Hybrid Confirmation-Related Iteration Request Feedback Iteration

Abstract

In some embodiments, a wireless device transmits a message A including a preamble and a transport block in response to triggering a two-step random access (RA) procedure. The wireless device receives a message B including an RA response indicating a first number of times to repeat transmission of Hybrid Acknowledgment Repeat Request (HARQ) feedback corresponding to message B. The wireless device then repeats transmission of the HARQ feedback the first number of times via an uplink control channel.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 040,745, filed June 18, 2020, which is incorporated herein by reference in its entirety. Summary of the Invention [Means for solving the problem]

[0002] In this disclosure, various embodiments are presented as examples of how the disclosed technology may be implemented and / or how the disclosed technology may be practiced in environments and scenarios. It will be apparent to those skilled in the relevant art that various changes in form and detail can be made without departing from the scope. Indeed, after reading the specification, it will become apparent to those skilled in the relevant art how to implement alternative embodiments. The present embodiments should not be limited by any of the exemplary embodiments. Embodiments of the present disclosure are described with reference to the accompanying drawings. Limitations, features, and / or elements from the disclosed exemplary embodiments may be combined to create further embodiments within the scope of the present disclosure. Figures highlighting features and advantages are shown by way of example only. The disclosed architecture is sufficiently flexible and configurable to be utilized in ways other than those shown. For example, the actions listed in any flowchart may be rearranged in some embodiments or used only as options. The present invention provides, for example, the following. (Item 1) 1. A method comprising: transmitting, by the wireless device, a message A including a preamble and a transport block in response to triggering a two-step random access (RA) procedure; monitoring a downlink control channel for downlink control information scheduling message B corresponding to message A; receiving the downlink control information indicating physical downlink shared channel (PDSCH) resources for the message B; receiving, via the PDSCH resource, the message B including an RA response, the RA response indicating a first repetition number of a Hybrid Acknowledgment Repeat Request (HARQ) feedback transmission corresponding to the message B; and transmitting the HARQ feedback indicating an acknowledgment of the receipt of the message B over an uplink control channel at the first repetition number. (Item 2) 1. A method comprising: transmitting, by the wireless device, a message A including a preamble and a transport block in response to triggering a two-step random access (RA) procedure; receiving message B including an RA response indicating a first repetition number of a Hybrid Acknowledgment Repeat Request (HARQ) feedback transmission corresponding to message B; transmitting the HARQ feedback at the first number of repetitions over an uplink control channel. (Item 3) Item 3. The method of item 2, further comprising monitoring a downlink control channel for downlink control information scheduling the message B corresponding to the message A. (Item 4) 4. The method of claim 3, further comprising receiving the downlink control information indicating a physical downlink shared channel (PDSCH) resource for the message B, wherein the message B is received via the PDSCH resource. (Item 5) 5. The method according to any one of items 2 to 4, wherein the HARQ feedback indicates an acknowledgement of receipt of the message B. (Item 6) 6. The method according to any one of items 2 to 5, wherein the RA response indicates a first number of times to repeat transmission of the HARQ feedback, and wherein transmitting the HARQ feedback at the first number of repetitions includes repeating transmission of the HARQ feedback at the first number of repetitions. (Item 7) the transport block of the message A, which contains a control channel service data unit (SDU); 7. The method of any one of items 2 to 6, further comprising completing the two-step RA procedure in response to the RA response of the message B including a contention resolution identity indicating the control channel SDU. (Item 8) The message B is a Medium Access Control (MAC) subheader including a preamble index identifying the preamble of the message A; A MAC payload including the RA response. (Item 9) 9. The method according to any one of items 2 to 8, wherein the RA response includes an uplink control channel resource indicator indicating the uplink control channel. (Item 10) The RA response of the message B is conflict resolution identity, a transmit power control command for the HARQ feedback; Timing Advance command, or 10. The method according to any one of items 2 to 9, comprising at least one of a cell radio network temporary identifier. (Item 11) 11. The method according to any one of items 2 to 10, wherein the RA response comprises a successRAR MAC protocol data unit (PDU). (Item 12) Initiating beam obstruction recovery; and receiving a radio resource control (RRC) reconfiguration message for handover to the second cell; receiving a physical downlink control channel (PDCCH) command; an initial access to the cell; triggering a positioning procedure; 12. The method of claim 2, further comprising: triggering the two-step RA procedure in response to at least one of: triggering an uplink coverage restoration procedure; (Item 13) 13. The method according to any one of items 2 to 12, wherein the HARQ feedback comprises a positive acknowledgement for message B in response to successful reception of message B. (Item 14) 14. The method of any one of items 2 to 13, further comprising receiving one or more messages indicating a number of iterations. (Item 15) Item 15. The method of item 14, wherein the RA response indicates the first iteration number from the plurality of iteration numbers. (Item 16) 16. The method according to any one of items 2 to 15, wherein the RA response includes a HARQ feedback timing indicator indicating a slot number for the HARQ feedback. (Item 17) Item 17. The method of item 16, further comprising transmitting the HARQ feedback in a second slot that occurs the number of slots after a first slot during which the message B is received. (Item 18) Item 18. The method according to any one of items 4 to 17, wherein the monitoring of the downlink control channel is in response to transmitting the message A. (Item 19) 19. The method according to any one of items 4 to 18, further comprising receiving, during the monitoring of the downlink control channel, the downlink control information scrambled by an RA Radio Network Temporary Identifier (RA-RNTI), the downlink control information including cyclic redundancy check bits. (Item 20) 20. The method of any one of items 4 to 19, further comprising monitoring the downlink control channel after transmitting the message A a second number of times. (Item 21) 22. The method of claim 21, wherein the second number of times is the same as the first number of times. (Item 22) 21. The method according to any one of items 2 to 20, wherein one or more bits of the RA response of the message B indicate the first number of times. (Item 23) the one or more bits of the RA response include an uplink control channel resource indicator; the uplink control channel resource indicator indicates the uplink control channel; 23. The method of claim 22, wherein the uplink control channel is associated with the first number of times. (Item 24) 24. The method of claim 22 or 23, wherein the one or more bits include one or more reserved bits of the RA response of the message B. (Item 25) 25. The method of any one of items 2 to 24, further comprising transmitting the message A a second number of times, the second number of times being determined based on the wireless device being of a first wireless device type. (Item 26) 26. The method of claim 25, wherein the wireless device of the first wireless device type is configured with a first number of receive antennas, the first number of receive antennas being smaller than a second number of receive antennas configured for a second wireless device type. (Item 27) 27. The method of claim 25 or 26, further comprising communicating with a base station by the wireless device of the first wireless device type within a first bandwidth that is smaller than a second bandwidth configured for a wireless device of a second wireless device type. (Item 28) said transmitting said message A; transmitting the preamble over a random access channel (RACH) resource; 28. The method according to any one of claims 2 to 27, comprising: for the two-step RA procedure, transmitting the transport block via a Physical Uplink Shared Channel (PUSCH) resource associated with the RACH resource. (Item 29) 29. The method of claim 28, further comprising receiving one or more radio resource control (RRC) messages including configuration parameters for the RACH resources and configuration parameters for the PUSCH resources for the two-step RA procedure. (Item 30) 30. The method of claim 29, wherein the one or more RRC messages indicate the second number of repetitions for the message A. (Item 31) 31. The method of any one of items 2 to 30, further comprising receiving one or more messages indicating a random access (RA) search space (SS) on a first initial bandwidth portion (BWP) of the cell. (Item 32) 32. The method of claim 31, further comprising monitoring a downlink control channel for downlink control information scheduling the message B via the RASS of the first initial BWP of the cell. (Item 33) Item 33. The method of item 32, wherein the first initial BWP of the cell is different from a second initial BWP of the cell for a second wireless device that is a second wireless device type different from the first wireless device type of the wireless device. (Item 34) The RA SS is an SS identifier for identifying the RA SS; Parameters indicating a downlink control channel monitoring period and a slot offset; the duration of the RASs; The number of symbols in the slot, Number of candidates, or 34. The method according to any one of items 31 to 33, comprising one or more parameters including at least one of the number of iterations for the RASS. (Item 35) 35. The method of claim 34, further comprising monitoring a downlink control channel for downlink control information scheduling message B based on the one or more parameters and via the RASS. (Item 36) 36. The method of claim 35, further comprising receiving the downlink control information at the first number of repetitions during the monitoring. (Item 37) 37. The method of any one of items 2 to 36, further comprising determining a reference signal (RS) from a plurality of RSs based on a measured RSRP of the RSs and a reference signal reception (RSRP) threshold. (Item 38) Item 38. The method of item 37, wherein the RS is determined from the plurality of RSs based on the RSRP being higher than the RSRP threshold. (Item 39) Item 39. The method of item 37 or 38, further comprising determining the RACH configuration from a plurality of RACH configurations for the two-step RA procedure based on a RACH configuration associated with the RS. (Item 40) The RACH configuration: a second number of repetitions for the preamble of the message A; one or more RSs associated with said RACH configuration; Starting frequency resource block, the RSRP threshold, Preamble reception target power value, the number of preamble transmissions allowed, or Item 39. The method of item 39, associated with at least one of the response windows for receiving an RA response. (Item 41) 41. The method of claim 39 or 40, wherein the RACH configuration is associated with the second number of repetitions for the preamble of the message A, and the method further comprises transmitting the preamble with the second number of repetitions via a RACH resource indicated by the RACH configuration. (Item 42) Item 42. The method of item 41, wherein the second number of times is different from the first number of times. (Item 43) determining a PUSCH resource associated with the RACH configuration, the PUSCH resource comprising: a third repetition number for the transport block of the message A; modulation and coding schemes, Number of slots, Start symbol, Indication of PUSCH mapping type, Storing frequency blocks, or 43. The method of any one of items 39 to 42, configured with parameters including at least one of the demodulation reference signal configurations. (Item 44) 44. The method of claim 43, wherein the PUSCH configuration is associated with the third number of repetitions, and the method comprises transmitting the transport block of the message A over the PUSCH resource indicated by a parameter of the PUSCH resource at the third number of repetitions. (Item 45) Item 45. The method of item 43 or 44, wherein the third number of times is the same as the second number of times. (Item 46) 1. 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 perform the method described in any one of items 1 to 45. (Item 47) 46. ​​A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method of any one of items 1 to 45. (Item 48) 1. A method comprising: receiving a message A including a preamble and a transport block in response to a two-step random access (RA) procedure triggered by a base station from a wireless device; transmitting a message B to the wireless device, the message B including an RA response indicating a first repetition number of a Hybrid Acknowledgment Repeat Request (HARQ) feedback transmission corresponding to the message B; receiving the HARQ feedback at the first number of iterations via an uplink control channel. (Item 49) A base station, 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 described in item 48. (Item 50) 49. 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 described in item 48. (Item 51) 1. A method comprising: receiving, by the wireless device, a configuration parameter indicating a first number of repetitions of a physical uplink control channel (PUCCH) resource; transmitting a message A including a preamble and a transport block based on triggering a two-step random access (RA) procedure; receiving a message B including an RA response indicating the PUCCH resource for acknowledgment feedback; and transmitting the acknowledgement feedback over the PUCCH resource for the first number of iterations. (Item 52) 52. The method of claim 51, wherein the configuration parameters further indicate a number of repetitions of the PUCCH resource, the number of repetitions including the first number of repetitions. (Item 53) 53. The method of claim 52, further comprising receiving downlink control information that schedules the message B corresponding to the message A based on transmitting the message A, the downlink control information indicating the first number of times for the acknowledgment corresponding to the message B from the plurality of times. (Item 54) 54. The method of claim 53, wherein transmitting the acknowledgement feedback includes determining the first number of repetitions of the acknowledgement feedback based on the downlink control information indicating the first number of times. (Item 55) 55. The method of any one of items 51 to 54, wherein the first number of repetitions comprises the first number of times for repeating the transmission of the acknowledgement feedback, and wherein the transmitting comprises repeating the transmission of the acknowledgement feedback the first number of times. (Item 56) The configuration parameters are: 56. The method according to any one of items 51 to 55, further indicating a random access channel (RACH) resource associated with the PUSCH resource. (Item 57) said transmitting said message A; transmitting the preamble over the RACH resource; 57. The method of claim 56, comprising transmitting the transport block over the PUSCH resource. (Item 58) 58. The method according to any one of items 51 to 57, wherein the message B corresponds to the message A. (Item 59) 59. A method according to any one of items 51 to 58, wherein the RA response indicates that the PUCCH resource corresponds to the confirmation feedback corresponding to the message B. (Item 60) Item 59. The method of any one of items 51 to 59, further comprising monitoring a downlink control channel for downlink control information scheduling the message B corresponding to the message A. (Item 61) 61. The method of any one of items 51 to 60, wherein the acknowledgement feedback comprises hybrid acknowledgement repeat request (HARQ) feedback. (Item 62) 62. The method of claim 60 or 61, comprising receiving the downlink control information indicating a physical downlink shared channel (PDSCH) resource for the message B, wherein the message B is received via the PDSCH resource. (Item 63) Item 63. The method according to any one of items 51 to 62, wherein the acknowledgement feedback indicates an acknowledgement of the receipt of the message B. (Item 64) 64. A method according to any one of items 56 to 63, wherein the RA response indicates a first number of times to repeat the transmission of the acknowledgement feedback, and wherein sending the acknowledgement feedback at the first number of repetitions includes repeating the transmission of the acknowledgement feedback at the first number of repetitions. (Item 65) the transport block of the message A, which contains a control channel service data unit (SDU); 65. The method of any one of items 51 to 64, further comprising completing the two-step RA procedure in response to the RA response of the message B including a contention resolution identity indicating the control channel SDU. (Item 66) The message B is a Medium Access Control (MAC) subheader including a preamble index identifying the preamble of the message A; A method according to any one of items 51 to 65, comprising: a MAC payload including the RA response. (Item 67) 67. The method according to any one of items 51 to 66, wherein the RA response includes an uplink control channel resource indicator indicating the uplink control channel. (Item 68) The RA response of the message B is Conflict Resolution Identity, a transmit power control command in response to said acknowledgement feedback; Timing Advance command, or Item 68. The method of any one of items 51 to 67, including at least one of a cell radio network temporary identifier. (Item 69) Item 69. The method of any one of items 51 to 68, wherein the RA response includes a successRAR MAC protocol data unit (PDU). (Item 70) Initiating beam obstruction recovery; and receiving a radio resource control (RRC) reconfiguration message for handover to the second cell; receiving a physical downlink control channel (PDCCH) command; an initial access to the cell; triggering a positioning procedure; 70. The method of any one of items 51 to 69, further comprising triggering the two-step RA procedure in response to at least one of: triggering an uplink coverage restoration procedure; (Item 71) Item 71. The method of any one of items 51 to 70, wherein the acknowledgement feedback comprises a positive acknowledgement to message B in response to successful receipt of message B. (Item 72) 72. The method according to any one of items 51 to 71, wherein the RA response includes an acknowledgement feedback timing indicator indicating the number of slots for the acknowledgement feedback. (Item 73) Item 73. The method of item 72, further comprising transmitting the acknowledgement feedback in a second slot that occurs the number of slots after a first slot during which the message B is received. (Item 74) Item 74. The method according to any one of items 60 to 73, wherein the monitoring of the downlink control channel is in response to transmitting the message A. (Item 75) 75. The method of any one of items 60 to 74, further comprising receiving, during the monitoring of the downlink control channel, the downlink control information scrambled by an RA Radio Network Temporary Identifier (RA-RNTI), the downlink control information including cyclic redundancy check bits. (Item 76) 76. The method of any one of items 60 to 75, further comprising monitoring the downlink control channel after transmitting the message A a second number of times. (Item 77) 22. The method of claim 21, wherein the second number of times is the same as the first number of times. (Item 78) Item 78. The method according to any one of items 51 to 77, wherein one or more bits of the RA response of the message B indicate the first number of times. (Item 79) the one or more bits of the RA response include an uplink control channel resource indicator; the uplink control channel resource indicator indicates the uplink control channel; Item 79. The method of item 78, wherein the uplink control channel is associated with the first number of times. (Item 80) 80. The method of claim 78 or 79, wherein the one or more bits include one or more reserved bits of the RA response of the message B. (Item 81) 81. The method of any one of items 78 to 80, further comprising transmitting the message A a second number of times, the second number of times being determined based on the wireless device being of a first wireless device type. (Item 82) Item 82. The method of item 81, wherein the wireless device of the first wireless device type is configured with a first number of receive antennas, the first number of receive antennas being smaller than a second number of receive antennas configured for a second wireless device type. (Item 83) Item 83. The method of item 81 or 82, further comprising communicating with a base station by the wireless device of the first wireless device type within a first bandwidth smaller than a second bandwidth configured for a wireless device of a second wireless device type. (Item 84) 84. The method according to any one of items 51 to 83, further comprising receiving one or more Radio Resource Control (RRC) messages including configuration parameters of the PUSCH resources for the two-step RA procedure. (Item 85) Item 85. The method of item 84, wherein the configuration parameters of the RACH resource are associated with the PUSCH resource for the two-step RA procedure. (Item 86) Item 86. The method of item 84 or 85, wherein the one or more RRC messages indicate the second number of repetitions for message A. (Item 87) 87. The method of any one of items 51 to 86, further comprising receiving one or more messages indicating a random access (RA) search space (SS) on a first initial bandwidth portion (BWP) of the cell. (Item 88) Item 88. The method of item 87, further comprising monitoring a downlink control channel for downlink control information scheduling the message B via the RASS of the first initial BWP of the cell. (Item 89) Item 89. The method of item 88, wherein the first initial BWP of the cell is different from a second initial BWP of the cell for a second wireless device that is of a second wireless device type different from the first wireless device type of the wireless device. (Item 90) The RA SS is an SS identifier for identifying the RA SS; Parameters indicating a downlink control channel monitoring period and a slot offset; the duration of the RASs; The number of symbols in the slot, Number of candidates, or 90. The method of any one of items 87 to 89, comprising one or more parameters, including at least one of the number of iterations for the RASS. (Item 91) 91. The method of claim 90, further comprising monitoring a downlink control channel for downlink control information scheduling message B based on the one or more parameters and via the RASS. (Item 92) Item 92. The method of item 91, further comprising, during the monitoring, receiving the downlink control information at the first number of repetitions. (Item 93) 93. The method of any one of items 51 to 92, further comprising determining a reference signal (RS) from a plurality of RSs based on a measured RSRP of the RSs and a reference signal reception (RSRP) threshold. (Item 94) Item 94. The method of item 93, wherein the RS is determined from the plurality of RSs based on the RSRP being higher than the RSRP threshold. (Item 95) Item 95. The method of item 93 or 94, further comprising determining a RACH configuration from a plurality of RACH configurations for the two-step RA procedure based on the RACH configuration associated with the RS. (Item 96) The RACH configuration: a second number of repetitions for the preamble of the message A; one or more RSs associated with said RACH configuration; Starting frequency resource block, the RSRP threshold, Preamble reception target power value, the number of preamble transmissions allowed, or Item 96. The method of item 95, associated with at least one of the response windows for receiving an RA response. (Item 97) Item 97. The method of item 95 or 96, wherein the RACH configuration is associated with the second number of repetitions for the preamble of the message A, and the method further includes transmitting the preamble with the second number of repetitions via a RACH resource indicated by the RACH configuration. (Item 98) Item 98. The method of item 97, wherein the second number of times is different from the first number of times. (Item 99) determining a PUSCH resource associated with the RACH configuration, the PUSCH resource comprising: a third repetition number for the transport block of the message A; modulation and coding schemes, Number of slots, Start symbol, Indication of PUSCH mapping type, Storing frequency blocks, or Item 99. The method of any one of items 95 to 98, configured with parameters including at least one of the demodulation reference signal configurations. (Item 100) Item 99. The method of item 99, wherein the PUSCH configuration is associated with the third number of repetitions, and the method includes transmitting the transport block of the message A over the PUSCH resource indicated by a parameter of the PUSCH resource at the third number of repetitions. (Item 101) Item 101. The method of item 99 or 100, wherein the third number of times is the same as the second number of times. (Item 102) 1. 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 perform the method described in any one of items 51 to 101. (Item 103) A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method of any one of items 51 to 101. (Item 104) 1. A method comprising: transmitting, by the base station to the wireless device, a configuration parameter indicating a first number of repetitions of a physical uplink control channel (PUCCH) resource; receiving a message A including a preamble and a transport block based on a triggered two-step random access (RA) procedure; sending a message B including an RA response indicating the PUCCH resource for acknowledgment feedback; receiving the acknowledgement feedback over the PUCCH resource at the first iteration number. (Item 105) A base station, 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 described in item 104. (Item 106) 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 described in item 104. [Brief explanation of the drawings]

[0003] Some examples of various embodiments of the present disclosure are described herein with reference to the drawings.

