A Multi-Class Mobility Model for Dynamic and Dependable Systems

The complex interactions inherent in mobile, dynamic systems require a representative model of node movement properties. Dynamic systems proposed within industry, particularly in the military domain, have a requirement for dependable communication and include heterogeneous nodes (varying from personal devices, to aircraft with complex sensors). Existing node mobility models have been found to not be adequate for capturing the properties of these systems due to their tendency to focus on systems with nodes of a single type, or characteristic. In this paper, a Multi-Class Mobility Model (MCMM) is proposed. This is a hybrid, class-based model operating with both single entity and group mobility patterns. Within this model nodes can be specified in a range of classes, based on their movement properties (including acceleration/deceleration factors and maximum speed). Simulation based experimentation implements MCMM, in conjunction with a previously proposed Quality of Service framework. This provides an opportunity to evaluate the mobility model in terms of its affect on system utilisation and stability. Through simulation, MCMM is compared with existing Random Walk/Random Waypoint and Reference Point Group Models. MCMM is shown to offer a more representative node movement, resulting in a comparable and representative system utilisation. This is achieved while offering a more stable system model with less communication disruption due to lost network connections.