Optimal Pricing and Load Sharing for Energy Saving With Cooperative Communications

Cooperative communications has long been proposed as an effective method for reducing the energy consumption of the mobile terminals (MTs) in wireless cellular networks. However, it is hard to implement due to the lack of incentives for the MTs to cooperate. In this paper, we propose a pricing mechanism to incentivize the uplink cooperative communications for the energy saving of MTs. We first consider the ideal case of MTs’ full cooperation under complete information. For this scenario as the benchmark case, where the private information of the helping MTs such as the channel and battery conditions is completely known by the source MT, the problem is formulated as a relay selection problem. Then, for the practical case of partial cooperation with incomplete information, the MTs need to cooperate under the uncertainties of the helping MTs’ channel and battery conditions. For this scenario, we propose a partial cooperation scheme with pricing where a source MT in low-battery level or bad channel condition is allowed to select and pay another MT in proximity to help forward its data to the base station (BS). We formulate the source MT’s pricing and load sharing problem as an optimization problem. Efficient algorithms based on dichotomous search and alternative optimization are proposed to solve the problem for the cases of splittable and nonsplittable data at the source MT, respectively. Finally, extensive numerical results are provided to show that our proposed cooperative communications scheme with pricing can significantly decrease both the communications and battery outages for the MTs, and can also increase the average battery level during the MTs’ operation.