Method for controlling access of terminal in communication system

Patent metadata

Field	Value
Publication number	US-2021120581-A1
Application number	US-202017043503-A
Country	US
Kind code	A1
Filing date	Mar 10, 2020
Priority date	Mar 14, 2019
Publication date	Apr 22, 2021
Grant date	—

Abstract

Provided is a method for controlling the access of a terminal in a communication system. An operation method of a terminal comprises the steps of: receiving, from a base station, configuration information for a two-step random access procedure; transmitting, to the base station, RA MSG-A including an RA preamble and an RA payload, on the basis of the configuration information; and receiving, from the base station, RA MSG-B, which is a response to the RA MSG-A. Therefore, communication system performance can be improved.

First claim

1 . An operation method of a terminal in a communication system, the operation method comprising:
receiving, from a base station, configuration information for a 2-step random access procedure; transmitting, to the base station, a random access (RA) message-A (MSG-A) including an RA preamble and an RA payload based on the configuration information; and receiving an RA MSG-B in response to the RA MSG-A from the base station, wherein the RA MSG-B includes one or more MAC sub protocol data units (subPDUs), each of the one or more MAC subPDUs includes a MAC subheader, and the MAC subheader includes a first indicator indicating a type of the MAC subPDU.

2 . The operation method according to claim 1 , further comprising receiving system information including information indicating a modulation and coding scheme (MCS) for the RA payload from the base station,
wherein the RA payload is transmitted based on the MCS level indicated by the system information.

3 . The operation method according to claim 1 , wherein the first indicator indicates that the MAC subPDU is a first type MAC subPDU including a backoff indicator (BI), that the MAC subPDU is a second type MAC subPDU including a fallback random access response (RAR), or that the MAC subPDU is a third type MAC subPDU including a successful RAR.

4 . The operation method according to claim 3 , wherein a size of the first indicator is 2 bits, a first bit of the 2 bits indicates the first type MAC subPDU or the second type MAC subPDU, and a second bit of the 2 bits indicates the third type MAC subPDU.

5 . The operation method according to claim 3 , further comprising, when the first indicator included in the RA MSG-B indicates the first type MAC subPDU, performing the 2-step random access procedure or the 4-step random access procedure based on the BI included in the RA MSG-B.

6 . The operation method according to claim 3 , further comprising, when the first indicator included in the RA MSG-B indicates the second type MAC subPDU, transmitting an RA MSG3 according to the 4-step random access procedure to the base station.

7 . The operation method according to claim 6 , wherein the RA MSG3 is transmitted using a resource indicated by an uplink (UL) grant included in the fallback RAR.

8 . The operation method according to claim 3 , wherein the RA MSG-B including the fallback RAR is generated based on a format of an RA MSG2 of the 4-step random access procedure.

9 . The operation method according to claim 3 , wherein, when the first indicator indicates the third type MAC subPDU, the 2-step random access procedure is terminated.

10 . The operation method according to claim 1 , wherein, when the RA MSG-B is received within an RAR window from a transmission ending time point of the RA preamble, a contention is determined to be resolved in the 2-step random access procedure.

11 . The operation method according to claim 1 , wherein the MAC subheader further includes a second indicator indicating whether the MAC subPDU is a fourth type MAC subPDU including a MAC service data unit (SDU), and the MAC SDU includes data or control information.

12 . The operation method according to claim 1 , wherein the MAC subheader further includes a third indicator indicating whether another MAC subPDU exists.

13 . An operation method of a base station in a communication system, the operation method comprising:
transmitting 2-step configuration information for a 2-step random access (RA) procedure to a terminal; transmitting 4-step configuration information for a 4-step random access procedure to the terminal; receiving a message 1 from the terminal by performing a monitoring operation using the 2-step configuration information and the 4-step configuration information; and when the message 1 is an RA message-A (MSG-A) of the 2-step RA procedure, transmitting an RA MSG-B including one or more MAC sub protocol data units (subPDUs) to the terminal, wherein each of the one or more MAC subPDUs includes a MAC subheader, and the MAC subheader includes a first indicator indicating a type of the MAC subPDU.

14 . The operation method according to claim 13 , further comprising transmitting system information including information indicating a modulation and coding scheme (MCS) for an RA payload included in the RA MSG-A to the terminal.

15 . The operation method according to claim 13 , wherein the first indicator indicates that the MAC subPDU is a first type MAC subPDU including a backoff indicator (BI), that the MAC subPDU is a second type MAC subPDU including a fallback random access response (RAR), or that the MAC subPDU is a third type MAC subPDU including a successful RAR.

16 . The operation method according to claim 15 , further comprising, when the first indicator included in the RA MSG-B indicates the second type MAC subPDU, receiving an RA MSG3 according to the 4-step random access procedure from the base station through a resource indicated by an uplink (UL) grant included in the fallback RAR.

17 . The operation method according to claim 15 , wherein the RA MSG-B including the fallback RAR is generated based on a format of an RA MSG2 of the 4-step random access procedure.

18 . The operation method according to claim 15 , wherein, when the RA MSG-B is received from the terminal within an RAR window from a transmission ending time point of the RA preamble, and the first indicator included in the RA MSG-B indicates the third type MAC subPDU, the 2-step random access procedure is terminated.

19 . The operation method according to claim 15 , wherein one MAC subPDU among the one or more MAC subPDUs includes a MAC service data unit (SDU) including control information or data, and a radio network temporary identifier (RNTI) for the one MAC subPDU including the MAC SDU is configured independently from an RNTI for another MAC subPDU including the BI, the fallback RAR, or the successful RAR.

20 . The operation method according to claim 13 , wherein the MAC subheader further includes a second indicator indicating whether the MAC subPDU is a fourth type MAC subPDU including a MAC service data unit (SDU), and the MAC SDU includes data or control information.

21 . The operation method according to claim 13 , wherein the MAC subheader further includes a third indicator indicating whether another MAC subPDU exists.

22 . An operation method of a terminal in a communication system, the operation method comprising:
receiving, from a base station, configuration information for a 2-step random access procedure; transmitting, to the base station, a random access (RA) message-A (MSG-A) including an RA preamble and an RA payload based on the configuration information; determining a random access-radio network temporary identifier (RA-RNTI) by using information of a radio resource through which the RA preamble is transmitted and a preconfigured offset; receiving downlink control information (DCI) including resource allocation information of an RA MSG-B from the base station by performing a physical downlink control channel (PDCCH) monitoring operation using the RA-RNTI; and receiving the RA MSG-B from the base station through a resource indicated by the resource allocation information included in the DCI.

23 . The operation method according to claim 22 , wherein the RA-RNTI for the 2-step random access procedure is configured differently from an RA-RNTI for a 4-step random access procedure.

24 . The operation metho

Assignees

• Electronics & Telecommunications Res Inst

Inventors

• Kim Jae Heung

Classifications

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W74/0836

  with 2-step access · CPC title

• H04W74/0838

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

• H04W74/0833 Primary

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

• H04W74/002 Primary

  Transmission of channel access control information · CPC title