The characterization of mobility and its effect on wireless ad hoc network protocols

A Mobile Ad hoc Network (MANET) is a collection of wireless nodes communicating with each other without any infrastructure. Among other impacting factors, mobility plays an important role in determining the protocol performance in MANET. To study the impact of mobility on performance of Mobile Ad Hoc Network (MANET) routing protocols in a systematic way, we propose the IMPORTANT (Impact of Mobility Patterns On Routing proTocol in the mobile Ad hoc NeTworks) framework.; In this framework, mobility is viewed as a multi-dimensional evaluation space, with each dimension to represent a specific mobility characteristic. Various protocol independent metrics are proposed to capture interesting mobility characteristics of mobility space and connectivity graph. By using a rich set of parameterized mobility models (including Random Waypoint, Random Walk, Reference Point Group Mobility, Freeway, Manhattan and City Section models), several 'test-suite' scenarios are chosen carefully to span the mobility space.; We demonstrate the utility of our test-suite by evaluating various MANET routing protocols, including traditional routing protocols (DSR, AODV and DSDV) mobility-assisted protocol (MAID). For traditional protocols, our results show that the protocol performance may vary drastically across mobility models. This effect is explained by the interaction of the mobility characteristics with the connectivity graph properties (link duration and path duration), in both a qualitative way and a quantitative way. We also attempt to decompose the protocols into mechanistic "building blocks" to gain a deeper insight into the performance variations across protocols in the face of mobility. For mobility-assisted protocol, the results indicate that the protocol performance at transitional state is significantly affected by mobility while the protocol performance at steady state is less sensitive to the underlying mobility. This phenomenon is also explained by the interaction of mobility characteristics with the connectivity graph properties (characteristics of age gradient tree).; Via these two case studies, we believe that IMPORTANT framework is a generic framework to evaluate the protocol performance for different MANET routing protocols with different mechanisms. I wish that the deep understanding of mobility gained in this thesis could help in designing efficient protocols for the wireless networks of the future.