Collaborative Research: Systematic Optimization in Wireless Multicasting

合作研究：无线组播系统优化

• 批准号: 0728966
• 负责人: Anthony Ephremides
• 金额: $ 23.4万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-15 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0728966&HistoricalAwards=false
• 关键词: Collaborative; Research; Systematic; Optimization; Wireless

Research AbstractMulticasting, where common information is transmitted from a source to multiple destinations, is the core component of many network applications such as multimedia distribution, information update, group conferencing, etc. Creative encoding of network trac at the intermediate terminals can significantly improve the throughput of a multicast over conventional replicate-and-forward approaches. Due to the open nature of the wireless medium, communication throughput of a wireless link depends on its transmission power and on the interference generated by nearby network terminals. The goal of this research is to develop a systematic framework for maximizing a general multicast utility function via the joint optimization of transmission power, rate, and schedule, within the framework of network coding.The investigators model a wireless ad hoc network by means of a topology graph, which contains point-to-point links and point-to-multipoint hyperarc links with coupled link throughput capacities. Under the assumption of optimal network coding, the research first develops an iterative gradient-steering" optimization framework. A network utility maximization problem is converted to a transmission scheduling problem that maximizes an approximated utility in its gradient direction, coupled with a steering vector update that continuously updates the approximated utility and its instantaneous gradient direction. The research then extends the framework to utility maximization for a network with multiple multicast sessions. Finally, the research develops distributed algorithms to optimize a global utility of a large scale network using local controllers. In addition to the planned research, the investigators will also try to extend the algorithm to ad hoc networks with time varying channels where utility maximization requires efficient exploitation of the channel diversity gain.

研究摘要媒介物是从源传输到多个目的地的共同信息，是许多网络应用程序的核心组成部分，例如多媒体分布，信息更新，小组会议等。在中间终端，网络TRAC的创造性编码可以显着改善与传统重复和前面的方法相比，多播的吞吐量。由于无线介质的开放性质，无线链接的通信吞吐量取决于其传输功率和附近网络终端产生的干扰。这项研究的目的是在网络编码的框架内开发一个系统的框架，通过连接的传输功率，速率和时间表的联合优化，通过连接的传输功率，速率和时间表来最大化一般的多播实用程序功能。研究人员通过拓扑图进行了无线临时网络模型，该拓扑图形图表包括点对点链接，其中包含点对点链接和点对点链接链接，以及与couplaper链接通过coupled链接链接链接。在最佳网络编码的假设下，研究首先开发了一个迭代梯度传动“优化框架”。网络公用事业最大化问题转换为传输调度问题，该问题最大程度地沿其梯度方向近似近似的效用，并连续更新近似的效用效率和其实用方向的转向矢量更新，从而实现了一个近似的效率。多播会议。