SDN-Enabling Multihop Wireless Networks

多跳无线网络(MWN)已经在一系列领域建立起来：车载自组织网络、移动自组织网络、无线Mesh网络、无线传感器网络、家庭网络，甚至是蜂窝网络的扩展。节点的协作性质和没有固定的基础设施使它们在需要快速部署、低成本或支持强大移动性的地方非常有吸引力。这种网络的组网协议是基于这样的假设而设计的，即节点需要协作来实现网络范围内的目标，所有节点都参与操作和管理网络。同时，有线网络正经历着向软件定义网络(SDN)的范式转变。SDN提出了一种具有(逻辑上)中央控制器的网络体系结构，该中央控制器收集关于整个网络的信息。该中央实体在整个网络范围内做出有关路由和资源使用的决策。网络路由器和交换机变得简单得多，因此成本也更低。它们由SDN控制器指示如何转发分组，从而不再需要它们参与任何网络范围的决策。其目标是促进新的和创新的服务的引入，简化网络管理，允许更好/更优化地使用资源，并降低提供通信服务的成本。*这种SDN范例与当今MWN中预先采用的分布式网络协议有根本的不同。然而，SDN对于这样的网络也是很有前途的。例如，WMN受到严重的资源限制(带宽、能量等)。具有网络全局知识的中央控制器可以在整个网络范围内优化资源使用。然而，在高延迟、损耗和带宽受限的无线链路上有效地支持这一范例并不是一件容易的事。在我们的研究中，我们正在探索如何在多跳无线网络中最好地部署SDN架构。其关键思想是应用各种集群方法来减少开销、提高响应性并提供健壮性。我们将通过多种方式展示我们提议的设计的优势。我们将应用和评估流行的SDN技术，如流量工程或网络切片。我们还将设计和实施新的全局优化，以应对MWN的独特挑战。*研究成果将简化部署并增加未来MWN的灵活性。它将使我们能够将有线SDN中的许多进步应用于MWN。因此，互联网服务供应商将更容易提供农村网状网络，以便在偏远社区提供互联网接入，或供应商在家庭网络中提供新服务。此外，通过SDN管理MWN将使电信公司更容易将其作为接入网络与类似基于SDN的下一代核心网络整合。*

Multihop wireless networks (MWNs) have established themselves in a range of domains: vehicular ad-hoc networks, mobile ad-hoc networks, wireless mesh networks, wireless sensor networks, home networking, or even as extensions in cellular networks. The co-operative nature of the nodes and the absence of a fixed infrastructure make them very attractive where fast deployment, low cost, or support for strong mobility is required. Networking protocols for such networks have been designed with the assumption that nodes need to co-operate to achieve network-wide goals, with all nodes involved in operating and managing the network.******At the same time, wired networks are seeing a paradigm shift towards Software-Defined Networking (SDN). SDN proposes a network architecture with a (logically) central controller that collects information about the whole network. This central entity makes network-wide decisions about routes and resource usage. The network routers and switches become much simpler and consequently cheaper. They are instructed by the SDN controller how to forward packets, removing the requirement for them to be involved in any network-wide decisions. The goal is to facilitate the introduction of new and innovative services, to simplify network management, to allow for better/more optimized use of resources, and to reduce the costs of offering communication services.******This SDN paradigm is fundamentally different from the distributed network protocols prelevant in today's MWNs. However, SDN is quite promising for such networks as well. WMNs, for example, are severely resource-limited (bandwidth, energy, etc.). The central controller, having global knowledge of the network, can optimize resource usage network-wide. Yet efficiently supporting this paradigm over high-latency, lossy, and bandwidth-constrained wireless links is not trivial. In our research, we are exploring how to best deploy the SDN architecture in multihop wireless networks. The key idea is to apply various clustering approaches to reduce overhead, improve responsiveness, and provide robustness. We will demonstrate the advantages of our proposed designs in a number of ways. We will apply and evaluate popular SDN techniques such as traffic engineering or network slicing. We will also design and implement new global optimizations that address the unique challenges of MWNs.******The research outcomes will simplify the deployment and increase the flexibility of future MWNs. It will enable us to apply many of the advances made in wired SDNs to MWNs. As a result, it will become easier for ISPs to offer rural mesh networks that provide Internet access in remote communities or for vendors to offer new services in home networks. Furthermore, managing MWNs via SDN will make it easier for telcos to integrate them as access networks with next-generation core networks that are similarly based on SDN.***