-DL or DL-UL configuration may refer to configuration signaling for configuring a downlink, an uplink, and / or a flexible slot within a specific time interval. The slot format or TDD configuration or TDD UL-DL configuration may be one or more control signaling that configures which slots and / or symbols are used for the downlink, uplink, and are flexible within a specific time interval. The base station may configure the slot format configuration or TDD configuration for the wireless device via the physical layer (e.g., DCI) or a higher layer signal (e.g., SIB or RRC). For external coverage, the slot format or TDD configuration may be preconfigured or stored in the memory of the wireless device.

[0235] In an exemplary embodiment, the wireless device may receive a sidelink subcarrier spacing (SCS) and / or a sidelink resource pool configuration and / or a slot format configuration from the base station as a physical layer (e.g., DCI) or a higher layer signal (e.g., MAC CE or SIB or RRC). For external coverage, the sidelink SCS, the sidelink resource pool configuration, and / or the slot format configuration may be preconfigured for the wireless device or may be configured from another wireless device via a physical sidelink broadcast channel (PSBCH) that can convey some system information for sidelink operation. The wireless device may be indicated in milliseconds by a first reservation period. The wireless device may determine a second reservation period based on the sidelink SCS, the sidelink resource pool configuration, and / or the sidelink slot format configuration. For example, the wireless device may convert a first reservation period indicated in milliseconds based on the sidelink SCS, the sidelink resource pool configuration, and / or the sidelink slot format configuration into a second reservation in slot units. After the conversion, the wireless device may select one or more transmission resources based on the second reservation period. The wireless device can transmit a transport block via the selected one or more resources. FIG. 23 shows a flowchart of this embodiment.

[0236] In one embodiment, when a wireless device performs resource reservation, the wireless device may be configured in units or milliseconds for a first reservation period from the upper layer. Next, the wireless device may determine a second reservation period in slot units based on the first reservation period, the sidelink SCS, and the resource pool configuration. Specifically, the wireless device may receive the configuration of the sidelink SCS for the sidelink bandwidth part (BWP) from the base station as a physical layer (e.g., DCI) or an upper layer signal (e.g., RRC or SIB), or the sidelink SCS may be configured by another wireless device, or pre-configured parameters stored in the USIM or memory of the wireless device. The sidelink SCS can be configured as part of the sidelink BWP configuration. Depending on the sidelink SCS, the time interval of one slot can be changed. For example, the length of the time interval of one slot is 1 millisecond for an SCS of 15 kHz, 0.5 millisecond for an SCS of 30 kHz, 0.25 millisecond for 60 kHz, and 0.125 millisecond for 120 kHz. Each SCS can be expressed as 15kHz*2 u and may be represented as such, where u can be an integer determined to correspond to the sidelink SCS. The wireless device may determine a part of the valid sidelink slots during the period of the configured resource pool, where the period may be pre-set or configured by the base station or may be fixed. A part of the valid sidelink slots can be defined by the number obtained by dividing the number of sidelink slots (denoted by N) by the total number of slots (e.g., 20*2 u , where u is determined by the SCS).

[0237] For example, the period for determining a part of the valid sidelink slots can be the same as the slot configuration period configured by the base station, such as "dl-UL-TransmissionPeriodicity", or can be fixed as a number, such as 20 milliseconds. The wireless device can use the number of sidelink slots configured in the resource pool configuration during a fixed time, i.e., 20 milliseconds, to determine a part of the valid sidelink slots. The fixed period can be independent of the TDD configuration periodicity or dl-UL-TransmissionPeriodicity. The total number of 20-millisecond slots can be used to determine a second reservation period. A part of the valid sidelink slots is the number of valid sidelink slots divided by the total number of slots. The second reservation period can be converted to the number of sidelink slots by multiplying the first reservation period in milliseconds by 2 u . When the part of the sidelink slots within a specific time interval is not 100%, the first reservation for deriving the second reservation period may be expanded or reduced by that portion R, where R represents the portion of the valid sidelink slots within a predetermined time interval or a configurable time interval. As a result, the second reservation period may be determined as the product of 2 u and R, expressed by the formula, P second-reservation-period = P first-reservation-period * 2 u * R. Here, P first-reservation-period is the first reservation period, and P second-reservation-period means the second reservation period. Since R = N / (20 * 2 u ), the formula can be rewritten as P second-reservation-period = P first-reservation-period * 2 u * R = P first-reservation-perio d * N / 20.

[0238] In some embodiments of the embodiment, the first reservation period indicated in milliseconds can be adaptively converted to the number of logical slots according to the sidelink SCS or resource pool configuration without unnecessary delay or inaccurate resource reservation. Further, even while the wireless device is transmitting and receiving, the reservation period in milliseconds indicated by the upper layer can send signals to each other, and the conversion operation may be effectively performed within the slot domain. Therefore, the information bits in the control channel can be consistently designed regardless of the resource pool configuration and / or sidelink SCS configuration.

