Colour-based forwarding scheme with variable-range transmission power in AODV

Broadcasting is a crucial part of ad hoc routing protocols. Designing efficient forwarding scheme can reduce redundancy and collisions. Recently, we have proposed an Energy-Efficient Adaptive Forwarding Scheme (EEAFS) that uses 1-hop neighbourhood knowledge, in addition to a transmission power classification scheme to group mobile devices based on their transmission power level. Based on this classification scheme, gateway nodes that are located in the overlapping areas of different groups, are selected to forward the broadcast message. This paper has two main contributions to further improve the EEAFS. 1) Assigning a colour to each group of nodes in the network, to increases the awareness of the gateway nodes located between different groups of similar transmission power levels. 2) Developing a weight-based coordination approach between the gateway nodes to minimising the overlapping. This contributes to reducing the redundancy and collisions especially, in high dense regions. By using variable transmission power, we not only reduce the congestion, interference and conserve energy, but we also effectively involve the node's transmission power level in the forwarding decision-making process. Our solution is implemented and extensively evaluated by using ns-2. The simulation results show that the proposed broadcast technique is scalable and can significantly reduce collisions at the MAC layer by achieving up to 70 percent reduction in packet loss ratio. It also reduces end-to-end delay while consuming less energy.