Comparison of coordinated and uncoordinated PHY/MAC schemes for beaconing

Beaconing is an important technique for the broadcast of surveillance information, e.g., between aircraft, as well as for the exchange of neighborhood information in mobile ad-hoc networks. For aeronautical communication and surveillance, the scarcity of available spectrum is an important issue. Therefore, this paper compares the spectral efficiency of two advanced beaconing schemes to plain Aloha. The first advanced method uses coordinated medium access within self-organized network cells. The second option is uncoordinated, like plain Aloha, but uses strong error correction coding and successive interference cancellation to decode multiple overlapping messages. The results show that for aeronautical beaconing, both advanced solutions promise a much higher efficiency than plain Aloha. Under optimistic assumptions, the coordinated cellular approach could be somewhat ahead of the advanced Aloha scheme. Yet, for safety-critical aeronautical applications, the advantage may be seen as too small to outweigh drawbacks of the coordinated approach like its dependence on, e.g., accurate time synchronization between users.