UNDERWATER COMMUNICATION APPARATUS AND COMMUNICATION NETWORK

摘要

A personal underwater communication device which comprises: A display; A memory unit for storing a plurality of preset messages, each message being assigned a common message identification code; Means for assigning a unique identification code to each personal device; Means for selecting one of said preset messages, to be transmitted to a receiving device; Means for selecting one or more receiving devices to which a message is to be transmitted; Means for producing a string encoding said message identification code and the identification code of the transmitting device; Means for modulating said string with at least one ultrasound acoustic modulating frequency, thereby to produce a modulated signal; Means for transmitting said modulated signal in water; Means in each device for receiving transmitted ultrasound acoustic modulated signals; Means for demodulating modulated signals which are received by said device, thereby to produce a demodulated string; Means for decoding a message from said demodulated string; and Means for displaying on the display of the receiving device the received message and the identification code of the transmitting device.