Patent ID: 6856811

Claim:
A portable communication network comprising: plural portable communications units, each providing: (a) a unit code, (b) a wave energy transceiver enabled for direct communication with any other one of the communications units over a limited range, (c) means for assigning a target code to each signal transmission, (d) means for detecting the target code in each signal reception, (e) means for processing a received signal when the target code of the received signal equals the unit code, and (f) means for retransmitting a received signal when the target code of the received signal differs from the unit code; wherein each one of the units is enabled for measuring a time delay between an interrogation and a reply with another of the units and for sending position information of said one of the units within a reply message, the one of the units enabled further for determining a relative position on the Earth of the one of the units by a triangulation method; whereby, through signal repeating, communication is enabled between any two of the communications units when their separation is greater then the limited range.