Efficiency Analysis and Improvement of SIP-based Push-to-Talk over Cellular

“Push-to-talk over Cellular” (PoC) which is wireless technology and is used on mobile telecom network can enable cell phones capability of one-to-many communications, as the walkie-talkie. PoC is a new potential communication service using cellular network without the defect of walkie-talkie limited communication distance. In this paper, the performance of today´s PoC is evaluated, and the results show that senders may not be able to start talking until about six seconds after pushing the talk key. A long waiting time for users will negatively affect the use of PoC. Therefore, a performance improving scheme is presented in our work to reduce waiting time and number of messages for PoC users.