Wireless Device Support Resource Selection for Sidelink

Abstract

The first wireless device receives from the second wireless device a first indication of one or more first resources for sidelink transmission of the first wireless device, the first wireless device receives from one or more third wireless devices one or more indications of one or more second resources reserved for transmission by the one or more third wireless devices, and the wireless device transmits one or more transport blocks over one or more third resources determined based on the one or more first resources and the one or more second resources.

Description

Background Art

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 063,234, filed on August 8, 2020, which is hereby incorporated 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, ways to implement 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 by way of example 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 may be at least partially based 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] The base station can communicate with a mixture of wireless devices. The wireless devices and / or the base station can support multiple technologies and / or multiple releases of the same technology. The 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 the 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 the 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 the coverage area that are executed 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 older release of LTE or 5G technology. The present invention provides, for example, the following. (Item 1) A method comprising: receiving, by a first wireless device, from a second wireless device, a first message indicating one or more first resources within a resource pool for sidelink transmission of the first wireless device; receiving, by the first wireless device, from one or more third wireless devices, one or more second messages indicating one or more second resources reserved by the one or more third wireless devices for transmission; determining one or more third resources based on the one or more first resources and the one or more second resources; selecting one or more transmission resources based on the one or more third resources; transmitting one or more transport blocks via the one or more transmission resources. (Item 2) A method comprising: receiving, by a first wireless device, from a second wireless device, a first message indicating one or more first resources within a resource pool for sidelink transmission of the first wireless device; receiving, by the first wireless device, from one or more third wireless devices, one or more second messages indicating one or more second resources reserved by the one or more third wireless devices for transmission; determining one or more third resources based on the one or more first resources and the one or more second resources; transmitting one or more transport blocks via one or more of the one or more third resources. (Item 3) A method comprising: receiving, by a first wireless device, from a second wireless device, a first indication of one or more first resources for sidelink transmission of the first wireless device; receiving, by the first wireless device, from one or more third wireless devices, one or more indications of one or more second resources reserved by the one or more third wireless devices for transmission; Transmitting one or more transport blocks via the one or more third resources determined based on the one or more first resources and the one or more second resources, a method comprising. (Item 4) The method according to item 3, wherein the first resource is within a resource pool. (Item 5) The method according to any one of items 3 to 4, further comprising determining one or more third resources based on the one or more first resources and the one or more second resources. (Item 6) The method according to any one of items 3 to 5, further comprising selecting one or more transmission resources based on the one or more third resources. (Item 7) The method according to any one of items 3 to 6, further comprising skipping a sensing operation in response to receiving the indication of the one or more first resources. (Item 8) The method according to item 7, wherein the sensing operation includes receiving one or more indications of the one or more second resources. (Item 9) The method according to item 8, wherein the sensing operation further includes measuring a received signal received power (RSRP) of the one or more second resources. (Item 10) The method according to item 9, wherein the sensing operation further includes comparing the RSRP with a threshold. (Item 11) The method according to item 10, wherein the sensing operation further includes determining one or more fourth resources based on the RSRP and the threshold. (Item 12) The method according to item 11, wherein the one or more third resources are determined based on the one or more fourth resources and the one or more first resources. (Item 13) The method according to any one of items 3 to 12, wherein the indication of the one or more first resources is received via a media access control control element (MAC CE). (Item 14) The method according to any one of items 3 to 13, wherein the indication of the one or more first resources is received via a radio resource control (RRC) message. (Item 15) The method according to any one of items 3 to 14, wherein the one or more indications of the one or more second resources are received via sidelink control information (SCI). (Item 16) The method according to any one of items 3 to 15, further comprising receiving, from a base station, an indication that wireless device assistance resource selection is enabled or disabled. (Item 17) The method according to item 16, wherein the receiving of the indication is based on the wireless device assistance resource selection being enabled. (Item 18) A wireless device, comprising: one or more processors; and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform the method according to any one of items 1 to 15. (Item 19) A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any one of items 1 to 15. (Item 20) A system, comprising: a base station; one or more first processors and a first memory storing first instructions that, when executed by the one or more first processors, cause a first wireless device to: receive, from a second wireless device, an indication of one or more first resources for sidelink transmission of the first wireless device; receive, from one or more third wireless devices, one or more indications of one or more second resources reserved for transmission by the one or more third wireless devices; and transmit one or more transport blocks via the one or more third resources determined based on the one or more first resources and the one or more second resources; one or more second processors and a second memory storing second instructions that, when executed by the one or more second processors, cause the second wireless device to: transmit the indication of the one or more first resources for sidelink transmission of the first wireless device; one or more third processors and a third memory storing third instructions that, when executed by the one or more third processors, cause the third wireless device to: A third memory storing a second instruction for causing to transmit one or more displays of the one or more second resources reserved for being transmitted by the one or more third wireless devices, and a third wireless device including the same. (Item 21) A method comprising: receiving, by a first wireless device, from a second wireless device, a configuration message indicating one or more first resources within a resource pool; selecting, by the first wireless device, one or more second resources based on the one or more first resources within the resource pool; selecting, by the first wireless device, one or more transmission resources from the one or more second resources; and transmitting, by the first wireless device, to the second wireless device, one or more transport blocks via the one or more transmission resources. (Item 22) A method comprising: receiving, by a first wireless device, from a second wireless device, a message including one or more first resources within a resource pool; determining one or more second resources other than the one or more first resources within the resource pool; selecting one or more transmission resources based on the one or more second resources; and transmitting one or more transport blocks via the one or more transmission resources. (Item 23) The method according to Item 22, wherein the message is a configuration message. (Item 24) The method according to any one of Items 22 to 23, wherein the determining of the one or more second resources includes selecting the one or more second resources based on the one or more first resources within the resource pool. (Item 25) The method according to any one of Items 22 to 24, further comprising receiving, from a base station, an indication that wireless device assisted resource selection is enabled or disabled. (Item 26) The method according to Item 25, wherein the receiving of the message is based on the wireless device assisted resource selection being enabled. (Item 27) A wireless device comprising: one or more processors, A wireless device comprising: 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 21 to 26. (Item 28) 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 21 to 26. (Item 29) A system comprising: A base station; One or more first processors, and when executed by the one or more first processors, cause a first wireless device to Receive, from a second wireless device, a message including one or more first resources within a resource pool; Determine one or more second resources other than the one or more first resources within the resource pool; Select one or more transmission resources based on the one or more second resources; and A first memory storing first instructions that, when executed via the one or more transmission resources, cause one or more transport blocks to be transmitted, the first wireless device; One or more second processors, and when executed by the one or more second processors, cause the second wireless device to Transmit the message including the one or more first resources within the resource pool; A second memory storing second instructions that, when executed via the one or more transmission resources, cause the one or more transport blocks to be received, the second wireless device; a system comprising. (Item 30) A method comprising: Receiving, by a first wireless device, from a second wireless device, a configuration message indicating a first subset from a plurality of subsets within a resource pool; Selecting, by the first wireless device, a second subset other than the first subset from the plurality of subsets within the resource pool; Selecting, by the first wireless device, one or more transmission resources from the second subset; and Transmitting, by the first wireless device, one or more transport blocks via the one or more transmission resources. (Item 31) The method according to item 30, wherein the second subset of the plurality of subsets within the resource pool is temporally separated from the first subset. (Item 32) The method according to item 31, wherein the configuration message is received via a sidelink radio resource control message (RRC), a sidelink media access control (MAC) control element (CE), or a sidelink control information (SCI). (Item 33) The method according to any one of items 30 to 32, wherein the first wireless device and the second wireless device belong to a group. (Item 34) The method according to item 33, wherein the number of subsets is determined based on the number of members of the group. (Item 35) The method according to any one of items 33 to 34, wherein the group is a unicast group or a groupcast group. (Item 36) The method according to any one of items 30 to 35, wherein a subset from the plurality of subsets within the resource pool includes one or more slots within the resource pool. (Item 37) The method according to any one of items 30 to 36, further comprising receiving, from a base station, an indication that wireless device-assisted resource selection is enabled or disabled. (Item 38) The method according to item 37, wherein the receiving of the configuration message is based on the enabling of the wireless device-assisted resource selection. (Item 39) A wireless device, comprising one or more processors, and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform the method according to any one of items 30 to 36. (Item 40) A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any one of items 30 to 36. (Item 41) A system, comprising a base station, one or more first processors, and when executed by the one or more first processors, causing a first wireless device to receive, from a second wireless device, a configuration message indicating a first subset from a plurality of subsets within a resource pool, select, from the plurality of subsets within the resource pool, a second subset other than the first subset Selecting one or more transmission resources from the second subset, and A first memory storing a first instruction for causing transmission of the one or more transport blocks via the one or more transmission resources, the first wireless device comprising: One or more second processors, and when executed by the one or more second processors, to the second wireless device, Transmitting the configuration message indicating a first subset from a plurality of subsets within a resource pool, A second memory storing a second instruction for causing reception of the one or more transport blocks via the one or more transmission resources, the second wireless device comprising: a system. (Item 42) A method comprising: Receiving, by a first wireless device, from a second wireless device, a configuration message indicating a subset from a plurality of subsets within a resource pool; Based on sensing, selecting, by the first wireless device, one or more transmission resources from the subset; Transmitting, by the first wireless device, one or more transport blocks via the one or more transmission resources. (Item 43) The method according to item 42, wherein the configuration message is received via a sidelink radio resource control message (RRC), a media access control (MAC) control element (CE), or a sidelink control information (SCI). (Item 44) The method according to any one of items 42 to 43, wherein the