AODV-LD: Link Duration Based Routing for Multi-Hop Aircraft-to-Ground Communication

As the global air-traffic rises, current communication systems for aircraft like satellites and ground based infrastructure will reach their capacity limits. Especially for rural and oceanic regions, the establishment of an Aircraft Adhoc Network (AANET) is a promising solution. In this paper, a tailor-made routing protocol (Link Duration Based AODV) for communication of aircraft on trans-oceanic routes is proposed. It uses an estimation of the expected residual path duration to make informed routing decisions and establish especially long-lasting routes. Two alternative strategies to estimate route durations were designed: In the deterministic strategy (AODV-LD-D), the fact that aircraft mostly exhibit uniform motion is leveraged to estimate link durations from their position and velocity. The stochastic strategy (AODV-LD-S) employs the known and distinct distribution of link durations experienced by oceanic flights. Both strategies were evaluated on real-world aircraft traces over 72 days in simulation. It is shown that both strategies were able to improve the average route lifetime from around 800 s to over 1100 s with the stochastic strategy and even around 1500 s with the deterministic strategy. The increased route lifetime decreases the number of necessary control packets by as much as 44.2 ±8. 5%. Further, it was shown, that AODV-LD achieves the same packet delivery ratio as AODV in all scenarios. Both strategies increase the average hop count of routes by roughly one and therefore increase the average End-to-End delay by around 8ms which is the expected transmission delay for a single hop. Comparing the two strategies, it was observed that AODV-LD-D required a significantly higher amount of control data compared to AODV-LD-S.