Incentivizing Upload Capacity in P2P-VoD Systems: A Game Theoretic Analysis

Abstract

Abstract. Free riding has long been a serious problem in peer-to-peer (P2P) systems due to the selfish behavior of individual users. To conquer this problem, a key design issue of the P2P systems is to appropriately incentivize users to contribute resources. In P2P Video-on-Demand (VoD) applications, content providers need to incentivize the peers to dedicate bandwidth and upload data to one another so as to alleviate the upload workload of their content servers. In this paper, we design a simple yet practical incentive mechanism that rewards each peer based on its dedicated upload bandwidth. We use a mean field interaction model to characterize the distribution of number of peers in different video segments, based on which we characterize the content providers' uploading cost as a function of the peers' contribution. By using a game theoretic framework, we analyze the interaction between a content provider's rewarding strategy and the peers' contributing behaviors and derive a unique Stackelberg equilibrium. We further analyze the system efficiency in terms of the price of anarchy. Via extensive simulations, we validate the stability and efficiency of our incentive scheme.

Distributed Caching via Rewarding: An Incentive Scheme Design in P2P-VoD Systems

“…First, as we mentioned earlier, incentive designs include local storage and upload bandwidth. We have analyzed the latter issue in another paper [22], but it remains an open question on how to perfectly combine these two aspects of design, and how to incentivize distributed caching in lack of bandwidth. Second, it is interesting (yet difficult) to learn the real sensitivity function of peers in practical systems so as to make the incentive scheme more profitable.…”

“…While earlier works [5], [6], [8] are mainly for file sharing systems, recent works have been focusing on P2P streaming/VoD systems, for example, modified tit-for-tat protocol [16], [18], punishment-based [13] and reward-based [4], [22] mechanisms were proposed to provide incentives. Recently Wu et al [19] proposed an auction-based incentive protocol for P2P VoD streaming.…”

“…Both aspects are equally important because a peer cannot contribute if it fails to do either of them. Our previous work [22] focused on incentivizing the upload bandwidth. In this paper, we focus on stimulating peers to cache the needed video data.…”

On incentivizing caching for P2P-VoD systems

“…There have been number of research works on incentive issues for P2P systems, e.g., general framework [24], [16], service differentiation models [13], [9], reputation systems [8], [10], multilateral exchange systems [1] and Shapley value approach [14]. While the earlier works [7], [4], [6] are mainly for file sharing systems, recently some research works have been focusing on P2P streaming/VoD systems, e.g., modified tit-for-tat protocol [15], [17], punishment based [12] and reward based [22] mechanisms were proposed. These works incentivized the peers to upload and serve other peers, however, in a large scale distributed system, it is very hard for the peers to be smart enough to know what are the proper data that they should cache.…”

“…Both of the above are equally important because a peer cannot contribute if it fails to contribute either of them. Our previous work [22] has been focusing on incentivizing the upload bandwidth of peers. In this paper, we focus on the incentive scheme that stimulates peers to cache the needed video data.…”