A rendezvous-based data collection algorithm with mobile sink in wireless sensor networks

The main objective of wireless sensor networks is collecting data from ambient and transmitting achieved data to sink node. Limited energy resource for sensor node has posed so many challenges to these networks. The main constraint on wireless sensor networks is energy consumption which directly affects network lifetime. Lots of methods are proposed to improve these two parameters among which mobile sink method has shown considerable effects comparing to other presented methods. Indeed, using such method, several challenges of static sink methods are addressed such as funneling effect (non uniform energy consumption in the nodes located in the proximity of the sink node) and hot spot. As a result energy consumption decreases significantly which in turn prolongs network lifetime. In this paper, some nodes called rendezvous nodes are utilized to collect data. Source nodes transmit their sensed data to rendezvous nodes and sink node use traveling salesman algorithm and meet only these points in order to collect data. The use of Rendezvous Points allow the sink to collect amount of data at energy cost of multi-hop data communication at a time in the absence of traveling a long distance and thus extremely reduces data collection delay. If the virtual infrastructure of rendezvous-based protocol is properly designed, one can achieve scalability and energy efficiency. Simulation results, which are obtained in ns-2 environment, confirm the effectiveness of our method from energy saving and prolonged network lifetime in comparison with other methods.