[0004] [Figure 1A] 1 illustrates an example of a mobile communication network in which embodiments of the present disclosure may be implemented. [Figure 1B] 1 illustrates an example of a mobile communication network in which embodiments of the present disclosure may be implemented. [Figure 2A] The New Radio (NR) user plane and control plane protocol stacks are shown, respectively. [Figure 2B] The New Radio (NR) user plane and control plane protocol stacks are shown, respectively. [Figure 3] 2B illustrates an example of services provided between protocol layers of the NR user plane protocol stack of FIG. 2A. [Figure 4A] 2B illustrates an exemplary downlink data flow through the NR user plane protocol stack of FIG. 2A. [Figure 4B] 1 shows an example of the format of a MAC subheader in a MAC PDU. [Figure 5A] The mapping between downlink and uplink logical, transport, and physical channels is shown, respectively. [Figure 5B] The mapping between downlink and uplink logical, transport, and physical channels is shown, respectively. [Figure 6] FIG. 1 is an exemplary diagram illustrating RRC state transitions of a UE. [Figure 7] 1 shows an example of the configuration of an NR frame in which OFDM symbols are grouped. [Figure 8] 1 shows an example of a slot configuration in the time and frequency domain of an NR carrier. [Figure 9] An example of bandwidth adaptation using three configured BWPs for an NR carrier is shown. [Figure 10A] Three carrier aggregation configurations with two component carriers are shown. [Figure 10B] 10 shows an example of how aggregation cells can be configured into one or more PUCCH groups. [Figure 11A] 1 shows an example of an SS / PBCH block structure and location. [Figure 11B] 1 illustrates an example of a CSI-RS mapped to the time and frequency domain. [Figure 12A] Three examples of downlink and uplink beam management procedures are shown, respectively. [Figure 12B] Three examples of downlink and uplink beam management procedures are shown, respectively. [Figure 13A] A four-step contention-based random access procedure, a two-step contention-free random access procedure, and an alternative two-step random access procedure are shown, respectively. [Figure 13B] A four-step contention-based random access procedure, a two-step contention-free random access procedure, and an alternative two-step random access procedure are shown, respectively. [Figure 13C] A four-step contention-based random access procedure, a two-step contention-free random access procedure, and an alternative two-step random access procedure are shown, respectively. [Figure 14A] 10 shows an example of a CORESET configuration for bandwidth portions. [Figure 14B] 10 shows an example of CCE to REG mapping for DCI transmission on CORESET and PDCCH processing. [Figure 15] 1 illustrates an embodiment of a wireless device in communication with a base station. [Figure 16A] 1 shows an exemplary structure for uplink and downlink transmission. [Figure 16B] 1 shows an exemplary structure for uplink and downlink transmission. [Figure 16C] 1 shows an exemplary structure for uplink and downlink transmission. [Figure 16D] 1 shows an exemplary structure for uplink and downlink transmission. [Figure 17A] 10 shows an example of a MAC subheader. [Figure 17B]10 shows an example of a MAC subheader. [Figure 17C] 10 shows an example of a MAC subheader. [Figure 18A] 1 illustrates an example of a DL MAC PDU. [Figure 18B] 1 shows an example of a UL MAC PDU. [Figure 19] 10 shows an example of multiple LCIDs for downlink. [Figure 20] 1 shows an example of multiple LCIDs for the uplink. [Figure 21A] An example of a SCell activation / deactivation MAC CE format is shown below. [Figure 21B] An example of a SCell activation / deactivation MAC CE format is shown below. [Figure 22] An example of BWP activation / deactivation on a SCell is shown. [Figure 23A] An example of MIB configuration parameters is shown below. [Figure 23B] An example of MIB configuration parameters is shown below. [Figure 23C] An example of MIB configuration parameters is shown below. [Figure 24] 10 shows an example of an RRC configuration for an SIB1 message. [Figure 25] 1 shows an example of an RRC configuration for downlink BWP. [Figure 26] 1 shows an example of an RRC configuration of the search space. [Figure 27] 1 shows an example of an RRC configuration for two-step RACH on uplink BWP. [Figure 28] 1 shows an example of an RRC configuration for RACH. [Figure 29] 1 shows an example of an RRC configuration for RACH. [Figure 30] 1 shows an example of an RRC configuration for RACH. [Figure 31] 1 shows a flowchart of an exemplary RA procedure involving selection between a two-step RA type and a four-step RA type, according to some embodiments. [Figure 32]1 shows an example of an RRC configuration for RACH. [Figure 33A] 1 illustrates an example of an RA procedure with coverage enhancement, according to some embodiments. [Figure 33B] 1 illustrates an example of an RA procedure with coverage enhancement, according to some embodiments. [Figure 34] 1 illustrates an example of an RA procedure with RA type selection and coverage enhancement, according to some embodiments. [Figure 35] 1 shows an example of an RA procedure with RA type selection and coverage enhancement. [Figure 36] 1 illustrates an example of an RA procedure with coverage enhancement, according to some embodiments. [Figure 37A] 1 illustrates an example PDCCH configuration for an RA procedure, according to some embodiments. [Figure 37B] 1 illustrates an example PDCCH configuration for an RA procedure, according to some embodiments. [Figure 38] 1 illustrates an example PDCCH configuration for an RA procedure, according to some embodiments. [Figure 39] 1 illustrates an example PDCCH configuration for an RA procedure, according to some embodiments. [Figure 40] 1 illustrates a flowchart of an example of system information reception and random access for a wireless device, according to some embodiments. [Figure 41] 1 illustrates an example of an iteration of an RA procedure, according to some embodiments. [Figure 42] 10 illustrates an example of a repetitive indication of PUCCH resources for an RA procedure, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0005] Embodiments may be configured to operate as needed. The disclosed mechanisms may be executed when certain criteria are met, for example, in a wireless device, a base station, a wireless environment, a network, a combination of the above, etc. Exemplary criteria may be based at least in part on, for example, wireless device or network node configuration, traffic load, initial system settings, packet size, traffic characteristics, a combination of the above, etc. Once one or more criteria are met, various exemplary embodiments may be applied. Thus, it may be possible to implement exemplary embodiments that selectively implement the disclosed protocols.

[0006] A base station can communicate with a mix of wireless devices. Wireless devices and / or base stations can support multiple technologies and / or multiple releases of the same technology. Wireless devices may have certain capabilities depending on the category and / or capabilities of the wireless devices. When this disclosure refers to a base station communicating with multiple wireless devices, this disclosure may also refer to a subset of all wireless devices in the coverage area. For example, this disclosure may refer to multiple wireless devices of a given LTE or 5G release that include a given capability and are located in a given sector of the base station. In this disclosure, multiple wireless devices may refer to selected wireless devices and / or a subset of all wireless devices in the coverage area that perform according to the disclosed methods, etc. There may be multiple base stations or multiple wireless devices in the coverage area that may not comply with the disclosed methods. For example, those wireless devices or base stations may operate based on an older release of LTE or 5G technology.

[0007] As used herein, the terms "a," "an," and similar terms are interpreted as "at least one" and "one or more." Similarly, any term ending in the suffix "(s)" should be interpreted as "at least one" and "one or more." As used herein, the term "may" is interpreted as "may, for example." In other words, the term "may" indicates that the phrase following the term "may" is one example of multiple suitable possibilities and may or may not be used by one or more of various embodiments. As used herein, the terms "comprises" and "consists of" list one or more components of a described element. The term "comprises" is interchangeable with "includes" and does not exclude unlisted components included in a described element. In contrast, "consists of" provides a complete list of one or more components of a described element. As used herein, the term "based on" should be interpreted as "based at least in part on," rather than, for example, "based only on." As used herein, the term "and / or" refers to any possible combination of the listed elements. For example, "A, B, and / or C" can refer to A, B, C, A and B, A and C, B and C, or A, B, and C.

[0008] If A and B are sets and every element of A is also an element of B, then A is said to be a subset of B. Only non-empty sets and subsets are considered herein. For example, possible subsets of B = {cell1, cell2} are {cell1}, {cell2}, and {cell1, cell2}. The phrase "based on" (or equivalently, "based at least on") indicates that the phrase following the term "based on" is one example of many suitable possibilities that may or may not be used in one or more of various embodiments. The phrase "responsive to" (or equivalently, "at least in response to") indicates that the phrase following the phrase "responsive to" is one example of many suitable possibilities that may or may not be used in one or more of various embodiments. The phrase "according to" (or equivalently, "at least in response to") indicates that the phrase following the phrase "according to" is one example of many suitable possibilities that may or may not be used in one or more of various embodiments. The phrase "adopted / used" (or equivalently "at least adopted / used") indicates that the phrase following the phrase "adopted / used" is one example of many suitable possibilities that may or may not be used in one or more of various embodiments.

[0009] The term configured may relate to the capacity of a device, regardless of whether the device is in an operational or non-operational state. Configured may also refer to specific settings of a device that affect the operational characteristics of the device, regardless of whether the device is in an operational or non-operational state. In other words, hardware, software, firmware, registers, memory values, etc. may be "configured" within a device, regardless of whether the device is in an operational or non-operational state, to provide the device with specific characteristics. Terms such as "control message originating in a device" may mean that the control message has parameters that can be used to configure specific characteristics in the device or that can be used to implement specific actions in the device, regardless of whether the device is in an operational or non-operational state.

[0010] In this disclosure, a parameter (or equivalently referred to as a field, or information element (IE)) can contain one or more information objects, which in turn can contain one or more other objects. For example, if parameter (IE)N contains parameter (IE)M, which contains parameter (IE)K, which in turn contains parameter (IE)J, then N contains K and N contains J. In an exemplary embodiment, when one or more messages contain multiple parameters, it means that a parameter of the multiple parameters is included in at least one of the one or more messages, but need not be included in each of the one or more messages.

[0011] Furthermore, many features presented above are described as optional by the use of "may" or parentheses. For the sake of brevity and readability, this disclosure does not explicitly describe each and every variation that may be obtained by selecting from a set of optional features. This disclosure should be construed as explicitly disclosing all such variations. For example, a system described as having three optional features can be embodied in seven ways: with only one of the three possible features, with any two of the three features, or with three of the three features.

[0012] 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 in combination with hardware, firmware, wetware (e.g., hardware with biological components), or a combination thereof, which may be behaviorally equivalent. For example, a module may be implemented as a software routine written in a computer language configured to run on a hardware machine (e.g., C, C++, Fortran, Java, Basic, Matlab, etc.) or 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), and complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages ​​such as assembly, C, and C++. FPGAs, ASICs, and CPLDs are often programmed using a hardware description language (HDL) such as Verilog or Verilog Hardware Description Language (VHDL), which configures the connections between the programmable device's less functional internal hardware modules. The above techniques are often used in combination to achieve a functional modular result.

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

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

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

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

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

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

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

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

[0021] The 3rd Generation Partnership Project (3GPP®) was formed in 1998 to provide global standardization of specifications for mobile communication networks similar to the mobile communication network 100 of FIG. 1A. To date, 3GPP® has produced specifications for three generations of mobile networks: a third-generation (3G) network known as Universal Mobile Telecommunications System (UMTS), a fourth-generation (4G) network known as Long Term Evolution (LTE), and a fifth-generation (5G) network known as 5G Systems (5GS). Embodiments of the present disclosure are described with reference to a RAN of a 3GPP® 5G network, referred to as Next Generation RAN (NG-RAN). Embodiments may be applicable to the RAN of other mobile communication networks, such as the RAN 104 of FIG. 1A, RANs of earlier 3G and 4G networks, and future networks not yet specified (e.g., a 3GPP® 6G network). NG-RAN implements 5G radio access technology known as New Radio (NR) and can be provisioned to implement other radio access technologies, including 4G radio access technology or non-3GPP radio access technologies.

[0022] 1B illustrates another example mobile communication network 150 in which embodiments of the present disclosure may be implemented. The mobile communication network 150 may be, for example, a PLMN run by a network operator. As shown in FIG. 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 may be implemented and operate in the same or similar manner as the corresponding components described with respect to FIG. 1A.

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

[0024] As shown in FIG. 1B, the 5G-CN 152 includes an access and mobility management function (AMF) 158A and a user plane function (UPF) 158B, shown in FIG. 1B as a single component AMF / UPF 158 for simplicity. The UPF 158B may act as a gateway between the NG-RAN 154 and one or more DNs. The UPF 158B may perform functions such as packet routing and forwarding, packet inspection and user plane policy rule enforcement, traffic usage reporting, uplink classification to support routing of traffic flows to one or more DNs, quality of service (QoS) processing for the user plane (e.g., packet filtering, gating, uplink / downlink rate enforcement, and uplink traffic validation), downlink packet buffering, and downlink data notification triggering. The UPF 158B may 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-homed PDU sessions. The UE 156 may be configured to receive services via a PDU session, which is a logical connection between the UE and the DN.

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

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

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

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

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

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

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

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

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

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

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

[0036] 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 originate from the intended source). PDCP 214 and 224 may perform, for example, retransmission of untransmitted packets, in-sequence delivery and reordering of packets, and elimination of duplicate received packets for intra-gNB handover. PDCP 214 and 224 may perform packet duplication to improve the likelihood of a packet being received and to eliminate any duplicate packets at the receiver. Packet duplication may be useful for services that require high reliability.

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

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

[0039] The MAC 212 and MAC 222 may perform multiplexing / demultiplexing of logical channels and / or mapping between logical channels and transport channels. Multiplexing / demultiplexing may include multiplexing / demultiplexing of data units belonging to one or more logical channels to / from transport blocks (TBs) delivered to / from the PHYs 211 and 221. The MAC 222 may be configured to perform scheduling, scheduling information reporting, and priority handling between UEs through dynamic scheduling. Scheduling may be performed at the gNB 220 (at the MAC 222) for the downlink and uplink. The MACs 212 and 222 may be configured to perform error correction, priority handling between the logical channels of the UE 210 through 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)). The MAC 212 and MAC 222 may support one or more numerologies and / or transmission timings. In one embodiment, mapping restrictions on logical channel prioritization can control which numerology and / or transmission timing a logical channel can use. As shown in Figure 3, MACs 212 and 222 can offer logical channels as services to RLCs 213 and 223.

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

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

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

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

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

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

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

[0047] 5A and 5B show the mapping between logical 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, which carry control and configuration information in the NR control plane, or as traffic channels, which carry data in the NR user plane. Logical channels can be classified as dedicated logical channels, which are dedicated to a specific UE, or as common logical channels, which 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 unknown to the network at the cell level; a Broadcast Control Channel (BCCH) for conveying system information messages in the form of a Master Information Block (MIB) and several System Information Blocks (SIBs), which can be used by UEs to obtain information about how the cell is configured and how to operate 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 to and from a specific UE to configure the UE; - Dedicated Traffic Channel (DTCH) for transmitting user data to and from a specific UE.

[0048] Transport channels are used between the MAC and PHY layers and may be defined by how they transmit the information they transmit over the air interface. The set of transport channels defined by NR includes, for example: a paging channel (PCH) for transmitting paging messages originating 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 allows a UE to connect to the network without prior scheduling.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0064] Figure 7 shows an example of the structure of an NR frame in which OFDM symbols are grouped. NR frames may be identified by a system frame number (SFN). The SFN may repeat at a period of 1024 frames. As shown, one NR frame may be 10 milliseconds (ms) in duration and may include 10 subframes, each 1 ms in duration. The subframes may be divided into slots, each including, for example, 14 OFDM symbols per slot.

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

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

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

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

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

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

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

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

[0073] For an uplink BWP in 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) in 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) in the uplink BWP according to the configured numerology (e.g., subcarrier spacing and cyclic prefix length for the uplink BWP).

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

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

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

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

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

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

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

[0081] To provide greater data rates, carrier aggregation (CA) can be used to aggregate two or more carriers and transmit simultaneously to and from the same UE. The aggregated carriers in CA may be called component carriers (CCs). When using CA, there are many serving cells for the UE and one cell for the CC. A CC can have three configurations in the frequency domain:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0109] The uplink PT-RS (which may be used by the base station for phase tracking and / or phase noise compensation) may or may not be present depending on the RRC configuration of the UE. The presence and / or pattern of the uplink PT-RS may be configurable on a UE-specific basis by a combination of one or more parameters used for other purposes (e.g., Modulation and Coding Scheme (MCS)), which may be indicated by RRC signaling and / or DCI. If configured, the dynamic presence of the uplink PT-RS may be associated with one or more DCI parameters, including at least the MCS. The wireless network may support multiple uplink PT-RS densities defined in the time / frequency domain. The frequency domain density, if present, may be associated with at least one configuration of the scheduled bandwidth. The UE may assume the same precoding for the DMRS port and the PT-RS port. The number of PT-RS ports may be less than the number of DMRS ports in the scheduled resources. For example, the uplink PT-RS may be restricted to the UE's scheduled time / frequency period.

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

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

[0112] Antenna ports are defined such that the channel through which a symbol on an antenna port is carried can be inferred from the channel through which another symbol on the same antenna port is carried. When a first symbol and a second symbol are transmitted on the same antenna port, a receiver may infer the channel (e.g., fade gain, multipath delay, and / or the like) through which a second symbol on the antenna port is carried from the channel through which the first symbol on the antenna port is carried. A first antenna port and a second antenna port may be referred to as quasi-colocated (QCL) if one or more large-scale characteristics of the channel through which the first symbol on the first antenna port is conveyed can be inferred from the channel through 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.

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

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

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

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

[0117] In a beam management procedure, a UE may evaluate (e.g., measure) the channel quality of one or more beam pair links, including a transmit beam transmitted by a base station and a receive beam received by the UE. Based on the evaluation, the UE may transmit a beam measurement report indicating one or more beam pair quality parameters, including, for example, one or more beam 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).

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

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

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

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

[0122] The network (e.g., a gNB and / or ng-eNB of the network) and / or the UE may initiate a random access procedure. A UE in an RRC_IDLE state and / or a UE in an 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 an RRC_CONNECTED state. A UE may initiate a random access procedure to request uplink resources (e.g., for uplink transmission of SR when there are no available PUCCH resources) and / or to acquire 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., SIB2, SIB3, and / or other system information such as similar). A UE may initiate a random access procedure for a beam failure recovery request. The network may initiate a random access procedure to establish time alignment for handover and / or for SCell addition.

[0123] Figure 13A shows a four-step contention-based random access procedure. Before the procedure begins, the base station may 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 and / or be referred to as a preamble (or random access preamble). Msg2 1312 may include and / or be referred to as a random access response (RAR).

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

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

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

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

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

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

[0130] The UE receives Msg2 1312, which may include an RAR. In some scenarios, Msg2 1312 may include multiple RARs corresponding to multiple UEs. Msg2 1312 may be received after or in response to the transmission of Msg1 1311. Msg2 1312 may be scheduled on the DL-SCH and indicated on the PDCCH using the Random Access RNTI (RA-RNTI). Msg2 1312 may indicate that Msg1 1311 has been received by the base station. Msg2 1312 may include a time alignment command that the UE may use to adjust its 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 begin a time window (e.g., ra-ResponseWindow) in which it monitors the PDCCH for Msg2 1312. The UE may determine when to start the time window based on the PRACH opportunity the UE uses to transmit the preamble. For example, the UE may start the time window one or more symbols after the last symbol of the preamble (e.g., on the first PDCCH opportunity from the end of the preamble transmission). The one or more symbols may be determined based on numerology. The PDCCH may be within a common search space 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 on which the UE transmits the preamble. For example, the UE may determine the RA-RNTI based on an OFDM symbol index, a slot index, a frequency domain index, and / or an UL carrier indicator of the PRACH opportunity. Examples of the RA-RNTI may be as follows: RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id where s_id may be the index of the first OFDM symbol of the PRACH opportunity (e.g., 0≦s_id<14), t_id may be the index of the first slot of the PRACH opportunity 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 NUL carrier and 1 for SUL carrier). The UE may transmit Msg3 1313 in response to successful reception of Msg2 1312 (e.g., using the resources identified in Msg2 1312). Msg3 1313 may be used for contention resolution, for example, in the contention-based random access procedure shown in FIG. 13A. In some scenarios, multiple UEs may transmit the same preamble to the base station, and the base station may provide the UE with a corresponding RAR. If multiple UEs interpret the RAR as corresponding to themselves, a mismatch may occur. Contention resolution (e.g., use of Msg3 1313 and Msg4 1314) may be used to increase the likelihood that a UE does not mistakenly use the identity of another UE. To perform contention resolution, the UE may include a device identifier (e.g., C-RNTI, if assigned, TC-RNTI included in Msg2 1312, and / or any other suitable identifier) ​​in Msg3 1313.

[0131] Msg4 1314 may be received after or in response to the transmission of Msg3 1313. If a C-RNTI was included in Msg3 1313, the base station addresses the UE on the PDCCH using the C-RNTI. If the UE's unique C-RNTI is detected on the PDCCH, the random access procedure is determined to have completed successfully. If a TC-RNTI is included in Msg3 1313 (e.g., the UE is in RRC_IDLE state or is otherwise not connected to the base station), Msg4 1314 is received using the DL-SCH associated with the TC-RNTI. If the MAC PDU is successfully decoded and matches the CCCH SDU sent (e.g., transmitted) in Msg3 1313 or otherwise includes the corresponding UE contention resolution identity MAC CE, the UE can determine that contention resolution was successful and / or the UE can determine that the random access procedure has completed successfully.

[0132] A UE may be configured with a complementary uplink (SUL) carrier and a normal uplink (NUL) carrier. Initial access (e.g., random access procedure) may be supported on the uplink carrier. For example, a base station may configure a UE with two separate RACH configurations, one for the SUL carrier and one for the NUL carrier. For random access in a cell configured with an SUL carrier, the network may indicate which carrier (NUL or SUL) to use. The UE may determine the SUL carrier, for example, if the measured quality of one or more reference signals is lower than a broadcast threshold. Uplink transmissions of the random access procedure (e.g., Msg1 1311 and / or Msg3 1313) may remain on the selected carrier. The UE may switch uplink carriers during the random access procedure (e.g., between Msg1 1311 and Msg3 1313) in one or more instances. For example, the UE may determine and / or switch uplink carriers for Msg1 1311 and / or Msg3 1313 based on a channel clear assessment (eg, listen-before-talk).

[0133] 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 can send a configuration message 1320 to the UE before the procedure begins. The configuration message 1320 may be similar in some respects to the configuration message 1310. Figure 13B includes the transmission of two messages, Msg1 1321 and Msg2 1322. Msg1 1321 and Msg2 1322 may be similar in some respects to Msg1 1311 and Msg2 1312, respectively, shown in Figure 13A. As can be seen from Figures 13A and 13B, the contention-free random access procedure may not include messages similar to Msg3 1313 and / or Msg4 1314.

