A wireless multi-hop protocol for real-time applications

Mobile Ad-hoc NETworks (MANETs) have been gaining increasing popularity in recent years thanks to their ease of deployment and the low cost of their components. The routing protocols in ad hoc networks face the challenge of establishing and maintaining multi-hop routes while complying with mobility, bandwidth limitation and power constraints. The already demanding problem of offering wireless communication in a MANET becomes more complicated in the case of real-time systems where the loss or late arrival of a single item of data can cause serious problems. In this article, we propose a real-time wireless protocol for MANET capable of timely delivery of data. Taking advantage of a cross-layer design, it includes a novel medium access control mechanism and routing algorithm based on the link-quality among the nodes belonging to the network. The protocol manages message priority and is capable of multi-hop communications. It has been conceived mainly to provide real-time wireless communication for small robot teams, making possible the sharing of information such as kinematics or laser data. The validity of the protocol is proven by an in-depth theoretical analysis of its real-time characteristics and performance and through a set of real-world experiments.