[0239] In an exemplary embodiment, the wireless device may receive a slot format configuration and / or sidelink SCS from a base station, or the slot format configuration and / or sidelink SCS configuration may be preconfigured. The sidelink SCS may be part of the sidelink bandwidth part configuration. The wireless device may convert the first reservation period indicated in milliseconds to a second reservation period in slots based on the slot format configuration and SCS. The first reservation period may be configured from the upper layer or may be indicated by another wireless device via a control signal, such as PSCCH, or control information, such as SCI. The sidelink resource pool may be limitedly configured only with UL resources of the slot format configuration. By using this, the second reservation period can be determined using a part of the UL resources of the slot format. For example, if a part of the UL resources in the slot formation configuration is 50%, the second reservation period is 0.5 times the first reservation period and 2, which is a factor related to SCS u can be determined by multiplying. This can be represented by the following formula.

[0240] P second-reservation-period =P first-reservation-period *2 u * Part of the UL slot and / or UL symbol of the slot format configuration, where the slot format configuration can be assumed to be configured in the second unit.

[0241] The number of sidelink slots within a fixed period is determined by the resource pool configuration and the slot format configuration. The first resource set in the slot format configuration may be indicated as a UL slot or symbol. The second resource set among the first resource sets is configured by the sidelink resource pool. The sidelink resource pool bitmap may be applied to the UL slot or symbol. If the number of UL symbols in a slot is greater than the lower limit, the slot can be configured for valid sidelink slots.

[0242] For example, a part of the UL resources may be determined by parameters such as nrofUplinkSlots and / or nrofUplinkSymbols that send signals at a higher layer (e.g., RRC or SIB or DCI). nrofUplinkSlots and / or nrofUplinkSymbols are part of the slot format configuration or TDD configuration, can be configured by resources, and can be determined by a part of the UL resources during the slot configuration period. In one embodiment, the part of the UL resources is derived by ((nrofUplinkSlots * 1ms (= 0.001) / 2 u + nrofUplinkSymbols * 1ms / 2 u / 14) / (slot configuration period)) or ((nrofUplinkSlots * 1ms / 2^u) / (slot configuration period)). The latter is an example where slots in which only some symbols are configured as UL of the slot are not counted as part of the UL resources. If the sidelink slot is part of the slot format configuration, or if the sidelink slot is directly indicated or preconfigured by the base station, or if the sidelink slot is set independently of UL and DL and is flexible, a part of the SL slot rather than a part of the UL slot can be used to determine the second reservation period. For example, if the number of SL slots within the slot configuration period (which can be indicated by the base station or preconfiguration) is N and the SCS is indicated by u, a part of the sidelink resources can be determined as follows. A part of the SL resources = N * 1ms / 2u / Slot configuration period.

[0243] On the other hand, a situation where the TDD or slot format configuration is changed within a cell can be considered. At high carrier frequencies, the size of the cell can be reduced due to the large optical path loss at high carrier frequencies, and the ratio of DL and UL traffic can vary significantly because the number of wireless devices within the cell is small. If the TDD or slot format configuration is maintained in a specific configuration, waste of unnecessary resources or an increase in delay may occur. Therefore, adaptively changing the TDD configuration or slot format configuration can be a way to reduce resource efficiency and packet delay. When the TDD or slot format configuration is dynamically changed, the sidelink resource pool configuration and resource reservation operations can also be changed. For example, when the TDD or slot format configuration is changed, the sidelink resource pool bitmap mapping on the TDD configuration can also be changed. When the TDD or slot format configuration or the sidelink resource pool configuration is changed, the method of determining a part of the sidelink or uplink resources presented in some embodiments becomes unclear. For example, when the first slot format configuration is configured, the resource reservation period is indicated by the first wireless device, but the second slot format configuration is received before the specified reservation period elapses. It becomes unclear whether the slot format configuration for calculating a part of the sidelink or UL resources is the first slot format or the second slot format. The following embodiments and examples can solve this problem.

[0244] In an embodiment, the base station may configure the sidelink SCS to the wireless device via a reference slot format configuration or a TDD configuration (e.g., tdd-UL-DL-configuration), and / or a physical layer signal (e.g., DCI), or a higher layer signal (e.g., SIB or RRC). The reference slot format configuration or the TDD configuration may not be the same as the actual slot format configuration. The wireless device may determine a part of the uplink or sidelink resources based on the reference tdd-UL-DL-configuration and / or the sidelink SCS. The wireless device may convert a first reservation period indicated in milliseconds into a second reservation in slot units based on a part of the uplink or sidelink resources that can be determined based on the sidelink SCS and / or the reference slot format configuration. In one example, when the wireless device performs resource reservation, the wireless device may be configured in units or milliseconds for the first reservation period from the higher layer. Next, the wireless device may convert the first reservation period into a second reservation period in slot units based on the sidelink SCS and / or the reference slot format configuration. This can be represented by the following equation, P second-reservation-period =P first-reservation-period *2 u *Part of the UL slot and / or UL symbol of the reference slot format configuration. In this example, even when the actual TDD or slot format configuration is changed, a part of the sidelink or uplink resources is assumed to be constant from an average perspective. Regardless of the actual TDD or slot format configuration, the first reservation period (in milliseconds) is converted into the second reservation period (in slot units) using only the reference TDD or slot format configuration.

