On the Design of Incentive Mechanisms in Wireless Networks: a Game Theoretic Approach

In wireless communication networks, many protocols (e.g., IEEE 802.11 a/b/g Medium Access Control (MAC) protocols) have been designed assuming that users are compliant with the protocol rules. Unfortunately, a self-interested and strategic user might manipulate the protocol to obtain a personal advantage at the expense of the other users. This would lead to socially inefficient outcomes. In this thesis we address the problem of designing protocols that are able to avoid or limit the inefficiencies occurring when the users act selfishly and strategically. To do so, we exploit the tools offered by Game Theory (GT), the branch of mathematics that models and analyzes the interaction between strategic decision makers. The dissertation covers aspects related to wireless communications at different levels. We start analyzing the downlink radio resource allocation issue of a cellular network based on Orthogonal Frequency Division Multiple Access (OFDMA). We propose a suboptimal game theoretic algorithm able to preserve the modularity of the system and to trade–off between sum–rate throughput and fairness among the users of the network. Successively, we address the problem of promoting cooperation in wireless relay networks. To give the incentive for the users of a network to relay the packets sent by other users, we consider a dynamic scheduling in which cooperative users are rewarded with more channel access opportunities. Infrastructure sharing is another form of cooperation that might be exploit to meet the increasing rate demands and quality of service requirements in wireless networks. We analyze a scenario where two wireless multi–hop networks are willing to share some of their nodes – acting as relays – in order to gain benefits in terms of lower packet delivery delay and reduced loss probability. Bayesian Network analysis is exploited to compute the correlation between local parameters and overall performance, whereas the selection of the nodes to share is made by means of a game theoretic approach. Afterwards, our analysis focuses on channel access policies in wireless ad–hoc networks. We design schemes based on pricing and intervention to give incentives for the users to access the channel efficiently. Finally, we consider another important issue that arises when the users are strategic and selfish: when asked to report relevant information, the users might lie, if it is in their individual interest to do so. For a class of environments that includes many resource allocation problems in communication networks, we provide tools to design an efficient system, in which the users have the incentive to report truthfully and to follow the instructions, despite the fact that they are self–interested. We then apply our framework and results to design a flow control management system.