Efficient Data Dissemination Protocols in Pervasive Wireless Networks

Data Dissemination consists on spreading a large amount of information to all nodes belonging to a network. The peculiar characteristics of the system in use make this goal particularly interesting and challenging. Developing efficient data dissemination schemes for wireless ad hoc networks, for instance, is still an open issue due to the broadcast nature of the channel and to the need of managing all data transmissions in a distributed way. The former leads to a lot of problems related to the channel contention, collisions and interference. The latter requires to define algorithms which exploit only local information of the network and which are scalable and robust to the node mobility. The focus of this thesis is to investigate such wireless ad hoc networks by defining and developing data dissemination schemes which can be efficient. The efficiency of an algorithm mainly depends on the requirements imposed by the application scenario of that scheme. In general, they can be reliability, low latency, limited energy consumption and computational complexity and so on. Thus, the problem of efficiently disseminate data, as defined right now, is too wide and general. For these reasons, in this thesis, we will focus on two case studies. We will define two application scenarios in order to point out all the peculiarities and issues related to the data dissemination. In the first part we will focus on dissemination of alert messages in inter-vehicular networks while in the second part we will deal with the data dissemination problem in pervasive systems. We choose these two scenarios as they are specific, i.e., we can precisely define the initial requirements, constraints and objective. But they are also general, i.e., the solutions we will find, could be implemented in different contexts. Thus, the analysis of such case studies will give us a wide and detailed view of the data dissemination problem.