Trinh Thi Vu

US Patent:

8457631, Jun 4, 2013

Filed:

May 1, 2007

Appl. No.:

11/743057

Inventors:

Ojas T. Choksi - Farmers Branch TX, US
Ramesh Kalathur - Fairfax VA, US
Trinh D. Vu - Ashburn VA, US

Assignee:

Nextel Communications Inc. - Reston VA

International Classification:

H04W 4/00

US Classification:

4554351, 4554321, 4554322, 4554323

Abstract:

A wireless communications system includes a radio network facilitating wireless communications with a wireless subscriber unit, a dispatch application server providing dispatch communications services to the subscriber unit via the radio network, and an IP Multimedia Subsystem (IMS) infrastructure including a Proxy-Call Session Control Function (P-CSCF) and a Serving-CSCF (S-CSCF). The P-CSCF notifies the dispatch application server of subscriber unit registration events, allowing the dispatch application server to provide dispatch communications services without initiating a separate registration process. Dispatch communications are routed between the wireless subscriber unit and dispatch application server through the P-CSCF, bypassing the S-CSCF of the IMS infrastructure.