Contract-theoretic modeling for content delivery in relay-based publish-subscribe networks

Mobile social network (MSN) has been widely studied as a novel and effective way for communication in the current era of fast developing mobile devices, which enables the contents and services to be delivered opportunistically when mobile users contact. In this paper, we aim to optimize the content delivery from the content provider (CP) to the subscribers via relays in between. Tandem queueing model is applied to model the content delivery process, based on which absorbing Markov chain is used to derive the quality of the content delivery service received by the subscribers. The validity of the proposed queuing model has been verified by our simulation results. Observing that the content provider always has dominant control on the content delivery process and is pursuing the maximum profit by strategically designing the “rights” and “obligation” items for the subscribers, contract theory is adopted to reach an economically optimal solution. The numerical results verify the effectiveness of the contract-theoretic approach in maximizing the content provider's profit, and the capability to ensure the satisfaction of the heterogeneous subscribers with different quality of service (QoS) requirements.