电信CDMA网语音时延分析和改善措施研究

Analysis and improvement measures on voice delay of China Telecom's CDMA network

主要研究CDMA系统语音时延对用户感知的影响。首先,对CDMA网典型场景下的语音时延进行测试,并把测试结果与GSM,TD-SCDMA,WCDMA和固话等几种系统的语音时延进行比较。其次,重点分析CDMA虚拟网业务时延产生原因,提出2种改善措施:改造C网MSCe与固网SS之间SIP路由直接互通方式和改造SCP及软交换平台以开通IVPN主叫短号一次触发功能。最后,对上述2种改进后的方案进行测试,测试结果反映接续时长和语音时延都得到了较大的改善。

This paper mainly studies the impact of CDMA voice delay on the user perception. Firstly, tests were carried out for various service routing, and at the same time, the voice delay of CDMA is compared with GSM,TD-SCDMA, WCDMA, fixed-line networks. Secondly, analyzes the causes of voice delay in CDMA （ specially the virtual network）, and puts forward two measures of improvement that include adjustment SIP signaling to direct route between CDMA network and fixedline network, and remake of SCP, MSCe platform to achieve the ability of IVPN call on one time trigger. Finally, the 2 improved schemes are examined, the test results reflect that the connect time and the voice delay are all improved.