The Network-Based Candidate Forwarding Set Optimization for Opportunistic Routing

In wireless multi-hop networks, the opportunistic routing has advantages on packet delivery probability over deterministic routing. For reducing the transmission delay and duplicate transmission in opportunistic routing, the candidate forwarding set (CFS) optimization approach is proposed. Since the previous node-based approaches have disadvantages on improving the performance of opportunistic routing, we propose the network-based approach to address these disadvantages, named the Delay and Duplicate transmission Avoid CFS optimization algorithm, shorted as DDA. In DDA, the nodes in CFS are divided into different fully connected relay networks. For the forwarding nodes in CFS, more than one relay networks can be constructed and only one can be chosen as the final relay network. So, first, we propose the fully connected relay network recognition algorithm to judge whether the chosen network is fully connected or not. Next, the properties of these networks are investigated. Then, based on the multi-attribution decision making (MADM) theory, and taking the packet delivery probability (between sender and relay networks), the transmission delay, and the forwarding priorities of nodes into account, the DDA chooses the most appropriate relay network. The nodes in this relay network are selected as the final forwarding nodes. Based on these innovations, the transmission delay and duplicate transmission are reduced while the efficiency of the original opportunistic routing algorithms is kept. The simulation results illustrate the effectiveness of the network-based DDA algorithm.