1 Joint Scheduling and Fast Cell Selection in OFDMA Wireless Networks

Abstract—In modern broadband cellular networks, the omni-directional antenna at each cell is replaced by 3 or 6 directional antennas, one in every sector. While every sector can run its own scheduling algorithm, bandwidth utilization can be significantly increased if a joint scheduler makes these decisions for all the sectors. This gives rise to a new problem, referred to as “joint scheduling, ” addressed in this paper for the first time. The problem is proven to be NP-hard, but we propose efficient algorithms with a worstcase performance guarantee for solving it. We then show that the proposed algorithms indeed substantially increase the network throughput. Index Terms—Cellular networks, 4G mobile communication, Optimal scheduling. I

Game theoretic models for resource sharing in wireless networks

Wireless communications have been recently characterized by rapid proliferation of wireless networks, impressive growth of standard and technologies, evolution of the end-user terminals, and increasing demand in the wireless spectrum. New, more flexible schemes for the management of the available resources, from both the user and the network side, are necessary in order to improve the efficiency in the usage of the available resources.This work aims at shedding light on the performance modeling of radio resource sharing/allocation situations. Since, in general, the quality of service perceived by a system (e.g., user, network) strictly depends on the behavior of the other entities, and the involved interactions are mainly competitive, this work introduces a framework based on non–cooperative game theoretic tools. Furthermore, non–cooperative game theory is suitable in distributed networks, where control and management are inherently decentralized.First, we consider the case in which many users have to make decisions on which wireless access point to connect to. In this scenario, the quality perceived by the users mainly depends on the number of other users choosing the very same accessing opportunity. In this context, we also consider two–stage games where network make decisions on how to use the available resources, and users react to this selecting the network that maximizes their satisfaction. Then, we refer to the problem of spectrum sharing, where users directly compete for portions of the available spectrum. Finally, we provide a more complex model where the users utility function is based on the Shannon rate. The aim of this second part is to provide a better representation of the satisfaction perceived by the users, i.e., in terms of achievable throughput. Due to the complexity of the game model, we first provide a complete analytical analysis of the two–user case. Then, we extend the model to the N–user case. We mainly analyze this game through simulations. Finally, inspired by the results obtained numerically, we introduce stochastic geometry in the analysis of spectrum games in order to predict the performance of the game in large networks.Ph.D., Electrical Engineering -- Drexel University, 201

On access point association in wireless mesh networks

End users getting connectivity from wireless access networks want to choose the "best" access opportunity, that is, the best base station in cellular systems, and the best access point in WLANs. The metrics used to drive the association procedures are usually based on "local" parameters like the received signal strength, and the base station/access point's load. In case connectivity is provided through a Wireless Mesh Network the quality perceived by the user upon association depends also on "global" network-wide parameters. This paper studies the dynamics of network association in Wireless Mesh Networks by resorting to game theoretic tools. We show how the association problem can be formalized as a non-cooperative game in which end users selfishly play to minimize a perceived association cost which accounts for characteristics of the entire path to reach the WMN gateway. The quality of the Nash Equilibria for the proposed game are then quantitatively analyzed, and preliminary numerical results on the perceived association cost are derived for sample network topologies

On access point association in wireless mesh networks. WoWMoM

Abstract-End users getting connectivity from wireless access networks want to choose the "best" access opportunity, that is, the best base station in cellular systems, and the best access point in WLANs. The metrics used to drive the association procedures are usually based on "local" parameters like the received signal strength, and the base station/access point's load. In case connectivity is provided through a Wireless Mesh Network the quality perceived by the user upon association depends also on "global" network-wide parameters. This paper studies the dynamics of network association in Wireless Mesh Networks by resorting to game theoretic tools. We show how the association problem can be formalized as a non-cooperative game in which end users selfishly play to minimize a perceived association cost which accounts for characteristics of the entire path to reach the WMN gateway. The quality of the Nash Equilibria for the proposed game are then quantitatively analyzed, and preliminary numerical results on the perceived association cost are derived for sample network topologies