NeTS-NBD: Network Coding-Based Protection

网络生存性是网络运营商必须提供的一项重要要求。一般来说，生存性技术试图实现两个目标，即增加(A)检测故障并从故障中恢复的敏捷性和(B)资源效率。然而，这两个目标在大多数情况下是相互矛盾的，很难同时实现。这主要是因为灵活性需要使用昂贵的预配置保护电路，而工作连接无法使用这些电路。在本项目中，将使用网络编码来提供保护，以实现满足上述两个目标的可生存网络运行。具体地，预配置的保护电路将由多个连接共享，其中所有这样的连接同时在共享电路上传输它们的信号。其中信号在传输之前被组合的网络编码避免了信号之间的竞争和冲突，同时提供信号的备份副本，使得如果发生故障，可以容易且即时地从组合的信号中提取信号。本项目的目的是建立利用网络编码通过保护来支持可生存网络运营的理论和技术。在对网络编码下的网络生存性问题进行了严格的描述后，介绍了单链路故障下网络编码的网络保护理论。然后，该理论将被扩展到也处理多个链路和/或节点故障的情况。将针对特定类型的网络连接开发更强大的结果。然后将该理论应用到有线和无线网络中，在不同的层使用不同的协议来开发基于网络编码的保护的实现策略，该项目的智力优势在于将为使用网络编码以灵活、资源高效的方式支持保护提供理论基础，并介绍基于网络编码的保护的实现方法。这项研究的更广泛的影响是，它将为基于网络编码的生存性提供一种总体方法，该方法将扩展和应用于多种网络环境。私人投资促进机构预期，网络设备制造商将考虑采用已开发的技术，以便在其设备中采用，网络运营商将考虑在其网络中使用，因为这种方法将提供成本效益、敏捷性和灵活性。该项目还将在一个新的研究领域培训研究生，并探索网络编码新技术的新应用。

Network survivability is an important requirement that must be provided by network operators. In general, survivability techniques attempt to achieve two objectives, namely increasing (a) the agility of detecting and recovering from failure and (b) resource efficiency. However, these two objectives are in most cases contradictory and are difficult to achieve simultaneously. This is mainly because agility requires the use of expensive pre-provisioned protection circuits, which cannot be used by working connections.In this project, network coding will be used to provide protection as a means of achieving survivable network operation that satisfies the above two objectives. In particular, pre-provisioned protection circuits will be shared by multiple connections where all such connections transmit their signals simultaneously and on the shared circuits. Network coding, where signals are combined before transmission, avoids the contention and collision between the signals, while simultaneously providing backup copies of the signals such that if failures take place, the signals can be easily and instantaneously extracted from the combined signals. The purpose of this project is to establish the theory and techniques for using network coding to support survivable network operation through protection. After rigorously formulating the problem of network survivability under network coding, a theory for network protection using network coding under single link failures will be introduced. The theory will then be extended to also handle the cases of multiple link and/or node failures. Stronger results for specific types of network connections will be developed. The theory will then be applied to develop implementation strategies for network coding-based protection for wireline and wireless networks, using different protocols at different layers.The intellectual merit of this project is that it will provide the theoretical bases for the use of network coding to support protection in an agile, and resource efficient way, and will also introduce implementation methods for network coding-based protection. The broader impact of this research is that it will provide an overarching approach for network coding-based survivability, which will extend and apply to several networking environments. The PIs expect that the developed techniques will be considered by network equipment manufacturers for adoption in their equipment and by the network operators for use in their networks, as this approach will provide cost efficiency, agility and flexibility. The project will also train graduate students in a new area of research, and in exploring novel applications of the new technique of network coding.