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CN-121986538-A - Network assisted cell selection for two-step random access procedure

CN121986538ACN 121986538 ACN121986538 ACN 121986538ACN-121986538-A

Abstract

Aspects of the present disclosure relate to network assisted cell selection. In some embodiments, a network uses cells within a location to coordinate access between a UE and other cells (e.g., neighboring cells) that are candidates for a serving cell for the UE within the location, but may be in a power saving state of operation when the UE initiates an access procedure.

Inventors

  • H.Zheng

Assignees

  • 联想（新加坡）私人有限公司

Dates

Publication Date
20260505
Application Date
20241010
Priority Date
20241009

Claims (20)

  1. 1. A user equipment, UE, for wireless communication, comprising: At least one memory, and At least one processor coupled with the at least one memory and configured to cause the UE to: transmitting a PRACH preamble at a physical random access channel, PRACH, occasion of a first cell, and transmitting a corresponding MsgA PUSCH at a message A MsgA physical uplink shared channel, PUSCH, occasion of the first cell; Receiving a message B MsgB including a random access response; Identifying a serving cell based on receiving the MsgB, and And sending a connection completion message to the identified serving cell.
  2. 2. The UE of claim 1, wherein the connection completion message is a connection setup completion message or a connection restoration completion message.
  3. 3. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to: Detecting the first cell; selecting the first cell, and And monitoring system information of the first cell.
  4. 4. The UE of claim 1, wherein the serving cell is different from the first cell and transitions from a power saving state of operation to an active state of operation.
  5. 5. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to: cell detection is performed for the serving cell when the serving cell is different from the first cell.
  6. 6. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to: a configuration of a plurality of common physical downlink control channel PDCCH search spaces is received, Wherein each common PDCCH search space is associated with one or more neighboring cells from the first cell and at least one of the first cells.
  7. 7. The UE of claim 6, wherein the at least one processor is further configured to cause the UE to: Monitoring the plurality of common PDCCH search spaces to receive the MsgB, and The serving cell is identified based on detecting downlink control information, DCI, for MsgB delivery in a common PDCCH search space of the plurality of common PDCCH search spaces.
  8. 8. The UE of claim 6, wherein the at least one processor is further configured to cause the UE to: A first common PDCCH search space of the plurality of common PDCCH search spaces is monitored, the first common PDCCH search space being associated with the first cell.
  9. 9. The UE of claim 8, wherein: When the MsgB does not include an indication of the serving cell corresponding to the random access response, the UE identifies the first cell as the serving cell, and When the MsgB includes a second cell different from the first cell as an indication of the serving cell corresponding to the random access response, the UE identifies the second cell as the serving cell.
  10. 10. The UE of claim 9, wherein the indication of the second cell as the serving cell is included in a MAC subheader of a medium access control, MAC, subpacket data unit subPDU for the random access response.
  11. 11. The UE of claim 6, wherein the at least one processor is further configured to cause the UE to: monitoring a common PDCCH search space associated with the serving cell after the serving cell is identified, and And receiving an uplink grant for transmitting the connection completion message in the monitored common PDCCH search space.
  12. 12. The UE of claim 6, wherein the plurality of PDCCH search spaces are quasi co-located with a synchronization signal block SSB, Wherein the SSB is selected for the PRACH preamble transmission of the PRACH occasion of the first cell.
  13. 13. The UE of claim 6, wherein the first cell and the one or more neighboring cells are deployed in a same frequency layer.
  14. 14. The UE of claim 6, wherein the first cell and the one or more neighboring cells are deployed in different frequency layers.
  15. 15. The UE of claim 1, wherein the random access response included in the MsgB is a successful random access response successRAR.
  16. 16. The UE of claim 1, wherein when the random access response included in the MsgB is a fallback random access response fallbackRAR and the MsgB includes an indication of one or more candidate serving cells corresponding to the fallbackRAR, the processor is further configured to cause the UE to: Transmitting a message 3 Msg3 with measurement reports for the one or more candidate serving cells; Receive message 4 Msg4, and The serving cell is identified based on receiving the MsgB and the Msg 4.
  17. 17. A processor for wireless communication, comprising: At least one controller coupled with the at least one memory and configured to cause the processor to: transmitting a PRACH preamble at a physical random access channel, PRACH, occasion of a first cell, and transmitting a corresponding MsgA PUSCH at a message A MsgA physical uplink shared channel, PUSCH, occasion of the first cell; Receiving a message B MsgB including a random access response; Identifying a serving cell based on receiving the MsgB, and And sending a connection completion message to the identified serving cell.
  18. 18. A method performed by a user equipment, UE, the method comprising: transmitting a PRACH preamble at a physical random access channel, PRACH, occasion of a first cell, and transmitting a corresponding MsgA PUSCH at a message A MsgA physical uplink shared channel, PUSCH, occasion of the first cell; Receiving a message B MsgB including a random access response; Identifying a serving cell based on receiving the MsgB, and And sending a connection completion message to the identified serving cell.
  19. 19. A network entity for wireless communication, comprising: At least one memory, and At least one processor coupled with the at least one memory and configured to cause the network entity to: Receiving a PRACH preamble from a user equipment UE at a physical random access channel, PRACH, occasion of a first cell and receiving a corresponding MsgA PUSCH from the UE at a message A MsgA physical uplink shared channel, PUSCH, occasion of the first cell, and A message B MsgB including a random access response is sent, wherein delivery of the MsgB identifies a neighbor cell of the first cell as a serving cell for the UE.
  20. 20. The network entity of claim 19, wherein a common physical downlink control channel, PDCCH, search space comprising downlink control information, DCI, for the delivery of the MsgB identifies the neighboring cell of the first cell as the serving cell for the UE.

