Method, Device, and System for Handover of User Equipment Group

1. A method for handover of a user equipment group, the method comprising: determining, according to a measurement report of an agent user equipment (UE) and a measurement report of UE in a UE group that are sent by the agent UE, whether the agent UE and each UE in the UE group need to be handed over, wherein the UE group comprises the agent UE and each UE; when the agent UE and at least one UE in the UE group need to be handed over, sending a handover request message to a target base station (T-eNB), wherein the handover request message comprises at least context information of the agent UE and the at least one to-be-handed-over UE that needs to be handed over and a cooperative relationship between the agent UE and the to-be-handed-over UE; receiving a handover configuration message sent by the T-eNB and sending the handover configuration message to the agent UE, wherein the handover configuration message comprises at least a physical random access channel (PRACH) resource and a cell radio network temporary identifier (C-RNTI) that are allocated by the T-eNB to the agent UE and a C-RNTI that is allocated by the T-eNB to each to-be-handed-over UE that needs to be handed over; receiving a context release message sent by the T-eNB, and releasing context resources of the agent UE and the to-be-handed-over UE; initiating random access to the T-eNB according to the PRACH resource, and establishing an uplink synchronous connection to the T-eNB, wherein after the initiating random access to the T-eNB according to the PRACH resource, the method further comprises: if the initiating random access to the T-eNB according to the PRACH resource fails, initiating a synchronous-connection re-establishment request; and if synchronous-connection re-establishment fails, sending a re-establishment notification message to each to-be-handed-over UE in the UE group, to instruct each to-be-handed-over UE in the UE group to separately establish a synchronous connection.

2. The method according to claim 1 , further comprising: when the agent UE and the at least one piece of UE in the UE group need to be handed over, sending the handover request message to the T-eNB by using a mobility management entity (MME), wherein the handover request message comprises at least the context information of the agent UE and the at least one piece of to-be-handed-over UE that needs to be handed over and the cooperative relationship between the agent UE and the to-be-handed-over UE; receiving, by using the MME, the handover configuration message sent by the T-eNB and sending the handover configuration message to the agent UE, wherein the handover configuration message comprises at least the PRACH resource and the C-RNTI that are allocated by the T-eNB to the agent UE and the C-RNTI that is allocated by the T-eNB to each to-be-handed-over UE that needs to be handed over; and receiving, by using the MME, the context release message sent by the T-eNB, and releasing the context resources of the agent UE and the to-be-handed-over UE.

3. A method for handover of a user equipment group, the method comprising: sending a measurement report of agent UE and a measurement report of each UE in a user equipment (UE) group to a serving base station S-eNB, wherein the UE group comprises the agent UE and each UE; receiving a handover configuration message sent by the S-eNB, wherein the handover configuration message comprises at least a physical random access channel (PRACH) resource and a cell radio network temporary identifier (C-RNTI) that are allocated by a T-eNB to the agent UE and a C-RNTI that is allocated by the T-eNB to each to-be-handed-over UE that needs to be handed over; sending a handover configuration message separately to each to-be-handed-over UE, wherein the handover configuration message comprises at least the C-RNTI that is allocated by the T-eNB to the to-be-handed-over UE; and initiating random access to the T-eNB according to the PRACH resource, and establishing an uplink synchronous connection to the T-eNB, wherein after the initiating random access to the T-eNB according to the PRACH resource, the method further comprises: if the initiating random access to the T-eNB according to the PRACH resource fails, initiating a synchronous-connection re-establishment request; and if synchronous-connection re-establishment fails, sending a re-establishment notification message to each to-be-handed-over UE in the UE group, to instruct each to-be-handed-over UE in the UE group to separately establish a synchronous connection.

4. The method according to claim 3 , wherein after the establishing an uplink synchronous connection to the T-eNB, the method further comprises: sending a first handover complete message to the T-eNB; sending a second handover complete message separately to each to-be-handed-over UE in the UE group; and receiving a third handover complete message sent by each to-be-handed-over UE in the UE group and forwarding the third handover complete message to the T-eNB.

5. A method for handover of a user equipment group, the method comprising: sending a measurement report to agent user equipment (UE), so that the agent UE forwards the measurement report and a measurement report of the agent UE to a serving base station S-eNB; receiving a handover configuration message sent by the agent UE, wherein the handover configuration message comprises at least a cell radio network temporary identifier (C-RNTI) that is allocated by a target base station (T-eNB); completing handover of to-be-handed-over UE according to the C-RNTI, and sending a third handover complete message to the agent UE, so that the agent UE forwards the handover complete message to the T-eNB; initiating random access to the T-eNB according to a physical random access channel (PRACH) resource, and establishing an uplink synchronous connection to the T-eNB, wherein after the initiating random access to the T-eNB according to the PRACH resource, the method further comprises: if the initiating random access to the T-eNB according to the PRACH resource fails, initiating a synchronous-connection re-establishment request; and if synchronous-connection re-establishment fails, sending a re-establishment notification message to each to-be-handed-over UE in the UE group, to instruct each to-be-handed-over UE in the UE group to separately establish a synchronous connection.

