Patent ID: 7489899

Claim:
A method for building an information network via an antenna terminal or an antenna cable disposed in a house for receiving television broadcasting or radio broadcasting, the method comprising: step (a) of selecting at least one frequency not used by television broadcasting or radio broadcasting in an area where the house is located; step (b) of encoding transmission data; step (c) of generating a carrier wave having the frequency selected in step (a); step (d) of modulating said carrier wave using said encoded transmission data; step (e) of transmitting the modulated carrier wave via the antenna terminal or the antenna cable from a first information terminal; step (f) of receiving the carrier wave transmitted in step (b) and demodulating the carrier wave to produce reception data received by a second information terminal; step (g) receiving a first carrier wave from a first terminal and converting said carrier wave to an intermediate-frequency signal; step (h) amplifying said intermediate-frequency signal; step (i) demodulating the amplified intermediate-frequency signal to generate a baseband signal; step (j) separating a synchronous signal based on said baseband signal; and step (k) selecting said at least one frequency based on said synchronous signal.