first wireless device and the second wireless device belong to a group. (Item 45) The method according to item 44, wherein the number of subsets is determined based on the number of members of the group. (Item 46) The method according to any one of items 44 to 45, wherein the group is a unicast group or a groupcast group. (Item 47) The method according to any one of items 42 to 46, wherein the subset from the plurality of subsets within the resource pool includes one or more slots within the resource pool. (Item 48) The method according to any one of items 42 to 47, wherein the transmitting further includes the one or more transport blocks to the second wireless device. (Item 49) The method according to any one of items 42 to 48, further comprising receiving, from a base station, an indication that wireless device assistance resource selection is enabled or disabled. (Item 50) The method according to item 49, wherein the receiving of the configuration message is based on the wireless device assistance resource selection being enabled. (Item 51) A wireless device, comprising: one or more processors; and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform the method according to any one of items 42 to 48. (Item 52) A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any one of items 42 to 48. (Item 53) A system, comprising: a base station; a first wireless device including one or more first processors and a first memory storing first instructions that, when executed by the one or more first processors, cause the first wireless device to: receive, from a second wireless device, a configuration message indicating a subset from among a plurality of subsets within a resource pool; select, based on sensing, one or more transmission resources from the subset; and transmit one or more transport blocks via the one or more transmission resources; and a second wireless device including one or more second processors and a second memory storing second instructions that, when executed by the one or more second processors, cause the second wireless device to: transmit the configuration message indicating the subset from among the plurality of subsets within the resource pool; and receive the one or more transport blocks via the one or more transmission resources. (Item 54) A method, comprising: receiving, by a first wireless device, from a second wireless device, an assistance resource selection message including one or more first resources within a resource pool for sidelink transmission of the first wireless device; determining, based on sensing, one or more second resources within the resource pool; Determining one or more third candidate resources from an intersection of the one or more first resources and the one or more second resources; Selecting one or more transmission resources based on the one or more third candidate resources; Transmitting one or more transport blocks via the one or more transmission resources, a method. (Item 55) A method comprising: Receiving, by a first wireless device, from a second wireless device, a message including one or more first candidate resources of the second wireless device; Determining, by the first wireless device, one or more second candidate resources based on sensing; Determining, by the first wireless device, one or more third candidate resources based on an intersection of the one or more first candidate resources and the one or more second candidate resources; Selecting, by the first wireless device, one or more transmission resources from the one or more third candidate resources; Transmitting, by the first wireless device, one or more transport blocks via the one or more transmission resources, a method. (Item 56) A method comprising: Receiving, by a first wireless device, from a second wireless device, a message including one or more first candidate resources of the second wireless device; Determining an intersection of the one or more first candidate resources and one or more second candidate resources determined by a sensing operation; Transmitting, based on the intersection, one or more transport blocks via one or more transmission resources, a method. (Item 57) The method according to item 56, wherein the message is an assistance resource selection message. (Item 58) The method according to any one of items 56 to 57, wherein the one or more first candidate resources are first resources within a resource pool. (Item 59) The method according to any one of items 56 to 58, further comprising determining one or more second candidate resources based on the sensing operation. (Item 60) The method according to any one of items 56 to 59, wherein the one or more second candidate resources are second resources within a resource pool. (Item 61) The method according to any one of items 56 to 60, wherein the one or more first resources and the one or more second resources are within a resource pool. (Item 62) The method according to any one of items 56 to 61, wherein determining the intersection includes determining one or more third candidate resources based on the intersection. (Item 63) The method according to any one of items 56 to 62, further comprising selecting one or more transmission resources from the one or more third candidate resources. (Item 64) The method according to any one of items 56 to 63, wherein the sensing operation further includes measuring a received signal received power (RSRP) of the one or more second resources. (Item 65) The method according to any one of items 56 to 64, wherein the sensing operation further includes comparing the RSRP with a threshold value. (Item 66) The sensing operation includes measuring a sidelink reference signal received power (SL-RSRP), excluding one or more resources within a candidate resource set based on the SL-RSRP compared with a threshold value, and determining the one or more second candidate resources from the candidate resource set based on the exclusion. The method according to any one of items 56 to 65. (Item 67) The method according to item 66, wherein the candidate resource set is determined based on a packet delay budget and a resource reselection trigger time. (Item 68) The method according to any one of items 56 to 67, wherein transmitting further includes transmitting the one or more transport blocks to the second wireless device. (Item 69) The method according to any one of items 56 to 68, wherein the message is a media access control control element (MAC CE), a radio resource control (RRC) message, or a sidelink control information (SCI). (Item 70) The method according to any one of items 56 to 69, further comprising receiving, from a base station, an indication that wireless device-assisted resource selection is enabled or disabled. (Item 71) The method according to item 70, wherein receiving the message is based on the wireless device-assisted resource selection being enabled. (Item 72) A wireless device, comprising one or more processors, A wireless device, comprising: 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 54 to 71. (Item 73) 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 54 to 71. (Item 74) A system, comprising: a base station; one or more first processors, and when executed by the one or more first processors, cause a first wireless device to receive, from a second wireless device, a message including one or more first candidate resources for the second wireless device; determine an intersection of the one or more first candidate resources and one or more second candidate resources determined by a sensing operation; and a first memory storing first instructions that, based on the intersection, cause the first wireless device to transmit one or more transport blocks via one or more transmission resources. one or more third processors, and when executed by the one or more third processors, cause the second wireless device to transmit the message including the one or more first candidate resources for the second wireless device; and a third memory storing second instructions that, based on the intersection, cause the second wireless device to receive the one or more transport blocks via the one or more transmission resources. (Item 75) A method, comprising: receiving, by a first wireless device, from a second wireless device, a message including one or more first candidate resources of the second wireless device; in response to receiving the message, skipping, by the first wireless device, a sensing operation for determining one or more candidate resources; selecting, by the first wireless device, one or more transmission resources from the one or more first candidate resources; and transmitting, by the first wireless device, one or more transport blocks via the one or more transmission resources. (Item 76) wherein the sensing operation measures the side link reference signal received power (SL-RSRP), excludes one or more resources within a candidate resource set based on the SL-RSRP compared with a threshold value, and determines the one or more second candidate resources from the candidate resource set based on the exclusion, the method according to item 75 further comprising. (Item 77) The method according to item 76, wherein the candidate resource set is determined based on a packet delay budget and a resource reselection trigger time. (Item 78) The method according to any one of items 76 to 77, wherein the transmitting further comprises transmitting the one or more transport blocks to the second wireless device. (Item 79) The method according to any one of items 75 to 78, further comprising receiving, from a base station, an indication that wireless device assisted resource selection is enabled or disabled. (Item 80) The method according to item 79, wherein the receiving of the message is based on the enabling of the wireless device assisted resource selection. (Item 81) A wireless device, comprising: one or more processors; and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform the method according to any one of items 75 to 80. (Item 82) A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any one of items 75 to 80. (Item 83) A system, comprising: a base station; and a first wireless device including one or more first processors and a first memory storing first instructions that, when executed by the one or more first processors, cause the first wireless device to: receive, from a second wireless device, a message including one or more first candidate resources for the second wireless device; skip a sensing operation for determining one or more candidate resources in response to receiving the message; select one or more transmission resources from the one or more first candidate resources; and transmit one or more transport blocks via the one or more transmission resources. one or more second processors, and when executed by the one or more second processors, cause the second wireless device to send the message including the one or more first candidate resources for the second wireless device, and a second memory storing second instructions that, when executed via the one or more transmission resources, cause the one or more transport blocks to be received, the second wireless device including the second wireless device, a system. (Item 84) A method comprising: receiving, by a first wireless device, from a base station, an indication that wireless device assistance resource selection is enabled or disabled; when the indication is enabled, receiving, by the first wireless device, from a second wireless device, a configuration message indicating one or more first resources within a resource pool; selecting, by the first wireless device, one or more second resources other than the one or more first resources within the resource pool; selecting, by the first wireless device, one or more transmission resources from the one or more second resources; transmitting, by the first wireless device, one or more transport blocks to the second wireless device via the one or more transmission resources. (Item 85) A wireless device comprising: one or more processors; and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform the method of item 84. (Item 86) A non-transitory computer-readable medium including instructions that, when executed by one or more processors, cause the one or more processors to perform the method of item 84. (Item 87) A method comprising: transmitting, by a base station, to a first wireless device, an indication that wireless device assistance resource selection is enabled or disabled, wherein when the indication is enabled, the wireless device assistance resource selection configures the first wireless device to receive, from a second wireless device, a configuration message indicating one or more first resources within a resource pool and select a transmission resource for sidelink transmission. (Item 88) A base station, one or more processors, and a memory storing instructions that, when executed by the one or more processors, cause the base station to perform the method according to item 84. A base station comprising the same. (Item 89) A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to item 84. (Item 90) A system, one or more first processors, and a first memory storing first instructions that, when executed by the one or more first processors, cause a first wireless device to transmit a display indicating that wireless device assistance resource selection is enabled or disabled. A base station comprising the same. one or more second processors, and a second memory storing first instructions that, when executed by the one or more second processors, cause a first wireless device to receive, from the base station, the display indicating that the wireless device assistance resource selection is enabled or disabled, when the display is enabled, receive a configuration message indicating one or more first resources within a resource pool, select one or more second resources other than the one or more first resources within the resource pool, select one or more transmission resources from the one or more second resources, and transmit one or more transport blocks via the one or more transmission resources. A first wireless device comprising the same. one or more third processors, and a third memory storing second instructions that, when executed by the one or more third processors, cause a second wireless device to transmit the configuration message indicating the one or more first resources within the resource pool, and receive the one or more transport blocks via the one or more transmission resources. A second wireless device comprising the same. A system comprising the same.

