Cost Sharing Method for a Mobile Tethering with a Coalitional Game Theory

A tethering market is a system concept in which users share the cellular bandwidth of a user by using a tethering function. In this market, the user (tethering provider) can provide his/her own bandwidth to other users (tethering users), and the tethering users defray some of the costs paid by the tethering provider to the cellular network. Lee et al. derived the users' share of the cost that maximizes the sum of each user' s satisfaction in the tethering market. However, the maximized total satisfaction cannot guarantee that all users will be satisfied with their share of the cost. In other words, some users might have some excess. The existence of users having such an excess may lead to the collapse of the tethering market. In this paper, we derive the optimal cost share, with which all tethering users are satisfied. Moreover, the conventional tethering market model assumes that all tethering users select a tethering connection instead of a cellular connection. However, if the cellular charges are not very high or if the overhead of the tethering market increases, tethering users will choose a cellular connection instead of a tethering connection. Therefore, a tethering market requires the pricing boundary to be known so that users will know when it is better to choose a tethering connection. In this paper, we show the boundary that divides the parameter areas in which the tethering/cellular connections are stably chosen.