[0134] 13B may be initiated for beam failure recovery, other SI requests, SCell addition, and / or handover. For example, the base station may indicate or assign to the UE the preamble to be used for Msg1 1321. The UE may receive an indication of the preamble (e.g., ra-PreambleIndex) from the base station via PDCCH and / or RRC.

[0135] After transmitting the preamble, the UE may start a time window (e.g., ra-ResponseWindow) in which it monitors the PDCCH for 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 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) over the search space. In the contention-free random access procedure shown in FIG. 13B, the UE may determine that the random access procedure has completed successfully after or in response to transmitting Msg1 1321 and receiving 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 is successfully completed, for example, if the UE receives an RAR including a preamble identifier corresponding to the preamble transmitted by the UE and / or if the RAR includes a MAC sub-PDU including the preamble identifier. The UE may determine the response as an indication of confirmation to the SI request.

[0136] 13C shows another two-step random access procedure. Similar to the random access procedures shown in FIGS. 13A and 13B, the base station can send a configuration message 1330 to the UE before the procedure begins. Configuration message 1330 can be similar in some respects to configuration message 1310 and / or configuration message 1320. FIG. 13C includes the transmission of two messages, namely, Msg A 1331 and Msg B 1332.

[0137] Msg A 1331 may be transmitted by the UE in an uplink transmission. Msg A 1331 may include one or more transmissions of preamble 1341 and / or one or more transmissions of transport block 1342. Transport block 1342 may include content similar and / or equivalent to the content of Msg3 1313 shown in FIG. 13A. Transport block 1342 may include UCI (e.g., SR, HARQ ACK / NACK, and / or the like). The UE may receive Msg B 1332 after or in response to the transmission of Msg A 1331. Msg B 1332 may include content similar and / or equivalent to the content of Msg2 1312 (e.g., RAR) shown in FIGS. 13A and 13B and / or Msg4 1314 shown in FIG. 13A.

[0138] The UE can initiate the two-step random access procedure of Figure 13C for licensed and / or unlicensed spectrum. The UE may determine whether to initiate the two-step random access procedure based on one or more factors. The one or more factors may be the radio access technology in use (e.g., LTE, NR, and / or the like), whether the UE has a valid TA, the cell size, the RRC state of the UE, the type of spectrum (e.g., licensed vs. unlicensed), and / or any other suitable factor.

[0139] The UE may determine radio resources and / or uplink transmit power for the preamble 1341 and / or the transport block 1342 included in 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 transmission of the preamble 1341 (e.g., PRACH) and the time-frequency resources for transmission of the transport block 1342 (e.g., PUSCH) may be multiplexed using FDM, TDM, and / or CDM. The RACH parameters may enable the UE to determine the receive timing and downlink channel for monitoring and / or receiving Msg B 1332.

[0140] The transport block 1342 may include data (e.g., delay-sensitive data), a UE identifier, security information, and / or device information (e.g., International Mobile Subscriber Identity (IMSI)). The base station may send Msg B 1332 in 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 if the preamble identifier in Msg B 1332 matches the preamble transmitted by the UE and / or the UE identifier in Msg B 1332 matches the UE identifier (e.g., transport block 1342) in Msg A 1331.

[0141] The UE and the base station may exchange control signaling, which may be referred to as L1 / L2 control signaling, and may originate from the PHY layer (e.g., Layer 1) and / or the MAC layer (e.g., Layer 2). The control signaling may include downlink control signaling transmitted from the base station to the UE and / or uplink control signaling transmitted from the UE to the base station.

[0142] The downlink control signaling may include downlink scheduling assignments, uplink scheduling grants indicating uplink radio resources and / or transport formats, slot format information, preemption indications, power control commands, and / or any other suitable signaling. A UE may receive downlink control signaling in a payload transmitted by a base station on a physical downlink control channel (PDCCH). The payload transmitted on the PDCCH may be referred to as downlink control information (DCI). In some scenarios, the PDCCH may be a group-common PDCCH (GC-PDCCH) that is common to a group of UEs.

[0143] 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 an identifier of the UE (or an identifier of the group of UEs). Scrambling the CRC parity bits with an identifier may include modulo-2 addition (or exclusive-OR) of the identifier value and the CRC parity bits. The identifier may include a 16-bit value, the Radio Network Temporary Identifier (RNTI).

[0144] DCIs may be used for different purposes. The purpose may be indicated by the type of RNTI used to scramble the CRC parity bits. For example, a DCI with CRC parity bits scrambled with a paging RNTI (P-RNTI) may indicate paging information and / or system information change notification. The P-RNTI may be predefined as "FFFE" in hexadecimal. A DCI with CRC parity bits scrambled with a system information RNTI (SI-RNTI) may indicate a broadcast transmission of system information. The SI-RNTI may be predefined as "FFFF" in hexadecimal. A DCI with CRC parity bits scrambled with a random access RNTI (RA-RNTI) may indicate a random access response (RAR). A DCI with CRC parity bits scrambled with a cell RNTI (C-RNTI) may indicate a unicast transmission of dynamic scheduling and / or a random access of PDCCH order trigger. A DCI with CRC parity bits scrambled with the Temporary Cell RNTI (TC-RNTI) may indicate contention resolution (e.g., Msg3 similar to Msg3 1313 shown in FIG. 13A). Encodings of other RNTIs configured in the UE by the base station include Configured Scheduling RNTI (CS-RNTI), Transmit Power Control-PUCCH RNTI (TPC-PUCCH-RNTI), Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI), Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), Interruption RNTI (INT-RNTI), Slot Format Indication RNTI (SFI-RNTI), Semi-Persistent CSI RNTI (SP-CSI-RNTI), Modulation and Coding Scheme Cell RNTI (MCS-C-RNTI), and / or the like.

[0145] Depending on the purpose and / or content of the DCI, a base station may transmit the DCI in one or more DCI formats. For example, DCI format 0_0 may be used for scheduling the PUSCH in a cell. DCI format 0_0 may be a fallback DCI format (e.g., has a compact DCI payload). DCI format 0_1 ​​may be used for scheduling the PUSCH in a cell (e.g., has a larger DCI payload than DCI format 0_0). DCI format 1_0 may be used for scheduling the PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g., has a compact DCI payload). DCI format 1_1 may be used for scheduling the PDSCH in a cell (e.g., has a larger DCI payload than DCI format 1_0). DCI format 2_0 may be used to provide a slot format indication to a group of UEs. DCI format 2_1 may be used to inform a group of UEs of the physical resource blocks and / or OFDM symbols that the UE assumes are not intended for transmission to the UE. DCI format 2_2 may be used to transmit transmit power control (TPC) commands for PUCCH or PUSCH. DCI format 2_3 may be used to transmit a group of TPC commands for SRS transmission by one or more UEs. DCI formats for new features may be defined in future releases. DCI formats may have different DCI sizes or share the same DCI size.

[0146] After scrambling the DCI with the RNTI, the base station may process the DCI using channel coding (e.g., polarity coding), rate matching, scrambling, and / or QPSK modulation. The base station may map the coded and modulated DCI onto resource elements used and / or configured for the PDCCH. Based on the payload size of the DCI and / or the base station's coverage, the base station may transmit the DCI via the PDCCH occupying several consecutive control channel elements (CCEs). The number of consecutive CCEs (called 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 a resource block within an OFDM symbol. The mapping of the coded and modulated DCI onto resource elements may be based on a mapping of CCEs and REGs (e.g., CCE to REG mapping).

[0147] FIG. 14A illustrates an example of a CORESET configuration for a bandwidth portion. A base station may transmit DCI via a PDCCH on one or more control resource sets (CORESETs). A CORESET may include time-frequency resources on which a UE attempts to decode the DCI using one or more search spaces. A base station may configure CORESETs in the time-frequency domain. In the example of FIG. 14A, a first CORESET 1401 and a second CORESET 1402 occur at the first symbol in a slot. The first CORESET 1401 overlaps with the second CORESET 1402 in the frequency domain. A third CORESET 1403 occurs at the third symbol in a slot. A fourth CORESET 1404 occurs at the seventh symbol of the slot. The CORESETs may have different numbers of resource blocks in the frequency domain.

[0148] FIG. 14B shows an example of CCE-to-REG mapping for DCI transmission on a CORESET and PDCCH processing. The CCE-to-REG mapping may be interleaved (e.g., to provide frequency diversity) or non-interleaved (e.g., to facilitate frequency-selective transmission of interference coordination and / or control channels). A base station may perform different or identical CCE-to-REG mappings on different CORESETs. A CORESET may be associated with a CCE-to-REG mapping by RRC configuration. A CORESET may be configured with an antenna port quasi-co-location (QCL) parameter. The QCL parameter of an antenna port may indicate QCL information of a demodulation reference signal (DMRS) for PDCCH reception within the CORESET.

[0149] The base station may send an RRC message to the UE including configuration parameters of one or more CORESETs and one or more search space sets. The configuration parameters may indicate an association between the search space set and the CORESET. The search space set may include a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters may indicate the number of PDCCH candidates to be monitored per aggregation level, the PDCCH monitoring periodicity and PDCCH monitoring pattern, one or more DCI formats to be monitored by the UE, and / or whether the search space set is a common search space set or a UE-specific search space set. The set of CCEs in the common search space set may be predefined and known to the UE. The set of CCEs in the UE-specific search space set may be configured based on the UE's identity (e.g., C-RNTI).

[0150] As shown in FIG. 14B , the UE may determine time-frequency resources of the CORESET based on the RRC message. The UE may determine CCE-REG mapping (e.g., interleaved or non-interleaved, and / or mapping parameters) for the CORESET based on configuration parameters of the CORESET. The UE may determine the number of search space sets (e.g., up to 10) configured on the CORESET based on the RRC message. The UE may monitor a set of PDCCH candidates according to the configuration parameters of the search space sets. The UE may monitor a set of PDCCH candidates in one or more CORESETs to detect one or more DCIs. The monitoring may include decoding one or more PDCCH candidates of the set of PDCCH candidates according to the monitored DCI format. The monitoring may include decoding 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 DCI content of one or more PDCCH candidates having possible (or configured) DCI formats. The decoding may be referred to as blind-blind-combined-blind decoding. The UE may determine the valid DCI for the UE in response to a CRC check (e.g., scrambling bits against CRC parity bits of the DCI matching the RNTI value). The UE may process information included in the DCI (e.g., scheduling assignment, uplink grant, power control, slot format indication, downlink preemption, and / or the like).

[0151] 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) acknowledgment for a received DL-SCH transport block. The UE may transmit the HARQ acknowledgment 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 transmit format parameters (e.g., including multiple antennas and beamforming schemes) for the downlink transmission based on the received CSI. The uplink control signaling may include a scheduling request (SR). The UE may transmit the SR indicating that uplink data is available for transmission to the base station. The UE may transmit the UCI (e.g., a HARQ acknowledgment (HARQ-ACK), a CSI report, an SR, etc.) via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). A UE may transmit uplink control signaling over the PUCCH using one of several PUCCH formats.

[0152] There may be five PUCCH formats, and the UE may determine the PUCCH format based on the size of the UCI (e.g., the number of uplink symbols 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 two or fewer bits. The UE may transmit UCI on PUCCH resources using PUCCH format 0 if the transmission is more than one or two symbols and the number of HARQ-ACK information bits with positive or negative SR (HARQ-ACK / SR bits) is one or two. PUCCH format 1 may occupy between four and fourteen OFDM symbols and may contain two or fewer bits. The UE may use PUCCH format 1 if the transmission is four or more symbols and the number of HARQ-ACK / SR bits is one or two. PUCCH format 2 may occupy one or two OFDM symbols and may contain more than two bits. A UE may use PUCCH format 2 if the transmission is more than one or two symbols and the number of UCI bits is two or more. PUCCH format 3 may occupy between 4 and 14 OFDM symbols and may include more than two bits. A UE may use PUCCH format 3 if the transmission is four or more symbols, the number of UCI bits is two or more, and the PUCCH resources do not include orthogonal cover codes. PUCCH format 4 may occupy between 4 and 14 OFDM symbols and may include more than two bits. A UE may use PUCCH format 4 if the transmission is four or more symbols, the number of UCI bits is two or more, and the PUCCH resources include orthogonal cover codes.

[0153] The base station may transmit configuration parameters of multiple PUCCH resource sets to the UE, for example, using an RRC message. Multiple PUCCH resource sets (e.g., up to four sets) may be configured on the uplink BWP of the cell. A PUCCH resource set may be configured with a PUCCH resource set index, multiple PUCCH resources with the PUCCH resource identified by a PUCCH resource identifier (e.g., pucch-Resourceid), and / or the number (e.g., maximum number) of UCI information bits that the UE can transmit using one of the multiple PUCCH resources in the PUCCH resource set. When configured with multiple PUCCH resource sets, the UE may select one of the multiple PUCCH resource sets based on 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 less than or equal to two, the UE may select the first PUCCH resource set whose PUCCH resource set index is equal to '0'. If the total bit length of the UCI information bits is greater than 2 and less than or equal to a first configuration value, the UE may select a second PUCCH resource set having a PUCCH resource set index equal to '1'. If the total bit length of the UCI information bits is greater than the first configuration value and less than or equal to a second configuration value, the UE may select a third PUCCH resource set having a PUCCH resource set index equal to '2'. If the total bit length of the UCI information bits is greater than the second configuration value and less than or equal to a third value (e.g., 1406), the UE may select a fourth PUCCH resource set having a PUCCH resource set index equal to '3'.

[0154] After determining a PUCCH resource set from the multiple PUCCH resource sets, the UE may determine a PUCCH resource from the PUCCH resource set for UCI (HARQ-ACK, CSI, and / or SR) transmission. The UE may determine the PUCCH resource based on a PUCCH resource indicator in DCI (e.g., DCI format 1_0 or DCI format 1_1) received on the PDCCH. The 3-bit PUCCH resource indicator of the DCI may indicate one of the eight PUCCH resources in the PUCCH resource set. Based on the PUCCH resource indicator, the UE may transmit the UCI (HARQ-ACK, CSI, and / or SR) using the PUCCH resource indicated by the PUCCH resource indicator in the DCI.

[0155] 15 illustrates an example of a wireless device 1502 communicating with a base station 1504 in accordance with 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 network. Only one wireless device 1502 and one base station 1504 are shown in FIG. 15. However, it will be understood that a mobile communication network may include multiple UEs and / or multiple base stations having the same or similar configuration as that illustrated in FIG. 15.

[0156] The base station 1504 may connect the wireless device 1502 to a core network (not shown) via wireless communication over an air interface (or radio interface) 1506. The direction of communication from the base station 1504 to the wireless device 1502 over the air interface 1506 is known as the downlink, and the direction of communication from the wireless device 1502 to the base station 1504 over the air interface is known as the uplink. The downlink transmission may be separated from the uplink transmission using FDD, TDD, and / or some combination of the two duplexing techniques.

[0157] On the downlink, data transmitted from base station 1504 to wireless device 1502 may be provided to processing system 1508 of base station 1504. The data may be provided to processing system 1508 by, for example, a core network. On the uplink, data transmitted from wireless device 1502 to base station 1504 may be provided to processing system 1518 of wireless device 1502. Processing system 1508 and processing system 1518 may implement Layer 3 and Layer 2 OSI functions to process the data for transmission. Layer 2 may include, for example, the SDAP layer, the PDCP layer, the RLC layer, and the MAC layer with respect to Figures 2A, 2B, 3, and 4A. Layer 3 may include the RRC layer with respect to Figure 2B.

[0158] After processing by processing system 1508, data to be transmitted to wireless device 1502 may be provided to transmit processing system 1510 of base station 1504. Similarly, after processing by processing system 1518, data to be transmitted to base station 1504 may be provided to transmit processing system 1520 of wireless device 1502. Transmit processing system 1510 and transmit processing system 1520 may implement the OSI functions of Layer 1. Layer 1 may include the PHY layer with respect to FIGS. 2A, 2B, 3, and 4A. For transmit processing, the PHY layer may perform, for example, forward error correction coding of transport channels, interleaving, rate matching, mapping of transport channels to physical channels, modulation of physical channels, multiple-input multiple-output (MIMO) or multi-antenna processing, and / or the like.

[0159] At the base station 1504, a receive processing system 1512 may receive uplink transmissions from the wireless device 1502. At the wireless device 1502, a receive processing system 1522 may receive downlink transmissions from the base station 1504. The receive processing system 1512 and the receive processing system 1522 may implement the OSI functions of Layer 1. Layer 1 may include the PHY layer with respect to FIGS. 2A, 2B, 3, and 4A. For receive processing, the PHY layer may perform, for example, error detection, forward error correction decoding, deinterleaving, demapping of transport channels to physical channels, demodulation of the physical channels, MIMO or multi-antenna processing, and / or the like.

[0160] 15, the wireless device 1502 and the base station 1504 may include multiple antennas. The multiple antennas may be used to implement one or more MIMO or multi-antenna techniques, such as spatial multiplexing (e.g., single-user MIMO or multi-user MIMO), transmit / receive diversity, and / or beamforming. In other embodiments, the wireless device 1502 and / or the base station 1504 may have a single antenna.

[0161] Processing system 1508 and processing system 1518 may be associated with memory 1514 and memory 1524, respectively. Memory 1514 and memory 1524 (e.g., one or more non-transitory computer-readable media) may store computer program instructions or code that may be executed by processing system 1508 and / or processing system 1518 to perform one or more functions discussed herein. Although not shown in FIG. 15 , transmit processing system 1510, transmit processing system 1520, receive processing system 1512, and / or receive processing system 1522 may be coupled to memory (e.g., one or more non-transitory computer-readable media) that stores computer program instructions or code that may be executed to perform one or more of their respective functions.

[0162] The processing system 1508 and / or the processing system 1518 may include one or more controllers and / or one or more processors. The one or more controllers and / or the one or more processors may include, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) and / or other programmable logic devices, discrete gate and / or transistor logic, discrete hardware components, on-board units, or any combination thereof. The processing system 1508 and / or the processing system 1518 may perform at least one of signal coding / processing, data processing, power control, input / output processing, and / or any other functionality that may enable the wireless device 1502 and the base station 1504 to operate in a wireless environment.

[0163] Processing system 1508 and / or processing system 1518 may be connected to one or more peripheral devices 1516 and one or more peripheral devices 1526, respectively. The one or more peripheral devices 1516 and one or more peripheral devices 1526 may include software and / or hardware that provide features and / or functionality, such as a speaker, a microphone, a keypad, a display, a touchpad, a power source, a satellite transceiver, a universal serial bus (USB) port, a hands-free headset, a frequency modulation (FM) radio unit, a media player, an internet browser, an electronic control unit (e.g., for a vehicle), and / or one or more sensors (e.g., an accelerometer, gyroscope, temperature sensor, radar sensor, lidar sensor, ultrasonic sensor, light sensor, camera, and / or the like). Processing system 1508 and / or processing system 1518 may receive user input data and / or provide user output data from the one or more peripheral devices 1516 and / or one or more peripheral devices 1526. A processing system 1518 within the wireless device 1502 can receive power from a power source and / or can be configured to distribute power to other components within the wireless device 1502. The power source may include one or more power sources, such as a battery, a solar cell, a fuel cell, or any combination thereof. The processing system 1508 and / or the processing system 1518 can be connected to a GPS chipset 1517 and a GPS chipset 1527, respectively. The GPS chipset 1517 and the GPS chipset 1527 can be configured to provide geographic location information for the wireless device 1502 and the base station 1504, respectively.

[0164] FIG. 16A illustrates an exemplary structure for uplink transmission. A baseband signal representing a physical uplink shared channel may perform one or more functions. The one or more functions may include at least one of scrambling, modulation of scramble bits to generate complex-valued symbols, mapping of complex-valued modulation symbols onto one or several transmission layers, transform precoding to generate complex-valued symbols, precoding of the complex-valued symbols, mapping of the precoded complex-valued symbols to resource elements, generation of complex-valued time-domain single-carrier frequency-division multiple access (SC-FDMA) or CP-OFDM signals to antenna ports, and / or the like. In one example, if transform precoding is enabled, an SC-FDMA signal for uplink transmission may be generated. In one example, if transform precoding is not enabled, a CP-OFDM signal for uplink transmission may be generated according to FIG. 16A. These functions are illustrated by way of example, and it is anticipated that other mechanisms may be implemented in various embodiments.

[0165] 16B shows an exemplary structure for modulation and upconversion of a baseband signal to a carrier frequency. The baseband signal may be a complex-valued SC-FDMA or CP-OFDM baseband signal and / or a complex-valued Physical Random Access Channel (PRACH) baseband signal for an antenna port. Filtering may be used before transmission.

[0166] 16C illustrates an exemplary structure of a downlink transmission. The baseband signal representing the physical downlink channel can perform one or more functions. The one or more functions can include scrambling coded bits in a codeword to be transmitted on the physical channel, modulating the scrambled bits to generate complex-valued modulation symbols, mapping the complex-valued modulation symbols onto one or more transmission layers, precoding the complex-valued modulation symbols on the layers for transmission on the antenna ports, mapping the complex-valued modulation symbols of the antenna ports to resource elements, generating a complex-valued time-domain OFDM signal per antenna port, and / or the like. These functions are shown as examples, and it is anticipated that other mechanisms can be implemented in various embodiments.

[0167] 16D shows another example structure for modulation and upconversion of a baseband signal to a carrier frequency. The baseband signal may be a complex-valued OFDM baseband signal for an antenna port. Filtering may be used before transmission.

[0168] A wireless device may receive one or more messages (e.g., RRC messages) from a base station including configuration parameters for multiple cells (e.g., a primary cell, a secondary cell). The wireless device may communicate with at least one base station (e.g., two or more base stations for dual connectivity) via the multiple cells. The one or more messages (e.g., as part of the configuration parameters) may include physical, MAC, RLC, PCDP, SDAP, and RRC layer parameters for configuring the wireless device. For example, the configuration parameters may include parameters for configuring physical and MAC layer channels, bearers, etc. For example, the configuration parameters may include parameters indicating timer values ​​for the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, RRC layer, and / or communication channels.

