Method, and associated apparatus, for effectuating handover of communications in a bluetooth, or other, radio communication system

• US 6,834,192 B1
• Filed: 07/03/2000
• Issued: 12/21/2004
• Est. Priority Date: 07/03/2000
• Status: Expired due to Term

• Current Assignee: Terrestrial Comms LLC (IPValuation Partners, LLC)
• Original Assignee: Nokia Corporation
• Inventors: Nguyen, Phong, Sanda, Takako, Watanabe, Fujio
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Ramfuris, Sharad
• Application Number:
  US09/609,632
• Time in Patent Office: 1,632 Days
• Field of Search: 455/444, 455/436, 455/41.2, 455/502, 455/522, 455/437, 370/331, 370/332, 370/336, 370/338
• US Class Current: 455/444
• CPC Class Codes: H04W 36/03 Reselecting a link using a direct mode connection
• CPC Class Codes: H04W 36/035 in self-organising networks
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method, and associated apparatus, facilitates handover of communications with a mobile Bluetooth device operable to communicate packet data with other Bluetooth devices. Handover of communications is effectuated between fixed-infrastructure access points or other mobile Bluetooth devices formed in a scatternet. The device to which communications are to be handed-over becomes a slave to the Bluetooth device with which communications are ongoing, thereby to permit time synchronization thereto.

Claims

1. A method for handing over communications with a mobile communication device (MCD), the MCD initially operable to communicate with a communication network infrastructure via a first piconet prior to handover and with a second piconet after handover, wherein the first piconet comprises a first network access point and the second piconet comprises a second network access point and at least one second-piconet pre-handover slave device, said method comprising:

selecting initiation of handover of communication between the MCD and the network infrastructure via the first piconet to the second piconet responsive to a communication indicia representative of communications with the MCD;

placing the at least one second-piconet pre-handover slave device in a reduced power-level state subsequent to selecting initiation of handover;

causing at least one second-piconet communication device to become time-synchronized with the MCD; and

effectuating communications between the MCD and the network infrastructure by way of the second piconet.

2. The method of claim 1 wherein the second network access point is operating as the second piconet master, and wherein said operation of causing the at least one second-piconet communication device to become time-synchronized comprises the operations of:

making the second network access point a slave to the MCD;

time-synchronizing the slave formed of the second network access point to the MCD.

3. The method of claim 2 wherein said method of causing the at least one second-piconet communication device to become time-synchronized further comprises the operations of:

making the second-piconet pre-handover slave communication device a slave to the MCD; and

time-synchronizing the slave formed of the second-piconet pre-handover slave communication device to the MCD.

4. The method of claim 1 further comprising the operation of ceasing communication between the MCD and the network infrastructure via the first piconet subsequent to effectuating communications by way of the second piconet.

5. The method of claim 1 wherein the communication indicia responsive to which initiation of handover of communications is selected during said operation of selecting comprises signal power levels of signals detected by the MCD when operated in the first piconet.

6. The method of claim 1 wherein the first-piconet comprises at least one first-piconet pre-handover slave device, and further comprising the operation of placing the at least one first-piconet, pre-handover slave device in a reduced power-level state.

7. The method of claim 6 further comprising the additional operation, prior to said operation of causing the at least one second-piconet communication device to become time-synchronized of:

making the first-piconet pre-handover master communication device a slave to the MCD.

8. The method of claim 7 wherein the second second network access point defines a target cell, and wherein said operation of selecting initiation of handover occurs when the MCD enters the target cell.

9. The method of claim 1 wherein the first network access point, the second network access point, and the MCD each comprise a Bluetooth-compatible (BT) device, and wherein said operation of selecting initiation of handover comprises selecting initiation of handover of communications from a first BT piconet to a second BT piconet.

10. The method of claim 9 wherein the second piconet comprises a second-piconet pre-handover slave BT device and wherein, prior to said operation of causing, said method comprises the additional operation of:

placing the second-piconet pre-handover BT slave device in a reduced power-level state.

11. The method of claim 10 wherein the reduced power-level state into which the pre-handover BT slave device is placed comprises a HOLD mode.

12. The method of claim 10 wherein the reduced power-level state into which the pre-handover BT slave device is placed comprises a SNIFF mode.

13. The method of claim 10 wherein the reduced power-level state into which the pre-handover BT slave device is placed comprises a PARK mode.

14. The method of claim 9 wherein each BT device is identified by a temporary identifier selected from a set of temporary identifiers and wherein the reduced power-level state into which the pre-handover BT slave device is placed is a state in which the pre-handover BT slave device is stripped of the temporary identifier.

15. Apparatus for facilitating handing over communications of a mobile communication device (MCD), initially operable to communicate with a communication network infrastructure by way of a first piconet, to communicating with the network infrastructure by way of a second piconet, the first piconet including a first network access point and the second piconet including a second network access point and at least one second-piconet pre-handover slave device, said apparatus comprising:

a handover initiation selector coupled to receive indications of a communication indicia representative of communications with the MCD, said handover initiation selector for selecting initiation of handover of communications from the first piconet to the second piconet responsive to the indications of the communication indicia; and

a time-synchronizer coupled to receive indications of selection by said handover initiation selector of selection of the initiation of handover, said time synchronizer for causing the second network access point to become time-synchronized with the MCD, wherein the time-synchronizer is further for placing the at least one second-piconet pre-handover slave device in a reduced power-level state.

16. The apparatus of claim 15 wherein said time synchronizer makes the second network access point a slave to the MCD and time-synchronizes the slave formed of the pre-handover master device to the MCD.