Hierarchical management protocol for constructing a QoS communication path in wireless Ad Hoc networks

An Ad Hoc network consists of mobile hosts that can dynamically construct a wireless network without base stations. Due to the limited communication range, a source host usually needs other hosts to relay messages to the destination in a multi-hop manner. Consequently, establishing a routing path from the source to the destination is a basic requirement for providing communication service between any pair of mobile hosts. This study proposes a two-level management approach for efficiently constructing and maintaining a QoS routing path in Ad Hoc wireless networks, significantly reducing the quantity of control packets. In the first phase, the mobile hosts are partitioned into a number of complete graphs, each represented by a Supernode managed by an agent. The Ad Hoc network topology is thus transformed to an Agent-based Graph (AG). In the second phase, some agents of a larger degree than neighboring agents are selected as core nodes. The core nodes then virtually construct a Core Graph (CG). The proposed two-level hierarchical management and bandwidth-looking-ahead technologies can efficiently establish and maintain a QoS communication path at a low control packet cost. Simulation results indicate that the proposed management model significantly reduces the number of control packets in areas with very large numbers of mobile hosts. (C) 2007 Elsevier Inc. All rights reserved.