Abstract

Ad hoc and multihop wireless networks are becoming increasingly important for a variety of applications ranging from tactical military networks, to metro area WiFi networks, to sensor applications. Multihop wireless is motivated by the fact that many embedded wireless devices are power-limited and cannot communicate directly with a distant base station or access point. In addition, ad hoc network formation is motivated by mobile service scenarios, such as tactical or vehicular. Protocol design considerations are given for both mobile ad hoc network (MANET) and static (planned) mesh network scenarios. These include self-organization, resource discovery, medium access control, and routing. Existing routing protocols for MANETs, including Destination Sequenced Distance Vector (DSDV), Dynamic Source Routing (DSR), and Ad hoc On-demand Distance Vector (AODV), are described and performance comparisons are given. More recent work on cross-layer mesh-routing protocols is introduced, including cross-layer metrics such as Airtime or PHY/MAC Awate Routing Metric for Ad hoc networks (PARMA), as well as Integrated Routing and Medium Access (IRMA) control. The chapter concludes with implications for future IP protocols that would allow for seamless integration of multihop wired and wireless networks.

Introduction and Motivation

Wireless ad hoc and mesh networks have been an important research area for about two decades. Research topics like the network architecture and design, integration with TCP/IP, routing, and medium access control in the shared wireless medium have been discussed at length. However, the mobile and dynamic nature of the network introduces new challenges in self-organization, including neighbor and topology discovery, network management, and disconnected operation.