Broadcast-based unicast session method and apparatus

1 . A broadcast-based unicast session system, comprising an initiator device and at least one responder device, wherein the at least one responder device comprises a first responder device, wherein

the initiator device is configured to send a first unicast request message through periodic broadcast, wherein the first unicast request message comprises a unicast service type requested by the initiator device of a unicast session, unicast service data requested by the initiator device, and a first media access control (MAC) identifier and a first extension identifier of the initiator device, and the first extension identifier is different from the first MAC identifier;

the first responder device is configured to: receive the first unicast request message, and send, based on the received first unicast request message, a first unicast response message through broadcast, wherein the first unicast response message comprises a unicast service type responded by the first responder device of the unicast session, unicast service data responded by the first responder device, the first MAC identifier, the first extension identifier, and a second MAC identifier and a second extension identifier of the first responder device, and the second extension identifier is different from the second MAC identifier;

the initiator device is further configured to: receive the first unicast response message, and send, based on the received first unicast response message, a first unicast acknowledgment message through broadcast, wherein the first unicast acknowledgment message comprises acknowledgment information of the unicast service data responded by the first responder device, the first MAC identifier, the first extension identifier, the second MAC identifier, and the second extension identifier, wherein the first unicast acknowledgment message comprises a message layer and a radio link control layer, wherein content information of the first unicast acknowledgment message at the radio link control layer is carried by a data packet, and the message layer of the first unicast acknowledgment message comprises information used to indicate an attribute of a unicast message; and

the first responder device is further configured to: receive the first unicast acknowledgment message, and perform service processing related to the unicast session based on the first unicast acknowledgment message.

2 . A broadcast-based unicast session apparatus, comprising at least one processor and at least one memory coupled to the at least one processor, wherein the at least one memory stores program instructions, which when executed by the at least one processor cause the apparatus to:

send a first unicast request message through periodic broadcast, wherein the first unicast request message comprises a unicast service type requested by an initiator device of a unicast session, unicast service data requested by the initiator device, and a first media access control (MAC) identifier and a first extension identifier of the initiator device, and the first extension identifier is different from the first MAC identifier;

receive a first unicast response message sent by a first responder device through broadcast, wherein the first unicast response message comprises a unicast service type responded by the first responder device, unicast service data responded by the first responder device, the first MAC identifier, the first extension identifier, and a second MAC identifier and a second extension identifier of the first responder device, and the second extension identifier is different from the second MAC identifier; and

send, based on the received first unicast response message, a first unicast acknowledgment message through broadcast, wherein the first unicast acknowledgment message comprises acknowledgment information of the unicast service data responded by the first responder device, the first MAC identifier, the first extension identifier, the second MAC identifier, and the second extension identifier, wherein the first unicast acknowledgment message comprises a message layer and a radio link control layer, wherein content information of the first unicast acknowledgment message at the radio link control layer is carried by a data packet, and the message layer of the first unicast acknowledgment message comprises information used to indicate an attribute of a unicast message.

3 . The apparatus according to claim 2 , wherein when executed by the at least one processor the program instructions further cause the apparatus to:

receive a second unicast response message sent by a second responder device through broadcast, wherein the second unicast response message comprises a unicast service type responded by the second responder device, unicast service data responded by the second responder device, the first MAC identifier, the first extension identifier, and a third MAC identifier and a third extension identifier of the second responder device; and

select, from a plurality of unicast response messages comprising the first unicast response message and the second unicast response message, at least one unicast response message comprising the first unicast response message as a responded unicast response message, wherein a MAC identifier of the initiator device comprised in each of the at least one unicast response message is the first MAC identifier, and an extension identifier of the initiator device comprised in each unicast response message is the first extension identifier.

4 . The apparatus according to claim 3 , wherein the at least one unicast response message used as the responded unicast response message further comprises a third unicast response message sent by a third responder device through broadcast;

the third unicast response message comprises a unicast service type responded by the third responder device, unicast service data responded by the third responder device, the first MAC identifier, the first extension identifier, and a fourth MAC identifier and a fourth extension identifier of the third responder device; and wherein when executed by the at least one processor the program instructions further cause the apparatus to:

receive, the third unicast response message sent by the third responder device through broadcast; and

send, based on the third unicast response message, a second unicast acknowledgment message through broadcast, wherein the second unicast acknowledgment message comprises acknowledgment information of the unicast service data responded by the third responder device, the first MAC identifier, the first extension identifier, the fourth MAC identifier, and the fourth extension identifier.

