HAP: a heterogeneous ad hoc protocol

Ad hoc wireless networks are becoming an important infrastructure for developing networking applications due to their decentralized nature, improved scalability as compared to wireless managed networks, minimal configuration and fast deployment. However, such networks show several limitations regarding their capacity and are, in general, impractical for stand alone commercial applications; in fact, such networks are mostly used for emergency applications. However, the features of ad hoc networks can be useful to extend the connectivity of wireless networks, while taking into account node mobility. In this paper we propose a Heterogeneous Ad hoc Protocol (HAP), which aims to extend the connectivity of a wireless networks. HAP is a cross layer protocol that operates on the link, MAC, and network layers, which takes into account the impact of the mobility on each of these layers. The objective of HAP is thus to overcome limitations of existing protocols, especially regarding mobility. HAP can be useful for developing applications in pedestrian and community networks.Peer ReviewedPostprint (published version

Topology Control in Heterogeneous Wireless Networks: Problems and Solutions

Previous work on topology control usually assumes homogeneous wireless nodes with uniform transmission ranges. In this paper, we propose two localized topology control algorithms for heterogeneous wireless multi-hop networks with nonuniform transmission ranges: Directed Relative Neighborhood Graph (DRNG) and Directed Local Spanning Subgraph (DLSS). In both algorithms, each node selects a set of neighbors based on the locally collected information. We prove that (1) the topologies derived under DRNG and DLSS preserve the network connectivity; (2) the out degree of any node in the resulting topology by DLSS is bounded, while the out degree cannot be bounded in DRNG; and (3) the topologies generated by DRNG and DLSS preserve the network bi-directionality