Method of accomplishing handover of packet data flows in a wireless telecommunications system

• US 6,466,556 B1
• Filed: 12/16/1999
• Issued: 10/15/2002
• Est. Priority Date: 07/23/1999
• Status: Expired due to Term

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Boudreaux, Paul H.
• Primary Examiner(s): Kincaid, Lester G.
• Application Number:
  US09/464,316
• Time in Patent Office: 1,034 Days
• Field of Search: 370/331, 370/332, 370/355, 370/389, 370/400, 370/401, 370/395, 370/396, 370/397, 370/390, 455/432, 455/435, 455/436, 455/438, 455/442, 455/445, 455/455, 455/426
• US Class Current: 370/331
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node

Abstract

A method of controlling handover of real-time packet data flow within a wireless telecommunications system packet domain without disrupting communication between user equipment and the anchor packet gateway. In a preferred embodiment, the wireless telecommunications system includes user equipment such as a wireless telephone, a serving wireless gateway, a drift wireless gateway, and an anchor packet gateway. Once it is determined that handover of real-time packet data flow is needed, the drift wireless gateway is prepared to become the serving wireless gateway. The anchor packet gateway is then prepared for serving wireless gateway relocation by having the anchor packet gateway initiate bicasting of downlink packet data flow. Uplink and downlink packet data flows are then monitored at the drift wireless gateway and the drift wireless gateway and the serving wireless gateway are synchronized for relocation. The drift wireless gateway is then utilized as the new serving wireless gateway.

Claims

1. A method of controlling handover of real-time packet data flow within a wireless telecommunications system packet domain featuring user equipment, a serving wireless gateway, a drift wireless gateway, and an anchor packet gateway without disrupting communication between said user equipment and said anchor packet gateway, said method comprising:

(a) preparing the drift wireless gateway to become the serving wireless gateway;

(b) preparing the anchor packet gateway for serving wireless gateway relocation by having said anchor packet gateway initiate bicasting of downlink packet data flow;

(c) monitoring uplink and downlink packet data flows at the drift wireless gateway and synchronizing the drift wireless gateway and the serving wireless gateway for relocation; and

(d) utilizing the drift wireless gateway as a new serving wireless gateway.

2. The method as recited in claim 1, wherein the wireless telecommunications system is a universal mobile telecommunications system.

3. The method as recited in claim 1, wherein the wireless gateway is a radio network controller.

4. The method as recited in claim 1, wherein the anchor packet gateway is a gateway general packet radio service support node.

5. The method as recited in claim 1, wherein the user equipment comprises a wireless telephone.

6. The method as recited in claim 1, wherein the user equipment comprises a data processing system.

7. A system of controlling handover or real-time packet data flow within a wireless telecommunications system packet domain featuring user equipment, a serving wireless gateway, a drift wireless gateway, and an anchor packet gateway without disrupting communication between said user equipment and said anchor packet gateway, said system comprising:

(a) means for preparing the drift wireless gateway to become the serving wireless gateway;

(b) means for preparing the anchor packet gateway for serving wireless gateway relocation by having said anchor packet gateway initiate bicasting of downlink packet data flow;

(c) means for monitoring uplink and downlink packet data flows at the drift wireless gateway and means for synchronizing the drift wireless gateway and the serving wireless gateway for relocation; and

(d) means for utilizing the drift wireless gateway as a new serving wireless gateway.

8. The system as recited in claim 7, wherein the wireless telecommunications system is a universal mobile telecommunications system.

9. The system as recited in claim 7, wherein the wireless gateway is a radio network controller.

10. The system as recited in claim 7, wherein the anchor packet gateway is a gateway general packet radio service support node.

11. The system as recited in claim 7, wherein the user equipment comprises a wireless telephone.

12. The system as recited in claim 7, wherein the user equipment comprises a data processing system.

13. A computer program product in computer readable media for use in a data processing system for controlling handover or real-time packet data flow within a wireless telecommunications system packet domain featuring user equipment, a serving wireless gateway, a drift wireless gateway, and an anchor packet gateway without disrupting communication between said user equipment and said anchor packet gateway, said method comprising:

(a) first instructions for preparing the drift wireless gateway to become the serving wireless gateway;

(b) second instructions for preparing the anchor packet gateway for serving wireless gateway relocation by having said anchor packet gateway initiate bicasting of downlink packet data flow;

(c) third instructions for monitoring uplink and downlink packet data flows at the drift wireless gateway and synchronizing the drift wireless gateway and the serving wireless gateway for relocation; and

then

(d) fourth instructions for utilizing the drift wireless gateway as a new serving wireless gateway.

14. The computer program product as recited in claim 13, wherein the wireless telecommunications system is a universal mobile telecommunications system.

15. The computer program product as recited in claim 13, wherein the wireless gateway is a radio network controller.

16. The computer program product as recited in claim 13, wherein the anchor packet gateway is a gateway general packet radio service support node.

17. The computer program product as recited in claim 13, wherein the user equipment comprises a wireless telephone.

18. The computer program product as recited in claim 13, wherein the user equipment comprises a data processing system.

19. A method of providing communications with a mobile station, comprising the steps of:

providing a data packet path from a node to a gateway, wherein said data packet path traverses a first node controller and a second node controller;

sending uplink data packets from said second node controller to said gateway via a radio access bearer connection;

receiving downlink data packets from said gateway to said second node controller via said radio access bearer connection; and

responsive to a request relocate a serving node controller from said second node controller to said first node controller,

duplicating said uplink data packets from said gateway and sending duplicated uplink data packets to said first node controller;

sending said uplink data packets from said first node controller to said gateway;

wherein said gateway marks uplink data packets sent to said first node controller and to said second node controller as duplicates and wherein said first node controller and said second node controller mark said uplink data packets as duplicates;

said first node controller correlates said uplink data packets received from said gateway with said uplink data packets received from said second node controller; and

responsive to a determination that said first node controller is ready to become said serving node controller, refraining from sending uplink data packets from said gateway to said second node controller and refraining from sending said downlink data packets from said first node controller to said second node controller.