基于网络编码和多访问点协作的视频多播方案

随着智能手机和平板等无线设备的普及,基于互联网的视频浏览成为无线设备的重要功能。然而,由于无线网络的链路间存在干扰、可靠性较低,为了提高视频多播传输的可靠性,文中分析了覆盖区域发生重叠的访问点间相互协作对于提高系统增益和系统公平性的作用,提出一种基于网络编码和多访问点协作的视频多播方案。该方案首先将每个视频划分为大小相同的报文段,并利用RLNC机制对每个段的报文进行编码。然后以使用户接收到的报文数量的期望值最大化的同时,实现公平调度为目标,考虑了访问点间的完全干扰和非完全干扰两种模型,将访问点间的传输范围发生重叠时的视频多播问题建模为线性规划优化问题,提出了双阶段启发式算法来进行求解,该算法通过利用多个访问点来获取空间和时间分集增益,提高了数据传输的可靠性,通过允许发生干扰的访问点并行传输数据,提高了系统效用。最后的仿真实验也验证了本文方案在接收报文总量、解码报文数量和公平性方面的有效性。

Video Multicast Scheme Based on Network Coding and Coordinated Multiple Access Points

As the popularity of wireless devices(e.g. smartphones and tablets)increases, watching videos over the Internet is becoming a main device application. However, due to the reliability of wireless network links between interference is low, in order to improve the reliability of video multicast transmission, the effect of the access points which coverage area are overlapped use can improve the system gain and system fairness by using mutual cooperation is analysed in this paper, and a video multicast scheme based on network coding and coordinated multiple access points is proposed. In this scheme, each video is divided into the equal size packet segments, and the packets of each segment is coded by the random linear network coding mechanism. And then our goal is to have a fair scheduling that maximizes the expected number of packets that the users receive, Considered the complete interference and the non- complete interference between access points, the video multicast problem when the transmission range overlap occurs is modeled as the linear programming optimization problem, and two-stage heuristic algorithm is proposed to solve this problem, which Through the use of multiple access points to obtain the spatial and temporal diversity gain, improve the reliability of data transmission, and through allow the interference of the access point to parallel transmission of data to improve the system"s effectiveness. Finally, the simulation results verify the effectiveness of the proposed scheme in terms of the total amount of the received packets, the number of decoded packets and the fairness.