Method and apparatus for handoff of a wireless packet data services connection

• US 20060187883A1
• Filed: 03/27/2006
• Published: 08/24/2006
• Est. Priority Date: 12/06/2000
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rezaiifar, Ramin, Abrol, Nischal
• Granted Patent: US 7,561,555 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04W 40/36 due to handover

Abstract

A novel method and apparatus is disclosed for performing seamless handoff of a mobile station (MS) between Radio Access Networks (RANs) that use different types of wireless interfaces. The described embodiments enable an MS to handoff between different RANs without causing routing ambiguity, and without substantial loss of network data. Upon moving from the coverage area of a first RAN using a first wireless interface to the coverage area of a second RAN using a second wireless interface, an MS determines whether routing ambiguity may result from the change of RAN and, based on the determination, triggers a re-registration of its network address. A foreign agent (FA) within a packet data serving node (PDSN) monitors network address re-registrations in order to determine whether multiple RAN-PDSN (R-P) connections are being created for the same MS. Based on this determination, the PDSN terminates redundant R-P network connections resulting from movement of the MS between different RANs.

Claims

1. In a packet data serving node of a communications network, a method of routing data packets between an IP network and a radio access network comprising:

allocating an IP address to an International Mobile Station Identity (IMSI); and

purging a foreign agent of table entries associating the IP address to other IMSI values.