Analytical Modeling of Wireless Communication Systems

4Modeling Information Sharing

It is now commonly acknowledged that cars in the near future will increasingly resemble a communication hub, sporting arrays of GPS navigators, DVD players, videogame consoles and sleek LCD screens flashing the latest traffic alerts, breaking news or local sightseeing information. Of course, the exchange of audio and video clips would require that vehicles are equipped with a high bit rate radio interface and gigabytes of storage. However, although some already envision peer-to-peer networks on wheels, it is quite likely that the first cooperative networked environment among moving vehicles will feature short-lived data exchanges, mostly about vehicular traffic updates or advertisements for a local store running the latest seasonal sale. In such highly impersonal context, most pieces of information are likely to be of general use, and therefore a sensible dissemination and caching policy would be desirable.

This chapter studies the dynamics of information exchange in an inter-vehicular network (IVN), and the system ability to maintain a given information density along the road. To do so, a simple Markovian model is presented. Through the model, the system parameters that guarantee a sustainable information exchange on the network can be identified and system performance can be effectively evaluated.

4.1. System scenario

Consider a set of N different pieces of information in which vehicular users may be interested, each type of information being ...