Efficient RTSP-based multiple buffering and packet transmission methods for delivering OMA PoC Box service

OMA (Open Mobile Alliance) PoC (Push-to-talk over Cellular) integrates group voice-video communications, internet services, and multimedia services for use at terminals. It allows the use of PoC Box for users who cannot participate in PoC sessions for a variety of reasons such as absence, emergency situations, and battery discharge. The PoC standard recommends that RTSP (Real Time Streaming Protocol) be used when media is transmitted from a PoC Box to a PoC terminal. While for a RTSP-based VOD service a large packet size is used to take advantage of fast wired networks, a RTSP-based transmission method that takes into account the nature of wireless communication environments is needed for the PoC service. To enable a user to effectively access important information in in-transit media via playback control and to reduce playback delay, this paper proposed buffering and packet transmission methods, the performance and adequacy of which were verified through testing. The buffering methods are Alternating Double Buffering, Advance Partition Multiple Buffering, and On-Demand Multiple Buffering, while the packet transmission methods are Same-Priority Packet Transmission and Priority-based Packet Transmission.