ABSTRACT
This chapter analyses the working of the latest opportunistic protocols proposed for underwater acoustic sensor networks (UASNs) and identifies their issues and drawbacks. Opportunistic protocols proposed for UASNs are divided into two categories: geographic routing protocols and pressure-based routing protocols. Geographic routing protocols utilizes the location information of nodes, while pressure-based routing protocols uses the pressure-level information for making routing decisions in UASNs. Most of the protocols in these two categories suffer from few issues and problems leading to their limited performance in UASNs. The opportunistic routing (OR) protocols proposed for UASNs are mainly classified into two major categories: location-based protocols and pressure-based protocols. Location-based category of protocols uses the position information of the deployed sensor nodes in the network for generating the probable forwarding candidate set, in prioritizing the candidate set and in making the decision on the best forwarder device.