[0245] In one embodiment, the base station may configure the scaling value and / or the sidelink SCS for the wireless device via a physical layer signal (e.g., DCI) or a higher layer signal (e.g., SIB or RRC) to convert a first reservation period in milliseconds into a second reservation period in slots. The scaling value can be configured for each resource pool, each BWP, each carrier, or each UE. The wireless device may convert the first reservation period into the second reservation period based on the scaling value and / or the sidelink SCS. Here, the scaling value may be a value corresponding to a part of the UL resource or the sidelink resource from the average sense of the slot format or the TDD configuration. In this embodiment, as another alternative to the method of configuring the reference TDD configuration described above in some embodiments, the base station may indicate / configure a scaling value (or the ratio of the effective UL resource or the sidelink resource) for directly converting the reservation period for the wireless device. Regarding the external network coverage, the scaling value may be pre-configured or fixed. In one embodiment, the base station may configure the sidelink resource pool configuration, or the sidelink resource pool configuration may be pre-configured (for external coverage) for the wireless device, and a scaling value table may be defined based on the sidelink resource pool configuration. Based on the resource pool configuration, the wireless device may determine the scaling value based on the scaling value table. For example, a part of the sidelink resources configured within a 10 millisecond (or X millisecond) resource pool, the scaling value table, where for 20% of the part of the sidelink resources, the scaling value is 20, for 20 - 40 of the part of the sidelink resources, the scaling value is 30, for 40 - 60 of the part of the sidelink resources, the scaling value is 50, for 60 - 80 of the part of the sidelink resources, the scaling value is 70, etc. Finer or coarser granularity may be considered. FIG. 24 shows a table for this embodiment. This embodiment may avoid the signaling overhead for explicit signaling of the scaling value.

[0246] In one embodiment, the base station may configure a first scaling value and / or a sidelink SCS for the wireless device via a physical layer signal (e.g., DCI) or a higher layer signal (e.g., SIB or RRC) to convert a first reservation period in milliseconds into a second reservation period in slots. The first scaling value may be configured per resource pool, per BWP, per carrier, or per UE. The wireless device may calculate a second scaling value as the first scaling value * (the number of available UL slots in X milliseconds, or the number of sidelink slots in X milliseconds), where X may be pre-specified or configured by the base station. Assuming that the resource pool is only applied to semi-static UL, the resource pool may constitute the "spareness" of the resource pool, and the actual UL availability may be defined based on the actual slot format configuration.

[0247] In one embodiment, the wireless device may have different reservation period conversion behaviors according to the value of the first reservation period. For example, when the first reservation period is less than a threshold (e.g., 100 milliseconds), the first reservation period in milliseconds indicated by a higher layer or another wireless device may be converted into a second reservation period based only on the SCS. However, when the first reservation period is greater than the threshold, the first reservation period may be converted into a second reservation period based on the SCS and the slot format or the resource pool configuration. As a specific example, when the first reservation period is 100 milliseconds or less, the second reservation period is determined by multiplying the reservation period by 2 u only. When the first reservation period is 100 milliseconds or more, the wireless device may determine the second reservation period in slots by multiplexing the first reservation period with 2 u and a part of the UL or sidelink resources.

[0248] In an embodiment, the wireless device may perform a reservation operation for resources and slots after a first reservation period in milliseconds. If the slot is not a sidelink slot after the first reservation period, the wireless device may perform an actual transmission in the first sidelink slot that appears first in the slot after the first reservation period.

[0249] On the other hand, in some embodiments or examples, when the second reservation period is a non-integer value, a rule of using a value converted to an integer by applying a floor function or a ceiling function may be used. For example, the wireless device may determine the second reservation period as the ceiling function of the value obtained by multiplying 2^u and the first reservation period by a part of the uplink or sidelink resources. This is because the second reservation period must be an integer.

[0250] The sidelink resource pool is composed of only static UL resources and can minimize the variability of UL and DL resources. For example, the wireless device may receive a tdd-UL-DL-ConfigurationCommon signal from the base station. The tdd-UL-DL-ConfigurationCommon provides the following. - Reference SCS configuration μ by referenceSubcarrierSpacing ref - Pattern 1 Pattern 1 provides the following. - Slot configuration period of P milliseconds by dl-UL-TransmissionPeriodicity - Number of slots d containing only downlink symbols by nrofDownlinkSlots slots of - Number of downlink symbols d by nrofDownlinkSymbols sym of - Number of slots u containing only uplink symbols by nrofUplinkSlots slots of - Number of uplink symbols u by nrofUplinkSymbols symNumber

[0251] The value P = 0.625 milliseconds is only valid for μ ref = 3. The value P = 1.25 milliseconds is for μ ref = 2 or μ ref = 3 only. The value P = 2.5 milliseconds is for μ ref = 1, or μ ref = 2, or μ ref = 3 only. During the P - millisecond slot configuration period, the SCS configuration μ ref has S = P·2 μref slots included. From the S slots, the first d slots slot contains only downlink symbols, and the last u slots slot contains only uplink symbols. The d slots symbols after the first d sym slot are downlink symbols. The u slots symbols before the last u sym slot are uplink symbols. The remaining