[0169] When a timer is started, it begins running and may continue running until it is stopped or expires. A timer may be started if it is not running or restarted if it is running. A timer may be associated with a value (e.g., a timer may be started or restarted from a value, or may start from zero and expire when the value is reached). A timer's duration may not be updated until the timer is stopped or expires (e.g., due to BWP switching). A timer may be used to measure the period / window of a process. When this specification refers to implementations and procedures related to one or more timers, it will be understood that there are multiple ways to implement one or more timers. For example, it will be understood that one or more of multiple ways for implementing a timer may be used to measure the period / window of a procedure. For example, a random access response window timer may be used to measure the window time for receiving a random access response. In one embodiment, the time difference between two timestamps may be used instead of the start and expiration of the random access response window timer. When the timer is restarted, the process for measuring the time window may be restarted. Other example implementations may be provided for restarting the measurement of the time window.

[0170] A base station may transmit one or more MAC PDUs to a wireless device. In one embodiment, the MAC PDU may be a bit string whose length is byte-aligned (e.g., a multiple of 8 bits). In one embodiment, the bit string may be represented by a table with the most significant bit being the leftmost bit of the first row of the table and the least significant bit being the rightmost bit of the last row of the table. More generally, the bit string is read from left to right, then in row reading order. In one embodiment, the bit order of the parameter field in the MAC PDU is represented with the most significant bit first in the leftmost bit and the least significant bit last in the rightmost bit.

[0171] In one embodiment, the MAC SDU may be a bit string whose length is byte-aligned (e.g., a multiple of 8 bits). In one embodiment, the MAC SDU may be included in the MAC PDU after the first bit. In one embodiment, the MAC CE may be a bit string whose length is byte-aligned (e.g., a multiple of 8 bits). In one embodiment, the MAC subheader may be a bit string whose length is byte-aligned (e.g., a multiple of 8 bits). In one embodiment, the MAC subheader may be located immediately before the corresponding MAC SDU, MAC CE, or padding. The MAC entity may ignore the value of the reserved bit in the DL MAC PDU.

[0172] In one embodiment, a MAC PDU may include one or more MAC sub-PDUs, where a MAC sub-PDU includes a MAC subheader only (including padding), a MAC subheader and a MAC SDU, a MAC subheader and a MAC CE, and / or a MAC subheader and padding. The MAC SDUs may be of variable size. The MAC subheader may correspond to a MAC SDU, a MAC CE, or padding.

[0173] In one embodiment, if the MAC subheader corresponds to a MAC SDU, a variable-sized MAC CE, or padding, the MAC subheader may include a 1-bit R field, a 1-bit F field, a multi-bit LCID field, and / or a multi-bit L field.

[0174] Figure 17A shows an example of a MAC subheader with an R field, an F field, an LCID field, and an L field. In the example MAC subheader of Figure 17A, the LCID field may be 6 bits long, and the L field may be 8 bits long. Figure 17B shows an example of a MAC subheader with an R field, an F field, an LCID field, and an L field. In the example MAC subheader of Figure 17B, the LCID field may be 6 bits long, and the L field may be 16 bits long. If the MAC subheader supports fixed-size MAC CE or padding, the MAC subheader may include a 2-bit R field and a multi-bit LCID field. Figure 17C shows an example of a MAC subheader including an R field and an LCID field. In the example MAC subheader of Figure 17C, the LCID field may be 6 bits long, and the R field may be 2 bits long.

[0175] Figure 18A shows an example of a DL MAC PDU. Multiple MAC CEs, such as MAC CEs 1 and 2, can be arranged together. A MAC sub-PDU containing a MAC CE can be arranged before any MAC sub-PDU containing a MAC SDU or a MAC sub-PDU containing padding. Figure 18B shows an example of a UL MAC PDU. Multiple MAC CEs, such as MAC CEs 1 and 2, can be arranged together. A MAC sub-PDU containing a MAC CE can be arranged after all MAC sub-PDUs containing a MAC SDU. Furthermore, a MAC sub-PDU can be arranged before a MAC sub-PDU containing padding.

[0176] In one embodiment, the MAC entity of the base station can transmit one or more MAC CEs to the MAC entity of the wireless device. Figure 19 shows an example of multiple LCIDs that can be associated with one or more MAC CEs. The one or more MAC CEs include at least one of an SP ZP CSI-RS resource set activation / deactivation MAC CE, a PUCCH spatial relationship activation / deactivation MAC CE, an SP SRS activation / deactivation MAC CE, an SP CSI report activation / deactivation MAC CE for PUCCH, a UE-specific PDCCH TCI status indication MAC CE, a UE-specific PDSCH TCI status indication MAC CE, an aperiodic CSI trigger state sub-selection MAC CE, an SP CSI-RS / CSI-IM resource set activation / deactivation MAC CE, a UE contention resolution identity MAC CE, a timing advance command MAC CE, a DRX command MAC CE, a long DRX command MAC CE, an SCell activation / deactivation MAC CE (1 octet), an SCell activation / deactivation MAC CE (4 octets), and / or a duplicate activation / deactivation MAC CE. In one example, a MAC CE, such as a MAC CE transmitted by a MAC entity of a base station to a MAC entity of a wireless device, may have an LCID in a MAC subheader corresponding to the MAC CE. Different MAC CEs may have different LCIDs in the MAC subheader corresponding to the MAC CE. For example, an LCID given by 111011 in a MAC subheader may indicate that the MAC CE associated with the MAC subheader is a Long DRX command MAC CE.

[0177] In one embodiment, the MAC entity of the wireless device can transmit one or more MAC CEs to the MAC entity of the base station. Figure 20 illustrates an example of the one or more MAC CEs. The one or more MAC CEs may include at least one of a short buffer status report (BSR) MAC CE, a long BSR MAC CE, a C-RNTI MAC CE, a configured authorization confirmation MAC CE, a single-entry PHR MAC CE, a multiple-entry PHR MAC CE, a short barring BSR, and / or a long barring BSR. In one embodiment, the MAC CE may have an LCID in a MAC subheader corresponding to the MAC CE. Different MAC CEs may have different LCIDs in the MAC subheaders corresponding to the MAC CE. For example, an LCID given by 111011 in a MAC subheader may indicate that the MAC CE associated with the MAC subheader is a short barring command MAC CE.

[0178] In carrier aggregation (CA), two or more component carriers (CCs) may be aggregated. Using CA techniques, a wireless device may simultaneously receive or transmit on one or more CCs, depending on the capabilities of the wireless device. In one embodiment, a wireless device may support CA for adjacent and / or non-adjacent CCs. CCs may be organized into cells. For example, CCs may be organized into one primary cell (PCell) and one or more secondary cells (SCells). When configured with CA, a wireless device may have one RRC connection with the network. During RRC connection establishment / re-establishment / handover, the cell providing NAS mobility information may be the serving cell. During RRC connection re-establishment / handover procedures, the cell providing security input may be the serving cell. In one embodiment, the serving cell may refer to the PCell. In one embodiment, a base station may send one or more messages to a wireless device, including configuration parameters for a plurality of one or more SCells, depending on the capabilities of the wireless device.

[0179] When configured with CA, the base station and / or wireless device may use an SCell activation / deactivation mechanism to improve battery or power consumption of the wireless device. When a wireless device is configured with one or more SCells, the base station may activate or deactivate at least one of the one or more SCells. An SCell may be deactivated unless the SCell state associated with the SCell is set to "activated" or "dormant" upon configuration.

[0180] The wireless device may activate / deactivate the SCell in response to receiving the SCell Activation / Deactivation MAC CE. In one embodiment, the base station may send one or more messages including an SCell timer (e.g., sCellDeactivationTimer) to the wireless device. In one embodiment, the wireless device may deactivate the SCell in response to expiration of the SCell timer.

[0181] When the wireless device receives an SCell activation / deactivation MAC CE activating the SCell, the wireless device may activate the SCell. In response to the SCell activation, the wireless device may perform operations including SRS transmission on the SCell, CQI / PMI / RI / CRI reporting for the SCell, PDCCH monitoring on the SCell, PDCCH monitoring for the SCell, and / or PUCCH transmission on the SCell. In response to the SCell activation, the wireless device may start or restart a first SCell timer (e.g., sCellDeactivationTimer) associated with the SCell. The wireless device may start or restart the first SCell timer in a slot when the SCell activation / deactivation MAC CE activating the SCell is received. In one embodiment, in response to the SCell activation, the wireless device may (re)initialize one or more suspended configured uplink grants of configured grant type 1 associated with the SCell according to a stored configuration. In one embodiment, in response to activation of the SCell, the wireless device may trigger a PHR.

[0182] When the wireless device receives an SCell activation / deactivation MAC CE that deactivates an activated SCell, the wireless device may deactivate the activated SCell. In one embodiment, when a first SCell timer (e.g., sCellDeactivationTimer) associated with the activated SCell expires, the wireless device may deactivate the activated SCell. In response to deactivation of the activated SCell, the wireless device may stop the first SCell timer associated with the activated SCell. In one embodiment, in response to deactivation of the activated SCell, the wireless device may clear one or more configured downlink assignments and / or one or more configured uplink grants of configured uplink grant type 2 associated with the activated SCell. In one embodiment, in response to deactivation of the activated SCell, the wireless device may suspend one or more configured uplink grants of configured uplink grant type 1 associated with the activated SCell and / or flush HARQ buffers associated with the activated SCell.

[0183] When an SCell is deactivated, the wireless device may not perform operations including transmitting an SRS on the SCell, reporting CQI / PMI / RI / CRI of the SCell, transmitting on a UL-SCH on the SCell, transmitting on a RACH on the SCell, monitoring at least one first PDCCH on the SCell, monitoring at least one second PDCCH on the SCell, and / or transmitting a PUCCH on the SCell. When the at least one first PDCCH on the activated SCell indicates an uplink grant or a downlink assignment, the wireless device may restart a first SCell timer (e.g., sCellDeactivationTimer) associated with the activated SCell. In one embodiment, if at least one second PDCCH on a serving cell (e.g., a PCell or a SCell configured with a PUCCH, i.e., a PUCCH SCell) scheduling the activated SCell indicates an uplink grant or a downlink assignment for the activated SCell, the wireless device may restart a first SCell timer (e.g., sCellDeactivationTimer) associated with the activated SCell. In one embodiment, when an SCell is deactivated, if there is an ongoing random access procedure on the SCell, the wireless device may abort the ongoing random access procedure on the SCell.

[0184] Figure 21A shows an example of a one-octet SCell activation / deactivation MAC CE. A first MAC PDU subheader with a first LCID (e.g., "111010" as shown in Figure 19) can identify a one-octet SCell activation / deactivation MAC CE. The size of the one-octet SCell activation / deactivation MAC CE may be constant. The one-octet SCell activation / deactivation MAC CE may include a single octet. The single octet can include a first number of C fields (e.g., 7) and a second number of R fields (e.g., 1). Figure 21B shows an example of a four-octet SCell activation / deactivation MAC CE. A second MAC PDU subheader with a second LCID (e.g., "111001" as shown in Figure 19) can identify a four-octet SCell activation / deactivation MAC CE. The size of the 4-octet SCell activation / deactivation MAC CE may be constant. The 4-octet SCell activation / deactivation MAC CE may include 4 octets. The 4 octets may include a third number C field (e.g., 31) and a fourth number R field (e.g., 1).

[0185] In FIG. 21A and / or FIG. 21B, when an SCell having SCell index i is configured, C i The field may indicate the activation / deactivation status of the SCell with SCell index i. i When the field is set to 1, the SCell with SCell index i may be activated. i If the field is set to zero, the SCell with SCell index i may be deactivated. In one embodiment, if there is no SCell configured with SCell index i, the wireless device iThe R field may be ignored. In Figures 21A and 21B, the R field may indicate reserved bits. The R field may be set to zero.

[0186] A base station may configure a wireless device with an uplink (UL) bandwidth portion (BWP) and a downlink (DL) BWP to enable bandwidth adaptation (BA) on a PCell. If carrier aggregation is configured, the base station may further configure the wireless device with at least a DL BWP to enable BA on an SCell (i.e., there may be no UL BWP on the UL). For a PCell, the initial active BWP may be a first BWP used for initial access. For an SCell, the first active BWP may be a second BWP that the wireless device is configured to operate on when the SCell is activated. In paired spectrum (e.g., FDD), the base station and / or wireless device can switch between the DL BWP and the UL BWP individually. In unpaired spectrum (e.g., TDD), the base station and / or wireless device can switch between the DL BWP and the UL BWP simultaneously.

[0187] In one embodiment, the base station and / or wireless device can switch BWPs between configured BWPs via a DCI or a BWP inactivity timer. If a BWP inactivity timer is configured for a serving cell, the base station and / or wireless device can switch the active BWP to a default BWP in response to expiration of the BWP inactivity timer associated with the serving cell. The default BWP can be configured by the network. In one embodiment, for an FDD system, if configured with a BA, one UL BWP and one DL BWP for each uplink carrier can be simultaneously active in an active serving cell. In one embodiment, for a TDD system, one DL / UL BWP pair can be simultaneously active in an active serving cell. Operating with one UL BWP and one DL BWP (or one DL / UL pair) can improve battery consumption of a wireless device. BWPs other than the one active UL BWP and one active DL BWP with which the wireless device can operate can be deactivated. In a deactivated BWP, the wireless device may not monitor the PDCCH and / or may not transmit on the PUCCH, PRACH, and UL-SCH.

[0188] In one embodiment, a serving cell may be configured with up to a first number (e.g., four) of BWPs. In one example, for an activated serving cell, there may be one active BWP at any given time. In one example, BWP switching for a serving cell may be used to activate inactive BWPs and deactivate active BWPs at a time. In one example, BWP switching may be controlled by a PDCCH indicating a downlink assignment or an uplink grant. In one example, BWP switching may be controlled by a BWP inactivity timer (e.g., bwp-InactivityTimer). In one example, BWP switching may be controlled by a MAC entity in response to the initiation of a random access procedure. Upon addition of an SpCell or activation of an SCell, one BWP may be initially activated without receiving a PDCCH indicating a downlink assignment or an uplink grant. The active BWP for a serving cell may be indicated by RRC and / or PDCCH. In one example, for unpaired spectrum, a DL BWP may be paired with a UL BWP, and BWP switching may be common to both UL and DL.

[0189] FIG. 22 illustrates an example of BWP switching on an SCell. In one example, a wireless device may receive, from a base station, at least one RRC message including configuration parameters of the SCell and one or more BWP configurations associated with the SCell. The RRC message may include an RRC connection reconfiguration message (e.g., RRCReconfiguration), an RRC connection re-establishment message (e.g., RRCRestablishment), and / or an RRC connection setup message (e.g., RRCSetup). Of the one or more BWPs, at least one BWP may be configured as a first active BWP (e.g., BWP1) and one BWP may be configured as a default BWP (e.g., BWP0). The wireless device may receive a MAC CE to activate the SCell at the nth slot. The wireless device may start an SCell inactivity timer (e.g., sCellDeactivationTimer) and initiate CSI-related actions for the SCell and / or initiate CSI-related actions for the first active BWP of the SCell. In response to activating the SCell, the wireless device may start monitoring the PDCCH on BWP1.

[0190] In one embodiment, in response to receiving a DCI indicating a DL allocation on BWP1, the wireless device may start / restart a BWP inactivity timer (e.g., bwp-InactivityTimer) at the mth slot. The wireless device may switch back to the default BWP (e.g., BWP0) as the active BWP at the sth slot when the BWP inactivity timer expires. The wireless device may deactivate the SCell and / or stop the BWP inactivity timer when the sCellDeactivationTimer expires.

[0191] In one embodiment, the MAC entity may apply normal operations to the active BWP of the activated serving cell configured in the BWP, including transmitting on the UL-SCH, transmitting on the RACH, monitoring the PDCCH, transmitting the PUCCH, receiving the DL-SCH, and / or (re)initializing a suspended configured uplink grant of configured grant type 1, if any, according to the stored configuration.

[0192] In one embodiment, on an inactive BWP of each activated serving cell configured in the BWP, the MAC entity may not transmit on the UL-SCH, may not transmit on the RACH, may not monitor the PDCCH, may not transmit the PUCCH, may not transmit the SRS, may not receive the DL-SCH, may clear any configured downlink assignments and configured uplink grants of configured grant type 2, and / or may suspend any configured uplink grants of configured type 1.

[0193] In one embodiment, when a MAC entity receives a PDCCH for a BWP switch of a serving cell, the wireless device may perform a BWP switch to the BWP indicated by the PDCCH while a random access procedure associated with this serving cell is not in progress. In one embodiment, if the bandwidth fraction indicator field is configured with DCI format 1_1, the bandwidth fraction indicator field value may indicate an active DL BWP from a configured DL BWP set for DL ​​reception. In one embodiment, if the bandwidth fraction indicator field is configured with DCI format 0_1, the bandwidth fraction indicator field value may indicate an active UL BWP from a configured UL BWP set for UL transmission.

[0194] In one embodiment, for the primary cell, the wireless device may be provided with a default DL BWP among the configured DL BWPs by the higher layer parameter Default-DL-BWP. In one embodiment, if the wireless device is not provided with a default DL BWP by the higher layer parameter Default-DL-BWP, the default DL BWP may be the initial active DL BWP. In one embodiment, the wireless device may be provided with a timer value for the primary cell by the higher layer parameter bwp-InactivityTimer. If configured, the wireless device may increment the timer every 1 millisecond interval for frequency range 1 and every 0.5 milliseconds for frequency range 2 if running, when the wireless device is unable to detect DCI format 1_1 for paired spectrum operation, or when the wireless device is unable to detect DCI format 1_1 or DCI format 0_1 ​​for unpaired spectrum operation during the interval.

[0195] In one embodiment, if a wireless device is configured for a secondary cell with an upper layer parameter Default-DL-BWP indicating a default DL BWP among the configured DL BWPs, and the wireless device is configured with an upper layer parameter bwp-InactivityTimer indicating a timer value, the wireless device procedures on the secondary cell may be the same as those on the primary cell using the timer value for the secondary cell and the default DL BWP for the secondary cell.

[0196] In one embodiment, when a wireless device is configured with the higher layer parameter Active-BWP-DL-SCell being the first active DL BWP and with the higher layer parameter Active-BWP-UL-SCell being the first active UL BWP on a secondary cell or carrier, the wireless device can use the indicated DL BWP and the indicated UL BWP on the secondary cell as the first active DL BWP and the first active UL BWP on the secondary cell or carrier, respectively.

[0197] In one embodiment, the set of PDCCH candidates for the wireless device to monitor is defined in terms of a PDCCH search space set, which includes a CSS set or a USS set. The wireless device shall monitor PDCCH candidates in one or more of the following search space sets, which are defined by pdcch-ConfigSIB1 in the MIB or by searchSpaceSIB1 in PDCCH-ConfigCommon for DCI formats with CRC scrambled by SI-RNTI in the primary cell of the MCG:Type0-PDCCHCSS set configured by searchSpaceZero in PDCCH-ConfigCommon, Type0A-PDCCHCSS set configured by searchSpaceOtherSystemInformation in PDCCH-ConfigCommon for DCI formats with CRC scrambled by SI-RNTI in the primary cell of the MCG, Type1-PDCCHCSS set configured by ra-SearchSpace in PDCCH-ConfigCommon for DCI formats with CRC scrambled by RA-RNTI, MsgB-RNTI, or TC-RNTI in the primary cell, Type2-PDCCHCSS set configured by pagingSearchSpace in PDCCH-ConfigCommon for DCI formats with CRC scrambled by P-RNTI in the primary cell of the MCG -PDCCHCSS set, INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, CI-RNTI, or PS-RNTI and, for the primary cell only, a Type3-PDCCHCSS set configured by the SearchSpace in the PDCCH-Config with searchSpaceType=common for DCI formats with a CRC scrambled by C-RNTI, MCS-C-RNTI, or CS-RNTI, and a USS set configured by the SearchSpace in the PDCCH-Config with searchSpaceType=ue-Specific for DCI formats with a CRC scrambled by C-RNTI, MCS-C-RNTI, SP-CSI-RNTI, CS-RNTI, SL-RNTI, SL-CS-RNTI, or SL-L-CS-RNTI.

[0198] In one embodiment, the wireless device determines PDCCH monitoring opportunities on an active DL BWP based on one or more PDCCH configuration parameters, including a PDCCH monitoring periodicity within a slot, a PDCCH monitoring offset, and a PDCCH monitoring pattern. For search space sets (SSs), the wireless device:

number

number

number

number

[0199] In an embodiment, the wireless device performs the following for the search space set associated with s, CORESETp:

number

number

number

number

number

number

number

number

[0200] In one embodiment, a wireless device may monitor a set of PDCCH candidates according to configuration parameters of a search space set including multiple search spaces (SSs). The wireless device may monitor the set of PDCCH candidates in one or more CORESETs to detect one or more DCIs. The monitoring may include decoding one or more PDCCH candidates of the set of PDCCH candidates according to the monitored DCI format. The monitoring may include decoding DCI content of one or more PDCCH candidates having possible (or configured) PDCCH positions, possible (or configured) PDCCH formats (e.g., the number of CCEs, the number of PDCCH candidates in a common SS, and / or the number of PDCCH candidates in a UE-specific SS), and possible (or configured) DCI formats. The decoding may be referred to as blind decoding.

