ABSTRACT
The wireless sensor/actor network (WSAN) is a network of many small nodes in which there are a number of
sensor/actor. The sensor/actor has intense interaction with the physics environment. It receives the information of
the environment through the sensors and then reacts through the actors. The relation between the nodes is
wireless. Each node works independently and without the interference of human and is usually small with
limitations in the processing power, memory capacity, power supply, etc. The main task of a wireless sensor
network is gathering information from the under covered area. These information are gathered by the sensors
and are transferred based on the routine algorithms to the sink. The sensors in the sensor wireless networks have
limitations such as energy and computational power. We explain a general review of the mobile sink hierarchal
routing protocols in the wireless sensor networks and then compare each of these methods.
Keywords: - Wireless sensor networks, Hierarchical, Sink, Routing protocols