Communication method and apparatus for avoiding conflict
A communication method and an apparatus are provided. When a cell served by a distributed unit (DU) of an access network device and a neighboring cell use different timing, the DU may obtain timing configurations of a first cell and a second cell, or a random access channel (RACH) configuration that is of a second cell and that is based on timing of a first cell. When the method is applied to a RACH optimization scenario, the DU may determine, at same timing, RACH configurations of the two cells based on the foregoing obtained information, to accurately identify whether a RACH configuration conflict occurs between the cell and the neighboring cell, optimize the RACH configuration of the cell when the conflict occurs, and ensure a success rate and an access latency of random access performed by a terminal device.
1 . A communication method comprising:
receiving, by a centralized unit (CU) of a first access network device from a second access network device, a timing offset between a first cell and a second cell, wherein the first cell is served by a distributed unit (DU) of the first access network device, the second cell is a neighboring cell of the first cell, wherein the second cell is a cell served by the second access network device, and wherein the second access network device comprises a second CU and a second DU, and the second cell is a cell served by the second DU;
sending, by the CU, the timing offset between the first cell and the second cell to the DU; and
sending, by the CU and to the DU, a random access channel (RACH) configuration of the second cell,
wherein the timing offset between the first cell and the second cell, the RACH configuration of the second cell, and a RACH configuration of the first cell, are used by the DU to determine whether there is a conflict between the RACH configuration of the first cell and the RACH configuration of the second cell, and wherein based on the conflict between the RACH configuration of the first cell and the RACH configuration of the second cell, the RACH configuration for the first cell is reconfigured by the DU.
2 . The method according to claim 1 , wherein the timing offset between the first cell and the second cell comprises:
a frame number offset and a frame boundary offset between the first cell and the second cell;
a frame number offset, a subframe number offset, and a subframe boundary offset between the first cell and the second cell; or
a time offset, relative to a frame boundary of a same frame, between the first cell and the second cell.
3 . The method according to claim 1 , wherein the sending the timing offset between the first cell and the second cell to the DU comprises:
receiving, by the CU, a request message from the DU, wherein the request message is for requesting to obtain the timing offset between the first cell and the second cell, or requesting to obtain the RACH configuration of the second cell; and
sending, by the CU, the timing offset between the first cell and the second cell to the DU based on the request message.
4 . The method according to claim 3 , wherein the request message carries an identifier of the first cell.
5 . The method according to claim 1 , wherein the sending, by the CU, the timing offset between the first cell and the second cell to the DU comprises:
receiving, by the CU, an F1 setup request message from the DU; and
sending, by the CU, an F1 setup response message or a CU configuration update message to the DU, wherein the F1 setup response message comprises the timing offset between the first cell and the second cell, and wherein the CU configuration update message comprises the timing offset between the first cell and the second cell.
6 . A communication method comprising:
receiving, by a distributed unit (DU) of a first access network device, a timing offset between a first cell and a second cell from a centralized unit (CU) of the first access network device, wherein the timing offset is from a second access network device, wherein the first cell is served by the DU, the second cell is a neighboring cell of the first cell, wherein the second cell is a cell served by the second access network device, and wherein the second access network device comprises a second CU and a second DU, and the second cell is a cell served by the second DU;
storing, by the DU, the timing offset between the first cell and the second cell;
receiving, by the DU, a random access channel (RACH) configuration of the second cell from the CU;
determining, by the DU based on the timing offset between the first cell and the second cell, the RACH configuration of the second cell, and a RACH configuration of the first cell, whether there is a conflict between the RACH configuration of the first cell and the RACH configuration of the second cell; and
based on the conflict between the RACH configuration of the first cell and the RACH configuration of the second cell, reconfiguring, by the DU, the RACH configuration for the first cell.
7 . The method according to claim 6 , wherein the timing offset between the first cell and the second cell comprises:
a frame number offset and a frame boundary offset between the first cell and the second cell;
a frame number offset, a subframe number offset, and a subframe boundary offset between the first cell and the second cell; or
a time offset, relative to a frame boundary of a same frame, between the first cell and the second cell.
8 . The method according to claim 6 , wherein the receiving, by the DU, the timing offset between the first cell and the second cell comprises:
sending, by the DU, a request message to the CU, wherein the request message is for requesting to obtain the timing offset between the first cell and the second cell, or requesting to obtain a random access channel (RACH) configuration of the second cell; and
receiving, by the DU, the timing offset between the first cell and the second cell based on the request message.
9 . The method according to claim 6 , wherein the receiving, by the DU, the timing offset between the first cell and the second cell comprises:
sending, by the DU, an F1 setup request message to the CU; and
receiving, by the DU, an F1 setup response message or a CU configuration update message from the CU, wherein the F1 setup response message comprises the timing offset between the first cell and the second cell, and wherein the CU configuration update message comprises the timing offset between the first cell and the second cell.
10 . A communication system, comprising a centralized unit (CU) and distributed unit (DU), wherein:
the CU is configured to: obtain, from a second access network device, a timing offset between a first cell and a second cell, send the timing offset between the first cell and the second cell to the DU, and send, to the DU, a random access channel (RACH) configuration of the second cell, wherein the first cell is a cell served by the DU, the second cell is a neighboring cell of the first cell, and both the CU and the DU belong to a first access network device, wherein the second cell is a cell served by the second access network device, and wherein the second access network device comprises a second CU and a second DU, and the second cell is a cell served by the second DU; and
the DU is configured to: receive the timing offset between the first cell and the second cell, store the timing offset between the first cell and the second cell, receive a random access channel (RACH) configuration of the second cell from the CU, determine, based on the timing offset between the first cell and the second cell, the RACH configuration of the second cell, and a RACH configuration of the first cell, whether there is a conflict between the RACH configuration of the first cell and the RACH configuration of the second cell, and based on the conflict between the RACH configuration of the first cell and the RACH configuration of the second cell, reconfigure the RACH configuration for the first cell.
11 . The communication system according to claim 10 , wherein the CU is configured to:
receive a request message from the DU, wherein the request message is for requesting to obtain the timing offset between the first cell and the second cell, or requesting to obtain the RACH configuration of the second cell; and
send the timing offset between the first cell and the second cell to the DU based on the request message.
12 . The communication system according to claim 11 , wherein the request message carries an identifier of the first cell.
13 . The communication system according to claim 10 , wherein the CU is configured to:
receive an F1 setup request message from the DU; and
send an F1 setup response message or a CU configuration update message to the DU, wherein the F1 setup response message comprises the timing offset between the first cell and the second cell, and wherein the CU configuration update message comprises the timing offset between the first cell and the second cell.
14 . The communication system according to claim 10 , wherein the timing offset between the first cell and the second cell comprises:
a frame number offset and a frame boundary offset between the first cell and the second cell;
a frame number offset, a subframe number offset, and a subframe boundary offset between the first cell and the second cell; or
a time offset, relative to a frame boundary of a same frame, between the first cell and the second cell.
15 . The method according to claim 8 , wherein the request message carries an identifier of the first cell.