Multimedia streaming in Multi-Homed Hybrid Ad Hoc Networks: A model of network connectivity

In this paper we consider the scenario of a Multi-Homed Hybrid Ad Hoc Network, which consists of self-organized and self-configured mobile nodes that make use of two or more fixed gateways to connect to the Internet. Accordingly, different network segments 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. Within this scenario we focus on the modelling of the node connectivity, which is of practical interest for the design of rate control algorithms for multimedia streaming systems. We consider a network structure with gateways placed in a honey cell structure, where nodes move according to the RDMM (Random Direction Mobility Model). We then derive the probabilities for a node to change the route to connect to the Internet and to handover from a network to another, which both cause service interruptions that heavily affect the quality in multimedia streaming services. Numerical results show the accuracy of the proposed theoretical model with respect to simulated data and reveal the benefits of the model in controlling playback buffer starvation occurrences during video streaming.