Design And Implementation Of Soft Terminal’s Flow Control Function Based On Multi-Connection

With the development of network technology, on the one hand, an increasing number of terminal devices (such as smart phones, tablet PCs, laptops, etc.) can simultaneously support2G,3G and Wi-Fi networks; on the other hand, with the rapid growth of multimedia network applications, network resources has been unable to meet users’demand for network bandwidth.In order to improve the efficiency of data transmission, make full use of network resources, concurrent multi-connection between terminals has become the focus of attention in recent years. By using multiple network interfaces to achieve multi-connection technology has been proven to be an effective way to solve the problem of insufficiency of network bandwidth, to improve network throughput and transmission efficiency. This article is about the design and implementation of traffic transmission based on multi-connection technology.Within existing concurrent multi-connection technologies, most of them are improved or implemented based on transport protocols such as SCTP and TCP, meanwhile key technology is load balancing on multi-connections and congestion control on a single connection. But reliable transmission, requirements on retransmission of packet loss based on SCTP and TCP is not suitable for real-time audio and video streams scenarios. On the one hand, real-time stream media’s features are:data is dynamic, the size cannot be predicted in advance; high requirements on transmission delay and jitter; large amount of data decides high requirements on network throughput; allow a small amount of mass loss in the context of without affecting experience; on the other hand, they didn’t take connections’different properties and dynamic changes over time into account.The purpose of this paper is to design and implement concurrent multi-connection transmission technology under the environment of stream media applications. This paper is the study of concurrent multi-connection transport mechanism based on RTP, RTCP, UDP, with taking characteristics of stream media as well as dynamic changes about QoS of each connection into account, we propose a framework about multi-connection real-time stream media transmission, implement functions of multi-connection quality assessment, traffic scheduling allocation and congestion control, to maximize aggregate effective bandwidth of multiple networks, dynamically adjust transmission of each connection, improve the utilization of available bandwidth of each connection. In order to verify the validity, this paper uses simulation tool NS2to simulate modified protocol, compare and analyze differences in terms of throughput, delay and other performance indicators under multi-connections and a single connection. Finally, this paper is summarized and proposed thesis work areas for improvement.