HFC网络基于裁剪和连续传送次数的Vo IP服务排序分析

Analysis of Clip-Successive Based on Scheduling Algorithm for VoIP Services on HFC Network

在有线电视网络传送数字数据的协议中,DOCSIS 1.1标准定义了5种上传通道服务类型,用以支持有服务质量保证(quality-of-service,QoS)的服务,而UGS/AD服务类型是用来支持含有静音压缩的VoIP服务。根据各个数据流的质量服务参数(QoS parameters),缆线调制解调器终端系统(cable modemterm ination system,CMTS)必须在上传通道中提供适当的带宽给予传送。将VoIP的服务实现于DOCSIS1.1标准的HFC网络上,提出了应用在UGS/AD服务类型应用的语音服务头端排序算法,在无法有效降低包遗失率的情况下,期望能公平地分配语音包的传送机会,使得大多数的通话联机能够有相近的语音质量。

MSCN DOCSIS is the most popular standard among the protocols of digital data-over-cable. DOCSIS v1. 1 defines five types of services in upstream to support services with quality of service （QoS）. UGS/AD is designed to support VoIP （voice over IP） with silence suppression. According to the QoS parameters of each service flow, the cable modem termination system （CMTS） must offer them the available bandwidth to transmit. The focus of the thesis are to implement the VoIP services on the hybrid fiber coaxial （HFC） network with DOCSIS 1.1. It proposes a scheduling algorithm, which is applied to voice services of UGS/AD service type. It expected to assign all the transmission opportunities of voice packets fairly so that most of the call connections could have similar voice quality as we can＇t decrease the packet drop ratio effectively.