Residual Energy Aware Mobile Data Gathering In Wireless Sensor Networks

Internet of Things(IOT) is the combination of technology and life. With the development of IOT, smart equipment have been popularly used in daily life, one of these is wireless sensor network which has gaining an increasing interesting, and playing an crucial role in many sort of fields such as daily life, military affairs, business and so on for reason that they can be deployed within the areas that people difficultly to arrive or even cannot arrive. It is a good help for saving manpower and material resources and preventing some accidents happening. Besides, wireless sensor network is easy to install and maintain, it has been accepted nearly all over the world.Wireless Sensor Network, which is short for WSN, composed of a lot of wireless sensor nodes whose energy and computing capability are limited. They work in a mutual corporation way. The intrinsic characteristic of wireless sensor networks is the power limitation of sensor nodes. The most difficult challenge is how to save energy of sensor nodes so that the lifetime of a sensor network will be prolonged. The traditional method for prolonging the lifetime of whole network is clustering. This kind of methods is often sacrifice cluster head for other nodes. In fact, they are not good enough for the sake of performance.Using a mobile data collector(MDC) is introduced to achieve this goal. We suppose that all sensor nodes are kept static once deployed, a single MDC traverses the network to reduce the communication of relaying data among sensors. In general, we need to consider two factors when designing a traveling path of a MDC, i.e., data overflow on a sensor node and the timeliness of each data. In this paper, we aim to prolong lifetime of a sensor network by designing heuristic traveling paths of the MDC under these two constraints.It is obviously that a fixed MDC path leads to a quick energy consumption of the nodes near that path if the location of MDC path is not changeable. In addition, we believe that residual energy of each node is important to the life time of WSN. Based on these two aspects, we propose an iterative scheme which determines the traveling path of the MDC before each round of the data gathering. Our scheme consists of four steps. For each data gathering round, we first iteratively partition the network into clusters by spectral clustering, and then select a cluster head as polling point depended on residual energy. Following that, we construct a balanced data relay tree in each cluster. Last, we design a shortest path for the MDC. Since the paths of MDC are different in each round, the lifetime of the sensor network can be prolonged.Simulations reveal that our method is better than the existing methods and prolong the lifetime of wireless sensor network.