We study a spectrum sharing problem in an unlicensed band where multiple sys-tems coexist and interfere with each other. Due to asymmetries and selfish system behavior, unfair and inefficient situations may arise. We investigate whether efficiency and fairness can be obtained with self

Abstract. We study auction-based mechanisms for sharing spectrum among a group of users, subject to a constraint on the interference temperature at collocated receivers. The users access the channel using spread spectrum signaling and thus generate interference with each other. Each user receives a

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 loads. Channel conflicts among APs operated by different entities are currently resolved in an ad hoc manner 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 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�-colorable subgraph problem. We also study the speed of convergence in these games.

feasible within the next 5-10 years, Cognitive Radio is about making such radios smart enough to share spectrum and reduce the regulatory overhead. This is an impending wireless revolution that draws upon many signal-processing areas including robust detection, sensor networks, as well as the design

Abstract-One hundred years of spectrum sharing based on reuse the frequency bands that the primary users are not fixed frequency allocations have led to fracturing and poor using at a particular time and a particular location. The utilization. Present methods of frequency allocation combined

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 Wi

There has been considerable effort to let more wireless devices operate in “white space ” spectrum, i.e. within frequency bands and geographic areas where no wireless devices are active. Making white space available is certainly useful, but there are other sharing opportunities as well, some

We consider a spectrum sharing problem in which each wireless transmitter can select a single channel from a set of available channels, along with the transmission power. An Asynchronous Distributed Pricing (ADP) scheme is proposed, in which users exchange “price ” signals, that indicate

Abstract — We consider the problem of cooperative spectrum sharing among a primary user and multiple secondary users, where the primary user selects a proper set of secondary users to serve as the cooperative relays for its transmission. In return, the primary user leases portion of channel access

� Femtocells: very small, short range, low cost and low power base stations, installed by end-users for better indoor signal transmission and reception � More than 70 % of data traffic and 50 % of voice traffic originates