DHT-based localized service discovery in wireless mesh networks

Abstract

Wireless mesh networks (WMNs) provide high-bandwidth wireless network access to mobile clients in extensible, robust multi-hop networks. WMNs support distributed service provision and data storage, catering to the advanced capabilities of current mobile devices. Services and data discovery using undirected broadcast or multicast messages, as in traditional discovery protocols, significantly harms network performance due to interference and collisions. In contrast, distributed hash tables (DHTs) offer consistent mapping of service and data identifiers to the providing devices and therefore allow a directed unicast discovery and access. However, traditional DHTs place identifiers at arbitrary distant devices in the network, resulting in frequent use of long multi-hop routing paths. Such multi-hop transmissions suffer from performance loss at each hop and also degrade the overall network performance. We propose DLSD, a DHT-based localized index structure that establishes a hierarchy of locally bounded address spaces ranging from a few nearby devices to the whole network. Iterating through this hierarchy bottom-up allows devices to find the most local provider of the requested item, thereby minimizing multi-hop transmissions while ensuring global reachability. Through this reduction of routing hops, we maintain high transmission performance and minimize interference in the network. We evaluate the feasibility of our approach and show that it significantly reduces routing overhead and outperforms traditional service discovery and DHT approaches.