CLGR: Connectivity and link quality aware geographical routing using AHP-TOPSIS for FANETs

Flying Ad Hoc Networks (FANETs) have been getting considerable attention due to their widespread usage in military and civil operations. The unique features like high mobility, frequent topology change and unreliable communication links make it challenging to design a reliable routing solution for FANETs. Geographic routing is considered a scalable approach in highly dynamic scenarios, requiring only one-hop neighbour information for routing decisions. However, the problems associated with geographic routing, such as the presence of false positives in the neighbour table, local minima (or communication void), and unreliable communication links, affect the routing performance substantially. Therefore, the present article addresses these problems by providing connectivity and link quality aware geographical routing (CLGR) solution using the Analytic Hierarchy Process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Firstly, the strategy has been introduced for the management of neighbour table entries based on the link lifetime to purge the false positives on time. Then the AHP-TOPSIS based packet forwarding policy is designed, which considers multiple metrics like link quality, degree of connectivity, and progress to avoid communication voids and selects the next hop with a reliable communication link. In this, AHP has been applied to determine the weight of each metric impacting forwarding policy. The TOPSIS ranks the available alternatives to obtain the optimal next hop. Finally, the performance of the proposed scheme is evaluated using the network simulator ns-3. Results show that CLGR performs better than existing routing schemes with regard to packet delivery ratio, end-to-end delay, throughput, number of local minima, and number of false positives.