Brief Description of the Drawings

[0005] Some examples of various embodiments of the present disclosure are described herein with reference to the drawings.

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Mode for Carrying Out the Invention

[0038] 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" can represent A, B, C, A and B, A and C, B and C, or A, B, and C.

[0039] 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 that the phrase following the term "based on" is one example of a number of suitable possibilities where it 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 that the phrase following the term "in response to" is one example of a number of suitable possibilities where it 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 that the phrase following the term "in accordance with" is one example of a number of suitable possibilities where it may or may not be used in one or more of various embodiments. The phrase "employed / used" (or equivalently "at least employed / used") indicates that the phrase following the term "employed / used" is one example of a number of appropriate possibilities where it may or may not be used in one or more of various embodiments.

[0040] The term "configured" may 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 that the control messages can be used to configure certain characteristics in the device or have parameters that can be used to implement certain actions in the device regardless of whether the device is in an operating state or a non-operating state.

[0041] 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 have to be included in each of the one or more messages.

[0042] 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 a 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, by only one of the three possible features, by any two of the three features, or by all three of the three features.

[0043] Many of the elements described in the disclosed embodiments may 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 may be behaviorally equivalent. For example, a module may 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, and 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.

[0044] 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 can be, for example, a public land mobile network (PLMN) operated 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.

[0045] CN 102 can 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 can 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.

[0046] RAN 104 can connect CN 102 to the wireless device 106 via wireless communication on the air interface. As part of the wireless communication, RAN 104 can 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 can be separated from uplink transmission using frequency division duplexing (FDD), time division duplexing (TDD), and / or some combination of the two duplexing techniques.

[0047] The term "wireless device" is used throughout this disclosure to refer to and encompass any mobile device or fixed (non-portable) device for which wireless communication is necessary 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.

[0048] RAN104 may include one or more base stations (not shown). The term "base station" can 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, and can be used throughout this disclosure for that purpose. A base station may include at least one gNB central unit (gNB-CU) and at least one gNB distributed unit (gNB-DU).

[0049] 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 geographic area to support wireless device mobility.

[0050] 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 a sector site 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.

[0051] 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, such as coverage areas that overlap with the relatively large coverage areas provided by macrocell base stations. The small coverage areas can be provided in areas with high data traffic (or so-called hotspots), or areas with weak macrocell coverage. 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.

[0052] 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, namely the third generation (3G) network known as the Universal Mobile Telecommunications System (UMTS), the fourth generation (4G) network known as Long Term Evolution (LTE), and the 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). The 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 not yet specified (e.g., the 3GPP™ 6G network). The NG-RAN implements the 5G radio access technology known as New Radio (NR) and can be supplied to implement other radio access technologies, including 4G radio access technology or non-3GPP™ radio access technology.

[0053] Figure 1B shows a mobile communication network 150 of another embodiment in which the embodiments of the present disclosure can 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.

[0054] The 5G-CN 152 provides an interface for the UEs 156 to one or more 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, 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 with the CN of the 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 constituting the 5G-CN 152 can be defined as a network function that provides services via an interface 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).

[0055] As shown in FIG. 1B, 5G-CN152 includes an Access and Mobility Management Function (AMF) 158A and a User Plane Function (UPF) 158B, which can be simply described as shown as a single component AMF / UPF158 in FIG. 1B. 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) processing 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 the DN.

[0056] 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, reachability of idle mode UEs (e.g., control and execution of paging retransmission), registration area management, support for intra-system and inter-system mobility, access authentication, access permission including checking roaming rights, mobility management control (subscription and policy), support for network slicing, and / or selection of a Session Management Function (SMF). NAS may refer to functions operating between the CN and the UE, and AS may refer to functions operating between the UE and the RAN.

[0057] 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).

[0058] NG-RAN154 may connect 5G-CN 152 to UE156 via wireless communication on 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 on the air interface. For example, one or more of gNB160 and / or one or more of ng-eNB162 may include three antenna sets 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.

[0059] 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.

[0060] 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.

[0061] gNB 160 may provide NR user plane and control plane protocol termination towards UE 156 on the Uu interface. For example, gNB 160A may provide NR user plane and control plane protocol termination 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 termination 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 termination towards UE 156B on the Uu interface associated with the second protocol stack.

[0062] 5G-CN 152 was described as being configured to handle 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. Although only one AMF / UPF 158 is shown in Figure 1B, one gNB or ng-eNB may be connected to multiple AMF / UPF nodes to provide redundancy and / or load sharing across multiple AMF / UPF nodes.

[0063] As discussed, in Figure 1B, the interfaces between network elements (e.g., the Uu, Xn, and NG interfaces) may be associated with the protocol stacks used by the network elements to exchange data and signaling messages. The protocol stack may include two planes, namely, the user plane and the 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.

[0064] Figures 2A and 2B respectively show examples of the 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.

[0065] Figure 2A shows an NR user plane protocol stack including five layers implemented in UE210 and gNB220. At the bottom of the protocol stack, the 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 Systems Interconnection (OSI) model. The next four protocols above PHY211 and 221 include the media access control layers (MAC) 212 and 222, the radio link control layers (RLC) 213 and 223, the packet data convergence protocol layers (PDCP) 214 and 224, and the service data application protocol layers (SDAP) 215 and 225. Together, these four protocols may constitute layer 2 or the data link layer of the OSI model.

[0066] 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.

[0067] 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 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 remove any duplicate packets at the receiver. Packet duplication may be useful for services that require high reliability.

[0068] Although not shown in FIG. 3, PDCP 214 and 224 may perform mapping / demapping between split radio bearers and RLC channels in a dual-connectivity scenario. Dual-connectivity 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-connectivity. PDCP 214 and 224 may map / demap a split radio bearer between RLC channels belonging to a cell group.

[0069] 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 without depending on 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.

[0070] 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 the 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 may control which numerology and / or transmission timing a logical channel can use. As shown in Figure 3, MAC212 and 222 may provide logical channels to RLC213 and 223 as a service.

[0071] PHY211 and 221 may perform mapping of transport channels to physical channels and digital and analog signal processing functions to transmit and receive 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 Figure 3, PHY211 and 221 may provide one or more transport channels to MAC212 and 222 as a service.

[0072] 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, and generates two transport blocks (TBs) 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.

[0073] 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.

[0074] The remaining protocol layers in FIG. 4A can perform related functions (e.g., with respect to FIG. 3), add corresponding headers, and transfer each output to the next lower layer. For example, PDCP 224 can perform IP header compression and encryption and transfer its output to RLC 223. RLC 223 can 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 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 can be distributed over the entire MAC PDU. In LTE, the MAC sub-header can be placed entirely at the beginning of the MAC PDU. The NR MAC PDU structure can reduce processing time and related latency because the MAC PDU sub-header can be calculated before the complete MAC PDU is assembled.

[0075] 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 of the MAC SDU (such as in bytes) 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 the demultiplexing process, a flag (F) for indicating the size of the SDU length field, and a reserved bit (R) field for future use.

[0076] 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 preconfigured 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 can be identified by a reserved value in an LCID field indicating the type of control information included in the MAC CE.

[0077] Before describing the NR control plane protocol stack, the logical channels, transport channels, and physical channels, as well as 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.

[0078] 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, - A broadcast control channel (BCCH) for transmitting system information messages in the form of a master information block (MIB) and some system information blocks (SIB), 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, - And a dedicated traffic channel (DTCH) for transmitting user data between a particular UE.

[0079] Transport channels are used between the MAC layer and the PHY layer and can be defined by how the information they carry is transmitted over the air interface. The set of transport channels defined by NR includes, for example, - A paging channel (PCH) for 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 SIBs from the BCCH - An uplink shared channel (UL-SCH) for transmitting uplink data and signaling messages, - A random access channel (RACH) that enables a UE to connect to the network without prior scheduling.

[0080] The PHY can pass information between processing levels of the PHY using physical channels. A physical channel can have a related set of time-frequency resources for carrying 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) that 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 acknowledgement responses, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and scheduling requests (SR), and - A physical random access channel (PRACH) for random access, are included.

[0081] 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 (PSS), secondary synchronization signals (SSS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), sounding reference signals (SRS), and phase tracking reference signals (PT-RS). These physical layer signals are described in more detail below.

[0082] FIG. 2B shows an example of an 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 an 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.

[0083] 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.

[0084] 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.

[0085] 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).

[0086] In RRC connection 602, the UE may have an established RRC context and at least one RRC connection with the base station. The base station may be one of one or more base stations included in RAN104 shown in FIG. 1A, one of gNB160 or ng-eNB162 shown in FIG. 1B, gNB220 shown in FIGS. 2A and 2B, or any other base station similar to those described in the present disclosure. The base station to which the UE is connected may have the RRC context of the UE. 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 may be managed by the RAN (e.g., RAN104 or NG-RAN154). The UE may 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 serving the UE. The serving base station of the UE may 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 the connection release procedure 608, or may transition to RRC inactive 606 via the connection deactivation procedure 610.