Number

[0252] If tdd - UL - DL - ConfigurationCommon provides both pattern 1 and pattern 2, the wireless device sets the slot - per - slot format across the first number of slots as indicated by pattern 1, and the wireless device sets the slot - per - slot format across the second number of slots as indicated by pattern 2. Pattern 2 provides the following. - P in milliseconds for the slot configuration period by dl - UL - TransmissionPeriodicity 2 - The number d of slots containing only downlink symbols by nrofDownlinkSlots slots,2 Number ​- The number of downlink symbols d by nrofDownlinkSymbols sym of - The number of slots μ that contain only uplink symbols by nrofUplinkSlots slots,2 of - The number of uplink symbols μ by nrofUplinkSymbols sym,2 of

[0253] P 2 The applicable values of are the same as the applicable values of P. P + P 2 The slot configuration period of milliseconds is the first S = P · 2 μref slots and the second S 2 = P 2 · 2 μref including slots. S 2 From the S slots, the first d slots,2 slot contains only downlink symbols, and the last u slots,2 contains only uplink symbols. The first d slots,2 symbols after the slot are downlink symbols. The last u sym,2 symbols before the slot are uplink symbols. The remaining slots,2 u symbols before the last u sym,2 symbol are flexible symbols. The radio device expects P + P

Number

[0254] As a method of configuring a sidelink resource pool, it is possible to configure sidelink resources only within UL slots and / or UL symbols of a slot format, or to consider a TDD configuration such as tdd-UL-DL-ConfigurationCommon. In this operation, the base station may configure a sidelink resource pool bitmap for the radio device via the physical layer (e.g., DCI) or a higher layer signal (e.g., SIB, RRC), and the size of the sidelink resource pool bitmap may be equal to the number of uplink slots or the number of uplink slots + 1 of tdd-UL-DL-ConfigurationCommon. The former (sidelink resource pool bitmap size = # of UL slots in tdd-UL-DL-ConfigurationCommon) assumes that partial UL slots are not allocated as sidelink resources, and the latter (sidelink resource pool bitmap size = # of UL slots in tdd-UL-DL-ConfigurationCommon + 1) assumes that the sidelink resource pool bitmap can be allocated to partial UL slots. When the base station configures pattern 1 and pattern 2 with tdd-UL-DL-ConfigurationCommon, two sidelink resource pool bitmaps may be (pre-)configured, where the first bitmap may be for the UL resources of pattern 1 and the second bitmap may be for the UL resources of pattern 2. Although pattern 1 and pattern 2 are configured in a slot format configuration, if there is only one bitmap for the sidelink resource pool configuration, the radio device may recognize which of pattern 1 or pattern 2 the corresponding bitmap is according to the bitmap size. However, if the UL resource size of pattern 1 is the same as the UL resource size of pattern 2, the radio device may obscure which pattern the sidelink resource pool bitmap applies to. Therefore, when only one sidelink resource pool bitmap is configured, it may be assumed to apply to pattern 1.Alternatively, the sidelink resource pool bitmap is applied to Pattern 1 and Pattern 2 in sequence. If the number of UL resources in Pattern 1 does not match the size of the sidelink resource pool bitmap, repetition (the size of the sidelink resource pool bitmap may be smaller than the number of UL resources) or truncation (the size of the sidelink resource pool bitmap is larger than the UL resources) can be considered. Further, the sidelink resource pool bitmap may have the same periodic slot format or TDD configuration. For example, the periodicity of the sidelink resource pool bitmap may be the same as the slot configuration period of tdd-UL-DL-ConfigurationCommon. When Pattern 1 and Pattern 2 are configured in tdd-UL-DL-ConfigurationCommon, the sidelink resource pool configuration may have two bitmaps and two periodicities. This method is to configure the sidelink resource pool only with UL resources common to wireless devices, prevent the sidelink resource pool from changing dynamically, and align the sidelink resource pools among wireless devices.

[0255] In an embodiment, the wireless device may determine that only slots having the number of symbols (i.e., the lower limit) or more that constitute a slot are valid sidelink slots. In this case, the lower limit of the number of symbols constituting a slot may be determined in advance, or the base station may configure the lower limit for the wireless device via the physical layer (e.g., DCI) or a higher layer signal (e.g., SIB or RRC). For example, the lower limit may be determined by adding the minimum number of symbols constituting the PSCCH / PSSCH (control and data channels) and / or the minimum number of symbols constituting the PSFCH (feedback channel). For example, the number of symbols of the PSCCH / PSSCH may be 6. This is because when the number of symbols is less than a threshold, the DMRS configuration and / or the control channel data channel multiplexing option may not be defined. Further, a sidelink slot configured with less than a certain number of symbols may have a low coding rate and reduced reliability due to the absence of data transmission resource elements.