[0201] 23A illustrates example configuration parameters of a Master Information Block (MIB) for a cell (e.g., a PCell). In one embodiment, a wireless device may receive the MIB over a PBCH based on receiving a Primary Synchronization Signal (PSS) and / or a Secondary Synchronization Signal (SSS). The configuration parameters of the MIB include 6 bits of the system frame number (SFN) (systemFrameNumber), a subcarrier spacing indicator (subCarrierSpacingCommon), a frequency domain offset between the SSB and the overall resource block grid in number of subcarriers (ssb-SubcarrierOffset), an indicator indicating whether the cell is barred (cellBarred), a DMRS position indicator indicating the location of the DMRS (dmrs-TypeA-Position), and CORESET and SS parameters for a PDCCH (pdcch-ConfigSIB1) that includes a common CORESET, which includes the common search space and required PDCCH parameters.

[0202] In one embodiment, pdcch-ConfigSIB1 may include a first parameter (e.g., controlResourceSetZero) indicating a common Control Resource Set (CORESET) having ID#0 (e.g., CORESET#0) of the cell's initial BWP. controlResourceSetZero may be an integer from 0 to 15. Each integer from 0 to 15 may identify a configuration of CORESET#0. FIG. 23B shows an example of a configuration of CORESET#0. As shown in FIG. 23B, based on the value of the integer in controlResourceSetZero, the wireless device may determine an SSB and CORESET#0 multiplexing pattern, the number of RBs for CORESET#0, the number of symbols for CORESET#0, and an RB offset for CORESET#0.

[0203] In one embodiment, pdcch-ConfigSIB1 may include a second parameter (e.g., searchSpaceZero) common search space having ID#0 (e.g., SS#0) of the cell's initial BWP. searchSpaceZero may be an integer from 0 to 15. Each integer from 0 to 15 may identify a configuration of SS#0. FIG. 23C shows an example of a configuration of SS#0. As shown in FIG. 23C, based on the value of the searchSpaceZero integer, the wireless device may determine one or more parameters (e.g., O, M) for slot determination of PDCCH monitoring, a first symbol index for PDCCH monitoring, and / or the number of search spaces per slot.

[0204] In an embodiment, based on receiving the MIB, the wireless device may monitor the PDCCH over SS#0 of CORESET#0 to receive DCI scheduling System Information Block 1 (SIB1). The wireless device may receive DCI with a CRC scrambled with a System Information-Radio Network Temporary Identifier (SI-RNTI) for receiving SIB1.

[0205] FIG. 24 illustrates example RRC configuration parameters in a system information block (SIB). An SIB (e.g., SIB1) may include information relevant to evaluating whether a wireless device is allowed access to a cell and may also define the scheduling of other system information. The SIB may include radio resource configuration information common to all wireless devices and bar information applicable to unified access control. In one embodiment, a base station may transmit one or more SIBs to one wireless device (or multiple wireless devices). As shown in FIG. 24, the parameters of the one or more SIBs may include one or more parameters for cell selection related to a serving cell (e.g., cellSelectionInfo), one or more configuration parameters of the serving cell (e.g., in a ServingCellConfigCommonSIB IE), and one or more other parameters. The ServingCellConfigCommonSIB IE may include at least one of common downlink parameters of the serving cell (e.g., in a DownlinkConfigCommonSIB IE), common uplink parameters of the serving cell (e.g., in an UplinkConfigCommonSIB IE), and other parameters.

[0206] In an embodiment, the DownlinkConfigCommonSIB IE may include parameters of the initial downlink BWP of the serving cell (e.g., SpCell). The parameters of the initial downlink BWP refer to the BWP-DownlinkCommonIE (as shown in FIG. 25). The BWP-DownlinkCommon IE may be used to configure common parameters of the downlink BWP of the serving cell. The base station may configure the locationAndBandwidth so that the initial downlink BWP includes the entire CORESET#0 of this serving cell in the frequency domain. The wireless device may apply the locationAndBandwidth upon receiving this field (e.g., to determine the frequency location of the signal described in association with this locationAndBandwidth) but maintain the CORESET#0 until after receiving RRCSetup / RRCResume / RRCReestablishment.

[0207] In one embodiment, the UplinkConfigCommonSIB IE may contain parameters of the initial uplink BWP of the serving cell (e.g., SpCell). The parameters of the initial uplink BWP may be included in the BWP-UplinkCommon IE (as shown in Figure 27). The BWP-UplinkCommon IE may be used to configure common parameters of the uplink BWP. The common parameters of the uplink BWP are "cell-specific". The base station may ensure the necessary alignment with corresponding parameters of other wireless devices. The common parameters of the initial bandwidth portion of the PCell may be provided via system information. For all other serving cells, the base station may provide the common parameters via dedicated signaling.

[0208] FIG. 25 shows an example of RRC configuration parameters (e.g., BWP-DownlinkCommon IE) in the downlink BWP of a serving cell. A base station may transmit one or more configuration parameters of the downlink BWP (e.g., an initial downlink BWP) of a serving cell to one wireless device (or multiple wireless devices). As shown in FIG. 25, the one or more configuration parameters of the downlink BWP may include one or more generic BWP parameters of the downlink BWP, one or more cell-specific parameters for the PDCCH of the downlink BWP (e.g., in the pdcch-ConfigCommon IE), one or more cell-specific parameters for the PDSCH of this BWP (e.g., in the pdsch-ConfigCommon IE), and one or more other parameters. The pdcch-ConfigCommon IE may include a parameter of COESET#0 (e.g., controlResourceSetZero) that can be used in any common or UE-specific search space. The value of controlResourceSetZero may be interpreted like the corresponding bit in MIB pdcch-ConfigSIB1. The pdcch-ConfigCommon IE may include parameters for additional common control resource sets (e.g., commonControlResourceSet) that can be configured and used for any common or UE-specific search spaces. If the network sets this field, a ControlResourceSetId other than 0 is used for this ControlResourceSet. The control resource set parameters may be implemented as shown in Figure 25. The network configures commonControlResourceSet in SIB1 to include it in the bandwidth of CORESET#0. The pdcch-ConfigCommon IE may include parameters for a list of additional common search spaces (e.g., in commonSearchSpaceList). The search space parameters may be implemented based on the example in Figure 26.The pdcch-ConfigCommon IE may indicate a search space for paging (e.g., pagingSearchSpace), a search space for random access procedures (e.g., ra-SearchSpace), a search space for SIB1 messages (e.g., searchSpaceSIB1), common search space #0 (e.g., searchSpaceZero), and one or more other search spaces from a list of search spaces.

[0209] As shown in Figure 25, a control resource set (CORESET) may be associated with a CORESET index (e.g., ControlResourceSetId). A CORESET index of value 0 may identify a common CORESET configured in the MIB and ServingCellConfigCommon(controlResourceSetZero) and may not be used in the ControlResourceSet IE. A CORESET index with other values ​​may identify a CORESET configured by dedicated signaling or in SIB1. controlResourceSetId is unique among the BWPs of the serving cell. A CORESET may be associated with coresetPoolIndex, which indicates the index of the CORESET pool of the CORESET. A CORESET may be associated with a time duration parameter (e.g., duration), which indicates the continuous time duration of the CORESET in number of symbols. In an embodiment, as shown in FIG. 25 , the configuration parameters of the CORESET may include at least one of a frequency resource indication (e.g., frequencyDomainResources), a CCE-REG mapping type indicator (e.g., cce-REG-MappingType), multiple TCI states, an indicator indicating whether a TCI is present in the DCI, and the like. The frequency resource indication, which may include a number of bits (e.g., 45 bits), indicates frequency domain resources, with each bit of the indication corresponding to a group of 6 RBs, the grouping starting from the first RB group in the BWP of a cell (e.g., SpCell, SCell). The first (leftmost / most significant) bit corresponds to the first RB group in the BWP, and so on. A bit set to 1 indicates that the RB group corresponding to that bit belongs to the frequency domain resources of this CORESET. Bits corresponding to groups of RBs that are not completely included in the BWP for which the CORESET is configured are set to zero.

[0210] FIG. 26 illustrates an example of a configuration of a search space (e.g., SearchSpace IE). In one embodiment, one or more search space configuration parameters of the search space may include at least one of a search space ID (searchSpaceId), a control resource set ID (controlResourceSetId), a monitoring slot periodicity and offset parameter (monitoringSlotPeriodicityAndOffset), a search space period value (Period), a monitoring symbol indicator (monitoringSymbolsWithinSlot), a number of candidates for an aggregation level (nrofCandidates), and / or a search space type (searchSpaceType) indicating a common search space type or a UE-specific search space type. The monitoring slot periodicity and offset parameter may indicate a slot (e.g., within a radio frame) and a slot offset (e.g., relative to the start of a radio frame) for PDCCH monitoring. The monitoring symbol indicator may indicate which symbols of a slot a wireless device may monitor for a PDCCH on an SS. The control resource set ID may identify a control resource set in which the SS may be located.

[0211] FIG. 27 illustrates an example of an RRC configuration of an uplink BWP of a serving cell and RACH parameters, including a two-step RA type and a four-step RA type. In one embodiment, a base station may transmit one or more RRC messages (e.g., a BWP-UplinkCommon IE) to a wireless device, including configuration parameters for an RA procedure on an uplink BWP of a cell (e.g., a PCell or SCell). The cell may include a first plurality of downlink BWPs and a second plurality of uplink BWPs. The cell may include multiple uplink carriers. The multiple uplink carriers may include a normal uplink carrier (NUL) and / or a complementary uplink carrier (SUL). The configuration parameters may include a first configuration parameter (e.g., in the RA-ConfigCommon IE) of an RA procedure for a first RA type (e.g., a four-step RA type) and a second configuration parameter (e.g., in the RA-ConfigCommonTwoStepRA-r16 IE) of an RA procedure for a second RA type (e.g., a two-step RA type). In an embodiment, the configuration parameters may further include a third configuration parameter (e.g., MsgA-PUSCH-Config IE) of PUSCH resources for Message A (MSGA) transmission for a two-step RA type. The first configuration parameter configured on the BWP may indicate configuration parameters of cell-specific RA parameters that the wireless device may use for contention-based (CB) and contention-free (CF) RA and CB BFR in the BWP. The second configuration parameter configured on the BWP may indicate configuration parameters of cell-specific RA parameters that the wireless device may use for CB and CF two-step RA type procedures and two-step RA type CB BFR in the BWP. The third configuration parameter configured on the BWP may indicate configuration parameters of cell-specific MsgA (Message A, MSGA, etc.) PUSCH parameters that the wireless device may use for contention-based MsgA PUSCH transmission in the BWP. In an embodiment, the first configuration parameter for RA with a four-step RA type may be implemented based on the examples of Figures 28 and / or 30.The second configuration parameter of the 2-step RA type RA may be implemented based on the examples of Figures 29 and / or 30.

[0212] As shown in FIG. 27, the third configuration parameter of the PUSCH resource (e.g., in the MsgA-PUSCH-Config IE) may include a list of MsgA PUSCH resources (e.g., msgA-PUSCH-ResourceList) that the wireless device may use when transmitting MsgA. The number of PUSCH resources may match the number of preamble groups configured in the RACH-ConfigCommonTwoStepRA in the BWP. If the field is not set for the selected UL BWP, the wireless device may use the MsgA PUSCH configuration of the initial UL BWP. The third configuration parameter may further include a power offset value of the msgA PUSCH relative to the preamble reception target power (e.g., msgA-DeltaPreamble). As shown in FIG. 27, each MsgA PUSCH resource in the list of MsgA PUSCH resources may be associated with one or more parameters, including a preamble group indication (e.g., msgA-PUSCH-PreambleGroup) indicating the preamble group to which the MsgA PUSCH configuration is associated according to groupB-ConfiguredTwoStep in RACH-ConfigCommonTwoStepRA, one or more PUSCH resource time and / or frequency domain resource allocation parameters.

[0213] 28 shows an example of an RRC configuration for RACH parameters of a 4-step RA type. In one embodiment, the base station may send one or more RRC messages (e.g., RACH-ConfigCommon IE) to the wireless device indicating RACH parameters for the 4-step RA type. The RACH parameters for the 4-step RA type may include generic configuration parameters (e.g., in RACH-ConfigGenericIE), a total number of preambles for the RA procedure (e.g., totalNumberOfRA-Preambles), an indication of the relationship between RACH occasions and SSBs (e.g., ssb-perRACH-OccasionAndCB-PreamblesPerSSB), one or more configuration parameters (e.g., TB size threshold for preamble Group B selection, pathloss / RSRP threshold for preamble Group selection, number of preambles per SSB available in preamble Group B), a contention resolution timer value (e.g., ra-ContentionResolutionTimer), a first RSRP threshold for selecting SS blocks and corresponding PRACH resources (e.g., rsrp-ThresholdSSB), a second RSRP threshold for selecting SUL or NUL for the RA procedure (e.g., rsrp-ThresholdSSB-SUL), a PRACH root sequence index (e.g., prach-RootSequenceIndex), and one or more other parameters. The indication of the association between RACH occasions and SSBs may indicate, via a first field (CHOICE field), the number of SSBs per RACH occasion. The value oneEight may correspond to one SSB associated with eight RACH occasions, the value oneFourth may correspond to one SSB associated with four RACH occasions, etc. The indication of the association between RACH occasions and SSBs may indicate, via a second field (ENUMERATED field), the number of preambles per SSB. The value n4 may correspond to four preambles per SSB, the value n8 may correspond to eight preambles per SSB, etc.In one embodiment, the generic configuration parameters (eg, in the RACH-ConfigGeneric IE) may be implemented based on the example of FIG.

[0214] 29 shows an example of an RRC configuration for RACH parameters of a two-step RA type. In one embodiment, a base station may transmit one or more RRC messages (e.g., a RACH-ConfigCommonTwoStepRA IE) indicating RACH parameters for a two-step RA type. The RACH parameters for a two-step RA type may include a generic configuration parameter (e.g., a RACH-ConfigGenericTwoStepRA IE), a total number of preambles for an RA procedure (e.g., msgA-TotalNumberOfRA-Preambles), an indication of the association between a RACH occasion and an SSB (e.g., msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB), one or more configuration parameters (e.g., GroupB-ConfiguredTwoStepRA), a contention resolution timer value for a contention resolution timer (e.g., ra-ContentionResolutionTimer), an indication of the PRACH root sequence index (e.g., prach-RootSequenceIndex), and one or more other parameters. In one embodiment, the indication of the association between RACH occasions and SSBs may indicate, via a first field (CHOICE field), the number of SSBs per RACH occasion. The value oneEight may correspond to one SSB associated with eight RACH occasions, the value oneFourth may correspond to one SSB associated with four RACH occasions, etc. The indication of the association between RACH occasions and SSBs may indicate, via a second field (ENMERATED field), the number of preambles per SSB. The value n4 may correspond to four preambles per SSB, the value n8 may correspond to eight preambles per SSB, etc.In one embodiment, the RACH parameters for the two-step RA type may further include one or more RSRP thresholds, including a first RSRP threshold (e.g., msgA-RSRP-Threshold) for selecting a two-step RA type or a four-step RA type to perform the procedure (on the NUL), a second RSRP threshold (e.g., msgA-RSRP-ThresholdSUL) for selecting a two-step RA type or a four-step RA type to perform the procedure on the SUL, a third threshold (e.g., msgA-RSRP-ThresholdSSB) for selecting an SS block and corresponding PRACH resource, and a fourth RSRP threshold (e.g., msgA-RSRP-ThresholdSSB-SUL) for selecting a NUL or SUL to select an RA procedure. In one embodiment, the generic configuration parameters (e.g., in the RACH-ConfigGenericTwoStepRA IE) may be implemented based on the example of FIG. 30.

[0215] 30 shows an example of RRC configuration of RACH parameters for a 2-step RA type and a 4-step RA type. In one embodiment, a base station may transmit one or more RRC messages (e.g., RACH-ConfigGeneric IE) to a wireless device, including generic configuration parameters for the RA procedure for the 4-step RA type. The generic configuration parameters for the RA procedure for the 4-step RA type may include a PRACH configuration index (e.g., prach-ConfigurationIndex), a preamble target received power level (e.g., preambleReceivedTargetPower), a maximum number of RA preamble transmissions performed before declaring failure (e.g., preambleTransMax), a Msg2(RAR) window length in number of slots (e.g., ra-ResponseWindow), a power ramp step for the PRACH (e.g., powerRampingStep), an offset indication of the lowest PRACH transmission occasion in the frequency domain relative to PRB 0 (e.g., msg1-FrequencyStart), the number of FDMed PRACH transmission occasions in one iteration (e.g., msg1-FDM), etc. In one embodiment, the PRACH configuration index may identify a PRACH resource consisting of a preamble format, a number of subframes, a periodicity and offset, a starting symbol, a number of PRACH slots within a subframe, a number of time-domain PRACH occasions within a PRACH slot, and a PRACH duration.

[0216] As shown in FIG. 30, the base station may send one or more RRC messages (e.g., RACH-ConfigGenericTwoStepRA IE) to the wireless device that include generic configuration parameters for the RA procedure for the two-step RA type on the cell (or the cell's BWP). Generic configuration parameters for a two-step RA type RA procedure may include a PRACH configuration index (e.g., msgA-PRACH-ConfigurationIndex), a preamble target received power level (e.g., msgA-PreambleReceivedTargetPower), a maximum number of MsgA preamble transmissions performed before switching to a four-step RA procedure (e.g., msgA-TransMax), a maximum number of RA preamble transmissions performed before declaring a failure (e.g., preambleTransMax), a MsgB monitoring window length in number of slots (e.g., msgB-ResponseWindow), a power ramp step for the MsgA PRACH (e.g., msgA-PreamblePowerRampingStep), a number of MSgA PRACH transmission occasions multiplexed at one time (e.g., msgA-RO-FDM), an offset indication of the lowest PRACH transmission occasion in the frequency domain with respect to PRB0, etc. (e.g., msgA-RO-FrequencyStart), etc.

[0217] FIG. 31 shows a flowchart of an example of an RA procedure configured with multiple uplink carriers and multiple RA types. In one embodiment, a base station may transmit one or more RRC messages including configuration parameters for the RA procedure on a cell (or a BWP of the cell) to a wireless device. The cell may include an SUL and a NUL. The RRC messages may be implemented based on the examples of FIG. 23A, FIG. 23B, FIG. 23C, FIG. 24, FIG. 25, FIG. 26, FIG. 27, FIG. 28, FIG. 29, and / or FIG. 30. The RA procedure may be a two-step RA type (e.g., FIG. 13C) or a four-step RA type (e.g., FIG. 13A and / or FIG. 13B).

[0218] As shown in FIG. 31 , the wireless device may trigger an RA procedure based on configuration parameters of the RA procedure. The wireless device may trigger the RA procedure in response to initiation of beam failure recovery, receipt of an RRC reconfiguration message from the base station for handover to a second cell, and / or receipt of a command on the physical downlink control channel (PDCCH) from the base station. The wireless device may trigger an RA procedure for initial access to a cell, a positioning procedure, and / or an uplink coverage recovery procedure. In response to the triggering of the RA procedure, the wireless device may initialize the RA procedure. The wireless device may initialize one or more parameters of the RA procedure (e.g., a transmission counter, a transmission timer, a transmit power setting, a response window, etc.). Initiating the RA procedure may include at least one of determining a SUL or NUL for performing the RA procedure based on the measured RSRP and determining a two-step RA type or a four-step RA type for performing the RA procedure.

[0219] As shown in Figure 31, in response to triggering an RA procedure, the wireless device may measure the RSRP of the pathloss RS of the cell. The wireless device may select a pathloss RS (e.g., SSB or CSI-RS) from the multiple RSs configured by the base station with the highest RSRP value among the multiple RSs. The wireless device may select the pathloss RS from the multiple RSs based on the measured L1-RSRP (e.g., without L3 filtering) or the measured L3-RSRP (e.g., with L3 filtering).

[0220] As shown in FIG. 31 , the wireless device may determine whether the measured RSRP is lower than a first RSRP threshold (e.g., rsrp-ThresholdSSB-SUL, the RSRP threshold configured for SUL or NUL selection). In response to the RSRP being lower than the first RSRP threshold, the wireless device may select the SUL to perform the RA procedure. The wireless device may set a second RSRP threshold (e.g., RSRP_THRESHOLD_RA_TYPE_SELECTION) as the RSRP threshold configured for the RACH configuration on the SUL for the RA type selection (e.g., msgA-RSRP-ThresholdSUL). In response to the RSRP being higher than the first RSRP threshold, the wireless device may select the NUL to perform the RA procedure. The wireless device may set the second RSRP threshold as the RSRP threshold configured for the RACH configuration on the NUL for the RA type selection (e.g., msgA-RSRP-Threshold).

[0221] As shown in FIG. 31 , in response to selecting an uplink carrier (e.g., SUL or NUL) for performing an RA procedure, the wireless device may determine whether the RSRP is greater than a second RSRP threshold (e.g., RSRP_THRESHOLD_RA_TYPE_SELECTION). In response to the RSRP being greater than the second RSRP threshold, the wireless device may select a two-step RA type for performing the RA procedure on the NUL. After selecting the two-step RA type and selecting the NUL for the RA procedure, the wireless device may perform RA resource selection. The RA resource selection may include selecting an SSB from multiple SSBs, selecting a preamble group, selecting a preamble from the preamble group, determining a RACH occasion based on the selected SSB, determining an UL grant for a PUSCH resource of an MSGA (Message A) associated with the selected preamble and RACH occasion, and related HARQ information, etc. In one embodiment, the wireless device may select an SSB from multiple SSBs with an RSRP greater than a third RSRP threshold. The third RSRP threshold may be configured in an RRC message (e.g., msgA-RSRP-ThresholdSSB). In one embodiment, the wireless device may randomly select an SSB from the multiple SSBs when none of the multiple SSBs has an RSRP higher than the third RSRP threshold. Based on the RA resource selection, the wireless device may transmit the MSGA using the selected RACH occasion and associated PUSCH resource.

