Joint Power Allocation and Transmission Time Selection in Duty-cycled Wireless Sensor Networks

Energy-aware resource allocation plays an important role in battery-limited wireless sensor networks (WSNs), as it improves network performance, in terms of energy savings, and prolongs network lifetime as well. In this paper, we study a duty-cycled WSN where the sensor nodes transmit their data simultaneously to a central access point and then return to sleep mode (this process is repeated in each time period). In particular, we propose a joint power allocation and transmission time selection algorithm in order to minimize the maximum energy consumption of the sensor nodes, under power and time constraints as well as quality-of-service (QoS) requirements. In the problem formulation, we also take into account the circuit energy consumption of each sensor node. Moreover, the proposed algorithm, which is based on a successive convex approximation method, converges very quickly and achieves a Karush-Kuhn-Tucker (KKT) solution for the problem. Finally, numerical results reveal that the proposed technique provides significant performance gain when compared to a baseline scheme.