Systems and methods for providing random access channel (RACH) signaling to user equipment (UE) during inactive direct transmissions

Patent metadata

Field	Value
Publication number	US-12369200-B2
Application number	US-202418417452-A
Country	US
Kind code	B2
Filing date	Jan 19, 2024
Priority date	Aug 6, 2020
Publication date	Jul 22, 2025
Grant date	Jul 22, 2025

Abstract

Techniques discussed herein can facilitate inactive state transmissions for a Base Station (BS) via a 4-step or 2-step inactive state RACH process. One example aspect is a BS including communication circuitry and one or more processors communicatively coupled to the communication circuitry and configured to cause the BS to transmit a radio link quality threshold and an uplink data size for a Radio Resource Control (RRC) inactive data transmission. Receive a Random Access Channel (RACH) preamble in response to the radio link quality threshold and the uplink data size being satisfied. Receive the RRC inactive data transmission, and transmit a RACH message in response to receiving the RRC inactive data transmission.

First claim

What is claimed is:

1. A base station (BS) comprising:
a communication circuitry; and
one or more processors communicatively coupled to the communication circuitry and configured to cause the BS to:
transmit, by the communication circuitry, a radio link quality threshold and an uplink data size for a Radio Resource Control (RRC) inactive data transmission;
receive a Random Access Channel (RACH) preamble in response to the radio link quality threshold and the uplink data size being satisfied;
receive the RRC inactive data transmission; and
transmit, by the communication circuitry, a RACH message in response to receiving the RRC inactive data transmission.

2. The BS of claim 1 , wherein the RACH preamble is based on a dedicated RACH configuration for the RRC inactive data transmission.

3. The BS of claim 1 , wherein the one or more processors further cause the BS to:
configure a dedicated preamble group, and a message 1 (Msg1) or a message A (MsgA) preamble is one of the dedicated preamble group for the RRC inactive data transmission.

4. The BS of claim 1 , wherein the RACH preamble is a shared preamble for a RACH configuration of the RRC inactive data transmission and a RACH configuration for a RRC resume procedure.

5. The BS of claim 1 , wherein the RACH preamble is a message 1 (MSg1) or a message A (MsgA) preamble based on a RACH configuration for the RRC inactive data transmission, and the RACH message is a message 4 (Msg4) or a message B (MsgB) response.

6. The BS of claim 1 , wherein the one or more processors further cause the BS to:
transmit, by the communication circuitry, a repetition value according to a layer 1 (L1) signaling procedure;
receive one or more repetitions of the RRC inactive data transmission according to the repetition value; and
after a final reception of the one or more repetitions, transmit the RACH message.

7. The BS of claim 1 , wherein a message that comprises the RRC inactive data transmission comprises a medium access control control element (MAC CE) that comprises an inactive radio network temporary identifier (I-RNTI) or a truncated I-RNTI (I-RNTI/truncated I-RNTI) associated with the RRC inactive data transmission, or the message that comprises the RRC inactive data transmission is scrambled with the I-RNTI/truncated I-RNTI, and
wherein the one or more processors further cause the BS to:
determine the I-RNTI/truncated I-RNTI associated with the RRC inactive data transmission based on the MAC CE that comprises the I-RNTI/truncated I-RNTI, or
descramble the message that comprises the RRC inactive data with a set of potential I-RNTIs/truncated I-RNTIs that comprises the I-RNTI/truncated I-RNTI.

8. The BS of claim 7 , wherein the RACH message comprises a random access response (RAR) and the MAC CE comprising the I-RNTI/truncated I-RNTI; or
the RACH message comprises at least one of an uplink (UL) grant scrambled by the I-RNTI/truncated I-RNTI or a downlink (DL) assignment scrambled by the I-RNTI/truncated I-RNTI.

9. The BS of claim 7 , wherein the RACH message comprises at least one of an uplink (UL) grant scrambled by the I-RNTI/truncated I-RNTI or a downlink (DL) assignment scrambled by the I-RNTI/truncated I-RNTI, or
wherein the RACH message comprises a DL assignment with a schedule at least partially based on a temporary cell radio network temporary identifier (T-C-RNTI), wherein the DL assignment with the schedule at least partially based on the T-C-RNTI comprises the MAC CE comprising the I-RNTI.

