A Resource-Management System for Transmission Enhancement and Channel Diversity Exploitation in Wireless Mesh Networks

Abstract

Wireless Mesh Networks (WMN) have been in the focus of extensive research for more than one decade now. However, with a growing network size, routing behavior and performance become unpredictable and less reliant on longer multi-hop routes. The result is insufficient transmission capacity. In addition, vertical traffic lacks protection against horizontal traffic. These flaws threaten to create acceptance of this technology among professionals. Mesh nodes equipped with multiple WirelessLAN interfaces may significantly improve these conditions, along with hardware investments in an economically sustainable range; a fact which created much attention in the research community. Based on recent findings on multi-interface WMN design, the presented work describes the next steps towards an efficient resource management. If non-overlapping channels are used for communication, the system enables an optimal usage of the 802.11 spectrum on layer 2. To manage bundles of multiple WLAN links between mesh neighbors, a modified node architecture and a novel middle-layer software module have been created. Hop-to-hop load balancing in a bundle is included in each node. Packet scheduling is performed based on a set of pre-defined load balancing modes. These modes introduce awareness of current network conditions and cover a wide variety of requirements on mesh networks; from improved performance to robustness. Further inspiring technologies, like layer 2 forwarding and hop-top-hop priority queuing, have been tailored in the novel architecture. The achieved result is a flexible, multi-purpose platform, ranging from a commercially oriented mesh backbone to spontaneously set up emergency networks. A homogeneous mesh backbone is investigated and studied as the object of research, to which clients on lower levels can connect to. A set of simulator-driven measurements outline the effectivity of the multi-interface system.