Short Range High Speed PPP-based Underwater Acoustic Network System

A prototype underwater acoustic network system with 100 kilo bits per second (kbps) and point-to-point protocol (PPP) implementation was developed last year using a binary phase shift keying (BPSK) modulation for a new effective seafloor geodetic observing robot network system. At that time, a serial line was used for one-way data transmission because only one set of acoustic transmitter and receiver was available from our budget. In order to realize a transmission bit rate of above 500 kbps, now not only a new set of two-way acoustic communication hardware has been developed, but also the carrier frequency has been raised to 1-3 MHz from 500 kHz used in the old system. Presently we are trying to achieve above 500 kbps high bit rate.