Description

Network assisted cell selection for two-step random access procedure Cross Reference to Related Applications The present application claims priority from U.S. non-provisional patent application Ser. No. 18/910,893, filed on day 10, 2024, which claims priority from U.S. provisional patent application Ser. No. 63/589,405, filed on day 10, 2023, 11, which is incorporated herein by reference in its entirety. Technical Field The present disclosure relates to wireless communications, and more particularly to network assisted cell selection for random access procedures. Background A wireless communication system may include one or more network communication devices, such as base stations, that may support wireless communications for one or more user communication devices, which may also be referred to as User Equipment (UE) or other suitable terminology. A wireless communication system may support wireless communication with one or more user communication devices by utilizing resources (e.g., time resources (e.g., symbols, slots, subframes, frames, etc.) or frequency resources (e.g., subcarriers, carriers, etc.) of the wireless communication system. Additionally, the wireless communication system may support wireless communications across various radio access technologies, including third generation (3G) radio access technologies, fourth generation (4G) radio access technologies, fifth generation (5G) radio access technologies, and other suitable radio access technologies other than 5G (e.g., sixth generation (6G)). In some cases, the geographic location may include a Radio Access Network (RAN) with many base stations (or cells or network nodes) deployed at the location. For example, a location may include many densely deployed cells (e.g., small cells, distributed Multiple Input Multiple Output (MIMO)) to increase the capacity of the location, reduce or mitigate signal blocking problems, and so forth. Disclosure of Invention The article "a" or "an" preceding an element is not limited and should be understood to mean "at least one of the element or" one or more of the element. The terms "a," "an," "at least one," "one or more," and "at least one of one or more" are interchangeable. As used herein, including in the claims, a list of items (e.g., a list of items prefixed with a phrase such as "or" for at least one of the terms "or" for one or more of the terms "or" for one or two of the terms), such that, for example, a list of at least one of A, B, or C means a or B or C or AB or AC or BC or ABC (i.e., a and B and C). In addition, as used herein, the phrase "based on" should not be construed as a reference to a set of closed conditions. For example, example steps described as "based on condition a" may be based on both condition a and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on". Furthermore, as used herein, including in the claims, a "set" may include one or more elements. The present disclosure relates to methods, apparatus, and systems that facilitate UE access to cells in a power save or idle state during an access procedure. For example, the RAN may employ one cell within the location to coordinate access between the UE and other cells (e.g., neighboring cells) that are candidates for serving cells for the UE within the location, but may be in an operational power saving state when the UE initiates the access procedure. Some implementations of the methods and apparatus described herein may also include a UE including a processor and a memory coupled to the processor, the processor configured to cause the UE to transmit a Physical Random Access Channel (PRACH) preamble at a PRACH occasion of a first cell and a corresponding MsgA PUSCH at a message a (MsgA) Physical Uplink Shared Channel (PUSCH) occasion of the first cell, receive a message B (MsgB) including a random access response, identify a serving cell based on the receipt MsgB, and transmit a connection completion message to the identified serving cell. In some implementations of the methods and apparatus described herein, the connection completion message is a connection setup completion message or a connection restoration completion message. In some implementations of the methods and apparatus described herein, the processor is further configured to cause the UE to detect a first cell, select the first cell, and monitor system information of the first cell. In some implementations of the methods and apparatus described herein, the serving cell is different from the first cell and transitions from a power saving state of operation to an active state of operation. In some implementations of the methods and apparatus described herein, the processor is further configured to cause the UE to perform cell detection for the serving cell when the serving cell is different from the first cell. In some