Data Gathering Scheme In Wireless Sensor Networks Based On Mobile Sink

Recently, with the rise of "Internet of Things", Wireless Sensor Networks(WSNs) which is one of the core technologies of it is becoming a research hot pot all around the world. WSNs is a wireless network system that is self-organized through wireless communication between a great number of sensor nodes deployed in the given monitoring area.To realize the monitoring and controlling of the given area, the sensor nodes will send the sensed data to the users through WSNs when they collect the valuable data. WSNs is considered as one of the most influentialtechnologies of21century for its potential application value in the field of military defense, biological and medical treatment, environmental monitoring and so forth.The research of data gathering strategy in WSNs attracts lots of attentions in the past, because data gathering is the most important function of WSNs. Since there is a variety of defects in nodes’energy consumption("bottle-neck"effect, for example) for traditional staticdata gathering strategy of WSNs, dynamic data gathering algorithm is becoming the main trends of research direction of WSNs currently. However, although mobility solved many inherent problems of static WSNs, like "bottle-neck"effect, it also brings some new issues. The reliability of the networks is seriously weakened for the frequently changing of topology and links of WSNs which is leaded by the mobility of nodes. Therefore, this paper mainly analyzes the characteristics of WSNs based on mobile sink and brings out a high reliability data gathering scheme called HRDG-MS based on DDRP protocol.DDRP is a kind of data-driven scheme which can decrease the overhead of WSNs effectively, but it ignores another important matter of WSNs, that is reliability. So, a new data gathering algorithm called HRDG-MS with both low overhead and high reliability is introduced in the paper. HRDG-MS redesigns the data-driven based data collecting scheme, and in order to alleviate the Packet Loss Ratio, HRDG-MS combines three effective solutions from two aspects, namely static aspect and dynamic aspect. In the static aspect, a Load-Balance algorithm with comprehensive consideration of three elements which include the length of buffer queue, residual energy and distance to mobile sink is put forward. In the dynamic aspect, two novel strategiesare given, that is No-Route-Buffer mechanism and adaptive BEACON interval. Simulation results demonstrate that HRDG-MS have a low overhead almost the same as DDRP, but HRDG-MS get a remarkable preponderance in data gathering reliability.