A QoS Enhanced Routing Protocol in Wireless Sensor Networks

QoS is a key factor to the utility of Wireless Sensor Network (WSN) especially in the case of multiple sources data detecting with different time property. For environment detecting, there are not only same sensors just for one element but also heterogeneous sensors for multiple elements. Sometimes a single sensor has multiple functions to get several elements, which could be indicated to send the elements with different fashion. For example, temperature and humidity need been reported every one hour, but precipitation and wind speed/direction need been reported every half an hour in special situation. A High Available Sensor network protocol for Differentiated Services (HADS) was proposed, which combined the features of Directed Diffusion protocol (DD) and Low-Energy Adaptive Clustering Hierarchy routing protocol (LEACH). HADS computes the routing gradient with different metrics, and then constructs two types of routing gradient table for best-effort service and real-time service. A gateway node was introduced, which can connect two cluster heads and support both single route and multiple routes to achieve an alternate path via other cluster head to sink node. The simulation results shows that HADS protocol may provide a good services for two types of data transmission, and achieve the efficient power utilization and delay improvement within the whole network.