Automatic channel assignment and topology optimization in multi-radio wireless mesh networks

1. Motivation and description of demonstrated features Wireless mesh networks, comprised of nodes with multiple radio interfaces, are a promising technology for broadband residential Internet access or to provide connectivity for data transfer. In order to simplify network deployment, auto-configuration procedures that provide automatic network start-up, with minimum manual configuration of nodes, are increasingly important. In order to maximize the utilization of radio resources, efficient algorithms to select the optimal channel for the current radio propagation conditions are required. Typically, administrators manually determine the channels according to the measured signal propagation, and manually configure devices. This manual procedure is executed during initial network deployment, and whenever the network is upgraded or extended. The manual procedure requires many hours of human work, hence makes errors very costly. To address this, we have developed algorithms for fully automatic optimization of the channel assignment and topology optimization of the multi-radio wireless mesh networks. These algorithms work jointly with the auto-configuration, to provide fully automatic reconfiguration of the network and optimize the topology when nodes join or leave the network. They provide the network also with self-healing capabilities via automatic reconfiguration in response to errors. We consider a centralized architecture, where all decisions are taken in a central node, the Network Manager. The proposed solution consists of a network management server and agent software running on mesh nodes. The agents on the mesh nodes provide results from neighborhood scanning to the server, and apply the configuration provided by the server. The algorithms developed support two functions: automatic configuration and channel assignment. The auto-configuration allows the mesh nodes to join the network and receive the radio parameters from the Network Manager, and also supports re-configuration of the whole network when a node enters or exits the network, hence supporting self-healing capabilities in the case of node failures. The channel assignment algorithm is executed on the Network Manager. It selects the optimal channels for the interfaces of the mesh nodes. The communication between the mesh nodes and the server is realized using the CAPWAP and DHCP protocols. The channel assignment algorithm can work in two modes: incremental mode, integrated with auto-configuration, when the configuration is set for the nodes joining the network, and optimization mode where the manager initiates the optimization manually, after which the network executes scanning to find the current signal propagation conditions for all links, and reconfigures itself to improve the performance. In …