Secure access telephone extension system and method in a cordless telephone system

摘要: A method and system is provided for conducting secure power line carrier communications in full duplex over the lines of a building. Power current telephone extension systems utilize 1) single BASE unit per central office (for interfacing signals with line) 2) one or more EXTENSION units, each phone set said sets). The employs control logic providing A) multiple arbitration logic, B) privacy from eavesdropping C) security third party capture by means digital messaging base utilizing unique matching key (preamble) message instructing to change operating states, such as, during conversation an may be put on hold so that second can pick up line, rings units signal incoming call outgoing initiated user taking off hook access line. Matching random codes user. By this unauthorized (especially long distance calls) other users same building similar products prohibited.