[0087] 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 for 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 connection 602 via a connection establishment procedure 612 that may involve a random access procedure as discussed in more detail below.

[0088] 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 connection 602 compared to the transition from RRC idle 604 to RRC connection 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 connection 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.

[0089] The RRC state may be associated with the 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 having to broadcast 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).

[0090] 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.

[0091] 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 can include one or more cell identities, a list of RAI, or a list of TAI. In one embodiment, a base station can 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.

[0092] 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.

[0093] A gNB, such as gNB160 in Figure 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols). Numerologies with higher subcarrier spacing have shorter slot durations and, accordingly, more 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). Subframes within NR can be used as numerology-independent time references, while slots can be used as units 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.

[0098] FIG. 8 shows an example configuration of a slot in the time and frequency domains of an NR carrier. A slot contains resource elements (REs) and resource blocks (RBs). An RE is the smallest physical resource in NR. As shown in FIG. 8, an RE spans one OFDM symbol in the time domain by one subcarrier in the frequency domain. 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. These limitations, when 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.

[0099] 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.

[0100] 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 is scheduled to receive. This is called bandwidth adaptation.

[0101] 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.

[0102] 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.

[0103] 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 may configure the UE with a common search space on the PCell or on a primary secondary cell (PSCell) in an active downlink BWP.

[0104] For 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.

[0105] 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.

[0106] 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 the 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.

[0107] 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 a DCI indicating an active downlink BWP other than the default downlink BWP for the paired spectrum operation, or (b) when the UE detects a DCI indicating an active downlink BWP or an active uplink BWP other than the default downlink BWP or the uplink BWP for the 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.

[0108] 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 a 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).

[0109] 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.

[0110] 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 may 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 switch 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.

[0111] If the UE is configured with a set of downlink BWPs and a default downlink BWP in the timer values for a secondary cell, the UE procedure for switching the BWP on the secondary cell may be the same / similar to that on the primary cell. For example, the UE may 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.

[0112] To provide a higher 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 may have three configurations within the frequency domain.

[0113] 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).

[0114] In one embodiment, up to 32 CCs can be aggregated. The aggregated CCs may have the same or different bandwidths, subcarrier spacings, and / or duplexing schemes (TDD or FDD). The serving cell of a UE using CA may have a downlink CC. For FDD, one or more uplink CCs may 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.

[0115] 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).

[0116] The SCell configured for the UE can be activated and deactivated, for example, based on traffic and channel conditions. The deactivation of the SCell can mean that the reception of PDCCH and PDSCH on the SCell is stopped, and the transmission of PUSCH, SRS, and CQI on the SCell is 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).

[0117] 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.

[0118] 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. The 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. The 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.

[0119] 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.

[0120] 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. A transport block can be generated per allocation / grant per serving cell. The transport block and potential HARQ retransmissions of the transport block can be mapped to the serving cell.

[0121] On 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). On 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.

[0122] 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 suitable factor. In one embodiment, the UE may assume a subcarrier spacing for the SS / PBCH block based on the carrier frequency being monitored, provided that the radio network has not configured the UE to assume a different subcarrier spacing.

[0123] 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.

[0124] 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. If the PSS is found at a 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.

[0125] 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.

[0126] The PBCH may use QPSK modulation and may use forward error correction (FEC). The FEC may use polar coding. One or more symbols spanned by the PBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCH may include an indication of the 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. The 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 (RMSI) associated with the cell. The RMSI may include the system information block type 1 (SIB1). The SIB1 may include information necessary for the UE to access the cell. The UE may use one or more parameters of the MIB to monitor the PDCCH, which can be used to schedule the PDSCH. The PDSCH may include the SIB1. The SIB1 may be decoded using the parameters provided in the MIB. The PBCH may indicate the absence of the SIB1. Based on the PBCH indicating the absence of the SIB1, the UE may indicate a frequency. The UE may search for the SS / PBCH block at the frequency indicated by the UE.

[0127] The UE can assume that one or more SS / PBCH blocks transmitted with the same SS / PBCH block index are quasi-co-located (QCLed) (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 with different SS / PBCH block indices have different QCL for SS / PBCH block transmissions.

[0128] 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 embodiment, the first SS / PBCH block may be transmitted in a first spatial direction using a first beam, and the second SS / PBCH block may be transmitted in a second spatial direction using a second beam.

[0129] In one embodiment, within the frequency span of a carrier, the base station can transmit a plurality of SS / PBCH blocks. In one embodiment, the first PCI of the first SS / PBCH block of the plurality of SS / PBCH blocks may be different from the second PCI of the second SS / PBCH block of the plurality of SS / PBCH blocks. The PCI of SS / PBCH blocks transmitted at different frequency positions may be different or the same.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] The CSI-RS configuration may include one or more parameters indicating, for example, up to 32 antenna ports. The UE can 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 can 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.

[0134] 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 may support a maximum of eight orthogonal downlink DMRS ports per UE. In the case of multi-user MIMO, the DMRS configuration can support a maximum of four orthogonal downlink DMRS ports per UE. The radio network may 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 may transmit the downlink DMRS and the corresponding PDSCH using the same precoding matrix. The UE may use one or more downlink DMRS for coherent demodulation / channel estimation of the PDSCH.

[0135] 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).

[0136] The PDSCH may include one or more layers. The UE may assume that at least one symbol with DMRS is present on one or more layers of the PDSCH. The upper layer may configure up to three DMRSs for the PDSCH.

[0137] 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 or not 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.

[0138] 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.

[0139] 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.

[0140] 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 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. For example, the uplink PT-RS can be restricted to the UE's scheduled time / frequency period.

[0141] The SRS can be transmitted by the UE to the base station for channel state estimation in order 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 higher layer (e.g., RRC) parameters. For example, if 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 the same kind) of one or more SRS resource sets 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 transmission. 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, if PUSCH and SRS are transmitted in the same slot, the UE can be configured to transmit SRS after the transmission of PUSCH and the corresponding uplink DMRS.

[0142] 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, the 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.

[0143] An antenna port is defined such that the channel over which a symbol on the antenna port is transmitted can be inferred from the channel over 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 the 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 said to be quasi-co-located (QCL) if one or more large-scale characteristics of the channel over which the first symbol on the first antenna port is transmitted can be inferred from the channel over which the second symbol on 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.

[0144] 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.

[0145] 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, transmit coom, 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.

[0146] 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 transmit another CSI-RS associated with the beam of another UE using other subcarriers within the same RB (for example, those not used for transmitting CSI-RS1101). By using time domain multiplexing (TDM), the beams used by the UE can be configured such that the beams of the UE use symbols from the beams of other UEs.

[0147] 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.

[0148] 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).

[0149] 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 (each shown as an ellipse in the top and bottom rows of P1). 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 the clockwise direction when shown 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.

[0150] Figure 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 topmost and bottommost 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 topmost row 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.

[0151] 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., 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).

[0152] The UE may measure the quality of the beam pair link using one or more reference signals (RS) 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-RS of a channel (e.g., control channel, shared data channel, and / or the like). The RS resource of the channel and one or more DMRS may be QCL when the channel characteristics (e.g., Doppler shift, Doppler spread, mean delay, delay spread, spatial Rx parameters, fade, and / or the like) from the transmission to the UE via the RS resource are similar or identical to the channel characteristics from the transmission to the UE via the channel.

[0153] A network (e.g., the 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 to establish time alignment for SCell addition.

[0154] 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 random access preamble) and / or may be called a preamble. Msg2 1312 may include a random access response (RAR) and / or may be called a random access response (RAR).

[0155] The constituent message 1310 can be transmitted, for example, using one or more RRC messages. The one or more RRC messages can indicate one or more random access channel (RACH) parameters to the UE. The one or more RACH parameters can 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.

[0156] One or more RACH parameters provided in the configuration message 1310 may indicate one or more physical RACH (PRACH) opportunities available for transmission of Msg1 1311. The one or more PRACH opportunities may be 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.

[0157] 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 SSB and CSI-RS, a power offset between 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 a UE to determine at least one reference signal (e.g., SSB and / or CSI-RS) and / or an uplink carrier (e.g., a normal uplink (NUL) carrier and / or a supplementary uplink (SUL) carrier).

[0158] 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.

[0159] 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.

[0160] If the UE does not receive a response after preamble transmission, it may perform preamble retransmission. The UE may increase the uplink transmission power for preamble retransmission. The UE may select the initial preamble transmission power based on path loss measurement 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 step for preamble retransmission. The ramping step may be the amount of incremental increase in 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 decide that the random access procedure has failed to complete if, for example, the number of preamble transmissions exceeds a threshold configured by one or more RACH parameters (e.g., preambleTransMax).

[0161] The Msg2 1312 received by the UE may include a 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 Msg1 1311. The Msg2 1312 is scheduled on the DL-SCH and may be indicated on the PDCCH using a Random Access RNTI (RA-RNTI). The Msg2 1312 may indicate that Msg1 1311 has been received by the base station. The Msg2 1312 may include a timing alignment command that the UE can use to adjust the UE's transmission timing, a scheduling grant for the transmission of Msg3 1313, and / or a Temporary Cell RNTI (TC-RNTI). After 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). The one or more symbols may be determined based on the numerology. The PDCCH may be in a common search space configured by an RRC message (e.g., a Type1-PDCCH common search space). 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 and 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 a 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 suitable identifier) in Msg3 1313.

