Hand-off technique for a wireless network

• US RE43,307 E1
• Filed: 05/07/2009
• Issued: 04/10/2012
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Sliva, Vladimir Petr
• Primary Examiner(s): Ferguson, Keith
• Application Number:
  US12/437,094
• Time in Patent Office: 1,069 Days
• Field of Search: 455436-444, 455/422.1, 455/403, 455/567, 455/500, 455/517, 455/550.1, 455/560, 455/426.1, 455/426.2, 4554321-4323, 455/434, 455/435.2, 455/435.3, 370/331, 370/332, 370/334, 370/328, 370/329
• US Class Current: 455/436
• CPC Class Codes: H04W 36/0005 Control or signalling for completing the hand-off
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node

Abstract

A technique that relates to use of a known messaging sequence, e.g., ISANSWER messaging in the IS-41 protocol, in a heretofore unknown manner to improve hand-off procedures that may be established between a serving (anchor or intermediate) mobile switching center and a target (or border) mobile switching center is provided. Specifically, the ISANSWER message is selectively sent from the serving mobile switching center to the target mobile switching center during the hand-off process. The transmission of the ISANSWER message in this manner allows the target mobile switching center to terminate ring back to a caller when the mobile station answers the call after the handoff has been started, but while the mobile station is still within a cell area of the serving mobile switching center.

Claims

1. A method comprising:

initiating a hand-off procedure for a mobile device migrating between a first mobile switching center and a second mobile switching center;

determining that the hand-off procedure is being attempted during the initiation of a call to the mobile device from an associated communication device;

determining that the mobile device answers the call during the hand-off procedure, the mobile device still being within a geographic area corresponding to the first mobile switching center; and

,

transmitting a message from the first mobile switching center to the second mobile switching center, the message indicating that the call was answered.

2. The method as set forth in claim 1 wherein the initiating of the hand-off procedure includes providing the second mobile switching center with responsibility for providing ring back to the communication device.

3. The method as set forth in claim 1 further comprising receiving a return result in response to the transmitting.

4. The method as set forth in claim 1 further comprising completing the hand-off procedure.

5. The method as set forth in claim 1 wherein the message comprises an facility directive ISANSWER invoke message.

6. The method as set forth in claim 1 further comprising receiving the message.

7. The method as set forth in claim 6 further comprising terminating ring back based on the message.

8. The method as set forth in claim 1 wherein the hand-off procedure comprises hand-back procedures or hand-off to third procedures.

9. A system comprising:

means for initiating a hand-off procedure for a mobile device migrating between a first mobile switching center and a second mobile switching center;

means for determining that a communication device is attempting to establish a call with the mobile device during the hand-off procedure;

means for determining that the mobile device answers the call during the hand-off procedure, the mobile device being within a geographic area corresponding to the first mobile switching center; and

,

means for transmitting a message from the first mobile switching center to the second mobile switching center, the message indicating that the call was answered.

10. The system as set forth in claim 9 wherein the means for initiating the hand-off procedure includes means for providing the second mobile switching center with responsibility for providing ring back to the communication device.

11. The system as set forth in claim 9 further comprising means for receiving a return result in response to the transmitting.

12. The system as set forth in claim 9 further comprising means for completing the hand-off procedure.

13. The system as set forth in claim 9 wherein the message comprises a facility directive ISANSWER invoke message.

14. The system as set forth in claim 9 further comprising means for receiving the message.

15. The method as set forth in claim 14 further comprising means for ending ring back based on the message.

16. The system as set forth in claim 9 wherein the hand-off procedure comprises hand-back procedures or hand-off to third procedures.

17. A system comprising:

a first MSC operative to initiate a hand-off procedure for a mobile device migrating out of a geographic area corresponding to the first MSC, determine that a communication device is attempting to establish a call with the mobile device during the hand-off procedure, determine that the mobile device answers the call during the hand-off procedure while the mobile device is within the geographic area corresponding to the first MSC and transmit a message indicating that the call was answered; and

,

a second MSC operative to receive the message and end ring back based on the message.

18. The system as set forth in claim 17 wherein the first MSC is operative to provide the second MSC with responsibility for providing ring back to the communication device.

19. The system as set forth in claim 17 wherein the message comprises a facility directive message.

20. The system as set forth in claim 17 wherein the hand-off procedure comprises hand-back procedures or hand-off to third procedures.