On spectrum sharing games

Abstract

Efficient spectrum-sharing mechanisms are crucial to alleviate the bandwidth limitation in wireless networks. In this paper, we consider the following question: can free spectrum be shared efficiently? We study this problem in the context of 802.11 or WiFi networks. Each access point (AP) in a WiFi network must be assigned a channel for it to service users. There are only finitely many possible channels that can be assigned. Moreover, neighboring access points must use different channels so as to avoid interference. Currently these channels are assigned by administrators who carefully consider channel conflicts and network A preliminary version of this paper appeared in loads. Channel conflicts among APs operated by different entities are currently resolved in an ad hoc manner (i.e., not in a coordinated way) or not resolved at all. We view the channel assignment problem as a game, where the players are the service providers and APs are acquired sequentially. We consider the price of anarchy of this game, which is the ratio between the total coverage of the APs in the worst Nash equilibrium of the game and what the total coverage of the APs would be if the channel assignment were done optimally by a central authority. We provide bounds on the price of anarchy depending on assumptions on the underlying network and the type of bargaining allowed between service providers. The key tool in the analysis is the identification of the Nash equilibria with the solutions to a maximal coloring problem in an appropriate graph. We relate the price of anarchy of these games to the approximation factor of local optimization algorithms for the maximum k-colorable subgraph problem. We also study the speed of convergence in these games.

Non-cooperative facility location and covering games

“…The price of anarchy has been studied in a large and diverse number of games, e.g., in areas like routing and congestion [35,43,7], network creation [6,24], wireless ad-hoc networks [20,28], or facility location [45]. The price of stability [5] has been introduced more recently and studied for instance in network creation games [5,31] or linear congestion games [16].…”

Spectrum sharing methods for the coexistence of multiple RF systems: A survey

“…Coexistence of different Wi-Fi networks is studied in [105]. In this work, the authors consider the problem of channel conflicts among Access Points (APs) from different service providers.…”

A non-cooperative game-theoretic approach to channel assignment in multi-channel multi-radio wireless networks

“…Halldorsson et al [14] analyzed the fixed channel assignment problem in a game-theoretic context. Here, the work identifies NE outcomes with the solutions to a maximal colouring problem in an appropriate graph.…”