6. A method for handover of a user equipment group, the method comprising: receiving a handover request message sent by a serving base station S-eNB, wherein the handover request message comprises at least context information of agent user equipment (UE) and at least one piece of to-be-handed-over UE that is in a UE group and that needs to be handed over and a cooperative relationship between the agent UE and the to-be-handed-over UE; allocating resources to the agent UE and each to-be-handed-over UE that is in the UE group and that needs to be handed over, wherein the resources comprise at least a physical random access channel (PRACH) resource and a cell radio network temporary identifier (C-RNTI) that are allocated to the agent UE and a C-RNTI that is allocated to each to-be-handed-over UE that needs to be handed over; sending a handover configuration message to the S-eNB, wherein the handover configuration message comprises at least the PRACH resource and the C-RNTI that are allocated to the agent UE and the C-RNTI that is allocated to each to-be-handed-over UE that needs to be handed over; receiving an access request that is sent by the agent UE according to the PRACH resource, and establishing an uplink synchronous connection to the agent UE; receiving a handover complete message that indicates that the to-be-handed-over UE has completed handover according to the C-RNTI and that is forwarded by the agent UE, to learn that the to-be-handed-over UE has completed the handover; initiating random access to the T-eNB according to a physical random access channel (PRACH) resource, and establishing an uplink synchronous connection to the T-eNB, wherein after the initiating random access to the T-eNB according to the PRACH resource, the method further comprises: if the initiating random access to the T-eNB according to the PRACH resource fails, initiating a synchronous-connection re-establishment request; and if synchronous-connection re-establishment fails, sending a re-establishment notification message to each to-be-handed-over UE in the UE group, to instruct each to-be-handed-over UE in the UE group to separately establish a synchronous connection.

7. The method according to claim 6 , wherein after the receiving a handover complete message that indicates that the to-be-handed-over UE has completed handover according to the C-RNTI and that is forwarded by the agent UE, the method further comprises: sending a path conversion request to a mobility management entity (MME); receiving a path conversion confirm message that is sent by the MME after the MME converts downlink paths of the agent UE and the to-be-handed-over UE according to the path conversion request; and sending a context release message to the MME, so that the MME sends a context release command to the S-eNB, to cause the S-eNB to release context resources of the agent UE and the to-be-handed-over UE.

8. A device for handover of a user equipment group, the device comprising: a processor, configured to determine, according to a measurement report of the agent user equipment (UE) and a measurement report of UE in a UE group that are sent by the agent UE, whether the agent UE and each UE in the UE group need to be handed over, wherein the UE group comprises the agent UE and each UE; a transmitter, configured to: when the agent UE and at least one piece of UE in the UE group need to be handed over, send a handover request message to a target base station (T-eNB), wherein the handover request message comprises at least context information of the agent UE and the at least one piece of to-be-handed-over UE that needs to be handed over and a cooperative relationship between the agent UE and the to-be-handed-over UE; a receiver, configured to receive a handover configuration message sent by the T-eNB; and the transmitter, configured to send the handover configuration message to the agent UE, wherein the handover configuration message comprises at least a physical random access channel (PRACH) resource and a cell radio network temporary identifier (C-RNTI) that are allocated by the T-eNB to the agent UE and a C-RNTI that is allocated by the T-eNB to each to-be-handed-over UE that needs to be handed over; and the receiver, configured to receive a context release message sent by the T-eNB, and the processor, configured to release context resources of the agent UE and the to-be-handed-over UE, wherein the processor further configured to initiate random access to the T-eNB according to the PRACH resource, and establish an uplink synchronous connection to the T-eNB and further configured to: after the random access to the T-eNB is initiated according to the PRACH resource, if the random access to the T-eNB initiated according to the PRACH resource fails, initiate a synchronous-connection re-establishment request; and the transmitter, configured to: if synchronous-connection re-establishment fails, send a re-establishment notification message to each to-be-handed-over UE in the UE group, to instruct each to-be-handed-over UE in the UE group to separately establish a synchronous connection.

9. The device according to claim 8 , wherein the transmitter, configured to: when the agent UE and the at least one piece of UE in the UE group need to be handed over, send the handover request message to the T-eNB by using a mobility management entity (MME), wherein the handover request message comprises at least the context information of the agent UE and the at least one piece of to-be-handed-over UE that needs to be handed over and the cooperative relationship between the agent UE and the to-be-handed-over UE; the receiver, configured to receive, by using the MME, the handover configuration message sent by the T-eNB; and the transmitter, configured to send the handover configuration message to the agent UE, wherein the handover configuration message comprises at least the PRACH resource and the C-RNTI that are allocated by the T-eNB to the agent UE and the C-RNTI that is allocated by the T-eNB to each to-be-handed-over UE that needs to be handed over; and the receiver, configured to receive, by using the MME, the context release message sent by the T-eNB, and release the context resources of the agent UE and the to-be-handed-over UE.

