A mobility model for opportunistic routing protocols validation

Abstract

Opportunistic networks -as opposed to infrastructure networks- are built on-the-fly by mobile, intermittently connected ad-hoc nodes, allowing to run delay tolerant applications. The idea is always to store a message, to carry it for some time, and to forward it when a suitable mobile node happens to be in range, all this with the hope that, after some of these store-and-forward steps, the message will eventually arrive to its destination. In these conditions, the throughput and delay induced by the routing protocol depends on the network characteristics (number of nodes, movement patterns), data flow characteristics (load, data patterns), and how the parameters of the routing protocol adapt to such a network environment. In particular, the performance of the opportunistic networks depends on some mobility and connectivity characteristics of the involved nodes, such as number of connected components and diversity of encounters between nodes, and the opportunistic routing protocols must be tested and tuned to adapt to those characteristics. However, it is impossible to control such mobility and connectivity parameters in a real setup and complicated to control them in a simulated setup. This paper presents a new mobility model, designed to help with the evaluation of opportunistic routing protocols. The main feature of this model is to allow the configuration of its average number of connected components and the diversity of encounters between nodes. We show how we control those characteristics and we present an example of how the model is used in the evaluation of RON, a content-based opportunistic routing protocol.