Handover Control Method, Apparatuses and Communication System

1. A handover control method, comprising: receiving, by a serving base station, a measurement report from a user equipment which is to be handed over from a source cell served by the serving base station to a target cell served by a relay node, wherein the measurement report comprises a physical cell identity (PCI) of the target cell and an evolved-universal terrestrial radio access network (E-UTRAN) cell global identifier (ECGI) of the target cell; obtaining, by the serving base station, an identity of the relay node from the ECGI of the target cell, wherein the identity of the relay node is same as an identity of a control base station which controls the relay node, and the ECGI of the target cell comprises the identity of the relay node; sending, by the serving base station, a handover request to the control base station identified by the identity of the relay node, wherein the handover request comprises an identity of the target cell; and sending, by the control base station, the handover request to the relay node corresponding to the identity of the target cell.

2. The method according to claim 1 , further comprising before the control base station sending the handover request to the relay node: finding, by the control base station, the relay node according to the identity of the target cell.

3. The method according to claim 2 , wherein the identity of the target cell comprises at least one of the ECGI of the target cell and the PCI of the target cell.

4. The method according to claim 2 , wherein the finding, by the control base station, the relay node comprises: searching, by the control base station, the identity of the target cell in a list of one or more cell identities for one or more cells that are served by the relay node to obtain the relay node that serves the target cell, wherein the list is received by the control base station from the relay node.

5. The method according to claim 1 , further comprising: allocating, by the control base station, the identity of the control base station as the identity of the relay node to the relay node when the relay node accesses the control base station.

6. A handover control method, comprising: receiving, by a serving base station, a measurement report from a user equipment which is to be handed over from a source cell served by the serving base station to a target cell served by a relay node, wherein the measurement report comprises a physical cell identity (PCI) of the target cell and an evolved-universal terrestrial radio access network (E-UTRAN) cell global identifier (ECGI) of the target cell; obtaining, by the serving base station, an identity of the relay node from the ECGI of the target cell, wherein the identity of the relay node is same as an identity of a control base station which controls the relay node and the ECGI of the target cell comprises the identity of the relay node; and sending, by the serving base station, a handover request to the control base station identified by the identity of the relay node, wherein the handover request comprises an identity of the target cell.

7. The method according to claim 6 , wherein the identity of the target cell comprises at least one of the ECGI of the target cell and the PCI of the target cell.

8. A base station comprising a processing hardware platform executing instructions stored on a non-transitory computer-readable storage medium to perform functions as a plurality of modules, wherein in a situation where the base station serves as a serving base station of a user equipment which is to be handed over from a source cell that is served by the base station to a target cell that is served by a relay node, the plurality of modules comprising: an obtaining module, configured to obtain a physical cell identity (PCI) of the target cell and an evolved-universal terrestrial radio access network (E-UTRAN) cell global identifier (ECGI) of the target cell from a measurement report received from the user equipment, and obtain an identity of the relay node, wherein the identity of the relay node is same as an identity of a control base station which controls the relay node, and the ECGI of the target cell comprises the identity of the relay node; and a handover request sending module, configured to cause a handover request to be transmitted to the control base station identified by the identity of the relay node, wherein the handover request comprises the identity of the target cell.

9. The base station according to claim 8 , wherein the identity of the target cell comprises at least one of the ECGI of the target cell and the PCI of the target cell.

10. A communication system, comprising: a first base station, and a second base station controlling a relay node, wherein in a situation where the user equipment is to be handed over from a source cell that is served by the first base station to a target cell that is served by the relay node: the first base station is configured to: receive a measurement report from the user equipment, obtain an identity of the relay node from an evolved-universal terrestrial radio access network (E-UTRAN) cell global identifier (ECGI) of the target cell, and send a handover request to the second base station identified by the identity of the relay node, wherein the measurement report comprises a physical cell identity (PCI) of the target cell and the ECGI of the target cell, the identity of the relay node is same as an identity of the second base station, and the handover request comprises an identity of the target cell; the second base station is configured to receive the handover request from the first base station, and send the handover request to the relay node corresponding to the identity of the target cell.

11. The system according to claim 10 , wherein the second base station is further configured to before sending the handover request to the relay node: find the relay node according to the identity of the target cell.

12. The system according to claim 11 , wherein the second base station is configured to find the relay node according to the identity of the target cell as follows: searching the identity of the target cell in a list of one or more cell identities for one or more cells that are served by the relay node to obtain the relay node that serves the target cell, wherein the list is received by the second base station from the relay node.

13. The communication system according to claim 10 , wherein the identity of the target cell comprises at least one of the ECGI of the target cell and the PCI of the target cell.

14. A machine comprising: a processor executing instructions to perform functions as a plurality of modules, wherein the plurality of modules comprises: an obtaining module, configured to obtain, from a measurement report received from a user equipment, a physical cell identity (PCI) of a target cell and an evolved-universal terrestrial radio access network (E-UTRAN) cell global identifier (ECGI) of the target cell to which the user equipment is to be handed over from a source cell that is served by a serving base station, the a target cell being served by a relay node; the obtaining module is further configured to obtain an identity of the relay node from the ECGI of the target cell, wherein the identity of the relay node is same as an identity of a control base station which controls the relay node, and the ECGI of the target cell comprises the identity of the relay node; and a controlling module, configured to cause a handover request to be transmitted to the control base station, wherein the handover request comprises an identity of the target cell.