Underwater communication apparatus and communication method

An underwater communication network system comprising a plurality of personal underwater communication devices, wherein each device comprises:

• a display;
• a memory unit for storing a plurality of preset messages each having a unique message identification code;
• means for assigning and storing in said memory unit a unique device identification code for each of said plurality of personal underwater communication devices;
• means for selecting one of said plurality of preset messages for transmission;
• mean for selecting a receiving device to receive said transmission of said one of said plurality of preset messages;
• means for encoding said unique message identification code for said one of said plurality of preset messages and said unique device identification code of said receiving device into a string;
• means for modulating said string with a modulating frequency to produce an ultrasound acoustic modulated signal;
• means for transmitting said modulated signal in water;
• means for receiving a modulated signal;
• means for demodulating said received ultrasound acoustic modulated signal to produce a demodulated string;
• means for decoding said demodulated string to produce said unique message identification code for said one of said plurality of preset messages and said unique device identification code of said receiving device;
• and
• means for displaying on said display said decoded one of said plurality of preset messages and said unique device identification code of said receiving device.

A method of communicating between underwater devices comprising the steps of:

• assigning to a transmitting device an identification code;
• assigning to a receiving device at least two pairs of acoustic ultrasound frequencies, a first frequency of each pair for indicating a "1" level, and a second frequency of each pair for indicating a "0" level;
• encoding, at said transmitting device, a binary string comprising a message and said transmitting device identification code;
• modulating said string with said at least two pairs of acoustic ultrasound frequencies, said frequencies being identical to said at least two pairs of frequencies assigned to said receiving device, to produce a modulated signal;
• tuning said transmitting device to receive signals in said at least two pairs of frequencies assigned to said receiving device;
• transmitting said modulated signal to said receiving device;
• receiving said modulated signal at said receiving device;
• demodulating said received modulated signal to produce a string;
• decoding said string to produce a decoded message and a decoded identification code of said transmitting device;
• displaying said decoded message and said decoded identification code;
• encoding a binary string containing an acknowledgment message and a receiving device identification code;
• modulating said string with at least two pairs of acoustic ultrasound frequencies, said frequencies being identical to said at least two pairs of frequencies assigned to said transmitting device to produce a modulated acknowledgment signal;
• and
• transmitting said modulated acknowledgment signal to said transmitting device.

A personal underwater communication device for transmitting a user selected textual message for reception by a user selected receiving device, and for receiving and displaying a textual message from another underwater communication device, said communication device comprising:

• a display for displaying a textual message received from the another underwater communication device;
• a processor for providing an output to said display, said processor including memory within which is stored a plurality of textual messages and a unique message identification code for each of said stored plurality of textual messages, and a plurality of unique device identification codes for each of a plurality of other underwater communication devices, including unique device identification codes for the user selected receiving device and the another underwater communication device;
• and
• a hydrophone for transmitting and receiving, by said device, a transmitted acoustic signal and a received acoustic signal;
• said processor modulating one of said stored plurality of message identification codes that corresponds to the user selected textual message and communicating said modulated message identification code to said hydrophone for transmission thereby as the transmitted acoustic signal for receipt by the user selected receiving device;
• said processor demodulating the received acoustic signal transmitted by the another underwater communication device for receipt by said device, the received acoustic signal including one of said stored plurality of message identification codes corresponding to a textual message selected by a user of the another underwater communication device, said processor causing the textual message selected by the user of the another underwater communication device to be displayed by said display.

An underwater communication network comprising a plurality of underwater communication devices for transmitting a textual message to at least one user selected other underwater communication device and for receiving and displaying a textual message from at least one other underwater communication device, wherein each said underwater communication device comprises:

• a display for displaying a textual message received from the at least one other underwater communication device;
• an input device;
• a processor for receiving input from said input device and for providing an output to said display, said processor including memory within which is stored a plurality of textual messages and a unique message identification code for each of said stored plurality of textual messages, and a plurality of unique device identification codes for each of the plurality of underwater communication devices in said network, a user of said device selecting, using said input device, one of said stored plurality of textual messages for transmission and at least one of the plurality of underwater communication devices as a receiving device to receive said transmission;
• and
• a hydrophone for transmitting and receiving an acoustic signal;
• said processor modulating the message identification code corresponding to said user selected one of said stored plurality of textual messages, and communicating said modulated one of said stored plurality of message identification codes to said hydrophone for transmission thereby as a transmitted acoustic signal for receipt by the user selected receiving device;
• said processor demodulating a received acoustic signal transmitted by at least one other underwater communication device for receipt by said device, the received acoustic signal including one of said stored plurality of message identification codes corresponding to a textual message selected by a user of the at least one other underwater communication device, said processor causing the textual message selected by the user of the at least one other underwater communication device to be displayed by said display.

A personal electronic underwater communication device for transmitting a textual message to a user selected electronic underwater communication device and for receiving and displaying a textual message from another electronic underwater communication device, said underwater communication device comprising:

• a display for displaying a textual message received from the another electronic underwater communication device;
• a processor for providing an output to said display, said processor including memory within which is stored a plurality of textual messages and a unique message identification code for each of said stored plurality of textual messages, and a plurality of unique device identification codes for each of a plurality of other electronic underwater communication devices, including unique device identification codes for the user selected receiving device and the another electronic underwater communication device;
• and
• a hydrophone for transmitting and receiving by said device, a transmitted acoustic signal and a received acoustic signal;
• said processor modulating one of said stored plurality of message identification codes that corresponds to the user selected textual message and communicating said modulated message identification code to said hydrophone for transmission thereby as the transmitted acoustic signal for receipt by the user selected receiving device;
• said processor demodulating the received acoustic signal transmitted by the another electronic underwater communication device for receipt by said device, the received acoustic signal including one of said stored plurality of message identification codes corresponding to a textual message selected by a user of the another electronic underwater communication device, said processor causing the textual message selected by the user of the another electronic underwater communication device to be displayed by said display.