Credit-Based Relay Selection Algorithm Using Stackelberg Game

Public wireless networks usually comprise of self-interested users who are reluctant to cooperate with other users of the network unless and until they are provided with some incentives. This paper presents a new incentive-based relay selection algorithm, which motivates the self-interested in-range mobile users to act as relays providing network access to the out-of-range users, thus extending the coverage range of a wireless network. The new Credit-based Relay Selection (CRS) algorithm uses Stackelberg game employing a credit-based incentive mechanism, providing instantaneous as well as long-term benefit to the selfish in-range users. In addition to this, the CRS algorithm takes into account both the achievable data rate at the out-of-range user and fair consumption of battery power of in-range user as the relay selection criteria. Simulation results presented in this paper show that when the CRS algorithm is used for relay selection, it is advantageous even for the self-interested in-range users to participate in the relaying process to earn some benefit to utilize it when they move outside the transmission range of access point and need to buy assistance from other users. The CRS algorithm also provides better data rate to the out-of-range users as well as fair utilization of battery power of the in-range users compared to a default algorithm which uses Signal to Interference and Noise Ratio (SINR) as relay selection criterion.