Modeling of network connectivity in multi-homed hybrid ad hoc networks

A Hybrid Ad Hoc Network consists of self-organized and self-configured mobile nodes, which make use of a fixed gateway to connect to the Internet. When there are two or more gateways to the fixed network, this is referred to with MultiHomed Hybrid Ad Hoc Network. In this scenario, different networks are formed, each one associated with a different gateway. A node can maintain its connectivity to the Internet when moving from a network to another by performing handover procedures and changing its gateway to the Internet. This scenario is quite interesting for its capacity of increasing the geographical extension of a single mobile network. The major contribution of this work is to provide a preliminary modeling of the node connectivity in this framework. We consider a typical architecture with gateways organized in a honey cell structure, where nodes move according to the RDMM (Random Direction Mobility Model), and present a three-state Markov model that describes the moving node behaviour: mobility without route changes, route change, and handover. Notwithstanding the simplicity of the underlying assumptions, the proposed model represents a valid basis for the analysis of the connectivity performance in this scenario, whose accuracy has been proved by means of extensive simulations.