Facilitating group handover

• US 9,967,783 B2
• Filed: 02/15/2013
• Issued: 05/08/2018
• Est. Priority Date: 02/15/2013
• Status: Expired due to Fees

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Inventors: Yu, Ling, Van Phan, Vinh, Horneman, Kari Veikko
• Primary Examiner(s): Lai, Andrew
• Assistant Examiner(s): Kim, Harry H
• Application Number:
  US14/767,327
• Publication Number:
  US 20150382252A1
• Time in Patent Office: 1,908 Days
• CPC Class Codes: H04W 36/0027 for a plurality of data sessions of end-to-end connections, e.g. multi-call or multi-bearer end-to-end data connections
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 36/0064 of control information between different access points
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

There is provided a method, including: receiving, by a target base station, information that a handover of a plurality of user equipment currently connected to a source cell is needed to a target cell; causing a device-to-device, D2D, cluster generation, wherein each generated D2D cluster is controlled by a predetermined user equipment connected to the target cell and acting as a D2D cluster head; determining D2D cluster-specific radio resource commitment information for each generated D2D cluster; indicating corresponding D2D cluster-specific radio resource commitment information to each D2D cluster head; and receiving a handover request from at least one D2D cluster head, wherein the handover request is for handing at least one member of the corresponding D2D cluster over to the target cell.

Claims

1. A method at a user equipment for a group handover, comprising:

receiving an indication to act as a device-to-device (D2D) cluster head controlling a D2D cluster from a base station (BS);

receiving D2D cluster discovery information enabling transmission of a discovery signal corresponding to the D2D cluster from the BS;

transmitting the discovery signal according to the received D2D cluster discovery information in order to allow other user equipment to discover the D2D cluster;

receiving D2D cluster-specific radio resource commitment information determined by a target BS in a handover process of a plurality of user equipment from a source cell to a target cell;

performing admission control for the user equipment trying to access the D2D cluster on the basis of the received D2D cluster-specific radio resource commitment information; and

transmitting a handover request to the target BS regarding a handover of at least one member of the D2D cluster from the source cell to the target cell.

2. The method of claim 1, wherein the radio resource commitment information indicates a quota by which the D2D cluster head determines whether a user equipment connected to the source cell is to be included in the D2D cluster, and

wherein performing admission control for the user equipment trying to access the D2D cluster on the basis of the received D2D cluster-specific radio resource commitment information includes determining whether a user equipment connected to the source cell is to be included in the D2D cluster based on the quota indicated by the radio resource commitment information.

3. An apparatus in a target base station (BS), comprising:

at least one processor and

at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to;

receive information that a handover of a plurality of user equipment currently connected to a source cell is needed to a target cell;

generate a device-to-device, D2D, cluster generation, wherein each generated D2D cluster is controlled by a predetermined user equipment connected to the target cell and acting as a D2D cluster head;

determine D2D cluster-specific radio resource commitment information for each generated D2D cluster;

indicate corresponding D2D cluster-specific radio resource commitment information to each D2D cluster head; and

receive a handover request from at least one D2D cluster head, wherein the handover request is for handing at least one member of the corresponding D2D cluster over to the target cell.

4. The apparatus of claim 3, wherein each D2D cluster-specific radio resource commitment information defines at least one of the following:

a maximum number of user equipment acceptable by the corresponding D2D cluster, a maximum bit rate guaranteed by the corresponding D2D cluster, a list of identities that the corresponding D2D cluster head is allowed to allocate to user equipment joining the corresponding D2D cluster.

5. The apparatus of claim 3, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

perform the D2D cluster generation by selecting at least one user equipment of the target cell to act as the D2D cluster head; and

transmit an indication of the selected at least one D2D cluster head to the source BS.

6. The apparatus of claim 3, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

perform the D2D cluster generation by transmitting a request to the source base station to select at least one user equipment of the source cell to act as the D2D cluster head, wherein the selection is to be made on the basis of selection criteria indicated to the source base station; and

perform a handover of the selected at least one user equipment from the source cell to the target cell before the handover of the plurality of user equipment.

