UNDERWATER WIRELESS COMMUNICATION Communication between any two entities can be wired or wireless. The concept of wireless technology was started in 1923. As we all know, 70% of the earth is completely covered with water. It was necessary to develop a wireless network that could also work underwater. This is where the concept of acoustic waves comes from. Acoustic waves work best in water. They can also travel long distances within water and are very fast at radio waves. The concept of underwater wireless communication is a major breakthrough in the field of wireless communications. Applications include discovery of natural resources, marine phenomena, deep-sea archaeology, oceanographic data collection, etc. OPERATION For the operation of underwater wireless communication, acoustic waves are commonly used, which can travel longer distances. But when designing the acoustic channel, we may face problems such as low loss rate of sound propagation, i.e., severe frequency-dependent multipath. These facts make the design of underwater wireless communication difficult. There are several ways to use such communication to send and receive messages underwater. The most common is the use of hydrophones. As mentioned, underwater communication is difficult due to factors such as multi-path propagation, temporal channel variations, limited available bandwidth and strong signal attenuation, especially over long distances. The data rate in underwater communication is low compared to terrestrial communication, since underwater communication uses acoustic waves instead of electromagnetic waves. The important non-scalar components of the acoustic field...... middle of paper ......] , dynamic source routing [DSR]) are more appropriate for dynamic environments but involve higher latency and still require Source-initiated control packet flow to establish routes. Reactive protocols may be unsuitable for underwater networks because they also cause high latency in path establishment, which is amplified underwater by the slow propagation of acoustic signals. Geographic routing protocols (e.g., greedyface-greedy [GFG], partial topology knowledge forwarding [PTKF]) are very promising due to their scalability feature and limited signaling requirements. However, global positioning system (GPS) radio receivers do not function properly in the underwater environment. However, underwater sensing devices must estimate their current position, regardless of the chosen routing approach, to associate the sampled data with their 3D position.