Patent · US Expired

Mode shifting communications system and method

US7230930B2 · kind B2 · utility

31Cited by
8References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 23, 2004
Grant dateJun 12, 2007
Priority date
Expiry dateMar 23, 2024

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L65/4061
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

A digital network based communications system that establishes communications sessions to communicate via a simulated circuit-switch environment. Exemplary embodiments communicate between a first communications station (104) and a second communications station (106) using Voice over Internet Protocol (VOIP) techniques. Calls are setup (700), maintained and torn down (800) using Session Initiation Protocol and Session Description Protocol messages. Call modes are able to be changed between duplex and simplex without disconnection. Duplex calls are also able to be interrupted with a request for a simplex call. A receiver (104) engaged in a duplex call can receive a request for a simplex call, accept the simplex call or send a response message, and then resume the duplex call, all while maintaining the duplex call data communications session.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.