Opportunistic Routing in Wireless Multi-hop Networks: A Tutorial

Opportunistic Routing (OR) [1] is a new promising paradigm, which has been proposed as a way to increase the performance of wireless networks by exploiting its broadcast nature. It benefits from the broadcast characteristic of wireless mediums to improve the network performance. In OR, instead of pre-selecting a single specific node to be the next-hop as a forwarder for a packet, multiple nodes, usually called a Candidate Set, can potentially be selected as the next-hop forwarder. Hence, each node in OR can use different potential paths to send packets toward the destination. This is different from the traditional unipath routing which selects one next-hop forwarder before starting the transmission [2], [3]. By using OR, for each packet a dynamic route toward the destination is built, this is done according to the condition of the wireless links at the moment when the packet is being transmitted. In OR when a candidate receives a packet, it coordinate with the other candidates to decide which of them must forward the packet and which one must discard it. This tutorial gives a comprehensive review of the important issues and different aspects of the state of the art of OR. It will enable the attendees to understand the OR concept and to make contributions on their own.