[0222] As shown in FIG. 31 , in response to selecting a NUL for performing an RA procedure, the wireless device may determine whether the RSRP is greater than a second RSRP threshold (e.g., RSRP_THRESHOLD_RA_TYPE_SELECTION). In response to the RSRP being lower than the second RSRP threshold, the wireless device may select a 4-step RA type to perform the RA procedure on the NUL. After selecting the 4-step RA type and selecting a NUL for the RA procedure, the wireless device may perform RA resource selection. The RA resource selection may include selecting an SSB from a plurality of SSBs, selecting a preamble group, selecting a preamble from the preamble group, and determining a RACH occasion based on the selected SSB. In one embodiment, the wireless device may select an SSB from a plurality of SSBs with an RSRP higher than a fourth RSRP threshold. The fourth RSRP threshold may be configured in an RRC message (e.g., RSRP-ThresholdSSB). In one embodiment, the wireless device may randomly select an SSB from the plurality of SSBs when none of the plurality of SSBs has an RSRP higher than a fourth RSRP threshold. Based on the RA resource selection, the wireless device may transmit a preamble using the selected RACH occasion.

[0223] FIG. 32 shows an example of RRC configuration of RACH parameters with coverage enhancement. In one embodiment, a base station may transmit one or more RRC messages (e.g., PRACH-Config IE) including configuration parameters for PRACH configuration for RA procedure to a wireless device. The configuration parameters may include a frequency hopping parameter (e.g., prach-HoppingOffset), an initial PRACH CE level (e.g., initial-CE-level), a list of RSRP thresholds for PRACH resource set selection (e.g., rsrp-ThresholdsPrachInfoList), and one or more PDCCH configuration parameters (e.g., mpdcch-startSF-CSS-RA). The list of RSRP thresholds may include some of the RSRP thresholds for determining the CE level from multiple CE levels for PRACH. A first element may correspond to RSRP threshold 1, a second element may correspond to RSRP threshold 2, etc. The number of RSRP thresholds present in rsrp-ThresholdsPrachInfoList may be equal to the number of CE levels configured in prach-ParametersListCE minus 1. The configuration parameter may indicate a list of PRACH resource sets (e.g., PRACH-ParametersListCE), where each PRACH resource set corresponds to a respective CE level of multiple CE levels and may be associated with one or more PRACH parameters (e.g., PRACH-ParametersCE IE).The one or more PRACH parameters for the CE level may include a PRACH configuration index (e.g., prach-ConfigIndex), a number of PRACH repetitions per attempt for the CE level (e.g., numRepetitionPerPreambleAttempt), a maximum number of preamble transmission attempts for the CE level (e.g., maxNumPreambleAttemptCE), an initial PRACH CE level (e.g., initial-CE-level), a frequency offset parameter (e.g., prach-FreqOffset), a starting subframe indication (e.g., prach-StartingSubframe), a frequency hopping parameter (e.g., prach-HoppingConfig), one or more PDCCH configuration parameters (e.g., mpdcch-NumRepetition-RA indicating the number of repetitions of PDCCH transmission), etc. In one embodiment, the base station may send one or more RRC messages of an RA procedure to the wireless device before declaring failure, the RRC messages including a configuration parameter indicating the maximum number of RA preamble transmissions to perform (e.g., preambleTransMax or preambleTransMax-CE).

[0224] FIG. 33A illustrates examples of various coverage enhancement levels. In one embodiment, a base station may transmit one or more RRC messages to a wireless device, including configuration parameters for an RA procedure for coverage enhancement. The one or more RRC messages may be implemented based on the example of FIG. 32. As shown in FIG. 33A, the wireless device may be one of a wireless device (e.g., UE A) located in cell coverage of a first CE level (e.g., CE level 0), a wireless device (e.g., UE B) located in cell coverage of a second CE level (e.g., CE level 1), a wireless device (e.g., UE C) located in cell coverage of a third CE level (e.g., CE level 2), a wireless device (e.g., UE D) located in cell coverage of a fourth CE level (e.g., CE level 3), etc. The wireless device may determine a CE level for the RA procedure based on the RSRP of the pathloss RS and an RSRP threshold corresponding to the CE level, and perform the RA procedure based on the determined CE level.

[0225] FIG. 33B illustrates an example of a RACH procedure involving coverage enhancement. In one embodiment, a base station may transmit one or more RRC messages to a wireless device, including configuration parameters for an RA procedure for coverage enhancement over a cell. The one or more RRC messages may be implemented based on the example of FIG. 32. The one or more RRC messages may indicate multiple RSRP thresholds and multiple RACH resource sets. In one embodiment, each RACH resource set is associated with a respective CE level of multiple CE levels. The wireless device may determine a CE level for the RA procedure based on a comparison of the measured RSRP with multiple RSRP thresholds corresponding to the CE level among the multiple CE levels. The wireless device may be one of multiple wireless devices (e.g., UE A, UE B, UE C, and / or UE D) as shown in FIG. 32A. The wireless device may trigger an RA procedure. The wireless device may trigger the RA procedure in response to initiating beam failure recovery, receiving an RRC reconfiguration message from the base station for handover to a second cell, and / or receiving a command on the physical downlink control channel (PDCCH) from the base station. The wireless device may trigger an RA procedure for initial access to a cell, a positioning procedure, and / or an uplink coverage recovery procedure.

[0226] As shown in FIG. 33B , in response to triggering an RA procedure, the wireless device may measure the RSRP of the path loss RS of the cell. The wireless device may determine a CE level for the RA procedure based on the RSRP. In one example, if an RSRP threshold among the multiple RSRP thresholds corresponding to CE level 3 is configured, the measured RSRP is less than the RSRP threshold for CE level 3, and the wireless device is capable of supporting CE level 3, the wireless device may determine the CE level as CE level 3 for the RA procedure. If an RSRP threshold among the multiple RSRP thresholds corresponding to CE level 2 is configured, the measured RSRP is less than the RSRP threshold for CE level 2 and greater than the RSRP threshold for CE level 3, and the wireless device is capable of supporting CE level 2, the wireless device may determine the CE level as CE level 2 for the RA procedure. If an RSRP threshold of the multiple RSRP thresholds corresponding to CE level 1 is configured, and the measured RSRP is less than the RSRP threshold for CE level 1 and greater than the RSRP threshold for CE level 3 and the RSRP threshold for CE level 2, and the wireless device can support CE level 1, the wireless device may determine the CE level as CE level 1 for the RA procedure. If the measured RSRP is higher than the RSRP threshold for CE level 1, the wireless device may determine the CE level as CE level 0.

[0227] FIG. 33B illustrates that based on the determined CE level (e.g., CE level 3, CE level 2, CE level 1, and / or CE level 0), the wireless device may determine a RACH resource (e.g., a preamble and / or a RACH occasion) for the RA procedure. The wireless device may transmit the preamble with a number of repetitions (e.g., numRepetitionPerPreambleAttempt) by using the RACH occasion. The numerical value (e.g., numRepetitionPerPreambleAttempt) may be configured for the CE level in the RRC message, as shown in FIG. 32. In response to transmitting the preamble with the number of repetitions, the wireless device may monitor the PDCCH to receive an RA response (e.g., after the last preamble repetition).

[0228] 34 illustrates an example of a RACH procedure with RA type selection and coverage enhancement. In one embodiment, a base station may transmit one or more RRC messages to a wireless device that include configuration parameters for the RA procedure on a cell. The configuration parameters may include one or more parameters for multiple RACH resources on the cell.

[0229] In one embodiment, the multiple RACH resources may be grouped into multiple RACH resource sets. Each RACH resource set may include a first multiple RACH resources and one or more RSRP thresholds. Each RACH resource set may correspond to a respective CE level of the multiple CE levels. Each RACH resource set may include multiple RACH resource subsets, each RACH resource subset corresponding to a respective RA type of the multiple RA types. Each RACH resource subset may include a second multiple RACH resources.

[0230] In one embodiment, the multiple RACH resources may be grouped into multiple RACH resource sets. Each RACH resource set may include a first plurality of RACH resources and one or more RSRP thresholds. In one example, each RACH resource set may correspond to a respective RA type of a plurality of RA types. Each RACH resource set may include multiple RACH resource subsets, each RACH resource subset corresponding to a respective CE level of a plurality of CE levels. Each RACH resource subset may include a second plurality of RACH resources.

[0231] In one embodiment, the RA type may be a two-step RA type or a four-step RA type. The wireless device may perform the RA procedure with a two-step RA based on the example of Figure 13C. The wireless device may perform the RA procedure with a four-step RA type based on the example of Figure 13A (or Figure 13B when the RA procedure is a contention-free RA procedure).

[0232] As shown in Figure 34, the wireless device may trigger an RA procedure. The wireless device may trigger the RA procedure in response to initiating beam failure recovery, receiving an RRC reconfiguration message for handover to a second cell from the base station, and / or receiving a command on a physical downlink control channel (PDCCH) from the base station. The wireless device may trigger an RA procedure for initial access to a cell, a positioning procedure, and / or an uplink coverage recovery procedure.

[0233] As shown in Figure 34, in response to triggering an RA procedure, the wireless device may measure the RSRP of the pathloss RS. The pathloss RS may be an SSB or CSI-RS configured on the cell, or may be another cell based on the configuration. The wireless device may select the pathloss RS with the highest RSRP (e.g., L1-RSRP or L3-RSRP) among multiple RSs (e.g., SSB and / or CSI-RS).

[0234] As shown in FIG. 34, the wireless device may determine an RA type from a plurality of RA types and a CE level from a plurality of CE levels based on the measured RSRP of the path loss RS and one or more RSRP thresholds.

[0235] In one embodiment, multiple RACH resources are grouped into multiple RACH resource sets. Each RACH resource set associated with an RSRP threshold of one or more RSRP thresholds may correspond to a respective CE level of multiple CE levels. Each RACH resource set may include multiple RACH resource subsets. Each RACH resource subset of a RACH resource set may correspond to a respective RA type of multiple RA types. The wireless device may determine the CE level based on the measured RSRP and the RSRP threshold corresponding to the CE level. The wireless device may determine the CE level based on the measured RSRP and the RSRP threshold, for example, according to the implementation example of FIG. 33B. The wireless device may select a RACH resource set from the multiple RACH resource sets corresponding to the determined CE level. Based on the determined RACH resource set, the wireless device may determine a first RACH resource subset from the multiple RACH resource subsets of the RACH resource set based on the measured RSRP and a second RSRP threshold of one or more RSRP thresholds. In one embodiment, if the measured RSRP is greater than a second RSRP threshold, the wireless device may select a first RACH resource subset corresponding to a two-step RA type. The wireless device may perform an RA procedure with the two-step RA type based on the first RACH resource subset. The RA procedure with the two-step RA type may be performed based on the example of FIG. 13C. In one embodiment, if the measured RSRP is less than a second RSRP threshold, the wireless device may select a second RACH resource subset corresponding to a four-step RA type. The wireless device may perform an RA procedure with the four-step RA type based on the second RACH resource subset. The four-step RA procedure may be performed based on the example of FIG. 13A (or FIG. 13B when the RA procedure is a contention-free RA procedure).

[0236] In one embodiment, multiple RACH resources are grouped into multiple RACH resource sets. Each RACH resource set may correspond to a respective RA type of multiple RA types. Each RACH resource set may include multiple RACH resource subsets. Each RACH resource subset of a RACH resource set may correspond to a respective CE level of multiple CE levels. The wireless device may determine the RA type based on the measured RSRP and a first RSRP threshold for RA type selection. In response to the measured RSRP being greater than the first RSRP threshold, the wireless device may select a first RACH resource set from the multiple RACH resource sets corresponding to a 2-step RA type. In response to the measured RSRP being less than the first RSRP threshold, the wireless device may select a second RACH resource set from the multiple RACH resource sets corresponding to a 4-step RA type. Based on the determined RACH resource set (e.g., the first RACH resource set or the second RACH resource set), the wireless device may determine a first RACH resource subset from multiple RACH resource subsets of the RACH resource set based on the measured RSRP and one or more second RSRP thresholds for CE level determination.

[0237] In one embodiment, the wireless device may determine an SSB from the multiple SSBs based on a measured RSRP. The wireless device may determine an SSB from the multiple SSBs based on the measured RSRP of the SSB being greater than a third RSRP threshold. In one embodiment, if the determined RA type is a 4-step RA type, based on the determined SSB, the wireless device may select an RA resource (e.g., a RACH resource including a preamble and / or a RACH occasion) based on a RACH resource subset selected based on the above description. The wireless device may determine the number of preamble repetitions based on a determined CE level of the RACH resource subset. In one embodiment, if the determined RA type is a 2-step RA type, based on the determined SSB, the wireless device may select an RA resource (e.g., a RACH resource including a preamble and / or a RACH occasion and a PUSCH resource associated with the RACH resource) based on a RACH resource subset. The wireless device may determine the number of MSGA repetitions based on a determined CE level of the RACH resource subset.

[0238] As shown in Figure 34, based on the determined RA resource and number of times, the wireless device may transmit a preamble or an MSGA using the RA resource with the repetition number. In one embodiment, in response to determining a 2-step RA type, the wireless device may transmit an MSGA using an RA resource (e.g., a RACH resource and an associated PUSCH resource) with the repetition number. In one embodiment, in response to determining a 4-step RA type, the wireless device may transmit a preamble with the repetition number using an RA resource (e.g., a RACH resource). After transmitting the preamble or MSGA with the repetition number, the wireless device may monitor the PDCCH to receive an RAR corresponding to the preamble or MSGA.

[0239] Figure 35 shows an example of an RA procedure involving switching from a first CE level to a second CE level. In one embodiment, a wireless device may trigger an RA procedure (e.g., based on Figure 33B). The wireless device may determine a CE level from multiple CE levels based on the measured RSRP of the path loss RS and one or more RSRP thresholds, where the one or more RSRP thresholds may be used by the wireless device for CE level selection. The wireless device may determine a CE level based on the example of Figure 33B.

[0240] As shown in Figure 35, the wireless device may select a preamble and a RACH resource (or occasion) from one or more RACH resources associated with the CE level based on the RS. The wireless device may select an RS when the measured RSRP is higher than a second RSRP threshold (e.g., configured for RS selection). The wireless device may select a preamble and a RACH resource based on the example of Figure 33B.

[0241] As shown in Figure 35, the wireless device may use the RACH resource to transmit the preamble at a first number of repetitions (e.g., numRepetitionPerPreambleAttempt), where the first number is associated with the determined CE level. The first number may be configured for the CE level based on the example of Figure 32.

[0242] As shown in FIG. 35, the wireless device may monitor the PDCCH to receive a response to transmitting a preamble. The wireless device may monitor the PDCCH after the last repetition of the preamble transmission. The wireless device may determine whether a response is received while monitoring the PDCCH (e.g., when the RAR response window is running). In response to the received response, the wireless device may perform a Message3 transmission based on the example of FIG. 13A.

[0243] In response to not receiving a response (e.g., before the RAR response window expires), the wireless device may consider the preamble not successfully transmitted. As shown in FIG. 35, in response to not receiving a response, the wireless device may increment a first transmission counter (e.g., PREAMBLE_TRANSMISSION_COUNTER) and a second transmission counter (e.g., PREAMBLE_TRANSMISSION_COUNTER_CE). In response to not receiving a response, the wireless device may increment the first transmission counter by 1 and the second transmission counter by 1. The first transmission counter may be used to control preamble transmission before declaring a failure of the RA procedure. The second transmission counter may be used to switch to the next CE level (e.g., having a higher iteration count than the current CE level) to continue the RA procedure. The first transmission counter and the second transmission counter may be initialized to a first value (e.g., 0 or 1) when the wireless device initializes the RA procedure.

[0244] As shown in FIG. 35, the wireless device may determine whether the first transmission counter is greater than a first Tx number of the RA procedure (e.g., preambleTransMax-CE). The first Tx number may be configured by the base station in one or more RRC messages. In response to the first transmission counter being greater than the first Tx number, the wireless device may unsuccessfully complete the RA procedure.

[0245] As shown in FIG. 35, in response to the first transmission counter being less than or equal to the first Tx number, the wireless device may determine whether the second transmission counter is greater than a second Tx number (e.g., maxNumPreambleAttemptCE) for the CE level of the RA procedure. In response to the second transmission counter not being greater than the second Tx number, the wireless device may repeat transmission of the preamble, where transmitting the preamble includes transmitting the preamble the repetition number. The preamble may be the same as that used for the first transmission. The preamble may be selected to be different from that used for the first transmission based on the RSRP and the RSRP for RS selection.

[0246] As shown in FIG. 35, in response to the second transmit counter being greater than the second Tx number of the CE level, the wireless device may switch (or move) to the next CE level. The next CE level may be configured (or associated) with a higher repetition number than the first CE level. In response to the second transmit counter being greater than the second Tx number of the CE level, the wireless device may reset the second transmit counter (e.g., to an initial value, 0 or 1). In response to the second transmit counter being greater than the second Tx number of the CE level, the wireless device may not be able to reset the first transmit counter. In response to switching to the next CE level, the wireless device may select a preamble and associated RACH resources and transmit the preamble over the RACH resources for a second repetition number, the second number being configured for the next CE level. The wireless device may repeat the process until the first transmit counter is greater than the first Tx number or the wireless device receives a response from the base station.

[0247] In one embodiment, a wireless device may perform a two-step RA procedure (e.g., based on the example of FIG. 13C). The wireless device may select an RS having a measured RSRP higher than an RSRP threshold (e.g., configured for RS selection). The RSRP threshold may be configured based on the example of FIG. 27. The wireless device may select an RS based on the example of FIG. 31. The wireless device may determine a PRACH occasion (or resource) from multiple PRACH occasions based on the selected RS. The wireless device may select a preamble, a RACH occasion, and associated PUSCH resources for the MSGA based on the example of FIG. 31. The wireless device may transmit the MSGA using the RACH resource and the PUSCH resource. The wireless device may transmit a preamble for the MSGA using the RACH resource and transmit a TB for the MSGA using the PUSCH resource. The wireless device may monitor the PDCCH to receive a response to transmitting the MSGA. The wireless device may monitor the PDCCH after completing transmission of the preamble and TB. The wireless device may determine whether a response is received while monitoring the PDCCH (e.g., when the RAR response window is running). In response to a received response, the wireless device may complete the RA procedure with a two-step RA type based on the example of FIG. 13C. In response to not receiving a response (e.g., before the RAR response window expires), the wireless device may consider the MSGA not successfully transmitted. In response to not receiving a response, the wireless device may increment a transmission counter (e.g., PREAMBLE_TRANSMISSION_COUNTER). In response to not receiving a response, the wireless device may increment the transmission counter by 1. The transmission counter may be used to control preamble transmission before declaring a failure of the RA procedure. The transmission counter may be initialized to a first value (e.g., 0 or 1) when the wireless device initializes the RA procedure.

[0248] In one embodiment, the wireless device may determine whether the transmission counter is greater than a first maximum Tx number (e.g., preambleTransMax) for the RA procedure. The first maximum Tx number may be configured by the base station in one or more RRC messages. In response to the transmission counter being greater than the first maximum Tx number, the wireless device may unsuccessfully complete the RA procedure. In response to the transmission counter being less than or equal to the first maximum Tx number, the wireless device may determine whether the transmission counter is greater than a second maximum Tx number (e.g., msgA-TransMax) for a two-step RA type of the RA procedure. The second maximum Tx number may be configured for the wireless device for RA type switching. In response to the transmission counter not being greater than the second maximum Tx number, the wireless device may repeat transmitting the MSGA. The preamble of the MSGA may be the same as that used for the first transmission. The preamble may be selected to be different from that used for the first transmission based on the RSRP and the RSRP for RS selection.

[0249] In response to the transmit counter being greater than the second maximum Tx count for the 2-step RA type, the wireless device may switch (or move) from the 2-step RA type to the 4-step RA type. The wireless device may continue the RA procedure with the 4-step RA type. In response to switching to the 4-step RA type, the wireless device may perform initialization of variables specific to the RA type. In one embodiment, the wireless device may continue the RA procedure without resetting the first transmit counter and / or resetting the transmit power to an initial value. The wireless device may continue the RA procedure with the 4-step RA type based on the example of FIG. 13A or FIG. 13B.

[0250] In one embodiment, a wireless device may initialize an RA procedure (e.g., based on the example of FIG. 31) with a four-step RA type. The wireless device may select an RS having a measured RSRP higher than an RSRP threshold (e.g., configured for RS selection). The RSRP threshold may be configured based on the example of FIG. 28. The wireless device may select an RS based on the example of FIG. 31. The wireless device may determine a PRACH occasion (or resource) from multiple PRACH occasions based on the selected RS. The wireless device may select a preamble and a RACH occasion based on the example of FIG. 30. The wireless device may transmit a preamble using a RACH resource. The wireless device may monitor the PDCCH to receive a response to transmitting the preamble. The wireless device may monitor the PDCCH after completing transmission of the preamble. The wireless device may determine whether a response is received while monitoring the PDCCH (e.g., when the RAR response window is running). In response to the received response, the wireless device may transmit message 3 based on the example of FIG. 13A. In response to not receiving a response (e.g., before the RAR response window expires), the wireless device may consider the preamble not successfully transmitted. In response to not receiving a response, the wireless device may increment a transmission counter (e.g., PREAMBLE_TRANSMISSION_COUNTER). In response to not receiving a response, the wireless device may increment the transmission counter by 1. The transmission counter may be used to control preamble transmission before declaring a failure of the RA procedure. The transmission counter may be initialized to a first value (e.g., 0 or 1) when the wireless device initiates the RA procedure.

