Handover management using a broadcast channel in a network having synchronized base stations

• US 9,706,369 B2
• Filed: 11/12/2012
• Issued: 07/11/2017
• Est. Priority Date: 11/15/2011
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Dunn, Douglas, Comstock, David, Kalhan, Amit, Chang, Henry
• Primary Examiner(s): Jagannathan, Melanie
• Application Number:
  US14/358,325
• Publication Number:
  US 20140313969A1
• Time in Patent Office: 1,702 Days
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 36/0077 of access information of target access point
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 52/0203 in the radio access network or backbone network of wireless communication networks
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Handovers of mobile wireless communications device from a source base station to a target base station are managed by transmitting handover information over a shared broadcast channel. The handover information required by a mobile wireless communication device for performing a handover may be transmitted within a Multicast Broadcast Multimedia Services (MBfviS) Single Frequency Network (M8SFN) subframe in some circumstances. In one example, the handover information includes Uplink (UL) allocation information, timing advance (TA) information, and a Cell Radio Network Temporary Identifier (C-RNTI), The synchronization between base stations of the MBMS system allows for the elimination of some messaging required in conventional systems for synchronization between the mobile wireless communication service and a target base station. As a result the time for performing a handover is reduced.

Claims

1. A communication network comprising:

a source base station providing wireless communication service to a mobile wireless communication device;

a target base station time synchronized to the source base station and broadcasting, to the mobile wireless communication device, handover information over a broadcast channel shared by the source base station and the target base station, the handover information necessary for the mobile wireless communication device to perform a handover from the source base station to the target base station; and

a position monitor providing position information related to a position of the mobile wireless communication device, the target base station broadcasting the handover information at a time at least partially based on the position information.

2. The communication network of claim 1, wherein the handover information is broadcast within a Multicast Broadcast Multimedia Services (MBMS) Single Frequency Network (MBSFN) subframe.

3. The communication network of claim 2, wherein the handover information comprises uplink signal allocation identifying uplink resources assigned to the mobile wireless communication device.

4. The communication network of claim 2, wherein the handover information comprises a timing advance for use by the mobile wireless communication device to adjust transmission timing of uplink signals such that the uplink signals arrive at the target base station within a desired time window.

5. The communication network of claim 2, wherein the handover information comprises a Cell Radio Network Temporary Identifier (C-RNTI).

6. The communication network of claim 2, the C-RNTI is used by the source base station for communication with the mobile wireless communication device.

7. The communication network of claim 2, wherein the target base station refrains from transmitting a contention resolution message.

8. The communication network of claim 1, wherein the target base station broadcasts the handover information to the mobile wireless communication device in response to receiving a Random Access Preamble message from the mobile wireless communication device.

9. The communication network of claim 8, wherein the target base station refrains from sending a Random Access Response message in response to receiving the Random Access Preamble message from the mobile wireless communication device.

10. The communication network of claim 1, wherein the target base station broadcasts the handover information to the mobile wireless communication device in response to receiving a handover request message from the source base station and receiving a scheduled uplink transmission from the mobile wireless communication device.

11. The communication network of claim 10, wherein the source base station transmits a measurement report request to the mobile wireless communication device and the scheduled uplink transmission is a response to the measurement report request.

12. The communication network of claim 11, wherein the handover request message comprises:

a C-RNTI of the mobile wireless communication device.

13. The communication network of claim 11, wherein the handover request message comprises:

a timing advance currently used by the source base station for communication with the mobile wireless communication device.

14. The communication network of claim 11, wherein the handover request message comprises:

a relative position between a source cell provided by the source base station and a target cell provided by the target base station.

15. The communication network of claim 11, wherein the target base station requests a measurement report from the mobile wireless communication device in response to determining that there are no uplink transmissions scheduled from the mobile wireless communication device during the handover and wherein the measurement report is the scheduled uplink transmission.

16. A mobile wireless communication device comprising:

a receiver configured to receive a Multicast Broadcast Multimedia Services (MBMS) Single Frequency Network (MBSFN) subframe; and

a controller coupled to the receiver, the controller configured to process the MBMS MBSFN subframe, which comprises handover information necessary for the wireless communication device to perform a handover to a base station from another base station, the MBMS MBSFN subframe broadcasted at a time at least partially based on a position of the mobile wireless communication device and over a broadcast channel shared by both base stations.

17. The mobile wireless communication device of claim 16, wherein the handover information comprises uplink signal allocation identifying uplink resources assigned to the mobile wireless communication device.

18. The mobile wireless communication device of claim 16, wherein the handover information comprises a timing advance for use by the mobile wireless communication device to adjust transmission timing of uplink signals such that the uplink signals arrive at the base station within a desired time window.

19. The mobile wireless communication device of claim 16, wherein the handover information comprises a Cell Radio Network Temporary Identifier (C-RNTI).

20. The mobile wireless communication device of claim 16, wherein the mobile wireless communication device receives the MBSFN subframe comprising the handover information without receiving a contention resolution message.

21. The mobile wireless communication device of claim 16, wherein the mobile wireless communication device is configured to transmit a Random Access Preamble message to provide transmission of the handover information.

22. The mobile wireless communication device of claim 16, wherein the mobile wireless communication device is configured to transmit a scheduled uplink transmission and wherein the handover information is broadcast from the base station in response to a handover request message received from the another base station.

23. A base station comprising:

a transmitter configured to transmit a Multicast Broadcast Multimedia Services (MBMS) Single Frequency Network (MBSFN) subframe; and

a controller coupled to the transmitter, the controller configured to process the MBMS MBSFN subframe, which comprises handover information necessary for a wireless communication device to perform a handover to the base station from a source base station, the transmitter configured to transmit the MBMS MBSFN subframe at a time at least partially based on a position of the wireless communication device and over a broadcast channel shared by the base station and the source base station.

24. The base station of claim 23, wherein the handover does not include random access messages.

25. The base station of claim 24, wherein the handover does not include messages related to synchronization.