System and method for efficient selection of a packet data servicing node

• US 7,599,328 B2
• Filed: 12/27/2005
• Issued: 10/06/2009
• Est. Priority Date: 07/20/2001
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Dommety, Gopal K., Wu, Perng-Hwa A., Padala, Sudhakar R., Wang, Hancang, Ma, Qingming, Nee, Cheng-Lee
• Primary Examiner(s): Nguyen; Brian D
• Application Number:
  US11/319,347
• Publication Number:
  US 20060153129A1
• Time in Patent Office: 1,379 Days
• Field of Search: 370/329, 370/389, 370/356, 370/328, 370/230, 709/225, 709/226, 709/227, 709/229
• US Class Current: 370/329
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04W 36/02 Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 80/10 adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14

Abstract

A data communication system is provided that allows for the efficient management of data communication sessions requested from a plurality of packet data servicing nodes organized in a cluster, each member of the cluster managing a cluster session table which contains data identifying mobile units and packet data servicing nodes which are servicing data sessions with the mobile unit. As a mobile unit moves from one portion of the system to another, a network element will request a data session from a packet data servicing node, the packet data servicing node is then able to access the cluster session table to determine if the data session is already being served by another member of the cluster. If the data session is already in existence, the base station controller will be directed to request a data session from the packet data servicing node which is already servicing that session.

Claims

1. A data communication system, comprising:

a plurality of packet data servicing nodes operable to communicate with each other,

wherein each packet data servicing node is operable to store and manage a cluster session table, each cluster session table comprising a complete list of all presently active data communication sessions managed by the plurality of packet data servicing nodes within a cluster; and

wherein each packet data servicing node is operable to receive a request for a data communication session originating from a mobile unit presently being serviced by one of the plurality of packet data servicing nodes in an existing data communication session, and responsive to the request each packet data servicing node is operable to access its cluster session table to identify the packet data servicing node within the plurality that is presently servicing the mobile unit to service the requested data communication session.

2. The system of claim 1, wherein each packet data servicing node within the plurality is operable to select one of the plurality of packet data servicing nodes to service the data communication session by accessing the cluster session table and using information within the cluster session table to identify the packet data servicing node which is servicing the least number of data communication sessions at that particular time.

3. The system of claim 1, wherein each packet data servicing node within the plurality is operable to generate a message to a base station controller requesting a data communication session, the message comprising an address of an identified packet data servicing node which has been identified by the packet data servicing node transmitting the message through the use of the cluster session table.

4. The system of claim 3, wherein each packet data servicing node within the plurality is operable to use the cluster session table to determine if a requested data session is already being serviced by a different packet data servicing node, and, if so, to direct the requesting base station controller to contact the identified servicing packet data servicing node.

5. The system of claim 1, wherein each packet data servicing node within the plurality is operable to transmit at least a portion of the cluster session table to the remaining packet data servicing nodes within the plurality to allow for a resynchronization of the cluster session tables stored by each member of the plurality of packet data servicing nodes.

6. The system of claim 5, wherein each packet data servicing node within the plurality is operable to transmit at least a portion of its cluster session table on a periodic basis.

7. The system of claim 5, wherein each packet data servicing node within the plurality is operable to transmit at least a portion of its cluster session table when requested by one of the plurality of packet data servicing nodes upon the initialization of the requesting packet data servicing node.

8. A method of managing a data communication session comprising:

receiving a request for a data communication session from a mobile unit at a packet data servicing node;

accessing a cluster session table stored at and managed by the packet data servicing node, wherein the cluster session table comprises a complete list of all presently active data communication sessions within a cluster of packet data servicing nodes including the packet data servicing node receiving the request;

identifying an appropriate packet data servicing node within the cluster that is presently servicing the mobile unit in an existing data communication session to service the requested data communication session; and

transmitting a message to a base station controller requesting the data communication session, the message including an address for the identified appropriate packet data servicing node.

9. The method of claim 8, wherein the step of identifying an appropriate packet data servicing node to service the data communication session comprises the step of identifying a packet data servicing node within the cluster which is already servicing the data communication session by identifying the mobile unit associated with the requested data communication session in an entry within the cluster session table.

10. The method of claim 8, wherein the step of identifying the appropriate packet data servicing node within the cluster comprises the step of identifying using the cluster session table the member of the cluster which is servicing the fewest number of data communication sessions at the time of the request.

11. The method of claim 8, further comprising:

generating a session creation message comprising the identity of the mobile unit requesting the data communication session and the address for the identified appropriate packet data servicing node; and

transmitting the session creation message to the remaining members of the cluster.

12. The method of claim 11, wherein the step of transmitting the session creation message comprises the step of transmitting a plurality of session creation messages on a periodic basis.

13. The method of claim 11, wherein the step of transmitting the session creation message comprises the step of transmitting the session creation message when a predetermined number of the session creation messages have been generated and stored.

14. The method of claim 8, further comprising:

generating and transmitting a packet data servicing node keep-alive message from each member within the cluster to the remaining members of the cluster on a periodic basis such that each member of the cluster monitor the continuing processing capability of each member of the cluster.

15. The method of claim 8, further comprising:

requesting a copy of the cluster session table from each member of the cluster upon the initialization of a member of the cluster.