针对当前实时通信系统尚未实现PC到3G手机视频通信的现状,利用普通3G modem卡开发了从IP核心网到香港WCDMA标准3G无线网的网关.设计了一种简化的SIP协议,实现了由PC到3G手机的实时语音和视频通信.运行结果表明,通信质量满足多媒体会话的要求.
In today's realtime communication systems, direct video communications between personal computers (PCs) and the third generation (3G) mobile phones are still not available. In this paper, we use simple 3G modem cards to design and implement a gateway from IP core network to Wideband Code Division Multiple Access (WCDMA) 3G mobile network in Hong Kong. A simplified Session Initial Protocol (SIP) is designed to implement realtime video and voice communications between PCs and 3G mobile phones. By a series of experiments, we testify the efficiency and robustness of the proposed realtime multimedia system.