[0162] Msg4 1314 may be received after or in response to the transmission of Msg3 1313. If the C-RNTI was included in Msg3 1313, the base station uses the C-RNTI to address the UE on the PDCCH. If the UE's unique C-RNTI is detected on the PDCCH, it is determined that the random access procedure has completed successfully. 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 completed successfully.

[0163] 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 a 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 a channel clear assessment (e.g., listen before talk).

[0164] 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.

[0165] The random access procedure without contention shown in FIG. 13B can be initiated for beam failure recovery, other SI requests, 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.

[0166] 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 request.

[0167] 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 in some respects to the configuration message 1310 and / or the configuration message 1320. FIG. 13C includes the transmission of two messages, namely, Msg A 1331 and Msg B 1332.

[0168] 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 that is 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 may receive Msg B 1332. Msg B 1332 can include content that is 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.

[0169] 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.

[0170] 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.

[0171] The transport block 1342 may include data (e.g., delay-sensitive data), UE identifiers, 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).

[0172] 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.

[0173] 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.

[0174] 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 radio network temporary identifier (RNTI).

[0175] 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 having CRC parity bits scrambled with 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 having CRC parity bits scrambled with 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 having CRC parity bits scrambled with a random access RNTI (RA-RNTI) can indicate a random access response (RAR). DCI having CRC parity bits scrambled with 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 having CRC parity bits scrambled with 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 a Configured Scheduling RNTI (CS-RNTI), a Transmit Power Control-PUCCH RNTI (TPC-PUCCH-RNTI), a Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI), a Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), an Interruption RNTI (INT-RNTI), a Slot Format Indication RNTI (SFI-RNTI), a Semi-Persistent CSI RNTI (SP-CSI-RNTI), a Modulation and Coding Scheme Cell RNTI (MCS-C-RNTI), and / or the like.

[0176] 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 the 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 the cell (e.g., having more DCI payload than DCI format 0_0). DCI format 1_0 can be used for scheduling PDSCH within the 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 the 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 transmit 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 can be defined in future releases. DCI formats can have different DCI sizes or share the same DCI size.

[0177] 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 the 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 also be based on the mapping of the CCEs and REGs (e.g., CCE-to-REG mapping).

[0178] 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 the time-frequency resources that 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, the first CORESET 1401 and the second CORESET 1402 occur in the first symbol within the slot. The first CORESET 1401 overlaps with the second CORESET 1402 in the frequency domain. The third CORESET 1403 occurs in the third symbol within the slot. The 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.

[0179] 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.

[0180] 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).

[0181] 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 contained in the DCI (e.g., scheduling assignment, uplink grant, power control, slot format indication, downlink preemption, and / or the like).

[0182] 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.

[0183] 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 the 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.

[0184] The base station can 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) can be configured on the uplink BWP of the cell. A PUCCH resource set can 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 can 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 can select the first PUCCH resource set with a PUCCH resource set index equal to "0". If the total bit length of the UCI information bits is greater than 2 and less than or equal to a first configured value, the UE can select a second PUCCH resource set with 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 can select a third PUCCH resource set with 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 can select a fourth PUCCH resource set with a PUCCH resource set index equal to "3".

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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 by, for example, 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.

[0189] After being processed by the processing system 1508, 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, 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 the transport channel to a physical channel, modulation of the physical channel, multiple-input multiple-output (MIMO) or multi-antenna processing, and / or the like.

[0190] At base station 1504, reception processing system 1512 can receive uplink transmissions from wireless device 1502. At wireless device 1502, reception processing system 1522 can receive downlink transmissions from base station 1504. Reception processing system 1512 and reception processing system 1522 can implement the layer 1 OSI function. Layer 1 can include a 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.

[0191] As shown in FIG. 15, wireless device 1502 and base station 1504 can include multiple antennas. The multiple 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.

[0192] Processing system 1508 and processing system 1518 may each 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.

[0193] 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 the one or more processors may include, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and / or other programmable logic device, discrete gate and / or transistor logic, discrete hardware components, an on-board unit, 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.

[0194] Processing system 1508 and / or processing system 1518 may 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 may include software and / or hardware that provides 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 may 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 may be configured to receive power from a power source and / or distribute power to other components within the wireless device 1502. The power source may 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 may each be connected to a GPS chipset 1517 and a GPS chipset 1527. The GPS chipset 1517 and the GPS chipset 1527 may each be configured to provide geographical location information of the wireless device 1502 and the base station 1504.

[0195] FIG. 16A shows an exemplary structure for uplink transmission. The baseband signal representative of the physical uplink shared channel can perform one or more functions. These one or more functions can include 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 at least one of 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.

[0196] FIG. 16B shows an exemplary structure for modulation and upconversion of the baseband signal to carrier frequencies. 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.

[0197] FIG. 16C shows an exemplary structure of downlink transmission. A baseband signal representing a physical downlink channel can perform one or more functions. These one or more functions can 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.

[0198] 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.

[0199] 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 can include parameters for configuring physical layer and MAC layer channels, bearers, etc. For example, the configuration parameters may include parameters indicating values of timers for the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, RRC layer, and / or communication channels.

[0200] 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.

[0201] 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 sidelink (SL). Wireless devices can exchange sidelink communications via a sidelink interface (e.g., a PC5 interface). The sidelink 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 communications via a user plane interface (e.g., a Uu interface).

[0202] 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.

[0203] 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.

[0204] 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 the 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 can transmit sidelink synchronization signals, for example, by using PSBCH. The sidelink synchronization signals can include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS).

[0205] Sidelink resources can be configured for a wireless device in any suitable manner. The wireless device may be preconfigured for sidelink, for example, preconfigured with sidelink resource information. Additionally or alternatively, the network can broadcast system information related to a resource pool for sidelink. Additionally or alternatively, the network can configure a specific wireless device with a dedicated sidelink configuration. The configuration can identify sidelink resources used for sidelink operation (e.g., configuring a combination of sidelink bands).

[0206] A wireless device can operate in different modes, for example, an assist 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 can be selected to operate in the autonomous mode. For example, if the wireless device is in a connected mode (e.g., connected to a base station), the wireless device can be selected to operate in the assist mode (or commanded to operate by the base station). For example, the network (e.g., a base station) can instruct a connected wireless device to operate in a specific mode.

[0207] In the assisted 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 assisted mode may be referred to as a network-assisted mode, a gNB-assisted mode, or a base station-assisted mode. In the autonomous mode, the wireless device selects 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 sidelink resource usage of other wireless devices may be selected.

[0208] 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 those identified by the SCI). The wireless device may transmit using the selected sidelink resources.

[0209] 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 one or more slots, one or more subframes, and / or one or more OFDM symbols, for example. 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.

[0210] 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,....

[0211] 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 collide (or has a low probability of colliding) 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.

[0212] For different sidelink physical channels, different resource pools may be used. For example, the PSCCH may use a first resource pool, and the PSSCH may use a second resource pool. Different resource priorities may be associated with different resource pools. For example, data associated with a first QoS, service, priority, and / or other characteristics may use the first resource pool, and data associated with a second QoS, service, priority, and / or other characteristics may use the second resource pool. For example, a network (e.g., a base station) may configure the priority level of each resource pool, the services supported for each resource pool, etc. For example, a network (e.g., a base station) may configure a first resource pool for use by unicast UEs, a second resource pool for use by groupcast UEs, etc. For example, a network (e.g., a base station) may configure a first resource pool for transmitting sidelink data, a second resource pool for transmitting discovery messages, etc.

[0213] In sidelink operation, the following signaling protocols may be used. - PC5 (Proximity Service)-S (Signaling) or SL-S may refer to a sidelink signaling protocol that may be used for control plane signaling on the sidelink. For example, connection establishment, maintenance, and release messages may be transmitted over the PC5-S or SL-S protocol. In one embodiment, PC5-S is used for unprotected (control plane) messages and can establish security or protected (control plane) messages. An unprotected message may mean that a control plane message is transmitted before security establishment. A protected message may mean a control plane message after security establishment. - PC5-D (Discovery) may refer to a sidelink discovery signaling exchange protocol that may be used for discovery request or response message signaling on the sidelink. - PC5-RRC or SL-RRC may refer to the sidelink radio resource control protocol that can be used for UE capability information, CSI report related information, or AS layer configuration.

