BSTRACTOne of the major challenges in the design of wireless sensor network (WSN) is to reduce the energy consumption of sensor nodes for prolonging the network lifetime. In the sensor network, communication is the most energy consuming event. Therefore, most of the energy saving techniques conserve energy by adjusting different parameters of the trans-receiver. Among them, one of the promising methods is the transmission power control (TPC). In this paper, we investigated the effects of the link quality based TPC scheme employed to the
Ⅰ. IntroductionWireless Sensor Network (WSN) consists of low-powered devices capable of sensing and computing. As these small, inexpensive devices are battery powered, sensor nodes must be energy efficient [1][2][3][4][5][6][7] . The radio on a sensor node is usually the component that uses the most energy. The legacy MAC protocols of WSN conserve energy by introducing the concept of duty cycling where a node periodically alternates between active and inactive mode. However, there is a tradeoff between energy consumption and the latency in duty cycling MAC protocols. Radio-triggered power management is another alternative for energy conservation [8] . In radio-triggered power management, a special hardware component, a radio-triggered circuit, is connected to sensor node which wakes up the sensor node whenever it senses communication in the vicinity. The radio-triggered circuit prevents sensor nodes from duty cycling. Similarly, power control scheme is also an alternative to adjust transmit power for energy conservation. Besides saving energy, power control also improves spatial reuse of the wireless channel [9] .IEEE 802.15.4 standard uses fixed default power for transmission. Even though the commercial trans-receivers are programmable, the standard has not defined any power control mechanism. In this paper, we present the link quality based TPC algorithm which can be easily implemented into the IEEE 802.15.4 standard. The idea is to dynamically adjust the transmission power to discover and maintain a quality of the link between a pair of nodes instead of transmitting data at a full power capacity.The rest of this paper is organized as follows.Section II provides reviews on the legacy TPC schemes applied for WSN and introduces the motivation of this study. Section III presents the