[0256] In the existing technology, after the wireless device selects a resource, the wireless device may maintain the resource semi-persistently. For example, the wireless device may maintain the selected resource having a reservation periodicity for an integer number of times. The integer number of times of maintaining the selected resource may be called a resource reselection counter. The counter value decreases by 1 for each transmission. When multiple wireless devices have the same counter value, a half-duplex problem may occur. For example, different wireless devices may accidentally start transmissions on the same time resource and continue transmissions on the same time resource. This may cause the wireless device to be unable to receive packets.

[0257] To solve this problem, in the existing technology, a counter value between 5 and 15 is selected. This range of counter values may be related to the CR measurement window size. Assume that the wireless device has an average value of 10 counters and the wireless device has a reservation period of 100 milliseconds. Then, the wireless device can maintain transmissions on average for about 1000 milliseconds. Therefore, when the CR measurement window size is 1000 milliseconds, the wireless device can accurately measure CR on average.

[0258] When the CR measurement window size is flexibly configured by the base station, the accuracy of CR measurement may be reduced, and / or an unnecessarily long resource reservation may be made. For example, if the base station configures a wireless device with a CR measurement window size of 250 milliseconds and the reservation period is 100 milliseconds, the wireless device can maintain transmissions for 1000 milliseconds on average.

[0259] Exemplary embodiments of the present disclosure define a method for determining a range of sidelink resource reselection counters for transmitting one or more transport blocks via a sidelink. In an exemplary embodiment, a wireless device may determine a range of sidelink resource reselection counters based on the CR measurement window size. For example, for a CR measurement window size of 1000 milliseconds, the wireless device may determine a range of sidelink resource reselection counters between 5 and 15. For a CR measurement window size of 200 milliseconds, the wireless device may determine a range of sidelink resource reselection counters between 1 and 3. The wireless device may decrease the sidelink resource reselection counter value when the CR measurement size is small. The wireless device may use the sidelink resource reselection counter to transmit one or more transport blocks via the sidelink based on the range. Based on the exemplary embodiment, the wireless device may obtain an accurate CR measurement value and avoid an unnecessarily long resource reservation.

[0260] In the existing technology, a wireless device selects a resource once with a semi-persistent resource selection operation and maintains it for a specific number of integer times. The number of times to maintain the selected resource or the integer value can be called a counter. The wireless device determines the counter value before reselecting a resource and can maintain the selected resource for the same number of times as the counter. The counter value is decremented by 1 for each transmission. If multiple wireless devices have the same counter value, there can be a half-duplex problem where different wireless devices accidentally start transmissions on the same time resource, continue transmissions on the same time resource, and cannot receive packets. To solve this problem, a conventional operation of selecting a counter value between 5 and 15 is introduced. This range of counter values can also be related to the sensing window size. Since the wireless device has an average value of 10 counters and it can be assumed that the wireless device has a reservation period of 100 milliseconds, the wireless device can maintain transmissions on average for about 1000 milliseconds. Therefore, when the size of the sensing window is 1000 milliseconds, the wireless device can monitor the interval during which transmissions are maintained on average so that the sensing accuracy can be improved. In NR side links, all or part of the SCS, the channel busy ratio (CBR) measurement window size, the sensing window size, the channel occupancy ratio (CR) measurement window size, the slot format, and the resource pool configuration can be (pre-)configured. For example, the CR window size can be set to 1000 milliseconds or 1000 slots by (pre-)configuration, and the CBR measurement time window size can be set to 100 milliseconds and 100 slots by (pre-)configuration. The sensing window size can be (pre-)configured between 1000 + 100 milliseconds and 100 milliseconds. Figure 25 shows the timing relationship between the sensing window and the selection. The sensing window size is denoted as T0 in this figure. In this case, if the counter value is randomly selected only between 5 and 15, the sensing accuracy, or the accuracy of CR and CBR measurements, can be reduced. For example, when the base station configures the sensing window size T0 to 1000 + 100 milliseconds, the SCS is 60 kHz, the reservation period is 100 milliseconds, and the wireless device maintains transmissions for an average of 250 milliseconds.This can cause an increase in the inaccuracy of the sensing results within a 1000 + 100 millisecond sensing window.

[0261] In an embodiment, the counter range can be determined based on at least one or more of SCS, reservation period, CBR measurement window, CR measurement window, sensing window, slot format (or TDD configuration), and resource pool configuration. A counter range scaling function can be introduced. For example, when the reservation period Prsvp is 100 milliseconds or less, the counter range is the floor function or ceiling function of 100 / Prsvp *

[0515] . For example, the counter range can be determined based on SCS. For example, for an SCS of 2u * 15 kHz, the counter range is scaled up as (u + 1) *

[0515] . The counter range can be determined such that the average number of counters * reservation period is greater than or equal to the CBR measurement window. The counter range can be determined based on the CR measurement window size. For example, for a 1000 - slot CR window and an SCS of 30 kHz, the counter range is

[1030] . For example, the counter range can be 5 - 15 when the CR measurement window size is 1000 milliseconds. For example, the counter range can be 3 - 8 when the CR measurement window size is 500 milliseconds. For example, the counter range can be 2 to 4 when the CR measurement window size is 250 milliseconds. For example, the counter range can be 1 - 2 when the CR measurement window size is 125 milliseconds.