10. The BS of claim 1 , wherein the RRC inactive data transmission is initiated by the RACH preamble.

11. The BS of claim 1 , wherein the RRC inactive data transmission comprises uplink data other than a RRC resume request.

12. A method for a Base Station (BS), the method comprising:
transmitting a radio link quality threshold and an uplink data size for a Radio Resource Control (RRC) inactive data transmission;
receiving a Random Access Channel (RACH) preamble in response to the radio link quality threshold and the uplink data size being satisfied;
receiving the RRC inactive data transmission; and
transmitting a RACH message in response to receiving the RRC inactive data transmission.

13. The method of claim 12 , wherein the RRC inactive data transmission is initiated by the RACH preamble and the RRC inactive data transmission comprises uplink data other than a RRC resume request.

14. The method of claim 12 , wherein the method further comprises:
transmitting a repetition value according to a layer 1 (L1) signaling procedure;
receiving one or more repetitions of the RRC inactive data transmission according to the repetition value; and
after a final reception of the one or more repetitions, transmitting the RACH message.

15. The method of claim 12 , wherein a message that comprises the RRC inactive data transmission comprises a medium access control control element (MAC CE) that comprises an inactive radio network temporary identifier (I-RNTI) or a truncated I-RNTI (I-RNTI/truncated I-RNTI) associated with the RRC inactive data transmission, or the a message that comprises the RRC inactive data transmission is scrambled with the I-RNTI/truncated I-RNTI, and
wherein the method further includes:
determining the I-RNTI/truncated I-RNTI associated with the RRC inactive data transmission based on the MAC CE that comprises the I-RNTI/truncated I-RNTI, or
descramble the message that comprises the RRC inactive data transmission with a set of potential I-RNTIs/truncated I-RNTIs that comprises the I-RNTI/truncated I-RNTI.

16. The method of claim 15 , wherein the RACH message comprises a random access response (RAR) and the MAC CE comprising the I-RNTI/truncated I-RNTI; or
the RACH message comprises at least one of an uplink (UL) grant scrambled by the I-RNTI/truncated I-RNTI or a downlink (DL) assignment scrambled by the I-RNTI/truncated I-RNTI.

17. The method of claim 15 , wherein the RACH message comprises at least one of an uplink (UL) grant scrambled by the I-RNTI/truncated I-RNTI or a downlink (DL) assignment scrambled by the I-RNTI/truncated I-RNTI, or
wherein the RACH message comprises a DL assignment with a schedule at least partially based on a temporary cell radio network temporary identifier (T-C-RNTI), wherein the DL assignment with the schedule at least partially based on the T-C-RNTI comprises the MAC CE comprising the I-RNTI.

18. A baseband processor comprising one or more processors configured to:
output, for transmission, a radio link quality threshold and an uplink data size for a Radio Resource Control (RRC) inactive data transmission;
receive a Random Access Channel (RACH) preamble in response to one or more of the radio link quality threshold or the uplink data size being satisfied;
receive the RRC inactive data transmission comprising uplink data other than a RRC resume request; and
output, for transmission, a RACH message in response to receiving the RRC inactive data transmission.

19. The baseband processor of claim 18 , wherein the one or more processors are further configured to:
output, for transmission, a repetition value according to a layer 1 (L1) signaling procedure;
receive one or more repetitions of the RRC inactive data transmission according to the repetition value; and
after a final reception of the one or more repetitions, output the RACH message.

20. The baseband processor of claim 18 , wherein the one or more processors are further configured to: configure a dedicated preamble group, and a message 1 (Msg1)

Assignees

• Apple Inc

Inventors

• Xu Fangli
• Yao Chunhai
• Zhang Dawei
• Hu Haijing
• Xing Longda
• Shikari Murtaza A
• Vangala Sarma V
• Nimmala Srinivasan
• Zeng Wei

Classifications

• H04W74/0838

  using contention-free random access [CFRA] · CPC title

• H04W74/0833

  Random access procedures, e.g. with 4-step access · CPC title

• H04W74/002 Primary

  Transmission of channel access control information · CPC title

• H04W74/0836 Primary

  with 2-step access · CPC title

• H04W56/004

  compensating for timing error of reception due to propagation delay · CPC title