摘要 IP 组播技术是一种可以把单个数据信息同时分发到不同的用户去的网络技术。卫星网络固有的广播信道特性使得它很适合组播应用。然而目前针对卫星网络的可靠组播服务研究很少，虽然已经有一些关于地面Internet组播协议建议，但他们并不适合于卫星网络。在卫星网络组播传输中的一个关键技术是传输协议设计。该文提出一种基于Agent的宽带卫星网络可靠组播传输协议(ASMTP)。该协议利用接收端Agent来实现卫星组播，采用分组级FEC和本地差错恢复纠正传播中的非相关错误和相关错误。在ASMTP中，还实现了流量控制和拥塞控制机制。仿真结果表明，在卫星网络环境中，ASMTP性能优于MFTP(Multicast File Transport Protocol)，同时具有较好的网络可扩展性。
Abstract：In a wide variety of broadband applications, there is a need to distribute information to a potentially large number of receiver sites that are widely dispersed from each other. Communication satellites are a natural technology option and are extremely well suited for carrying such services because of the inherent broadcast capability of the satellite channel. Despite the potential of satellite multicast, there exists little support for reliable multicast services over satellite networks. Although several multicast protocols have been proposed for use over the Internet, they are not optimized for satellite networks. One of the key multicast components that are affected when satellite networks are involved in the communication is the transport layer. A novel Agent-based Satellite reliable Multicast Transport Protocols (ASMTP) is proposed in this paper for data dissemination over broadband satellite networks. This protocol employs agent in receivers group to implement reliable multicast transport for satellite networks. Packet level FEC and local error recovery are used to recover the correlated and uncorrelated packet losses. Flow and congestion control scheme are deployed also in ASMTP. Performance evaluation by simulations shows that ASMTP generally outperforms MFTP and achieves high scalability.
2007, Vol. 29 
