中文摘要：

针对多速率拥塞控制中存在的周期性丢包、拥塞响应速度缓慢等问题，提出基于延时抖动趋势的分层组播方案LM-DJT。该方案通过延时抖动趋势来推测当前网络状况，使接收端能够对网络拥塞进行早期检测，并将其引入到改进的TCP吞吐量公式中，用以估计当前传输路径的可用带宽，并据此进行相应的层次订阅调整。仿真实验表明LM-DJT能很好地适应网络环境的异构性，在保证带宽公平分配的情况下，具有较快的收敛和拥塞响应速度，引入较少的丢包。

英文摘要：

Layered multicast is a promising solution to address the problem ofmulticast congestion control in heterogeneity network. However, schemes using this solution suffer from slow response time and lack of fairness, and induce a lot of loss by slow response and failed join experiments. In this paper we propose a new layered multicast based on delay-jitter trend （LM-DJT）. LM-DJT introduces the delay-jitter trend model into an amended TCP throughput equation to estimate the TCP-friendly transmission rate, and each receiver adjusts its subscription layers according to the estimated transmission rate. Our simulation results show LM-DJT converges fast to the optimal layer of subscription, induces less loss to track the available bandwidth, and has inter-session fairness and TCP-friendliness.