[0262] In one example, the counter range of the sidelink resource reselection counter value can be determined based on SCS. For example, the counter range can be 5 - 15 when the SCS is 15 kHz.

[0263] In one embodiment, the counter range can be determined based on the sensing window size. For example, the counter range can be 5 to 15 when the sensing window size is 1000 milliseconds. For example, the counter range can be 3 to 8 when the sensing window size is 500 milliseconds. The counter range expansion / shrinkage value per reservation period can be (pre-)configured. For example, the counter range expansion / shrinkage value can be (pre-)configured to be inversely proportional to the reservation period. FIG. 26 shows an exemplary flowchart of this embodiment.

[0264] In the existing technology, a wireless device can drop reserved resources due to the display from high-priority packets. This operation can be called a preemption operation. For example, a first wireless device can reserve three resources. The sidelink control information on the first transmission resource can indicate two additional resources including the second transmission resource and the third transmission resource. When the preempting wireless device indicates a second transmission resource for preemption, the first wireless device can drop the second transmission resource and perform resource reselection.

[0265] The existing technology cannot consider previously selected resources for resource reselection. For example, any resource that overlaps with the previously selected third transmission resource within a time cannot be excluded from the candidate resources for resource reselection.

[0266] When the first wireless device selects any resource that overlaps with the third transmission resource within a time, the transmission power is divided, the in-band radiation increases, and the coverage can decrease.

[0267] Exemplary embodiments of the present disclosure determine a resource reselection procedure. In an exemplary embodiment, a wireless device may determine a transmission time resource reserved by the wireless device for transmitting a transport block via a sidelink. The wireless device may determine one or more first resources to be excluded from candidate resources for transmission of the transport block based on the transmission time resource. For example, the one or more first resources may be any resources that overlap in time with previously reserved resources. The wireless device may select a second resource for transmission from candidate resources other than the one or more first resources.

[0268] Based on the exemplary embodiment, the wireless device may avoid problems of power splitting, in-band radiation, and coverage reduction.

[0269] In one example, after a resource is reserved by a sensing operation, the wireless device may be considered to have an operation where it has to relinquish resource usage due to a high-priority packet. This operation may be referred to as a preemption operation. In FIG. 27, a first wireless device reserves three resources, and the first transmission indicates the positions of two additional resources via control signaling. However, if a preemption indication signal is received from a second wireless device having a high-priority packet after the first transmission and this preemption indication signal overlaps with the second transmission resource, the second transmission resource may be dropped and it is necessary to reselect the resource. Resources included in a time resource such as a third resource previously selected may be excluded from resource reselection. When a resource is selected with a time resource such as a third transmission resource, the transmission power may be split, the in-band radiation may increase, and the coverage may be reduced. To mitigate this problem, when reselecting a resource, the wireless device may exclude resources already selected for transmission and any resources that overlap with resources already selected within the time domain.

[0270] In an embodiment, the wireless device may identify transmission time resources reserved by the wireless device, and based on the identified transmission time resources, may determine a first resource to be excluded for selecting a second resource for sidelink transmission. The wireless device may select a second resource for sidelink transmission from resources other than the first resource, and may transmit a sidelink signal on the second resource. The wireless device may transmit transmission time resource information via a sidelink control channel. Resource (re)selection by the wireless device after identifying the transmission time resources. The resource (re)selection may be triggered by the arrival of a new packet or a preemption indication. The resource to be excluded may be any resource that overlaps with the transmission time resource within a time period. FIG. 28 shows an example of a flowchart of this embodiment.

[0271] In one example, the wireless device may receive from the base station one or more messages including a sidelink SCS, a slot formation configuration, and a sidelink resource pool configuration. The wireless device may convert a first reservation period in milliseconds into a second reservation period in slots based on the sidelink SCS, the slot format configuration, and / or the sidelink resource pool configuration, and based on the second reservation period, may select one or more transmission resources, and may transmit a transport block via the selected one or more resources. In this example, the first reservation period may be given by the upper layer in milliseconds, the 15 kHz SCS corresponds to μ = 0, μ = 1 at 30 kHz, μ = 2 at 60 kHz, μ = 4 at 120 kHz, μ = 8 at 240 kHz, etc. The wireless device may determine a part of the available sidelink resources within a period based on the slot format configuration and / or the sidelink resource pool configuration, where the period is preset or configured by the base station. The second reservation period can be obtained by multiplying 2 μ and in part by the first reservation period.

[0272] In one embodiment, the first wireless device may receive, from a base station, one or more messages including a sidelink subcarrier spacing (SCS), a slot format configuration, and / or a sidelink resource pool configuration. The first wireless device may receive, from a second wireless device, a PSCCH including a first reservation period in milliseconds and one or more frequency resources within a sidelink resource pool. The first wireless device may determine a second reservation period in slots based on the first reservation period, the sidelink SCS, the slot format configuration, and / or the sidelink resource pool configuration, and may determine an exclusion resource based on the second reservation period and the one or more frequency resources. Next, the first wireless device may select one or more transmission resources based on the excluded resources and may transmit a transport block via the selected resources.