[0251] In one embodiment, the wireless device may determine whether the transmission counter is greater than a maximum Tx number (e.g., preambleTransMax) for the RA procedure. The maximum Tx number may be configured by the base station in one or more RRC messages. In response to the transmission counter being greater than the maximum Tx number, the wireless device may unsuccessfully complete the RA procedure. In response to the transmission counter being less than or equal to the maximum Tx number, the wireless device may repeat the process including selecting an SSB, determining a RACH resource, transmitting a preamble, and monitoring the PDCCH. The wireless device may repeat the process until the transmission counter is greater than the maximum Tx number or the wireless device receives a response from the base station.

[0252] 36 shows an example of an RA procedure. In one embodiment, the base station may send one or more RRC messages (e.g., MIB, SIB1, SIB2, etc.) containing configuration parameters of a cell to the wireless device. The cell may be a PCell or a PSCell.

[0253] In one embodiment, the cell's configuration parameters may include one or more 4-step RA RACH configurations (rach-ConfigCommon) for 4-step RA on the cell's initial (uplink) BWP. Each rach-ConfigCommon may include a maximum number of RA preamble transmissions (e.g., preambleTransMax) performed for a 4-step RA type before declaring a failure of the RA procedure. Each rach-ConfigCommon may include a number of repetitions per preamble attempt (e.g., numRepetitionPerPreambleAttempt). numRepetitionPerPreambleAttempt may indicate the number of repetitions of a preamble transmission attempt before monitoring the PDCCH to receive an RAR for the preamble. After transmitting the number of repetitions of a preamble attempt, the wireless device may monitor the PDCCH to receive DCI scheduling an RAR for the preamble. Different 4-step RACH configurations may have different values ​​of preambleTransMax and / or numRepetitionPerPreambleAttempt.

[0254] In one embodiment, the configuration parameters may include one or more two-step RA RACH configurations (RACH-ConfigCommonTwoStepRA) for RAs with a two-step RA type on the initial (uplink) BWP of the cell. Each RACH-ConfigCommonTwoStepRA may include a first maximum number of RA preamble transmissions (e.g., preambleTransMax) performed before declaring a failure for the RA procedure and a second maximum number of MsgA preamble transmissions (e.g., msgA-TransMax) performed before switching from a two-step RA type to a four-step RA type. Different two-step RACH configurations may have different values ​​of preambleTransMax. Different two-step RACH configurations may also have different values ​​of msgA-TransMax.

[0255] In one embodiment, RACH-ConfigCommonTwoStepRA may include a first number of repetitions per preamble attempt (e.g., numRepetitionPerPreambleAttempt) for a two-step RA. The first numRepetitionPerPreambleAttempt may indicate a first number of repetitions of MsgA preamble transmission attempts for a two-step RA when the wireless device determines to perform a two-step RA (e.g., based on the example of FIG. 31). The wireless device may monitor the PDCCH to receive DCI scheduling an RAR for the MsgA preamble in response to and / or after transmitting the first number of repetitions of the MsgA preamble. RACH-ConfigCommonTwoStepRA may include a second number of repetitions per preamble attempt (e.g., numRepetitionPerPreambleAttempt) for a four-step RA. The second numRepetitionPerPreambleAttempt may indicate a second number of repetitions of preamble attempts for a four-step RA. In response to and / or after switching from a two-step RA type to a four-step RA type for an RA procedure, the wireless device may transmit a second number of repetitions of the preamble. The wireless device may monitor the PDCCH to receive DCI scheduling an RAR for the preamble after the wireless device finishes the second number of repetitions of the preamble. In one example, the first numRepetitionPerPreambleAttempt and the second numRepetitionPerPreambleAttempt of RACH-ConfigCommonTwoStepRA can have the same value or different values. Different two-step RACH configurations may have different values ​​of the first numRepetitionPerPreambleAttempt for the two-step RA type. Different two-step RACH configurations may have different values ​​of the second numRepetitionPerPreambleAttempt for the four-step RA type.

[0256] In one embodiment, each RACH configuration (two-step RACH configuration and / or four-step RACH configuration) on the initial BWP of a cell may be associated with one or more SSBs. The association between the RACH configuration and the SSBs may be included in the configuration parameters of SIB1.

[0257] In an embodiment, the configuration parameters for a cell may include configuration parameters for one or more RA search spaces (e.g., ra-SearchSpace) of a control resource set (CORESET) on the cell's initial downlink BWP. CORESET may be CORESET#0 or a common control resource set configured in PDCCH-ConfigComm as shown in FIG. 35. The RA search space may be a type1-PDCCH common search space in which a wireless device may monitor the PDCCH for receiving DCI in a DCI format having a CRC scrambled by the RA-RNTI or TC-RNTI on the cell's initial BWP. In a DCI format having a CRC scrambled by the RA-RNTI or TC-RNTI, the DCI may indicate scheduling information for an RAR message. In one example, the configuration parameters for each RA search space may include an SSB index or an SSB group index, indicating that the RA search space is associated with an SSB identified by the SSB index or a group of SSBs identified by the SSB group index. In an embodiment, the configuration parameters of each RA search space may include a number of PDCCH repetitions (e.g., PDCCH-NumRepetition) for DCI scheduling RAR messages. The number may indicate the maximum number of DCI transmissions from the base station via the PDCCH. Each RA search space may be associated with a different number of PDCCH repetitions.

[0258] In one embodiment, the cell configuration parameters may indicate an association of one or more RACH configurations with a corresponding one of one or more RA search spaces. In one embodiment, a RACH configuration may be associated with an RA search space based on at least one of the SSB of the RACH configuration, the SSB group of the RACH configuration, the number of repetitions per preamble (or MsgA preamble) attempt of the RACH configuration, the RA type of the RACH configuration, and the wireless device type or (capability) category. In one example, a RACH configuration may be associated with an RA search space in response to a RACH configuration having the same SSB index (or the same SSB group index) in the RA search space. In one example, a RACH configuration may be associated with an RA search space in response to a number of repetitions per preamble (or MsgA preamble) attempt of the RACH configuration (e.g., numRepetitionPerPresambleAttempt) that is equal to the number of repetitions of the PDCCH (e.g., PDCCH-NumRepetition) in the RA search space. In one embodiment, a RACH configuration configured by RACH-ConfigCommon may be associated with a first RA search space dedicated to four-step RA types. A RACH configuration configured by RACH-ConfigCommonTwoStepRA may be associated with a second RA search space dedicated to two-step RA types. In one embodiment, a first RACH configuration configured for a first wireless device type or category may be associated with a first RA search space dedicated to the first wireless device type or category. A second RACH configuration configured for a second wireless device type or category may be associated with a second RA search space dedicated to the second wireless device type or category.

[0259] As shown in Figure 36, the wireless device may trigger an RA procedure. The wireless device may trigger the RA procedure in response to initiating beam failure recovery, receiving an RRC reconfiguration message for handover to a second cell from the base station, and / or receiving a command on a physical downlink control channel (PDCCH) from the base station. The wireless device may trigger an RA procedure for initial access to a cell, a positioning procedure, and / or an uplink coverage recovery procedure.

[0260] As shown in FIG. 36, in response to triggering an RA procedure, the wireless device may measure the RSRP of the pathloss RS of the cell. The wireless device may select, from the plurality of RSs, a pathloss RS (e.g., SSB or CSI-RS) having the highest RSRP value among the plurality of RSs configured by the base station. The wireless device may select the pathloss RS from the plurality of RSs based on the measured L1-RSRP (e.g., without L3 filtering) or the measured L3-RSRP (e.g., with L3 filtering). In one embodiment, the wireless device may select, from the plurality of RSs, a pathloss RS (e.g., SSB or CSI-RS) having the highest RSRP value among the plurality of RSs configured by the base station. The plurality of RSs may be dedicated to a first wireless device type having reduced capabilities. The plurality of RSs may be a subset of SSBs, with the SSBs being used for a second wireless device type having normal capabilities.

[0261] In one example, a wireless device with reduced capabilities may be a wireless device with a reduced bandwidth (e.g., <=20 MHz for FR1, <=50 MHz for FR2, etc.), a reduced number of Tx / Rx antennas (e.g., 1 Tx / Rx, 1 Tx / 2Rx, etc.), reduced processing timing, reduced transmit power, and / or reduced processing capability compared to a wireless device with normal capabilities. A wireless device with normal capabilities may be a wireless device with a bandwidth (e.g., >20 MHz for FR1, >50 MHz for FR2, etc.), a number of Tx / Rx antennas (e.g., 2 Tx / 2Rx, 2 Tx / 4Rx, etc.), normal processing timing, normal transmit power, and / or normal processing capability.

[0262] In one embodiment, the wireless device may determine an RA type (not shown in FIG. 36) for the RA procedure. The wireless device may determine the RA type based on the example of FIG.

[0263] In one embodiment, the wireless device may determine a number of repetitions per preamble attempt for an RA procedure. The wireless device may determine the number of repetitions per preamble attempt based on a selected SSB. In one embodiment, based on the selected SSB, the wireless device may determine a RACH configuration associated with the selected SSB in accordance with configuration parameters of the RACH configuration. The wireless device may determine the number of repetitions per preamble attempt based on configuration parameters of the RACH configuration associated with the selected SSB.

[0264] As shown in FIG. 36, the wireless device may transmit a preamble (or MSGA) with a number of repetitions (e.g., the first repetition of the transmission shown in FIG. 36) based on the RA type and the number of repetitions per preamble attempt. In response to the RA type being a 2-step RA type, the wireless device may transmit an MSGA (e.g., a preamble via a PRACH and a TB via a PUSCH associated with the PRACH) with a number of repetitions. In response to the RA type being a 4-step RA type, the wireless device may transmit a preamble with a number of repetitions.

[0265] As shown in Figure 36, in response to transmitting a preamble (or MSGA) with the number of repetitions, the wireless device may determine an RA SS from one or more RA search spaces (SSs) configured by the base station for monitoring the PDCCH for responses to the preamble or MSGA. In one embodiment, the wireless device may determine an RA SS from one or more RA SSs based on at least one of the wireless device type / category of the wireless device, the SSB index of the selected SSB, the number of repetitions per preamble attempt, and the RA type (e.g., 2-step RA type, 4-step RA type).

[0266] In one embodiment, the wireless device may determine an RA SS from one or more RA SSs based on a RACH configuration associated with the selected SSB. The wireless device may select an RA SS from one or more RA SSs associated with the RA configuration based on the configuration of the cell.

[0267] In one embodiment, the wireless device may determine an RA SS from one or more RA SSs based on the selected SSB. The wireless device may select an RA SS from one or more RA SSs based on the RA SS associated with the selected SSB.

[0268] In one embodiment, the wireless device may determine an RA SS from one or more RA SSs based on the number of repetitions per preamble attempt of the RACH configuration. The wireless device may select an RA SS from one or more RA SSs having a number of repetitions of the PDCCH equal to the number of repetitions per preamble attempt of the RACH configuration.

[0269] In one embodiment, the wireless device may determine an RA SS from one or more RA SSs based on the RA type determined by the wireless device. In response to the RA type of the RA procedure being a two-step RA type, the wireless device may determine a first RA SS from one or more RA SSs dedicated to the two-step RA type. In response to the RA type of the RA procedure being a four-step RA type, the wireless device may determine a second RA SS from one or more RA SSs dedicated to the four-step RA type.

[0270] In one embodiment, the wireless device may determine an RA SS from one or more RA SSs based on the wireless device type / category of the wireless device. In one embodiment, in response to the wireless device being a first wireless device type / category (e.g., reduced capability / type), the wireless device may determine a first RA SS from one or more RA SSs dedicated to the first wireless device type / category. In one embodiment, in response to the wireless device being a second wireless device type / category (e.g., normal capability / type), the wireless device may determine a second RA SS from one or more RA SSs dedicated to the second wireless device type / category.

[0271] As shown in FIG. 36, based on the determined RA SS, the wireless device may monitor the PDCCH in response to transmitting a preamble (or MSGA) with a first number of repetitions to receive DCI having a CRC scrambled by the RA-RNTI via the determined RA SS, and the DCI is transmitted by the base station with a second number of repetitions. The second number of repetitions may be indicated by a configuration parameter of the determined RA SS. The wireless device may start a response window (e.g., ra-ResponseWindow) in response to transmitting the preamble with the first number of repetitions. In one example, the wireless device may start a response window (e.g., msgB-ResponseWindow) in response to transmitting the MSGA with the first number of repetitions. In one example, the first number of repetitions may be different from the second number of repetitions.

[0272] In one example, during the response window, the wireless device may monitor the PDCCH, e.g., by attempting to decode the DCI with the CRC scrambled by the RA-RNTI and the second iteration. In one embodiment, in response to receiving the DCI, e.g., by successfully decoding the DCI with the CRC scrambled by the RA-RNTI and / or the RAR indicating the preamble transmitted by the wireless device, the wireless device may stop the response window (e.g., ra-ResponseWindow or msgB-ResponseWindow). In one embodiment, the nth iteration of the transmission of the DCI may be 回目の In response to receiving the DCI in repetitions, n times may be less than the second number configured for the RASS, and the wireless device may stop monitoring the PDCCH and / or stop the response window. In one embodiment, the DCI may include a field indicating a third number of repetitions of the transmission of the DCI, and the third number may be less than the second number. 回目の In response to receiving the DCI repeatedly, n times less than the third number of times, the wireless device may stop monitoring the PDCCH and / or stop the response window.

[0273] In one example, if no response is received from the base station during the response window, the wireless device may increment a transmission counter. The wireless device may transmit a second preamble (or a second MSGA) at a first number of repetitions, then monitor the PDCCH to receive DCI at a second number of repetitions, and so on. The wireless device may repeat the four-step RA procedure until the transmission counter reaches a first maximum number of times (e.g., preambleTransMax) for declaring failure. The wireless device may repeat the two-step RA procedure until it reaches a second maximum number of times (e.g., msgA-TransMax) for switching from a two-step RA type to a four-step RA type. The wireless device may continue the RA procedure with the four-step RA type in response to switching from a two-step RA type to a four-step RA type, as shown above.

[0274] Figure 37A shows an example of SS configurations on a cell's initial BWP. In one example, a base station may transmit to a wireless device one or more RRC messages (e.g., MIB, SIB1, etc.) including PDCCH configurations for one or more SSs of the cell's initial BWP. In one example, the one or more SSs may include one or more type 0-PDCCH common CSSs (CSSs) for receiving DCI (with a CRC scrambled by the SI-RNTI) scheduling an SIB1 message, one or more type 0A-PDCCH CSSs for receiving DCI (with a CRC scrambled by the SI-RNTI) scheduling other system information messages, one or more type 1-PDCCH CSSs for receiving DCI (with a CRC scrambled by the RA-RNTI) scheduling an RAR message, and one or more type 2-PDCCH CSSs for receiving DCI (with a CRC scrambled by the P-RNTI) scheduling a paging message.

[0275] As shown in FIG. 37A, the one or more type 1-PDCCH CSSs may comprise a first type 1-PDCCH CSS dedicated to a first wireless device type / category (e.g., normal capability UEs) and a second type 1 CSS dedicated to a second wireless device type / category (e.g., reduced capability UEs). In one embodiment, the first type 1-PDCCH CSS may be associated with a single transmission of DCI via the PDCCH. The second type 1-PDCCH CSS may be associated with a repetition number of transmissions of DCI via the PDCCH. In one embodiment, the second type 1-PDCCH CSS may be associated with a different common CORESET than one of the first type 1-PDCCH CSSs. The second type 1-PDCCH CSS may be associated with a higher aggregation level than one of the first type 1-PDCCH CSSs.

[0276] In one example, in response to the wireless device being of a first wireless device type (e.g., having normal capability), the wireless device may select a first type1-PDCCH CSS from one or more Type1-PDCCH CSSs to monitor the PDCCH to receive DCI that schedules an RAR for the wireless device's preamble transmitted for the RA procedure, having a CRC scrambled by the RA-RNTI.

[0277] In one example, in response to the wireless device being of a second wireless device type (e.g., having reduced capabilities), the wireless device may select a first type1-PDCCH CSS from one or more Type1-PDCCH CSSs to monitor the PDCCH to receive DCI that schedules an RAR for the wireless device's preamble transmitted for the RA procedure, having a CRC scrambled by the RA-RNTI.

[0278] Figure 37B shows an example of type 1-PDCCH CSS configuration. In one example, a base station may transmit, to a wireless device, one or more RRC messages (e.g., MIB, SIB1, etc.) including PDCCH configurations for one or more Type 1-PDCCH CSSs of the cell's initial BWP. In one example, the one or more type 1-PDCCH CSSs may include a first type 1-PDCCH CSS associated with a first SSB, a second type 1-PDCCH CSS associated with a second SSB, and a third type 1-PDCCH CSS associated with a third SSB. The first type 1-PDCCH CSS may be configured with a first number of repetitions of PDCCH transmission of DCI for RAR. The second type 1-PDCCH CSS may be configured with a second number of repetitions of PDCCH transmission of DCI for RAR. The third type 1-PDCCH CSS may be configured with a third number of repetitions of PDCCH transmission of DCI for RAR. In one example, in response to the wireless device selecting a first SSB for the RA procedure, the wireless device may select a first type 1-PDCCH CSS from one or more type 1-PDCCH CSSs based on the first type 1-PDCCH CSS being associated with the first SSB. Similarly, the wireless device may select a second type 1-PDCCH CSS based on the second type 1-PDCCH CSS being associated with the second SSB when the wireless device selects a second SSB, etc.

[0279] 38 shows an example of an RA SS configuration for an RA procedure. In one example, the base station may send, to the wireless device, one or more RRC messages (e.g., MIB, SIB1, etc.) including PDCCH configurations for one or more Type 1-PDCCH CSSs of the cell's initial BWP.

[0280] In one embodiment, the one or more type 1-PDCCH CSSs may include a first type 1-PDCCH CSS associated with SSB 1 and a second type 1-PDCCH CSS associated with SSB 2, SSB 3, and SSB 4. The first type 1-PDCCH CSS may be configured with a first number of repetitions of DCI for RAR via the PDCCH. The second type 1-PDCCH CSS may be configured with a single transmission of DCI for RAR via the PDCCH. The first type 1-PDCCH CSS may be dedicated to wireless devices having a first type (e.g., reduced capability). The second type 1-PDCCH CSS may be dedicated to wireless devices having a second type (e.g., normal capability). In one embodiment, the first type1-PDCCH CSS and the second type1-PDCCH CSS may share the same CORESET (e.g., CORESET#0 or other common CORESET) of the initial BWP of the cell, or may be associated with different CORESETs of the initial BWP of the cell.

[0281] In one embodiment, in response to the wireless device being of a first type, the wireless device may select SSB 1 to perform the RA procedure from SSB 1, SSB 2, SSB 3, and SSB 4. The wireless device may select a first type1-PDCCH CSS to monitor the PDCCH to receive DCI scheduling the RAR, where the DCI may be transmitted by the base station at a first repetition number.

[0282] In one embodiment, in response to the wireless device being of the second type, the wireless device may select one from SSB2, SSB3, and SSB4 to perform the RA procedure. The wireless device may select a second type1-PDCCH CSS to monitor the PDCCH to receive DCI scheduling the RAR, which may be transmitted by the base station in a single transmission.

[0283] FIG. 39 shows an example of an RA SS configuration for an RA procedure. In one example, a base station may transmit, to a wireless device, one or more RRC messages (e.g., MIB, SIB1, etc.) including PDCCH configurations for one or more Type 1-PDCCH CSSs of the cell's initial BWP. In one embodiment, the one or more type 1-PDCCH CSSs may include a first type 1-PDCCH CSS dedicated to a two-step RA type and a second type 1-PDCCH CSS dedicated to a four-step RA type. The first type 1-PDCCH CSS may be configured with a first number of repetitions of DCI for RAR via the PDCCH. The second type 1-PDCCH CSS may be configured with a second number of repetitions of DCI for RAR via the PDCCH. The first type 1-PDCCH CSS may be dedicated to a wireless device performing an RA procedure with a first RA type (e.g., a two-step RA type). The second type1-PDCCH CSS may be dedicated to wireless devices that perform an RA procedure with a second RA type (e.g., a 4-step RA type). In one embodiment, the first type1-PDCCH CSS and the second type1-PDCCH CSS may share the same CORESET (e.g., CORESET#0 or other common CORESET) of the initial BWP of the cell, or may be associated with different CORESETs of the initial BWP of the cell.

[0284] In one example, the wireless device may determine a type 1-PDCCH CSS from one or more type 1-PDCCH CSSs based on the RA type. The wireless device may determine a first type 1-PDCCH CSS in response to the RA type of the RA procedure being a two-step RA type. The wireless device may determine a second type 1-PDCCH CSS in response to the RA type of the RA procedure being a four-step RA type. Based on the determined type 1-PDCCH CSS, the wireless device may monitor the PDCCH to receive DCI having a CRC scrambled by the RA-RNTI and scheduling an RAR message.

[0285] FIG. 40 illustrates an example of system information transmission for a wireless device with reduced capabilities. In one example, a base station may transmit a MIB message to the wireless device. The MIB message may include one or more configuration parameters of the cell based on the examples of FIGS. 23A, 23B, and / or 23C. In one embodiment, the base station may indicate whether a second SIB1 message dedicated to the first wireless device type (e.g., reduced capability) will be transmitted by setting one or more fields of the MIB message to a first value. In one embodiment, the one or more fields may include spare bits of the MIB message. In one embodiment, in response to the wireless device being a wireless device type with reduced capabilities, the wireless device may check the values ​​of the spare bits of the MIB message after receiving the MIB. In response to the wireless device being a wireless device type with normal capabilities, the wireless device may skip checking the values ​​of the spare bits of the MIB message after receiving the MIB.

