Cyber Times International Journal of Technology & Management

A Wireless Sensor Network (WSN) is a new paradigm in world of information in which large numbers of nodes are deployed densely to collect data and its impetus is to reliably direct this information to a sink. Such types of networks are highly dynamic in nature and though they have a special characteristic of self organism under dynamic conditions make them unreliable. Quality of Service (QoS) is a commanding factor which ensures the trust of various users of the network. Credibility and Stability of the network can be defined based on guaranteed QoS provided to the end users. In past many techniques have been proposed in order to guarantee QoS but none of them is perfect on various QoS parameters. In this paper, we reviewed the various QoS techniques in WSN and classified on the basis of major functionalities. Comparison of existing techniques is done based on parameters like delay, scalability, data integrity, reliability, energy efficiency, congestion, throughput and credibility. Finally, this paper proposes some open issues which focused on further improvement of existing QoS techniques.