Service-features-driven Concurrent Multipath Transmission Scheme In Wireless Networks

In recent years,with the rapid development of wireless access technology,more and more terminal devices are equipped with multiple network interfaces connected to the Internet.Users can utilize multiple network interfaces to get efficient delivery service through bandwidth aggregation.In addition,the rapid development of the Mobile Internet pushes a large number of new services which have emerged with different features,such as real-time streaming media services,etc.However,subject to the limitations of conventional TCP/IP protocol stack layered designing,existing transmission protocols are difficult to get useful information from other protocols,and they can not inspect upper layer service and perceive the features of underlying dynamic network environment.Thus,the transmission performance is impaired and can not satisfy the user's Quality of Experience.To address the aforementioned problems,this dissertation proposes service-features-driven concurrent multipath transmission scheme in wireless networks based on the Multi-path Transmission Protocol(MPTCP).The proposed scheme consists of the following contributions:(1)A scheme for service features perception by perceiving the upper layer service and obtaining service-related features used to guide decision-making of transmission modules;(2)A method for transmission quality assessment based on the features of the upper layer service and the state of transport layer transmission which can be used to assess the real-time transmission quality,and dynamically adjusts the transmission policy based on the transmission quality;(3)A weight-based data scheduling algorithm concerned about two important factors affecting MPTCP transmission performance,including round trip time and packet loss rate,with weight control mechanism to achieve an efficient data scheduling;(4)A packetization algorithm which can dynamically adjust packet size according to the changes in the network environment,in order to reduce the waste of bandwidth resources;(5)Based on the above work,designed a Partially Reliable MPTCP extension(PR-MPTCP),by discarding outdated data to avoid retransmiting invalid packets,while reducing the number of the Head of Line Blocking.This project group cooperated with Huawei and had submitted a draft about PR-MPTCP to Internet Engineering Task Force(IETF).In this dissertation,the popular network simulation software NS-2 was used for effectiveness validation and performance evaluation.Transmission performance of service,including FTP,CBR and RTP-based service,are evaluated.The results demonstrate the proposed schemes can better meet the transmission needs for the different features of services.Through the comparison,RTP-based service can obtain a better playback experience,and FTP and other services can get a higher quality of service(QoS).In addition,the dynamic packetization algorithm can effectively reduce the waste of bandwidth resources.