IP Library › Granted Patent US 12712673
Granted Patent B2
US 12712673 · App. 17/947,651 · Granted Aug 18, 2026

Communication method, access network device, terminal device, and core network device

Inventors: Bin Xu (Beijing, CN); Bingzhao Li (Beijing, CN)
Assignee: HUAWEI TECHNOLOGIES CO., LTD.
H04L1/1642H04W36/0064H04W36/0235H04W76/19H04W36/087
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Quick Facts
Patent No.
US 12712673
App. No.
17/947,651
Granted
Aug 18, 2026
Kind
B2
Abstract

A communication method, an access network device, a terminal device, and a core network device where the terminal device is handed over from a first access network device to a second access network device, the second access network device learns of first service progress of the first access network device based on a first sequence number of a data packet forwarded by the first access network device, without introducing additional progress exchange information between the two access network devices.

Claims (52)

1 . A communication method comprising:

receiving a first data packet and first core network sequence number, wherein the first core network sequence number is set by a core network device, the first core network sequence number indicates a sequence of the first data packet in at least one data packet;

determining a first sequence number of a first protocol layer of the first data packet based on the first core network sequence number, wherein the first sequence number of the first protocol layer of the first data packet is equal to a value of the first core network sequence number;

sending the first data packet to a terminal device; and

sending a handover command to the terminal device, wherein the handover command indicates the terminal device to handover from a first network device to a second network device.

2 . The method according to claim 1 , wherein the first protocol layer is a packet data convergence protocol (PDCP) layer.

3 . The method according to claim 1 , wherein the at least one data packet is of a first service, the first service is multicast service.

4 . The method according to claim 1 , further comprising:

setting the first sequence number of the first protocol layer of the first data packet based on the first core network sequence number when any one of establishment of a first protocol entity, re-establishment of the first protocol entity, and recovery of the first protocol entity occurs.

5 . The method according to claim 1 , further comprising:

sending a sequence number of a data packet of a first service to the second network device, wherein the sequence number indicates progress information of the first service at the first network device.

6 . The method according to claim 1 , wherein

a second core network sequence number corresponding to a second data packet matches the first core network sequence number, wherein the second data packet is from the core network device to the second network device, and data in the first data packet matches data in the second data packet.

7 . The method according to claim 1 , wherein

the first sequence number of the first protocol layer is usable by the first protocol layer to perform sorting or duplicate detection for the first data packet.

8 . The method according to claim 1 , further comprising:

receiving fifth indication information from the second network device, wherein the fifth indication information comprises a second sequence number N, and the second sequence number indicates a sequence number of the first data packet that is of the first service and that is sent by the second network device to the terminal device after handover of the terminal device is completed; and

when a sequence number of a data packet successfully sent by the first access network device to the terminal device is N−1, stopping, by the first network device, sending a data packet to the terminal device.

9 . A communications apparatus, comprising:

one or more processors in communications with a non-transitory memory configured to store program instructions;

wherein, when executed by the one or more processors, the instructions cause the one or more processors to:

receive a first data packet and first core network sequence number, wherein the first core network sequence number is set by a core network device, the first core network sequence number indicates a sequence of the first data packet in at least one data packet;

determine a first sequence number of a first protocol layer of the first data packet based on the first core network sequence number, wherein the first sequence number of the first protocol layer of the first data packet is equal to a value of the first core network sequence number; and

send the first data packet to a terminal device; and

send a handover command to the terminal device, wherein the handover command indicates the terminal device to handover from a first network device to a second network device.

10 . The communications apparatus according to claim 9 , wherein the first protocol layer is a packet data convergence protocol (PDCP) layer.

11 . The communications apparatus according to claim 9 , wherein the at least one data packet is of a first service, the first service is multicast service.

12 . The communications apparatus according to claim 9 , wherein the instructions further cause the one or more processors to:

set the first sequence number of the first protocol layer of the first data packet based on the first core network sequence number when any one of establishment of a first protocol entity, re-establishment of the first protocol entity, and recovery of the first protocol entity occurs.

13 . The communications apparatus according to claim 9 , further comprising:

sending a sequence number of a data packet of a first service to the second network device, wherein the sequence number indicates progress information of the first service at the first network device.

14 . The communications apparatus according to claim 9 , wherein

a second core network sequence number corresponding to a second data packet matches the first core network sequence number, wherein the second data packet is from the core network device to the second network device, and data in the first data packet matches data in the second data packet.

15 . The communications apparatus according to claim 9 , wherein

the first sequence number of the first protocol layer is usable by the first protocol layer to perform sorting or duplicate detection for the first data packet.

16 . The communications apparatus according to claim 9 , wherein the instructions further cause the one or more processors to:

receive fifth indication information from a second network device, wherein the fifth indication information comprises a second sequence number N, and the second sequence number indicates a sequence number of the first data packet that is of the first service and that is sent by the second network device to the terminal device after handover of the terminal device is completed; and

when a sequence number of a data packet successfully sent by the first access network device to the terminal device is N−1, stopping, by the first network device, sending a data packet to the terminal device.

17 . A communication method comprising:

receiving at least one data packet;

sending a first data packet and first core network sequence number to a first access network device, wherein the first core network sequence number indicates a sequence of the first data packet in the at least one data packet, wherein the first core network sequence number is for determining a first sequence number of a first protocol layer of the first data packet, and the first sequence number of the first protocol layer of the first data packet is determined equal to a value of the first core network sequence number.

18 . The method according to claim 17 , further comprising:

sending a second data packet, a second indication information, and second core network sequence number to a second access network device, wherein the second indication information indicates a sequence of the second data packet in the at least one data packet, the second core network sequence number is for determining a second sequence number of a first protocol layer of the second data packet, the second sequence number of a first protocol layer of the second data packet is determined equal to the value of the second core network sequence number;

wherein data in the second data packet is the same as data in the first data packet, a value of the first core network sequence number is equal to a value of the second core network sequence number.

19 . A communications apparatus, comprising:

one or more processors in communications with a non-transitory memory configured to store program instructions;

wherein, when executed by the one or more processors, the instructions cause the one or more processors to:

receive at least one data packet;

send a first data packet and first core network sequence number to a first access network device, wherein the first core network sequence number indicates a sequence of the first data packet in the at least one data packet, wherein the first core network sequence number is for determining a first sequence number of a first protocol layer of the first data packet, and the first sequence number of the first protocol layer of the first data packet is determined equal to a value of the first core network sequence number.

20 . The communications apparatus according to claim 19 , wherein, when executed by the one or more processors, the instructions further cause the one or more processors to:

send a second data packet, a second indication information, and second core network sequence number to a second access network device, wherein the second indication information indicates a sequence of the second data packet in the at least one data packet, the second core network sequence number is for determining a second sequence number of a first protocol layer of the second data packet, the second sequence number of a first protocol layer of the second data packet is determined equal to the value of the second core network sequence number;

wherein data in the second data packet is the same as data in the first data packet, a value of the first core network sequence number is equal to a value of the second core network sequence number.