[0214] In the existing technology, before a transmitter wireless device selects one or more transmission resources within a second time interval called a "selection window", it can decode one or more sidelink control signals (e.g., PSCCH or sidelink control information (SCI)) of other wireless devices during a first time interval called a "detection window". The transmitter wireless device can exclude resources reserved for use by other wireless devices from its set of transmission candidate resources within the selection window. For example, the detection window may refer to the time monitored for a predetermined / (pre-)configured time window before resource (re)selection is performed / triggered, and the selection window may refer to the time interval / duration between the first time when resource (re)selection is performed / triggered and the second time that satisfies the packet latency requirement. The transmitter wireless device can determine its set of transmission candidate resources within the selection window. FIG. 19 shows an example of a detection operation, a detection window, and a selection window. When resource (re)selection is triggered in the nth slot to transmit a packet, the detection window is before the nth slot, and the selection window is to determine the set of candidate resources such that the candidate resources within the set of candidate resources satisfy the packet latency requirement. This operation may be referred to as a "sidelink detection operation". The measurement result of sidelink RSRP (SL-RSRP) can be used for the sidelink detection operation. After decoding the sidelink control channel / information, the wireless device can measure the SL-RSRP based on the average received power of the DMRS transmitted on the resources indicated by the control channel. Specifically, the wireless device can measure the RSRP of the DMRS of the PSSCH (hereinafter referred to as PSSCH-RSRP) or PSCCH (hereinafter referred to as PSCCH-RSRP) in one or more subchannels indicated by the corresponding PSCCH of the PSSCH. The wireless device can measure the PSSCH-RSRP or PSCCH-RSRP for each candidate resource or subchannel, compare the measured value with a threshold, and determine whether the corresponding candidate resource is excluded from the set of transmission candidate resources.When the measured SL-RSRP is compared with a (sensing) threshold, if the SL-RSRP is greater than the threshold, the corresponding resource can be excluded from the set of transmission candidate resources. The sensing threshold can be determined by the priority value indicated by the received sidelink control channel / information and the priority value of the transmitter radio device. For example, a base station or pre-configuration stored in memory can configure a set of sensing thresholds for the radio device. FIG. 20 shows an example of a set of sensing thresholds. There are multiple sensing thresholds for each combination of priority levels of the priority level of the transmitter radio device (referred to as "Tx priority" in the figure) and the priority level indicated by the received sidelink control channel (referred to as "Rx priority" in the figure). Th(i,j) represents the sensing threshold of the i-th priority level of the transmitter radio device and the j-th priority level of the received sidelink control channel. After the SL-RSRP-based resource exclusion, if the remaining resources are less than X% (e.g., X = 20) of the total candidate resources, the transmitter radio device may increase the threshold by Y dB (e.g., Y = 3) and proceed with the SL-RSRP-based resource exclusion procedure again. If the amount of the remaining resources exceeds X% of the total candidate resources, the transmitter radio device reports the remaining candidate resources to the upper layer, and the upper layer may select one or more transmission resources from the remaining candidate resources. One or more transmission resources can be randomly selected from the remaining candidate resources. FIG. 21 shows an example of existing sensing and resource selection procedures. In summary, the radio device can exclude candidate resources where the measured SL-RSRP of the candidate resources is greater than the threshold, avoiding potential interference to ongoing transmissions of other UEs. The existing method is a method in which the transmitter radio device uses a sensing operation to avoid resources used by other transmitter radio devices. The transmitting radio device cannot select the optimal resources from the perspective of the receiving radio device.

[0215] In the existing technology, when the sensing coverage of the transmitter wireless device is insufficient, for example, when there is a strong interfering wireless device near the receiver wireless device but the transmitter wireless device cannot detect it, the transmitter wireless device may select poor resources for the receiver wireless device. The poor resources may have strong interference, and the decoding performance on the poor resources may deteriorate. This problem is sometimes called the hidden node problem.

[0216] FIG. 22 shows an example of the hidden node problem. In the figure, it is assumed that wireless devices #1 and #3 use the same resources, but wireless device #1 cannot detect the signal of wireless device #3 or can measure a weak SL-RSRP measurement value. Wireless device #2 can receive the transmission of the signal of wireless device #1 but receives strong interference from wireless device #3.

[0217] Assuming that the first wireless device communicates with the second wireless device in unicast, in the existing technology, the first wireless device does not differentiate the resources used by the second wireless device and can perform resource exclusion operations and resource selection operations using the RSRP measurement results. For example, the second wireless device may select resources for transmitting sidelink transmissions in a specific slot. Based on the existing technology, although the first wireless device may have received sidelink control information from the second wireless device, the first wireless device may select a second resource within the same slot. The second resource and the resource may not overlap in the frequency domain but may overlap in the time domain. In this case, since the first wireless device cannot receive and transmit simultaneously, it cannot communicate with the second wireless device. This problem is sometimes called the half-duplex problem.

[0218] FIG. 23A shows an example of two wireless devices that exchange (side link) signals. Wireless device #1 transmits a side link signal in slot n, and wireless device #2 transmits a side link signal in slot n. FIG. 23B shows an example of resource selection for two wireless devices. When two wireless devices transmit side link signals simultaneously (e.g., in slot n), if the wireless device does not have a full-duplex transceiver that means the full-duplex transceiver can transmit and receive simultaneously, the wireless device cannot receive side link signals simultaneously. When wireless device #1 is performing sensing and resource selection procedures, if wireless device #1 cannot recognize the resources used by wireless device #2, wireless device #1 may select resources within the same slot.

[0219] To avoid the half-duplex problem and / or the hidden node problem, the first wireless device can specially process the resources used by the second wireless device. For example, other resources included in the slot of the resources used by the second wireless device may be preferentially excluded from the candidate resource set or resource selection of the first wireless device. In this operation, the first wireless device may be able to know that a specific resource is used by the second wireless device, and for this purpose, the source ID or destination ID indicated in the side link control information (SCI) may be used. For example, when the first wireless device decodes an SCI transmitted from a specific resource, if the destination ID indicated by the SCI is the same as the ID of the first wireless device, the resource may be determined to be used by the second wireless device.

[0220] In the existing technology, source ID information and / or destination ID information can be transmitted via a second-stage SCI. The SCI may be divided into two categories. The first category may include information used for sensing operations, and the second category may include information used for HARQ combining and / or CSI feedback operations. For example, the first category may indicate resource allocation information, resource reservation period, priority level, number of DMRS ports, MCS, and the size of the second-stage SCI. For example, the second category may indicate HARQ process number, NDI, RV, source ID, destination ID, CSI request, zone ID, communication range requirement, HARQ feedback enable / disable indicator, and cast type indicator. The first category can be used for any cast type, while the second category can be used for group cast or unicast. The wireless device can transmit the first-category information via the first-stage SCI and the second-category information via the second-stage SCI. The two-stage SCI may be encoded separately, so the wireless device can decode them separately. In the existing technology, since all the information required for the sensing operation can be indicated via the first-stage SCI, the second-stage SCI may not be required. Returning to ID-based resource exclusion, when the first wireless device wants to know that a specific resource is being used by the second wireless device, second-stage SCI decoding is required. This means that the first wireless device needs to decode all of the first-stage SCI and the second-stage SCI during the sensing procedure, which can increase the complexity of the calculation or decoding and also increase the sensing operation delay because it may take additional time to complete the sensing operation in order to decode the second-stage SCI.

[0221] Exemplary embodiments of the present disclosure define a method for wireless device-assisted resource selection. Exemplary embodiments define procedures or methods for exchanging resource set information between wireless devices and for selecting one or more transmission resources based on the resource set. For example, a first wireless device may receive, from a second wireless device, a message indicating a resource set for excluding resources from a candidate resource set. The first wireless device may first exclude the resources indicated by the resource set from the candidate resource set and then perform sensing and resource selection procedures on the remaining candidate resource set. Exemplary embodiments also define procedures or methods for indicating a candidate resource set from a second wireless device to a first wireless device. For example, the first wireless device may receive, from the second wireless device, a message indicating the candidate resource set, the first wireless device may skip the sensing procedure and selectively perform the sensing procedure on the candidate resource set, or after the sensing procedure, determine an intersection between a first candidate resource set based on sensing and a second candidate resource set provided by the second wireless device. Based on the exemplary embodiments, the first wireless device may select better resources or resources having weak interference observed by the second wireless device. Further, the first wireless device may avoid a half-duplex problem with the second wireless device and the decoding performance may be improved. These and other features of the present disclosure are described below.

[0222] In an exemplary embodiment, the first radio may receive, from a second wireless device, a configuration message indicating a first subset from among a plurality of subsets within a resource pool. For example, the resource pool may be divided into a plurality of subsets within the time domain. In the resource pool, the first subset may include all even slots, and the second subset may include all odd slots. As the number of subsets increases, the nth subset within the resource pool may include a group of slots where each slot of the group of slots satisfies mod(side link slot index, # of subsets)=n-1, where mod(a,b) is the modulo operation of a and b (the remainder after dividing a by b). FIG. 24A shows an example of resource pool partitioning in the time domain when the number of subsets is 2. FIG. 24B shows an example of resource pool partitioning in the time domain when the number of subsets is 4. The number of each slot indicates the subset number. When a plurality of subsets are separated in time, the half-duplex problem can be avoided. For example, the resource pool may be divided into a plurality of subsets within the frequency domain. In the resource pool, the first subset may include a first group of RBs or sub-channels, and the second subset may include a second group of RBs of sub-channels. When the number of subsets increases, more frequency division may be used. FIG. 25A shows an example of resource pool partitioning in the frequency domain when the number of subsets is 2. FIG. 25B shows an example of resource pool partitioning in the frequency domain when the number of subsets is 4. When a plurality of subsets are separated in the frequency domain, in-band emission (IBE) interference is reduced, and the packet latency using one subset can be reduced. For example, the resource pool may be divided into a plurality of subsets in the time and frequency domains. Two parameters may be used. 1) N: time domain division, and 2) M: frequency domain division.The partitioning of each time and frequency domain may be continuously indexed first on an axis (e.g., time first or frequency first), and each index may apply a modular operation to determine a subset index. FIGS. 26A and 26B show examples of resource pool partitioning in the time and frequency domains. In FIG. 26A, it is assumed that N = 2 and M = 2, and the first indexing of frequency is applied. Since there are resources every N slots in each subset, latency issues may be reduced. In FIG. 26B, it is assumed that N = 2 and M = 3, and the first indexing of frequency is applied. Based on one embodiment, the half-duplex problem may be reduced, and IBE interference may also be reduced.

