ITR: Collaborative Research: Optimization and Integrated Control of Low Power Wireless Multimedia Networks

ITR：协作研究：低功耗无线多媒体网络的优化和集成控制

• 批准号: 0082064
• 负责人: Mary Irwin
• 金额: $ 49.86万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0082064&HistoricalAwards=false
• 关键词: ITR; Collaborative; Research; Optimization; Integrated

Recent years have seen an explosive growth in the number of multimedia devices and communication tech-nologies. While these multimedia technologies still depend on wireline links, the future of multimedia com-munication is in wireless. Mobile multimedia networks will provide seamless communication between roam-ing users. Applications such as video conferencing or internet access will become available from any where in the world. Widely varying classes of network traffic (traffic heterogeneity) that change over time will be generated by multimedia applications. The network itself will consist of both wireline and wireless links (network heterogeneity). We are already beginning to feel this change.A major constraint in multimedia wireless technology is the limited power budget. Mobile devices such as laptops and personal digital assistants have limited battery life. The re-chargeable battery technology has resulted only in a small increase in battery efficiency. So, it is important to optimize network protocols for minimum power to ensure the continued growth of wireless based multimedia communication. Many attempts have been made towards this goal at individual layers of the network protocol stack. Most of these efforts have concentrated only at the physical and link layers. In this proposal, we deal with the wireless network protocol stack as a whole and provide a unified framework to optimize both computation and transmission power at various layers of the protocol stack. A power manager serves as the central core of our framework. Thedifferent layers of the protocol stack communicate with each other through the power manager that makes adaptive policy decisions based on the network, traffic, and power limitations. This is a uniqueness of the proposal. In the conventional model, the network layers have minimal or no communication at all leading to poor performance compared to the proposed framework. The proposed methods strive to optimize the quality of service (QoS) with minimum power consumption at the mobile wireless nodes. Towards achieving our objectives we consider the following research issues :Adaptive source coding and modulation strategies at the physical layer that minimize power for a desired reliability. The adaptation is done based on channel state estimates produced by the link layer.New error-resilient coding methods that do not have the drawbacks of the conventional forward error correcting codes. Little overhead, graceful degradation, and simple encoding and decoding that reduce the power requirements for computations are the main strengths of the coder. The coders are especially well-suited for state-of-the-art compression standards like JPEG, MPEG, and H.263. Radically different on-line channel state estimators are also proposed.Power-aware transport control protocols that distinguish between various channel and battery state.Application layer adaptation mechanisms to conserve power. The mechanisms use techniques from networking and signal processing areas to improve the performance.Adaptive power manager (integrated controller) policies that control the entire wireless network from a global point of view. Reliability, bandwidth, robustness and power considerations are taken into account for policy decisions.A simulation framework to experiment with different hardware configurations and network topologies and constraints. The developed framework will be help to validate and update our theories. This tool that will be made available through the web will be invaluable for other researchers in designing future energy-efficient wireless multimedia systems.

近年来，多媒体设备和通信技术融合的数量爆炸性增长。 尽管这些多媒体技术仍然取决于有线链接，但多媒体communication的未来是无线的。移动多媒体网络将在漫游用户之间提供无缝的通信。视频会议或互联网访问等应用程序将从世界上的任何地方获得。多媒体应用程序将生成随着时间的变化而变化的网络流量（流量异质性）的广泛不同的类别。网络本身将包括有线和无线链接（网络异质性）。我们已经开始感受到这种变化。多媒体无线技术的主要限制是有限的功率预算。笔记本电脑和个人数字助手等移动设备的电池寿命有限。可重新电的电池技术仅导致电池效率的提高较小。因此，重要的是优化网络协议以确保基于无线的多媒体通信的持续增长。在网络协议堆栈的各个层中，已经对此目标进行了许多尝试。这些努力中的大多数仅集中在物理和链接层上。在此提案中，我们整体上处理了无线网络协议堆栈，并提供了一个统一的框架，以优化协议堆栈各个层的计算和传输功率。电力经理是我们框架的核心核心。协议堆栈的各个层次分别通过电力管理器相互通信，该电力管理器会根据网络，流量和电源限制做出自适应政策决策。这是该提议的独特性。在常规模型中，与提议的框架相比，网络层的通信范围很少或根本没有导致性能差。提出的方法努力优化移动无线节点的最低功耗，以优化服务质量（QoS）。 为了实现我们的目标，我们考虑以下研究问题：在物理层处的自适应源编码和调制策略，以最大程度地减少所需可靠性的功率。改编是基于链接层产生的通道状态估计进行的。新的错误 - 弹性编码方法没有常规正向错误纠正代码的缺点。降低计算功率要求的几乎没有开销，优雅的降级以及简单的编码和解码是编码人员的主要优势。编码人员特别适合JPEG，MPEG和H.263等最新的压缩标准。还提出了截然不同的在线通道状态估计量。具有区分各种通道和电池状态的功率感知传输控制协议。应用层适应机制以节省功率。这些机制使用网络和信号处理区域中的技术来改善性能。自适应电源管理器（Integrated Controller）策略，从全局的角度控制整个无线网络。在政策决策中考虑了可靠性，带宽，鲁棒性和权力注意事项。一个模拟框架，试验不同的硬件配置以及网络拓扑和约束。开发的框架将有助于验证和更新我们的理论。将通过网络提供的该工具对于其他研究人员设计未来的节能无线多媒体系统将是无价的。