Collaborative Research: Design and Restoration Techniques for Fault Tolerant Wireless Access Networks

合作研究：容错无线接入网络的设计和恢复技术

• 批准号: 9980516
• 负责人: David Tipper
• 金额: $ 14.92万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-10-01 至 2004-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9980516&HistoricalAwards=false
• 关键词: Collaborative; Research; Design; Restoration; Techniques

The past decade has seen an increase in the deployment of wireless networks supporting mobile communication and an exponential growth rate in the number of users. The majority of wireless networks function as wireless access networks to provide a means for untethered access to resources that reside primarily in a wired network. Such wireless access networks include analog and digital cellular phone networks, Personal Communication Systems networks, many wireless local area networks, and mobile data services. In general, the novelty of mobility has satisfied users of current wireless access networks, despite the decrease in the quality and scope of service offerings as compared to wireline networks. As ongoing research extends the capabilities of wireless access networks to include multimedia services at higher data rates, an increase in the public's demand for and dependence on mobile services will result. Ultimately, users will demand the same reliable service guarantees, that is characteristic of wireline based telecommunications and data networks. The critical importance of providing communication service in the face of failures has been recognized in the public switched telephone network and a great deal of attention has been paid to making these networks survivable and self-healing. However, little emphasis has been placed on understanding or improving the survivability of wireless access networks. The unique aspects of wireless access networks (e.g., user mobility, wireless channel environment, power conservation, etc.) implies that survivability techniques for wired networks have limited applicability. The objective of this project is to develop a comprehensive treatment of survivability for wirelessaccess networks. The project will have two main thrusts. First is survivable network design and analysis. Techniques for analyzing the survivability of wireless access networks will be developed. This includes identifying metrics that are useful for quantifying mobile network performance during normal and abnormal (failure) operating modes and determining a methodology for estimating the metrics. Given appropriate metrics, wireless access network topology design and capacity allocation algorithms which incorporate survivability strategies will be developed. This includes the cell-site architecture and the topology of the network interconnecting the cells to the fixed infrastructure. Both initial topology design and the problem of modifying an existing topology to improve the survivability will be addressed. Secondly, traffic restoration algorithms will be developed which aim at making the best use of available network resources after a failure. This work will concentrate on the design and analysis of priority based traffic restoration techniques to provide users service continuity while minimizing network congestion. A multi-layer approach involving a coordinated strategy among network layers will be developed. The restoration algorithms will be suitable for automatic invocation by network components, resulting in a self-healing network. Special emphasis will be placed on the analysis of transient network congestion immediately following failures andincorporating its effect into the network design and traffic restoration algorithms. An additional focus will be placed on minimizing the effects of wireless access network failures on the attached wired transport and signaling networks. The work will initially address current wireless access networks (i.e., PCS), but will later address evolving wireless access architectures including mobile data services (e.g., CDPD, GPRS) and next generation systems (e.g., wireless ATM). The research will be conducted using techniques from optimization, queueing and communication theory. Additionally, due to the complexities involved, simulation combined with the use of empirical data and heuristic algorithms will be used. The significance of this research will be its contributions to the limited base of knowledge of wireless access network survivability. The results of the work should benefit the future design and deployment of survivable wireless access networks.

在过去的十年中，支持移动的通信的无线网络的部署增加，用户数量呈指数增长率。大多数无线网络用作无线接入网络，以提供对主要驻留在有线网络中的资源的无限制接入的手段。这种无线接入网络包括模拟和数字蜂窝电话网络、个人通信系统网络、许多无线局域网和移动的数据服务。一般而言，移动性的新奇已经满足了当前无线接入网络的用户，尽管与有线网络相比服务供应的质量和范围有所下降。随着正在进行的研究将无线接入网络的能力扩展到包括更高数据速率的多媒体服务，将导致公众对移动的服务的需求和依赖的增加。最终，用户将要求同样可靠的服务保证，这是有线电信和数据网络的特点。 在公共交换电话网中，已经认识到在故障面前提供通信服务的关键重要性，并且已经对使这些网络能够生存和自愈给予了大量的关注。然而，很少有人把重点放在理解或提高无线接入网络的生存性。无线接入网络的独特方面（例如，用户移动性、无线信道环境、功率节省等）这意味着有线网络的生存性技术具有有限的适用性。 这个项目的目标是开发一个全面的治疗无线接入网络的生存性。 该项目将有两个主要目标。首先是可生存网络的设计和分析。将开发用于分析无线接入网络的生存性的技术。 这包括识别用于在正常和异常（故障）操作模式期间量化移动的网络性能的度量，以及确定用于估计度量的方法。给出适当的指标，无线接入网络的拓扑结构设计和容量分配算法，将生存性策略。这包括小区站点架构和将小区与固定基础设施互连的网络拓扑。初始拓扑设计和修改现有的拓扑结构，以提高生存性的问题将得到解决。其次，将开发流量恢复算法，其目的是在故障后最大限度地利用可用的网络资源。这项工作将集中在基于优先级的流量恢复技术的设计和分析上，以提供用户服务连续性，同时最大限度地减少网络拥堵。将开发一种涉及网络层之间协调策略的多层方法。恢复算法将适合于网络组件的自动调用，从而产生自愈网络。特别强调的是分析故障后的瞬时网络拥塞，并将其影响纳入网络设计和流量恢复算法。另一个重点将放在最大限度地减少无线接入网络故障对连接的有线传输和信令网络的影响。这项工作最初将解决当前的无线接入网络（即，PCS），但稍后将解决包括移动的数据服务（例如，CDPD、GPRS）和下一代系统（例如，无线ATM）。 这项研究将使用优化，优化和通信理论的技术进行。此外，由于所涉及的复杂性，模拟结合使用经验数据和启发式算法将被使用。这项研究的意义在于它的贡献有限的基础知识的无线接入网络的生存性。研究结果对未来可生存无线接入网络的设计和部署具有一定的参考价值。