7. The apparatus of claim 3, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

determine D2D cluster discovery information for enabling a discovery of each D2D cluster head;

transmit corresponding D2D cluster discovery information to the corresponding D2D cluster head in order to enable the D2D cluster head to transmit the discovery signal according to the transmitted D2D cluster discovery information; and

transmit the D2D cluster discovery information to a source base station in order to enable the source base station to indicate the D2D cluster discovery information to the plurality of user equipment of the source cell.

8. The apparatus of claim 7, wherein the D2D cluster discovery information comprises at least one of the following with respect to each D2D cluster:

discovery signal information, advertising information, discovery channel information, priority information, D2D cluster operation mode.

9. The apparatus of claim 7, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

detect that at least one D2D cluster head is not accepting new members to join the corresponding D2D cluster anymore;

update the D2D cluster discovery information to indicate that the corresponding D2D cluster is not accepting new members anymore; and

cause a transmission of the updated D2D cluster discovery information to the source base station.

10. The apparatus of claim 3, wherein the handover request comprises at least one of the following:

identifier of the source cell, identifier of the at least one member, and the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to;

establish radio configuration for the at least one member to be handed over and indicating the established radio configuration to the at least one member via the D2D cluster head.

11. The apparatus of claim 3, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

perform mode switching for the at least one member of the D2D cluster from a D2D mode to a conventional cellular mode.

12. An apparatus in a source base station (BS), comprising:

at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to;

receive device-to-device, D2D, cluster discovery information from a target BS in a handover process of a plurality of user equipment from a source cell to a target cell, wherein the D2D discovery information indicates discovery of at least one predetermined user equipment connected to the target cell and the predetermined user equipment acts as a D2D cluster head controlling a corresponding D2D cluster; and

transmit the D2D cluster discovery information to the plurality of user equipment currently connected to the source cell.

13. The apparatus of claim 12, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

receive a request from the target BS to select at least one user equipment of the source cell to act as a D2D cluster head;

select the at least one user equipment of the source cell on the basis of selection criteria, wherein the selection criteria are obtained from the target BS; and

perform a handover of the selected at least one user equipment from the source cell to the target cell before the handover of the plurality of user equipment.

14. The apparatus of claim 13, wherein the selection criteria comprises at least one of the following with respect the to-be-selected at least one user equipment:

an identifier, required capabilities, a required priority status, required active service types, a required target cell downlink measurement result.

15. The apparatus of claim 12, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

keep a backhaul connection active after radio services to the user equipment of the source cell has been switched off; and

utilize the backhaul connection for routing data between the target cell and core network.

16. An apparatus at a user equipment for a group handover, comprising:

at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to;

receive an indication to act as a device-to-device, D2D, cluster head controlling a D2D cluster from a base station (BS);

receive D2D cluster discovery information enabling transmission of a discovery signal corresponding to the D2D cluster from a base station (BS);

transmit the discovery signal according to the received D2D cluster discovery information in order to allow other user equipment to discover the D2D cluster;

receive D2D cluster-specific radio resource commitment information determined by a target BS in a handover process of a plurality of user equipment from a source cell to a target cell;

perform admission control for the user equipment trying to access the D2D cluster on the basis of the received D2D cluster-specific radio resource commitment information; and

transmit a handover request to the target BS regarding a handover of at least one member of the D2D cluster from the source cell to the target cell.

17. The apparatus of claim 16, wherein the D2D cluster-specific radio resource commitment information defines at least one of the following:

a maximum number of user equipment acceptable by the D2D cluster, a maximum bit rate guaranteed by the D2D cluster, a list of identities that the D2D cluster head is allowed to allocate to a user equipment joining the D2D cluster.

18. The apparatus of claim 16, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

allocate an identifier to each user equipment joining the D2D cluster from a set of predetermined identifiers acquired from the target base station.

19. The apparatus of claim 16, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

detect that the indicated D2D cluster-specific radio resource commitment is fully utilized; and

restrain from the transmission of the discovery signal.

20. The apparatus of claim 16, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

transfer at least part of the contexts of the user equipment associated with the handover request to the target base station.