5 . The apparatus according to claim 2 , wherein the first unicast request message further comprises first sending indication information, used to indicate at least one of a quantity of times of repeated sending or a repeated sending interval of the first unicast response message.

6 . The apparatus according to claim 2 , wherein the sending a first unicast acknowledgment message through broadcast includes repeatedly sending the first unicast acknowledgment message through broadcast, and the first unicast response message further comprises second sending indication information, used to indicate at least one of a quantity of times of repeated sending, a repeated sending interval, or remaining waiting time of the first unicast acknowledgment message.

7 . The apparatus according to claim 6 , wherein at least one of an actual quantity of times of repeated sending or an actual repeated sending interval of the first unicast acknowledgment message is determined based on the second sending indication information.

8 . The apparatus according to claim 2 , wherein the first unicast request message further comprises the second MAC identifier and the second extension identifier, and the second extension identifier is different from the second MAC identifier.

9 . The apparatus according to claim 2 , wherein when executed by the at least one processor the program instructions further cause the apparatus to:

receive a fourth unicast response message from the second responder device, wherein the fourth unicast response message comprises the unicast service type responded by the second responder device, the unicast service data responded by the second responder device, the first MAC identifier, a fifth extension identifier different from the first extension identifier, and the MAC identifier and the extension identifier of the second responder device; and

send a second unicast request message through periodic broadcast, wherein the second unicast request message comprises the unicast service type requested by the initiator device of the unicast session, the unicast service data requested by the initiator device, and an updated MAC identifier and the first extension identifier of the initiator device, and the updated MAC identifier of the initiator device is different from the first MAC identifier.

10 . A broadcast-based unicast session apparatus, comprising at least one processor and at least one memory coupled to the at least one processor, wherein the at least one memory stores program instructions, which when executed by the at least one processor cause the apparatus to:

receive a first unicast request message sent by an initiator device of a unicast session through periodic broadcast, wherein the first unicast request message comprises a unicast service type requested by the initiator device, unicast service data requested by the initiator device, and a first media access control (MAC) identifier and a first extension identifier of the initiator device, and the first extension identifier is different from the first MAC identifier;

send, based on the received first unicast request message, a first unicast response message through broadcast, wherein the first unicast response message comprises a unicast service type responded by a first responder device of the unicast session, unicast service data responded by the first responder device, the first MAC identifier, the first extension identifier, and a second MAC identifier and a second extension identifier of the first responder device, and the second extension identifier is different from the second MAC identifier, wherein the first unicast response message comprises a message layer and a radio link control layer, wherein content information of the first unicast response message at the radio link control layer is carried by a data packet, and the message layer of the first unicast response message comprises information used to indicate an attribute of a unicast message;

receive a first unicast acknowledgment message from the initiator device, wherein the first unicast acknowledgment message comprises acknowledgment information of the unicast service data responded by the first responder device, the first MAC identifier, the first extension identifier, the second MAC identifier, and the second extension identifier; and

perform service processing related to the unicast session based on the first unicast acknowledgment message.

11 . The apparatus according to claim 10 , wherein the sending a first unicast response message through broadcast includes repeatedly sending the first unicast response message through broadcast, and the first unicast request message further comprises first sending indication information, used to indicate at least one of a quantity of times of repeated sending or a repeated sending interval of the first unicast response message.

12 . The apparatus according to claim 11 , wherein at least one of an actual quantity of times of repeated sending or an actual repeated sending interval of the first unicast response message is determined based on the first sending indication information.

13 . The apparatus according to claim 10 , wherein the first unicast response message further comprises second sending indication information, used to indicate at least one of a quantity of times of repeated sending, a repeated sending interval, or remaining waiting time of the first unicast acknowledgment message.

14 . The apparatus according to claim 13 , wherein when executed by the at least one processor the program instructions further cause the apparatus to:

re-send the first unicast response message through broadcast, based on the first unicast acknowledgment message being not received within the remaining waiting time start from sending the first unicast response message.

15 . The apparatus according to claim 10 , wherein the first unicast request message further comprises the second MAC identifier and the second extension identifier; and

when executed by the at least one processor the program instructions further cause the apparatus to: send the first unicast response message through broadcast, when the second MAC identifier in the first unicast request message is the same as a current MAC identifier of the first responder device, and the second extension identifier in the first unicast request message is the same as an extension identifier of the first responder device.