Patent ID: 8313025

Claim:
A transmission system comprising: a tag having a radio, the radio having a backscatter transceiver coupled to an antenna wherein the backscatter transceiver has a digital backscatter transmission mode using electromagnetic signals and an analog backscatter transmission mode using electromagnetic signals and digital logic connected to the backscatter transceiver; a terminal that communicates wirelessly with the tag, the terminal having a radio wherein the terminal radio transmits using backscatter transmission mode and sends a carrier wave signal to the tag radio; the digital logic of the tag radio performing the processes of: determining if the tag radio can use the digital backscatter transmission mode; determining, if the tag radio can use digital backscatter transmission mode, that the tag radio is operating in a protocol environment that uses only two states; using the analog backscatter transmission mode if it is determined that the tag radio cannot use digital backscatter transmission, wherein the tag radio operates in an environment that has more than two states; modulating a carrier wave signal using changes in load impedance to represent the information that is to be transmitted to the terminal using analog backscatter transmission mode; completing the transmission to the terminal if it is determined that the information using backscatter transmission is transmitted; and repeating the modulation of the carrier wave signal if it is determined that the transmission of the information to the terminal was not completed.