Patent ID: 7609157

Claim:
An antenna proximity determining system, said antenna proximity determining system comprising: a transmitter unit including a transmitting antenna, said transmitter unit generating a digital signal including at least one data word encoded using forward error correction coding, said transmitter unit transmitting the digital signal by way of the transmitting antenna such that the digital signal is an attenuating field radiating from the transmitting antenna, each of the at least one data word being transmitted at a respective data transmission rate, the digital signal indicating the respective data transmission rate corresponding to each of the at least one data word; and a receiver unit adapted to be carried by the animal, said receiver unit receiving the digital signal, decoding the at least one data word, and noting the respective number of bit errors detected for each of the at least one data word, the respective number of bit errors detected for each of the at least one data word and the respective data transmission rate corresponding to each of the at least one data word defining a plurality of zones, said receiver unit delivering a stimulus to the animal when the receiver unit is within at least one of the plurality of zones.