[0273] In one embodiment, a wireless device may receive, from a base station, one or more messages including a subcarrier spacing (SCS), a channel busy ratio (CBR) measurement window, a channel occupancy ratio (CR) measurement window, a sensing window, a slot format configuration, and a resource pool configuration. The wireless device may determine, based on at least one of the SCS, the CBR measurement window, the CR measurement window, the sensing window, the slot format, and the resource pool configuration, an integer value range for the number of resource reservations for one or more transport blocks via a sidelink. The wireless device may select a number of reservations within the integer value range and may select one or more frequency resources with the selected number of reservations. Next, the wireless device may transmit a sidelink transport block on the selected one or more frequency resources with the selected number of reservations.

[0274] In one embodiment, the wireless device may identify a transmission time resource reserved by the wireless device, and based on the identified transmission time resource, determine a first resource to be excluded for selecting a second resource for sidelink transmission. The wireless device may select a second resource for sidelink transmission from resources other than the first resource, and may transmit a sidelink signal on the second resource. The wireless device may transmit transmission time resource information via a sidelink control channel. After identifying the transmission time resource, the wireless device may trigger resource (re)selection. The resource (re)selection may be triggered by a new packet arrival indication or a preemption indication, and the resources to be excluded are any resources that overlap with the transmission time resource within a time period.

[0275] According to various embodiments, for example, devices such as wireless devices, off-network wireless devices, base stations, and / or the like can include one or more processors and a memory. The memory can store instructions that, when executed by one or more processors, cause the device to perform a series of actions. Exemplary embodiments of the actions are illustrated in the accompanying figures and specification. Further embodiments can be created by combining features from various embodiments.

[0276] FIG. 29 is a flowchart showing one aspect of an exemplary embodiment of the present disclosure. At 2910, the wireless device may determine a second reservation period in slot units based on a first reservation period in milliseconds and the number of sidelink slots within a fixed period. For example, the number of sidelink slots may be based on a resource pool configuration. At 2920, the wireless device may transmit a transport block via one or more transmission resources based on the second reservation period.

[0277] Figure 30 is a flowchart showing an aspect of an exemplary embodiment of the present disclosure. At 2910, the wireless device may determine a second reservation period in slot units based on a first reservation period in milliseconds and the number of sidelink slots within a fixed period. For example, the number of sidelink slots may be based on a resource pool configuration. At 2920, the wireless device may transmit a transport block via one or more transmission resources based on the second reservation period.

[0278] Figure 31 is a flowchart showing an aspect of an exemplary embodiment of the present disclosure. At 3110, the wireless device may determine a range of sidelink resource reselection counters for transmitting one or more transport blocks via a sidelink based on a CR measurement window size. At 3120, the wireless device may transmit one or more transport blocks via the sidelink based on the range.

[0279] Figure 32 is a flowchart showing an aspect of an exemplary embodiment of the present disclosure. At 3210, the wireless device may transmit one or more transport blocks via a sidelink based on a range of sidelink resource reselection counter values, where the range corresponds to a CR measurement window size.

[0280] Figure 33 is a flowchart showing an aspect of an exemplary embodiment of the present disclosure. At 3310, the wireless device may select a second resource from candidate resources other than one or more first resources based on transmission time resources reserved by the wireless device. At 3320, the wireless device may transmit a transport block via the second resource of the sidelink.

[0281] According to an exemplary embodiment, the first wireless device can receive one or more messages indicating a slot format configuration and a resource pool configuration from a base station. The first wireless device can receive physical sidelink control information (SCI) indicating a first reservation period in milliseconds (ms) from a second wireless device. The first wireless device can determine a second reservation period in slot units based on the first reservation period and the number of sidelink slots within a fixed period. For example, the number of sidelink slots may be based on a resource pool configuration and a slot format configuration. The first wireless device can select one or more transmission resources based on the second reservation period. The first wireless device can transmit a transport block via the one or more transmission resources.

[0282] According to an exemplary embodiment, at least one of the one or more messages can be a radio resource control message. At least one of the one or more messages can be a system information block.

[0283] According to an exemplary embodiment, the first wireless device can receive sidelink control information indicating a first reservation period in milliseconds (ms) from a second wireless device. The first wireless device can determine a second reservation period in slot units based on the first reservation period and the number of sidelink slots within a fixed period. For example, the number of sidelink slots may be based on a resource pool configuration and a slot format configuration. The first wireless device can transmit a transport block via one or more transmission resources based on the second reservation period. The first wireless device can select one or more transmission resources based on the second reservation period.

[0284] According to an exemplary embodiment, a first wireless device can receive sidelink control information indicating a first reservation period in milliseconds (ms) from a second wireless device. The first wireless device can determine a second reservation period in slot units based on the first reservation period and the number of sidelink slots within a fixed period. The number of sidelink slots may be based on a slot format configuration. The slot format configuration may be a reference slot format configuration. The slot format configuration may or may not be the same as the actual slot format configuration. The first wireless device can transmit a transport block via one or more transmission resources based on the second reservation period. The number of sidelink slots may be further based on a resource pool configuration.

