Abstract
In this paper, the topic we focus on is constructing maximum-lifetime data gathering tree in unreliable sensor networks. The power levels of sensor nodes can be adjustable dynamically to be enough to reach its target node on transmitting. Sensor node will send an acknowledgement when receiving a message. Erroneous or lost packets are retransmitted. In-network data aggregation is also employed to aggregate sensor data while they are being forwarded toward to the base station. We derive an upper bound on the lifetime of the optimal data gathering tree. For a given initial tree, an algorithm is developed to construct a data gathering tree by iteratively rearranging the current tree and improving the lifetime. Simulations are performed to study the performance of the algorithm.