Reverse engineering MAC

— This paper reverse-engineers backoff-based random-access MAC protocols in ad-hoc networks. We show that the contention resolution algorithm in such protocols is implicitly participating in a non-cooperative game. Each link attempts to maximize a selfish local utility function, whose exact shape is reverse engineered from the protocol description, through a stochastic subgradient method in which the link updates its persistence probability based on its transmission success or failure. We prove that existence of a Nash equilibrium is guaranteed in general. The minimum amount of backoff aggressiveness needed for uniqueness of Nash equilibrium and convergence of the best response strategy are established as a function of user density. Convergence properties and connection with the best response strategy are also proved for variants of the stochastic-subgradient-based dynamics of the game. Together with known results in reverse engineering TCP and BGP, this paper completes the recent e...

• Type: Conference
• Year: 2006
• Where: WIOPT
• Authors: Ao Tang, Jang-Won Lee, Jianwei Huang, Mung Chiang, A. Robert Calderbank
• Keywords: Nash Equilibrium, Random-access Mac Protocols, Reverse Engineering, WIOPT 2006, Wireless Networks