[0285] According to an exemplary embodiment, a first wireless device can receive sidelink control information indicating a first reservation period in milliseconds (ms) from a second wireless device. The first wireless device can determine a second reservation period in slot units based on the first reservation period and the number of sidelink slots within a fixed period, where the number of sidelink slots is based on a resource pool configuration. The first wireless device can transmit a transport block via one or more transmission resources based on the second reservation period. The number of sidelink slots may be further based on a slot format configuration.

[0286] According to an exemplary embodiment, a first wireless device can determine a second reservation period in slot units based on the first reservation period in milliseconds (ms) and the number of sidelink slots within a fixed period. The number of sidelink slots may be based on a resource pool configuration. The first wireless device can transmit a transport block via one or more transmission resources based on the second reservation period.

[0287] According to an exemplary embodiment, a first wireless device may receive a first reservation period from an upper layer of the first wireless device. The first reservation period may be received from a second wireless device via an SCI. In one example, the number of sidelink slots may further be based on a slot format configuration. In one example, a resource pool configuration indicates one or more sidelink slots within a fixed period.

[0288] According to an exemplary embodiment, a first wireless device may determine a second reservation period in slot units based on the first reservation period in milliseconds (ms) and the number of sidelink slots within a fixed period, where the number of sidelink slots is based on a slot format configuration. The first wireless device may transmit a transport block via one or more transmission resources based on the second reservation period. The first reservation period may be received from an upper layer of the first wireless device. The upper layer may be an application layer. In one example, the first reservation period may be received from a second wireless device via an SCI. The number of sidelink slots may further be based on a resource pool configuration. In one example, the slot format configuration is a cell-specific time division duplex (TDD) uplink (UL) and downlink (DL) configuration (TDD UL-DL configuration). The slot format configuration may indicate one or more sidelink slots within a fixed period. The fixed period may be 20 milliseconds. The fixed period may not depend on the periodicity of the TDD UL-DL configuration. The fixed period may not depend on the periodicity of the slot format configuration. The first wireless device may convert the first reservation period in milliseconds into the second reservation period in slot units based on the number of sidelink slots within the fixed period.

Claims

1. A method comprising: a first wireless device determining a number of sidelink slots configured in a sidelink resource pool configuration over a fixed period; the first wireless device determining a reservation period in slot units based on a first reservation period in milliseconds (ms) and the number of sidelink slots; transmitting a transport block via one or more transmission resources based on the reservation period; and a method comprising the above.

2. The method according to claim 1, further comprising determining the number of sidelink slots based on a bitmap of the sidelink resource pool.

3. The method according to any one of claims 1 to 2, wherein the first reservation period is received from an upper layer of the first wireless device.

4. The method according to any one of claims 1 to 3, wherein the first reservation period is transmitted to a second wireless device via sidelink control information (SCI).

5. The method according to any one of claims 1 to 4, wherein the number of sidelink slots is further based on a slot format configuration.

6. The method according to claim 5, wherein the slot format configuration is a cell-specific time division duplex (TDD) uplink (UL) and downlink (DL) configuration.

7. The method according to any one of claims 1 to 6, wherein the sidelink resource pool configuration indicates one or more sidelink slots within the fixed period.

8. Determining the reservation period includes converting the first reservation period in milliseconds into the reservation period in slot units based on the number of sidelink slots within the fixed period, according to the method of any one of claims 1 to 7.

9. The number of sidelink slots within the fixed period is further based on the number of valid sidelink slots, wherein the valid sidelink slots have a number of uplink symbols greater than a threshold, according to the method of any one of claims 1 to 8.

10. The method according to claim 9, wherein the threshold is indicated by a base station.

11. A wireless device comprising: one or more processors; A memory for storing instructions, where when the instructions are executed by the one or more processors, the wireless device is caused to implement the method according to any one of claims 1 to 10, the memory and A wireless device comprising.

12. A non-transitory computer-readable medium for storing instructions, where when the instructions are executed by one or more processors of a wireless device, the wireless device is caused to implement the method according to any one of claims 1 to 10, the non-transitory computer-readable medium.

13. A system, A first wireless device, where the first wireless device includes one or more first processors and a first memory for storing first instructions, and when the first instructions are executed by the one or more first processors, Determining the number of sidelink slots configured in a sidelink resource pool configuration over a fixed period; Determining a reservation period in slot units based on a first reservation period in milliseconds (ms) and the number of the sidelink slots; Transmitting a transport block via one or more transmission resources based on the reservation period; Causing the first wireless device to perform, the first wireless device and A second wireless device, where the second wireless device includes one or more second processors and a second memory for storing second instructions, and when the second instructions are executed by the one or more second processors, causing the second wireless device to receive the transport block via the one or more transmission resources based on the reservation period, the second wireless device A system comprising.

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