Hybrid landmark routing in ad hoc networks with heterogeneous group mobility

Scalability is an important consideration in the design any large network. In ad hoc networks, scalability is particularly critical as node mobility imposes additional challenges to growth. For example, frequent updates required by mobility make the conventional proactive routing protocols unable to work in large mobile ad hoc networks. Traditionally, node mobility in a wireless ad hoc network is viewed as the superposition of individual, dependent random moves of each node. In reality, mobile users tend to exhibit some kinds of collective group mobility patterns especially when the network size grows large. In fact, group mobility has been exploited to improve the scalability of network protocols such as routing. For example, LANMAR routing uses mobile groups the basis of hierarchical network architecture. However, the original LANMAR routing assumes that ALL nodes move in groups (e.g. homogeneous group mobility), which is quite unrealistic. In general, moving teams do coexist with individual roaming nodes creating what may be called heterogeneous group mobility scenarios, this paper, we propose a hybrid landmark routing (hybrid LANMAR) scheme which takes advantages of group mobility to improve network scalability, while at the same time supporting individual mobility efficiently. Mobile groups are explored following way similar to LANMAR routing and individually moving nodes e handled in an on-demand fashion. In this way, we gracefully integrate advantages of both proactive and on-demand routing. Simulation results show that hybrid LANMAR can greatly improve network scalability in heterogeneous motion scenarios.