Energy efficient hybrid routing protocol for underwater acoustic sensor network

Underwater acoustic sensor networks (UW-ASNs) are deployed in the water to gather the information of interest. They can gather information regarding temperature, pressure, pollution and environment of the ocean. There is requirement of energy efficient routing protocols to convey information to the sink. Energy efficient routing protocols used in terrestrial networks are not suitable for underwater acoustic sensor networks because they are more prone to errors in underwater. In this paper, energy efficient routing protocols used in underwater wireless sensor network such as Vector-Based Forwarding Protocol (VBF), Depth Based Routing protocol (DBR), Reliable and Energy Balanced Routing Algorithm (REBAR) are discussed. In VBF, header field of each packet carries the positions of the sender, the target, and the forwarder. Header field of packet is large so useful information in one packet is small. To transfer information from source to sink it requires more packets to transfer so it consume large amount of energy to transfer data. In DBR, a data packet has a field that records the depth information of its recent forwarder and is updated at every hop. It uses 5 sinks over the surface so packet will reach the sink earlier than VBF. In REBAR, uses adaptive radius of the pipe whose radius vary according the distance from the sink. A new energy efficient routing protocol is also designed which is hybrid approach of DBR and REBAR. It uses adaptive radius of the pipe and five sinks over the surface.