[0223] In one embodiment, a second wireless device may send a configuration message to a first wireless device indicating subset indexes of a plurality of subsets to the first wireless device. The configuration message may further include the N and / or M values of the resource pool partitioning configuration. In one embodiment, the configuration message may further include the number of subsets. In one embodiment, the second wireless device may send a configuration message indicating a bitmap. The bitmap may include a bit array having a predetermined length or a configured length. The configuration message may further include the start offset of the bitmap and / or the number of repetitions of the bitmap. The length, start offset, and / or number of repetitions of the bitmap may be configured by a base station via SIB or RRC, or they may be configured by a wireless device via PC5-RRC or sidelink MAC CE or SCI. The first approach may facilitate the determination of the signaling bit size, while the second approach may be used for a more dynamic representation of resource subsets. This approach may provide better flexibility for time domain subset representation. In one embodiment, the second wireless device may send a configuration message indicating a bitmap and a frequency resource (or partition) index. This approach may further limit the frequency domain from the perspective of the second wireless device.

[0224] In one embodiment, the first wireless device may select a second subset other than the first subset from a plurality of subsets within a resource pool. For example, the first wireless device may exclude the first subset from the candidate resource set and determine the second subset by the remaining resource sets from the candidate resource set. The first subset may be indicated to the second wireless using it. For example, the second wireless device may determine the first subset based on the resource selection of the second wireless device. For example, the second wireless device may indicate a subset that overlaps as much as possible with the transmission resource. The second wireless device may send a configuration message indicating the subset to the first wireless device. When the first wireless device excludes the first subset, it means that the half-duplex problem can be avoided. For example, the second wireless device may identify the subset based on sensing. For example, the second wireless device may indicate that the subset overlaps as much as possible with the worst resources based on SL-RSRP measurement. The second wireless device may send a configuration message indicating the subset to the first wireless device. The first wireless device may avoid selecting resources that are in the worst situation or are subject to strong interference. FIGS. 27A and 27B show examples of resource exclusion. Wireless device #2 may indicate subset index #0, and wireless device #1 may exclude resources within subset #0. Wireless device #1 can select one or more transmission resources only within subset #1.

[0225] In one embodiment, when there are multiple candidates in the second subset, the first wireless device may select a subset considering the half-duplex problem. For example, in the embodiment of FIG. 26B, when the second wireless device indicates subset index #0 to the first wireless device, subset indices #1 and #2 may be excluded, and the first wireless device may select one subset from subset indices #3, 4, 5. The first wireless device may select a second subset based on the first subset indicated by the second wireless device. Based on the embodiment, the wireless device may avoid the half-duplex problem.

[0226] In one embodiment, the number of subsets within a resource pool may be determined based on the number of wireless devices within a group. For example, for a unicast group, two subsets may be sufficient, and for a groupcast including four wireless devices, four subsets may be used. If the number of wireless devices within a group is too large, the remaining subsets may be empty or may include very little time and / or frequency resources. To avoid this, the number of subsets cannot be the same as the number of wireless devices within a group. For example, there may be a mapping table between the number of subsets and the number of wireless devices within a group. FIG. 28 shows an example of a mapping table between the number of subsets within a group and the number of wireless devices. The mapping table may be configured by a base station or a wireless device. For example, the base station may transmit a configuration message indicating the mapping table to the wireless device via SIB or RRC.

[0227] In one embodiment, when the second wireless device transmits a configuration message to the first wireless device to indicate the first subset, the configuration message may be transmitted via a PC5 - RRC or PC5 - S or sidelink MAC CE message. When the first wireless device and the second wireless device may transmit a connection request or connection establishment, the configuration message may be transmitted or received to / from the first wireless device or the second wireless device. These upper layer signals (e.g., PC5 - RRC, PC5 - S, or sidelink MAC CE) may be transmitted on a long - term basis. The first wireless device may not need to decode the second - stage SCI in the sensing or resource selection procedure, and thus the implementation complexity or the SCI decoding latency may be reduced.

[0228] In one embodiment, when a second wireless device transmits a configuration message to a first wireless device to indicate a first subset, the configuration message can be transmitted via sidelink control information. This approach can be used for a more dynamic display of the first subset. The configuration message can be transmitted via a second stage SCI. To avoid over-decoding the second stage SCI, in the first stage SCI, abstracted identity (ID) information can be indicated by using reserved fields. The abstracted ID can be created based on a source ID and / or a destination ID. The source ID and / or the destination ID can be transmitted via the second stage SCI. For example, the abstracted ID can be generated by an XOR operation of the source ID and the destination ID. Further, the XORed ID may be truncated to reduce the bit size. For example, the second wireless device may transmit to the first wireless device an ID field having a reduced size via a reserved field of the first stage SCI and / or abstracted (e.g., a single ID can be determined based on the source ID and the destination ID) information, and the second wireless device may transmit to the first wireless device a configuration message indicating the first subset via the second stage SCI. Based on the ID having the reduced size and / or the abstracted (identification) information, the first wireless device can determine whether to perform second stage SCI decoding during the sensing procedure. Although unnecessary second stage SCI decoding may occur due to the size reduction or abstraction, there may be one or more required second stage SCIs in the decoded second stage SCI. Based on some embodiments, the complexity of the second stage SCI decoding may be reduced, and a more dynamic resource subset display may be supported.

[0229] In one embodiment, the first wireless device may select one or more transmission resources from a second subset. Since some of the worst resources indicated by the second wireless device may already be excluded, the first wireless device may have better transmission resource options. In existing resource selection procedures, a wireless device may evaluate the remaining resource amount (e.g., X%) within candidate resources in a resource pool. If the amount of the remaining resources is greater than X%, the remaining resources may be reported to a higher layer (e.g., the MAC layer). Otherwise, the wireless device may increase a sensing threshold and repeat this procedure until the remaining resources of X% are satisfied. This procedure may have several iterations. When an additional resource exclusion step is applied, the number of total candidate resources (Z) for evaluating X% may decrease. For example, if Y% of the resources are excluded from the candidate resources by excluding the first subset from all the candidate resources, Z * Y resources may be the number of all the candidate resources. In a different way, evaluating X% may be changed to evaluating X * Y% for reporting the remaining resources to a higher layer. Based on some examples, the number of iterations for resource selection / exclusion, or the resource selection processing delay, may be reduced.

[0230] In one embodiment, the first wireless device may transmit one or more transport blocks via one or more transmission resources. The one or more transport blocks may be transmitted to a second wireless device. The one or more transport blocks may be transmitted to a third wireless device. The third wireless device may be a wireless device within the same group as the first wireless device and / or the second wireless device.

[0231] In an exemplary embodiment, the first wireless device may receive, from the second wireless device, a configuration message indicating a subset from among a plurality of subsets within a resource pool. Note that any of the above-described subset indication approaches may be used for subset indication. If the second wireless device indicates an additional candidate resource set (e.g., a subset from among a plurality of subsets within a resource pool), the first wireless device may consider it for resource selection. For example, the first wireless device may select one or more transmission resources from the subset based on sensing. The first wireless device may determine a candidate resource set based on the packet delay budget. This means that the selection window size may be determined based on the packet delay budget. In the candidate resource set, the first wireless device may first determine a second candidate resource set based on the intersection of the candidate resource set and the subset indicated by the second wireless device. The first wireless device may select one or more transmission resources from the second candidate resource set. FIG. 29 shows an example of a diagram of an exemplary embodiment. The second wireless device may indicate a subset within a resource pool. The first wireless device may select a transmission resource within the subset. The dashed box area means the second candidate resource set. In this approach, the sensing complexity may be reduced. In this figure, Resource A does not affect the resource selection of the first wireless device. This is because a reservation for Resource A cannot be in the second candidate resource set. Therefore, the first wireless device may skip the sensing operation for Resource A, thereby reducing the decoding complexity and battery consumption for the sensing operation.

[0232] In an exemplary embodiment, the first wireless device may receive, from a second wireless device, a message including one or more first candidate resources for the second wireless device. The first wireless device may determine one or more second candidate resources based on sensing. The sensing may include measuring a sidelink reference signal power (SL-RSRP) and, based on the SL-RSRP, comparing it with a threshold to exclude one or more resources in a candidate resource set, and based on the exclusion, determining one or more second candidate resources from the candidate resource set. FIG. 30 shows an example of a resource selection procedure. The second wireless device may indicate one or more first candidate resources to the first wireless device based on sensing or selection of a transmission resource. The first wireless device may execute a sensing procedure and determine one or more second candidate resources. The first wireless device may determine one or more third candidate resources based on the intersection of the one or more first candidate resources and the one or more second candidate resources. In this figure, the overlapping part is the one or more third candidate resources. The first wireless device may report the third candidate resources to a higher layer (e.g., the MAC layer), and the higher layer may determine one or more transmission resources. In one embodiment, the first wireless device may report the same one or more second candidate resources as the existing operation. The MAC layer can determine one or more third candidate resources based on the intersection of the one or more first candidate resources and the one or more second candidate resources. The difference between the approaches may be which layer (e.g., the PHY layer or the MAC layer) is responsible for this operation. The first wireless device may select one or more transmission resources from the one or more third candidate resources and transmit one or more transport blocks via the one or more transmission resources. Based on the embodiment, the wireless device may maintain the existing procedures as much as possible, but by determining the intersecting resources, the wireless device may select better resources for sidelink transmission.