10. A device for handover of a user equipment group, the device comprising: a transmitter, configured to send a measurement report of agent UE and a measurement report of each UE in a user equipment (UE) group to a serving base station S-eNB, wherein the UE group comprises the agent UE and each UE; a receiver, configured to receive a handover configuration message sent by the S-eNB, wherein the handover configuration message comprises at least a physical random access channel (PRACH) resource and a cell radio network temporary identifier (C-RNTI) that are allocated by the T-eNB to the agent UE and a C-RNTI that is allocated by the T-eNB to each to-be-handed-over UE that needs to be handed over; the transmitter, configured to send a handover configuration message separately to each to-be-handed-over UE, wherein the handover configuration message comprises at least the C-RNTI that is allocated by the T-eNB to the to-be-handed-over UE; and a processor, configured to initiate random access to the T-eNB according to the PRACH resource, and establish an uplink synchronous connection to the T-eNB, wherein the processor further configured to: after the random access to the T-eNB is initiated according to the PRACH resource, if the random access to the T-eNB initiated according to the PRACH resource fails, initiate a synchronous-connection re-establishment request; and the transmitter, configured to: if synchronous-connection re-establishment fails, send a re-establishment notification message to each to-be-handed-over UE in the UE group, to instruct each to-be-handed-over UE in the UE group to separately establish a synchronous connection.

11. The device according to claim 10 , wherein the transmitter, configured to: after the uplink synchronous connection to the T-eNB is established, send a first handover complete message to the T-eNB; and send a second handover complete message separately to each to-be-handed-over UE in the UE group; and the receiver, configured to receive a third handover complete message sent by each to-be-handed-over UE in the UE group and forward the third handover complete message to the T-eNB.

12. A device for handover of a user equipment group, the device comprising: a transmitter, configured to send a measurement report to agent user equipment (UE), so that the agent UE forwards the measurement report and a measurement report of the agent UE to a serving base station S-eNB; a receiver, configured to receive a handover configuration message sent by the agent UE, wherein the handover configuration message comprises at least a cell radio network temporary identifier (C-RNTI) that is allocated by a target base station (T-eNB); and a processor, configured to complete handover of to-be-handed-over UE according to the C-RNTI, and the transmitter, configured to send a third handover complete message to the agent UE, so that the agent UE forwards the handover complete message to the T-eNB, wherein the processor further configured to initiate random access to the T-eNB according to a physical random access channel (PRACH) resource, and establish an uplink synchronous connection to the T-eNB and further configured to: after the random access to the T-eNB is initiated according to the PRACH resource, if the random access to the T-eNB initiated according to the PRACH resource fails, initiate a synchronous-connection re-establishment request; and the transmitter, configured to: if synchronous-connection re-establishment fails, send a re-establishment notification message to each to-be-handed-over UE in the UE group, to instruct each to-be-handed-over UE in the UE group to separately establish a synchronous connection.

13. A device for handover of a user equipment group, the device comprising: a receiver, configured to receive a handover request message sent by a serving base station S-eNB, wherein the handover request message comprises at least context information of agent user equipment (UE) and at least one piece of to-be-handed-over UE that needs to be handed over and a cooperative relationship between the agent UE and the to-be-handed-over UE; a processor, configured to allocate resources to the agent UE and each to-be-handed-over UE that is in the UE group and that needs to be handed over, wherein the resources comprise at least a physical random access channel (PRACH) resource and a cell radio network temporary identifier (C-RNTI) that are allocated to the agent UE and a C-RNTI that is allocated to each to-be-handed-over UE that needs to be handed over; and send a handover configuration message to the S-eNB, wherein the handover configuration message comprises at least the PRACH resource and the C-RNTI that are allocated to the agent UE and the C-RNTI that is allocated to each piece of to-be-handed-over UE that needs to be handed over; the receiver, configured to receive an access request that is sent by the agent UE according to the PRACH resource, and establish an uplink synchronous connection to the agent UE; the receiver, configured to receive a handover complete message that indicates that the to-be-handed-over UE has completed handover according to the C-RNTI and that is forwarded by the agent UE, to learn that the to-be-handed-over UE has completed the handover, wherein the processor further configured to initiate random access to the T-eNB according to the PRACH resource, and establish an uplink synchronous connection to the T-eNB and further configured to: after the random access to the T-eNB is initiated according to the PRACH resource, if the random access to the T-eNB initiated according to the PRACH resource fails, initiate a synchronous-connection re-establishment request; and a transmitter, configured to: if synchronous-connection re-establishment fails, send a re-establishment notification message to each to-be-handed-over UE in the UE group, to instruct each to-be-handed-over UE in the UE group to separately establish a synchronous connection.

14. The device according to claim 13 , wherein the device further comprises: the transmitter, configured to: after the handover complete message that indicates that the to-be-handed-over UE has completed the handover according to the C-RNTI and that is forwarded by the agent UE is received, send a path conversion request to a mobility management entity (MME); the receiver, configured to receive a path conversion confirm message that is sent by the MME after the MME converts downlink paths of the agent UE and the to-be-handed-over UE according to the path conversion request; and the transmitter, configured to send a context release message to the MME, so that the MME sends a context release command to the S-eNB, to cause the S-eNB to release context resources of the agent UE and the to-be-handed-over UE.