[0286] As shown in FIG. 40, in response to one or more bits (e.g., spare bits) of the MIB message being set to a first value (e.g., 1), the wireless device may determine that a dedicated SIB1 (first SIB1 for the reduced capability wireless device) is to be transmitted. In response to one or more bits (e.g., spare bits) of the MIB message being set to a first value (e.g., 1), the wireless device may use a first system information RNTI (SI-RNTI) for the reduced capability wireless device to receive DCI scheduling the dedicated SIB1 for the reduced capability wireless device. Based on the first SI-RNTI, the wireless device may monitor the PDCCH to receive DCI scheduling the first SIB1. The wireless device may receive the first SIB1 based on reception of DCI having a CRC scrambled by the first SI-RNTI. The wireless device may initialize an RA procedure based on the first SIB1, for example, based on the example of FIG. 36.

[0287] As shown in FIG. 40, in response to one or more bits (e.g., spare bits) of the MIB message being set to a second value (e.g., 0), the wireless device may determine that the first SIB1 will not be transmitted for the reduced-capability wireless device. The wireless device may determine to receive the second SIB1 (e.g., for a normal-capability wireless device type). In response to one or more bits (e.g., spare bits) of the MIB message being set to a second value (e.g., 0), the wireless device may determine a second SI-RNTI (e.g., the same as for the normal-capability wireless device) that may be used to receive DCI scheduling the second SIB1 for the normal-capability wireless device. The second SIB1 may be implemented based on the example of FIG. 24. Based on the second SI-RNTI, the wireless device may monitor the PDCCH to receive DCI scheduling the second SIB1. The wireless device may receive the second SIB1 based on receiving DCI having a CRC scrambled by the second SI-RNTI. The wireless device may initiate an RA procedure based on the second SIB1, for example, based on the example of FIG.

[0288] In one embodiment, the first SIB1 may indicate a first initial BWP for wireless devices with reduced capacity in the cell. The second SIB1 may indicate a second initial BWP for wireless devices with normal capacity in the cell. The first initial BWP may be the same as or different from the second initial BWP. In response to the first initial BWP being the same as the second initial BWP, the first SIB1 and the second SIB1 may indicate different RACH configurations and / or different PDCCH configurations, etc.

[0289] In one embodiment, the base station may transmit the first SIB1 and the second SIB1 using independent and / or separate configuration parameters of the cell. In response to being a normal capability wireless device type or a legacy wireless device type, the wireless device may skip checking the spare bits of the MIB to receive DCI (having a CRC scrambled by the second SI-RNTI) scheduling the second SIB1 and / or may monitor the PDCCH. In response to being a reduced capability wireless device type, the wireless device may check the spare bits of the MIB and / or determine whether to receive the first SIB1 based on the first SI-RNTI or the second SI-RNTI.

[0290] As shown in FIG. 40, based on one or more bits of the MIB, the wireless device may determine whether to use a first SI-RNTI to receive SIBI or a second SI-RNTI to receive SIB1.

[0291] In one example, in response to one or more bits (e.g., spare bits) of the MIB message being set to a second value (e.g., 0), the wireless device may determine that the first SIB1 for the reduced-capability wireless device will not be transmitted by the base station. A wireless device having a reduced-capability wireless device type may determine that the base station does not support the reduced-capability wireless device type based on setting one or more bits (e.g., spare bits) of the MIB message to the second value. The wireless device may, for example, set one or more bits (e.g., spare bits) of the second cell's MIB message to the first value and perform a cell selection procedure to search for a second cell that supports the reduced-capability wireless device type.

[0292] In one embodiment, the first SI-RNTI and the second SI-RNTI may have different fixed values. The first SI-RNTI (e.g., FFFD in hexadecimal) may be predefined and known to all wireless devices with reduced capabilities. The first SI-RNTI (e.g., FFFD in hexadecimal) may be unknown to wireless devices with normal capabilities. The second SI-RNTI (e.g., FFFF in hexadecimal as in legacy systems) may be predefined and known to all wireless devices with normal or reduced capabilities.

[0293] In one example, the wireless device may be a reduced-capability wireless device type. Compared to a normal-capability wireless device, the wireless device may support a narrower bandwidth (e.g., <=20 MHz for FR 1 or <=50 MHz for FR 2), a smaller number of Tx / Rx antennas (e.g., 1 Tx / 1 Rx or 1 Tx / 2 Rx), a longer processing timing (e.g., a longer beam switching timing, a longer BWP switching timing, etc.), a lower processing capability (e.g., a smaller MIMO layer that does not support the same slot scheduling, etc.), and / or a lower transmit power. In response to receiving an RAR including an MSGB for a two-step RA procedure, the wireless device may transmit HARQ-ACK feedback to the base station via a PUCCH resource, along with HARQ-ACK feedback indicating whether reception of the MSGB was successful. The two-step RA procedure may be implemented based on the exemplary embodiment described above with reference to FIG. 13C. By implementing existing techniques, a base station may not be able to correctly receive the HARQ-ACK for the MSGB from the wireless device due to the limited capabilities of this reduced-capability wireless device type. Because the base station does not receive and detect the HARQ-ACK, the wireless device and the base station must repeat the RA procedure, resulting in increased power consumption for the wireless device, increased uplink interference to other wireless devices, and / or increased downlink signaling overhead for the base station. There is a need to improve the coverage of PUCCH transmission of HARQ-ACK feedback for reduced-capability wireless devices.

[0294] One exemplary embodiment may include a base station transmitting an RAR indicating a number of repetitions for HARQ-ACK feedback for MSGB of a two-step RA type. In one example, the RAR may be a new RAR format that is different from the legacy RAR format. The RAR may include one or more bits that indicate the number of repetitions for HARQ-ACK feedback. In one example, the RAR may be a legacy RAR format (e.g., successRAR as defined in 3GPP Rel. 16 specifications). A wireless device with reduced capability may check whether one or more R bits in the RAR are set to a first value and may determine the number of repetitions for HARQ-ACK feedback. A wireless device with normal capability may skip checking one or more R bits in the RAR. The exemplary embodiment may maintain backward compatibility of wireless devices and / or reduce processing complexity, for example, without increasing the RAR format.

[0295] One example embodiment may include a base station transmitting an RRC message indicating multiple repetitions of HARQ-ACK feedback for MSGB of a two-step RA type. The base station may transmit an RAR including one or more bits indicating one of the multiple repetitions for the HARQ-ACK feedback. The one or more bits of the RAR may include at least one of one or more R bits, a TPC field, a HARQ feedback timing indicator, a PUCCH resource indicator, a timing advance command, etc. The combination of RRC and RAR to indicate the repetition number for the HARQ-ACK feedback may improve uplink coverage of HARQ-ACK transmissions from reduced-capability wireless devices.

[0296] One example embodiment may include a base station transmitting a DCI (with a CRC scrambled by the RA-RNTI) including a bit field indicating the number of repetitions of HARQ-ACK feedback for MSGB of a two-step RA type. The base station may transmit an RRC message indicating multiple repetitions of HARQ-ACK feedback for MSGB of a two-step RA type. The DCI, with a CRC scrambled by the RA-RNTI and scheduling an RAR, may include a bit field indicating one of multiple repetitions of HARQ-ACK feedback. The combination of RRC and DCI to indicate the number of repetitions for HARQ-ACK feedback may improve uplink coverage of HARQ-ACK transmissions from reduced-capability wireless devices.

[0297] FIG. 41 illustrates an example of random access for a wireless device with coverage enhancement. In one embodiment, a base station may transmit one or more RRC messages (e.g., MIB, SIB1, SIB2, etc.) including cell configuration parameters to the wireless device. The cell may be a PCell or a PSCell. In one embodiment, the cell configuration parameters may include one or more first RACH configurations for a four-step RA (rach-ConfigCommon) and one or more second RACH configurations for a two-step RA type (RACH-ConfigCommonTwoStepRA) on the cell's initial uplink BWP. The cell configuration parameters may also include configuration parameters for one or more RA search spaces (e.g., ra-SearchSpace) of a control resource set (CORESET) on the cell's initial downlink BWP. The one or more first RACH configurations, one or more second RACH configurations, and one or more RA search spaces may be implemented based on the example of FIG. 36. The two-step RA procedure may be implemented based on the exemplary embodiment described above with respect to FIG. 13C.

[0298] In one example, a wireless device may trigger an RA procedure based on the example of Figure 36. The wireless device may select one RACH configuration from one or more first RACH configurations and one or more second RACH configurations based on the example of Figure 36. The wireless device may select one RA search space from one or more RA search spaces based on the example of Figure 36.

[0299] 41, the wireless device may transmit a preamble (or MSGA) at a first number of repetitions for the RA procedure based on the selected RACH configuration. The wireless device may determine the first number (e.g., numRepetitionPerPreambleAttempt) based on the selected RACH configuration.

[0300] As shown in Figure 41, the wireless device may monitor the PDCCH via the selected RA search space to receive DCI scheduling a preamble or an RAR for MSGA. The base station may transmit DCI with a CRC scrambled by the RA-RNTI with a second repetition count. The wireless device may determine the second repetition count (e.g., PDCCH-NumRepetition) based on the selected RA search space. In one example, numRepetitionPerPreambleAttempt and PDCCH-NumRepetition may have different values.

[0301] In one example, the DCI may not include the number of repetitions for the transmission of the DCI. The base station may not indicate the actual number of repetitions for the transmission of the DCI in the DCI, for example, if the maximum number of repetitions for the DCI (indicated by the RA search space configuration parameter) is not very large (e.g., less than 8, 10, 20, etc.). By not indicating the actual number of repetitions for the transmission of the DCI, the base station may maintain the same (or similar) DCI format f as in the legacy system. Exemplary embodiments may ensure backward compatibility.

[0302] As shown in Figure 41, the wireless device may receive a DCI while monitoring the PDCCH over the RA search space. The DCI may include a third number indicating a number of repetitions of the RAR (or MSGB) over the PDSCH resource. In response to receiving the DCI, the wireless device may receive the RAR with the repetition number.

[0303] In one example, the RAR may be a fallbackRAR for the MSGB, where the fallbackRAR is a fixed size and includes a reserved bit (e.g., set to 0), an index value T that is used to control the amount of timing adjustment that the MAC entity may apply. A The 27-bit uplink grant indication may include a frequency hopping flag, a PUSCH frequency resource allocation indication, a PUSCH time resource allocation indication, an MCS indication, a TRP command for PUSCH, a CSI request indication, and / or a channel access type and CP extension indication.

[0304] In one embodiment, the RAR may be a successRAR for MSGB. The successRAR may have a different MAC PDU format than the fallbackRAR. In one embodiment, the successRAR may be a fixed size and may include a contention resolution identity (e.g., 48 bits) containing the UL CCCH SDU, three reserved bits (e.g., set to 0 seconds), a TPC command (e.g., 2 bits) for the PUCCH resource containing the HARQ feedback for MSGB, a HARQ feedback timing indicator (e.g., 3 bits), a PUCCH resource indicator (e.g., 4 bits), and an index value T used to control the amount of timing adjustment the MAC entity may apply. Aand a C-RNTI (for example, 16 bits) indicating an identifier used by the MAC entity during the RA procedure.

[0305] As shown in Figure 41, in response to the RAR including the successRAR indicating the PUCCH resource and the HARQ feedback timing indicator, the wireless device may determine the fourth number of repetitions for the HARQ-ACK for receiving the MSGB. In one embodiment, the wireless device may determine the fourth number of repetitions based on a configuration parameter of the PUCCH resource. In one embodiment, the base station may transmit to the wireless device a configuration parameter of the PUCCH resource indicating the fourth number of repetitions. In one embodiment, the wireless device may determine the fourth number of repetitions based on a bit field of the successRAR.

[0306] Figure 42 shows an example of a PUCCH resource repetition indication for HARQ feedback for MSGB in a two-step RA procedure. In one embodiment, a wireless device may receive an RAR (e.g., successRAR) in response to transmitting an MSGA for a two-step RA procedure. The wireless device may determine the number of repetitions of HARQ feedback for MSGB based on the format of the successRAR. As shown in Figure 42, the base station may use one or more reserved bits in the successRAR to indicate the number of repetitions of HARQ feedback for MSGB.

[0307] In one embodiment, in response to the wireless device being a normally capable wireless device type, the wireless device may ignore one or more reserved bits in the successRAR. The wireless device may transmit HARQ feedback to MSGB using a single transmission over the PUCCH resource indicated by the PUCCH resource indicator.

[0308] In one embodiment, in response to the wireless device being a reduced capability wireless device type, the wireless device may check the value of one or more reserved bits in successRAR to determine a repetition of HARQ feedback to MSGB via the PUCCH resource indicated by the PUCCH resource indicator.

[0309] In one embodiment, if one or more R bits indicate a first value (e.g., 0), the wireless device may determine no repetition (e.g., a single transmission of HARQ feedback). If one or more R bits indicate a second value (e.g., 1), the wireless device may determine to transmit HARQ feedback with a first repetition. The mapping between the values ​​of the one or more R bits and the actual repetition number values ​​may be configured or predefined in the wireless device and known.

[0310] In one embodiment, the base station may indicate the actual number of repetitions of the HARQ feedback through a combination of the RRC and the RAR. In one embodiment, the base station may transmit to the wireless device cell configuration parameters, such as configuration parameters indicating a first value of one or more R bits of the RAR corresponding to the actual first number of repetitions of the HARQ feedback for MSGB and a second value of one or more R bits of the RAR corresponding to the actual second number of repetitions of the HARQ feedback for MSGB. In response to receiving the RAR, the wireless device may determine the actual number of repetitions for the HARQ feedback for MSGB based on the values ​​of the one or more R bits of the RAR. Based on the determined actual number of repetitions, the wireless device may transmit HARQ feedback for MSGB via the PUCCH resource of the RAR and with the determined actual number of repetitions, with a starting slot determined based on the HARQ feedback timing indicator in the RAR.

[0311] Based on the example of Figure 42, the wireless device may determine the number of repetitions of HARQ feedback for MSGB over PUCCH resources based on one or more bits of the RAR (e.g., successRAR for a two-step RA procedure). Exemplary embodiments may indicate the number of repetitions of HARQ feedback by reusing an existing RAR message with a new interpretation of one or more reserved bits. Exemplary embodiments may maintain backward compatibility and reduce wireless device processing complexity for receiving different MAC PDU formats. Exemplary embodiments may improve coverage of HARQ feedback for MSGB, for example, for reduced-capability wireless devices.

[0312] In one example, the wireless device may determine the number of repetitions for HARQ-ACK feedback for MSGB based on the DCI (having a CRC scrambled by the RA-RNTI) and / or an RRC message. In one example, the base station may transmit an RRC message indicating a configuration parameter of the cell, where the configuration parameter indicates a number of repetitions for HARQ feedback for MSGB. The wireless device may receive DCI having a CRC scrambled by the RA-RNTI and scheduling MSGB. The DCI may include a bit field indicating a number of repetitions among a number of repetitions for HARQ feedback for MSGB. The wireless device may transmit HARQ feedback with the number of repetitions via a PUCCH resource for MSGB. Exemplary embodiments may improve coverage of HARQ feedback for MSGB, for example, for wireless devices with reduced capacity.

[0313] In one example, a wireless device may transmit a preamble in response to triggering a random access (RA) procedure. The wireless device may monitor a downlink control channel to receive downlink control information, where the DCI indicates a downlink allocation for an RA response to the preamble. The wireless device may receive a transport block including the RA response based on receiving the DCI. The wireless device may transmit hybrid acknowledgement repeat request feedback with a repetition count and over an uplink control channel resource in a slot, where the RA response indicates the count, the uplink control channel resource, and the slot.

[0314] In one embodiment, the RA procedure may be a two-step RA type. In response to the RA procedure being a two-step RA type, the wireless device may transmit a transport block over an uplink data channel associated with the random access channel configuration of the preamble. The wireless device may transmit the preamble with a second number of repetitions, the second number of repetitions being configured for the RA procedure. In response to transmitting the preamble and the transport block, the wireless device may monitor a downlink control channel.

[0315] In one embodiment, the wireless device may transmit the transport block with a second number of repetitions, the second number of repetitions being configured for the RA procedure.

[0316] In one embodiment, the wireless device may receive DCI with cyclic redundancy check bits scrambled by the RA radio network temporary identifier while monitoring the downlink control channel.

[0317] In one embodiment, the RA response may include a preamble index that identifies the preamble transmitted by the wireless device.

[0318] In one embodiment, one or more bits of the RA response may indicate a count, and the one or more bits may include one or more reserved bits of the RA response.

[0319] In one embodiment, the RA response may include an uplink control channel resource indicator indicating an uplink control channel resource, a HARQ feedback timing indicator indicating a slot, and at least one of a contention resolution identity, a transmit power control command for the HARQ feedback, a timing advance command, and / or a cell radio network temporary identifier.

[0320] In one embodiment, the wireless device may determine an RS from the plurality of RSs based on a measured RSRP of the RS and an RSRP threshold. The wireless device may determine an RS from the plurality of RSs based on the RSRP being higher than the RSRP threshold. The wireless device may determine a RACH configuration associated with the RS from the plurality of RACH configurations. The wireless device may transmit a preamble for the RA procedure via a RACH occasion of the RACH configuration at a second number of repetitions. The second number of repetitions may be determined based on configuration parameters of the RACH configuration.

[0321] In one embodiment, the RA procedure may be triggered in response to initiation of beam failure recovery by the wireless device, receipt of an RRC reconfiguration message from the base station for handover to a second cell, and / or receipt of a Physical Downlink Control Channel (PDCCH) command from the base station. The RA procedure may be triggered for initial access to a cell, a positioning procedure, and / or an uplink coverage recovery procedure.

Claims

1. 1. A method comprising: A wireless device receives one or more radio resource control (RRC) messages, the one or more RRC messages comprising: a plurality of iterations for Hybrid Automatic Repeat Request (HARQ) feedback for one or more messages of a Random Access (RA) procedure; a plurality of second repetitions for transmitting a preamble of the RA procedure; and For the RA procedure: determining an RA type from a four-step RA type and a two-step RA type based on a reference signal received power (RSRP) and a first RSRP threshold; determining a second number of iterations from the plurality of second numbers of iterations based on the RSRP and one or more second RSRP thresholds; after initiating the RA procedure and based on the RA type of the RA procedure, transmitting the preamble for the second number of repetitions of the plurality of second number of repetitions; receiving one or more Downlink Control Information (DCI), the one or more DCI comprising: scheduling the one or more messages of the RA procedure; a bit field indicating a number of repetitions among the plurality of repetitions for the HARQ feedback for the one or more messages; receiving the one or more messages; transmitting the HARQ feedback for the one or more messages over a physical uplink control channel (PUCCH) for the number of repetitions; A method comprising:

2. The method described in claim 1, wherein the one or more messages of the RA procedure include a message B (MsgB) of the two-step RA type of the RA procedure.

3. A method as described in claim 1 or 2, wherein the one or more messages of the RA procedure include information of message 4 (Msg4) of the 4-step RA type of the RA procedure.

4. The method according to any one of claims 1 to 3, further comprising, after initiating the RA procedure, transmitting a first message including the preamble based on the two-step RA type of the RA procedure or the four-step RA type of the RA procedure.

5. The one or more RRC messages further indicate a plurality of thresholds for the RA procedure, the plurality of thresholds comprising: the first threshold value for determining the RA type from the four-step RA type and the two-step RA type; the one or more second thresholds for determining the second number of iterations from among the plurality of second numbers of iterations; The method of claim 1 , comprising:

6. The method of any one of claims 1 to 5, wherein the one or more messages include a random access response (RAR) to a preamble transmission.

7. the one or more RRC messages further indicate a third number of repetitions of the one or more DCIs for the RA procedure; The method according to any one of claims 1 to 5, wherein the one or more DCIs are received based on a third number of repetitions from the plurality of third number of repetitions.

8. 1. A method comprising: a base station transmitting one or more radio resource control (RRC) messages to a wireless device, the one or more RRC messages comprising: a plurality of iterations for Hybrid Automatic Repeat Request (HARQ) feedback for one or more messages of a Random Access (RA) procedure; a plurality of second repetitions for transmitting a preamble of the RA procedure; and receiving the preamble based on an RA type of the RA procedure and a second number of repetitions of the plurality of second numbers of repetitions; For the RA procedure: The RA type is determined from a 4-step RA type and a 2-step RA type based on a reference signal received power (RSRP) and a first RSRP threshold; the second number of iterations is determined from the plurality of second numbers of iterations based on the RSRP and one or more second RSRP thresholds; and transmitting one or more Downlink Control Information (DCI) to the wireless device, the one or more DCI comprising: scheduling the one or more messages of the RA procedure; a bit field indicating a number of repetitions among the plurality of repetitions for the HARQ feedback for the one or more messages; transmitting the one or more messages to the wireless device; receiving the HARQ feedback for the one or more messages from the wireless device via a physical uplink control channel (PUCCH) for the number of repetitions; A method comprising:

9. The method described in claim 8, wherein the one or more messages of the RA procedure include a message B (MsgB) of the two-step RA type of the RA procedure.

10. A method as described in claim 8 or 9, wherein the one or more messages of the RA procedure include information of message 4 (Msg4) of the 4-step RA type of the RA procedure.

11. The method of any one of claims 8 to 10, further comprising receiving, from the wireless device, a first message including the preamble based on the two-step RA type of the RA procedure or the four-step RA type of the RA procedure.

12. The one or more RRC messages further indicate a plurality of thresholds for the RA procedure, the plurality of thresholds comprising: the first threshold value for determining the RA type from the four-step RA type and the two-step RA type; the one or more second thresholds for determining the second number of iterations from among the plurality of second numbers of iterations; The method of claim 11 , comprising:

13. The method of any one of claims 8 to 12, wherein the one or more messages include a random access response (RAR) to a preamble transmission.

14. 1. An apparatus comprising: one or more processors; a memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform a method according to any one of claims 1 to 13; An apparatus comprising:

15. A non-transitory computer readable medium comprising instructions that, when executed by one or more processors of a device, cause the device to perform the method of any one of claims 1 to 13.

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