Reachability-Based Packet Scheduler of Multipath QUIC for Heterogeneous Mobile Networks

In recent years, we need more bandwidth to enjoy entertainment contents such as video streaming, music and online gaming. To gain enough bandwidth, technologies that combine bandwidth by using multiple interfaces at same time are desired. Multipath transport protocols which combine multiple paths for packet delivery at the transport layer are a promising technology. Such protocols have a mechanism, called “packet scheduler”, to select the interface to send a packet. However, existing studies of the packet scheduler have not explicitly considered the compatibility of mobility with bonding of bandwidth. Therefore, when smartphone users move out of coverage of communication networks such as wireless Local Area Network (LAN) and Long Term Evolution (LTE) by vehicle, packet loss occurs, leading to a decrease of throughput. In this study, we propose a packet scheduler that selects an appropriate communication path so that packets can reach the peer before it moves out of the coverage. Based on routes of a vehicle and the position and communication range of the access point, the time at which a communication path will be lost is predicted. In addition, we employ MPQUIC (Multipath QUIC (Quick UDP Internet Connections)), which is a multipath transport protocol proposed as the extension of QUIC protocol, to reduce the ACK packet loss in multipath communication, and to reduce the time until the starts of retransmission. We evaluated the number of packet losses, the throughput and the time until starts of retransmission using a simulator and show the superiority of proposed method.

大规模低轨卫星互联网传输层关键技术研究与展望

随着卫星技术的发展,低轨卫星网络因其低成本、高容量、低时延等优势正在被越来越多的组织采用,如One Web、Space X等。低轨卫星网络不仅能够提供全覆盖的服务,甚至还能在超远距离数据传输中实现比地面网络更低的延迟。随着卫星星座技术的逐渐成熟,大规模低轨卫星互联网有望为全球用户提供无缝高速互联网接入。在大规模低轨卫星互联网中,传输层协议对于提供高可靠、低延迟的通信服务至关重要。然而,大规模低轨卫星网络的高误码率、星地切换以及频繁的网络拓扑变化等特点,使得传统地面网络传输协议难以满足大规模卫星互联网服务质量要求。因此,开发适用于大规模低轨卫星互联网的新型传输协议机制势在必行。针对大规模低轨卫星互联网新特征与传输服务需求,从传输层协议、拥塞控制算法、传输层编码技术以及多路径传输协议等多个方面,探讨了大规模低轨卫星网络下传输层关键技术发展,分析了当前大规模低轨卫星互联网传输服务面临的主要挑战。将为大规模低轨卫星互联网传输层关键技术的研究提供一定的发展思路与技术参考。

新型互联网多路径传输协议拥塞控制机制分析

新型互联网平台中,WIFI、云计算、4G数据传输体系逐步完善导致网络多路径传输模式的出现,以往TCP模式在各种应用中导致其不能有效建立网络连接,为网络多路径传输造成了阻碍,而多路径传输协议主要是利用资源共享的方式将数据流进行分散控制,从而有效提升网络传输的有效性,文章以多路径传输协议拥塞控制机制为入手点,对网络多路径传输协议的有效应用进行了简单的分析。

多路径传输协议缓存研究分析

首先介绍了MPTCP协议的技术原理,其次对TCP协议和MPTCP协议的缓存大小和吞吐量的关系进行研究分析,根据研究结果提出了一个针对低延时、高带宽场景的缓存数学计算模型,用于计算MPTCP缓存大小,最后设计了一组本地实验和NorNet Core测试床实验进行分析.实验结果表明,根据模型所设计的缓存取值仅为当前Linux内核缓存默认值的一半,大大减少了资源浪费的同时传输也达到了吞吐量的最大值.