[0233] In an exemplary embodiment, the first wireless device may receive, from a second wireless device, a message including one or more first candidate resources for the second wireless device. In response to receiving the message, the first wireless may skip a sensing operation for determining one or more candidate resources.

[0234] Thereby, the processing delay for sensing or skipping a sensing operation for a time window can be reduced. For example, the period or time window for skipping the sensing operation may be (pre-)configured or fixed. For example, the first wireless device may send a first configuration message to the second wireless device indicating a request for assistance information for resource selection. The second wireless device may send a second configuration message to the first wireless device indicating one or more first candidate resources as assistance information. The second configuration message may further include the size of the time window for the validity of the assistance information. The size of the time window may be (pre-)configured by the second wireless device based on channel variation or mobility. Based on the vehicle speed, the window size may be determined. For example, the size of the time window may be (pre-)configured by a base station. The base station may send a configuration message to the first wireless device indicating the size of the window or a timer for skipping the sensing operation. The first wireless device may be triggered to start a timer for skipping the sensing operation when there is assistance information from the time the second wireless device was received. The configuration message may be sent via RRC or SIB. FIG. 31 shows an example of a signal flow.

[0235] The first wireless device may report the first candidate resources to an upper layer (e.g., the MAC layer), or the MAC layer may ignore one or more second candidate resources if they are reported by a lower layer (e.g., the PHY layer) based on sensing. FIG. 32 shows an example of resource selection. The first wireless device may select one or more transmission resources from one or more first candidate resources and transmit one or more transport blocks via the one or more transmission resources. The one or more transport blocks may be transmitted to a second wireless device. In one embodiment, the first wireless device may transmit a configuration message indicating a resource selection trigger time and a packet delay budget to the second wireless device. The configuration message may further include a processing delay (or the ability of the processing delay, where the ability may indirectly indicate the processing delay) between the resource reselection trigger time and the start time of the selection window. These parameters may be useful for providing one or more first candidate resources from the second wireless device. The second wireless device may determine one or more first candidate resources based on at least one of the parameters such as the resource reselection trigger time (e.g., a slot), the packet delay budget, and the processing delay between the resource reselection trigger time and the start time of the selection window.

[0236] In an exemplary embodiment, the first wireless device may receive, from a base station, a message indicating activation or deactivation of wireless device assistance resource selection. For example, the message may be an SIB or an RRC message. Any example or embodiment mentioned in different paragraphs for a second wireless device that provides a subset of resources or one or more resources may be referred to as wireless device assistance resource selection. When the indication is shown to be valid, the first wireless device may receive, from the second wireless device, a subset of resources or one or more resources for resource selection of the first wireless device. The indication may be applied to a resource pool or a group of wireless devices, or a bandwidth part or a carrier. In some scenarios, for example, in an interference-limited scenario, the transmitter-side sensing operation is not accurate and the system performance may not be sufficient. In this case, the base station may indicate that the wireless device assistance resource selection operation is enabled for the resource pool. The wireless device selecting the resource pool may have some assistance information from a receiving wireless device or other wireless devices in the same group. Based on the example, the overall system performance or packet reception ratio may be improved.

[0237] In an exemplary embodiment, the first wireless device may receive, from a base station, a message indicating an option of a wireless device assistance resource selection method. For example, the message may be an SIB or an RRC message. Any example or embodiment mentioned in different paragraphs for a second wireless device that provides a subset of resources or one or more resources may be referred to as a wireless device assistance resource selection method. The base station may select one option and indicate it to the wireless device. The second wireless device may indicate a subset of resources to assist in resource selection for the first wireless device.

[0238] In one embodiment, the first wireless device may receive, from a second wireless device, a configuration message indicating one or more first resources within a resource pool. The first wireless device may select one or more second resources based on the one or more first resources within the resource pool. The first wireless device may select one or more transmission resources from the one or more selected resources. The first wireless device may transmit one or more transport blocks to the second wireless device via the one or more transmission resources.

[0239] In one embodiment, the first wireless device may receive, from a second wireless device, a configuration message indicating a first subset from a plurality of subsets within a resource pool. The first wireless device may select a second subset other than the first subset from the plurality of subsets within the resource pool. The first wireless device may select one or more transmission resources from the second subset. The first wireless device may transmit one or more transport blocks to the second wireless device via the one or more transmission resources. For example, a subset of the plurality of subsets within the resource pool may include resources that are temporally separated from other subsets. For example, the message may be received via a sidelink radio resource control message. For example, the first wireless device and the second wireless device may belong to a group. For example, the number of subsets may be determined based on the number of members within the group. For example, the group may be a unicast group or a groupcast group. For example, a subset from the plurality of subsets within the resource pool may include one or more slots within the resource pool.

[0240] In one embodiment, the first wireless device may receive, from a second wireless device, a configuration message indicating a first subset from among a plurality of subsets within a resource pool. Based on sensing, the first wireless device may select one or more transmission resources from the subset. The first wireless device may transmit one or more transport blocks to the second wireless device via the one or more transmission resources. For example, the configuration message may be received via a sidelink radio resource control message.

[0241] In one example, the first wireless device may receive, from the second wireless device, a message including one or more first candidate resources for the second wireless device. Based on sensing, the first wireless device may determine one or more second candidate resources. The first wireless device may determine one or more third candidate resources based on an intersection of the one or more first candidate resources and the one or more second candidate resources. The first wireless device may select one or more transmission resources from the one or more third candidate resources. The first wireless device may transmit one or more transport blocks via the one or more transmission resources.

[0242] In one example, the first wireless device may receive, from the second wireless device, a message including one or more first candidate resources for the second wireless device. In response to receiving the message, the first wireless device may skip a sensing operation for determining one or more candidate resources. The first wireless device may select one or more transmission resources from the one or more first candidate resources. The first wireless device may transmit one or more transport blocks via the one or more transmission resources.

Claims

1. A method comprising: a first wireless device receiving, from a base station, a system information block, the system information block including: radio resources of a sidelink resource pool; and an indication of whether wireless device assisted resource selection is enabled or disabled for the sidelink resource pool; the first wireless device receiving, from a second wireless device via a sidelink, a configuration message indicating a subset from a plurality of subsets within the sidelink resource pool based on the indication that the wireless device assisted resource selection is enabled; the first wireless device selecting, based on a sensing operation, one or more transmission resources from the subset; and the first wireless device transmitting one or more transport blocks via the one or more transmission resources.

2. The method according to claim 1, wherein the first wireless device and the second wireless device belong to a group.

3. The method according to claim 2, wherein the number of subsets of the plurality of subsets within the sidelink resource pool is determined based on the number of members within the group.

4. The method according to any one of claims 2 to 3, wherein the group is a unicast group or a groupcast group.

5. The method according to any one of claims 1 to 4, wherein the subset includes one or more first resources within the sidelink resource pool.

6. A wireless device comprising: one or more processors; and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform the method according to any one of claims 1 to 5.

7. A non-transitory computer-readable medium including instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any one of claims 1 to 5.

8. A method comprising: a first wireless device receiving, from a base station, a system information block, the system information block including: ​ ​ ​ The wireless resources of a sidelink resource pool, and an indication of whether wireless device assisted resource selection is enabled or disabled for the sidelink resource pool and, the first wireless device transmitting, based on the indication that the wireless device assisted resource selection is enabled, a configuration message to a second wireless device via a sidelink, indicating a subset from among a plurality of subsets within the sidelink resource pool the first wireless device receiving, in response to the transmitting, one or more transport blocks via one or more transmission resources from the subset A method comprising: **Claim 9** The method according to claim 8, wherein the first wireless device and the second wireless device belong to a group. **Claim 10** The method according to claim 9, wherein the number of subsets of the plurality of subsets within the sidelink resource pool is determined based on the number of members within the group. **Claim 11** The method according to any one of claims 9 to 10, wherein the group is a unicast group or a groupcast group. **Claim 12** The method according to any one of claims 8 to 11, wherein the subset includes one or more first resources within the sidelink resource pool. **Claim 13** A wireless device, comprising: one or more processors; and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform the method according to any one of claims 8 to 12. A wireless device comprising: **Claim 14** A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any one of claims 8 to 12. **Claim 15** A system, comprising: a base station; and a first wireless device, the first wireless device comprising one or more first processors and a first memory storing first instructions that, when executed by the one or more first processors, receive a system information block from the base station, the system information block comprising The radio resources of the sidelink resource pool, and an indication of whether radio device assisted resource selection is enabled or disabled for the sidelink resource pool, and and receiving, from a second radio device via a sidelink, a configuration message indicating a subset from among a plurality of subsets within the sidelink resource pool, based on the indication that the radio device assisted resource selection is enabled; selecting, based on a sensing operation, one or more transmission resources from the subset; causing the first radio device to transmit one or more transport blocks via the one or more transmission resources A first memory for including, a first radio device, the second radio device, the second radio device including one or more second processors and a second memory storing second instructions, which when executed by the one or more second processors, transmit the configuration message indicating the subset from among the plurality of subsets within the sidelink resource pool; receive the one or more transport blocks via the one or more transmission resources A second memory for including, a second radio device including, a system.

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