Wireless extension for cable television signals
View Patent ↗A wireless link provides an extension to cable television signals for a television receiver that does not have access to a coaxial cable. Analog and digital cable channels are processed and transmitted over the wireless link. Security of the signal is provided by transmitting encrypted data and decrypting at the receiving node. The conditional access encryption inherent in the data can insure communication security or encryption may be performed at the transmitting node.
1. A wireless extension for transmitting analog and digital television signals from one location to another comprising:
a sending unit comprising:
a remote control interface for receiving a channel selection command;
at least one tuner for receiving both analog and digital television signals responsive to the remote control interface with an RF input and a tuner output;
a digital demodulator for receiving the tuner output and producing a digital stream containing MPEG encoded program information;
an MPEG demultiplexer for receiving the MPEG information from the digital demodulator and selecting at least one MPEG program to produce a first MPEG stream;
an MPEG encoder receiving the tuner output and producing a second MPEG stream;
a selector for selecting between the first MPEG stream and the second MPEG stream, wherein an active MPEG stream is selected;
a digital lock detector in the digital demodulator for detecting a digital signal lock condition;
an analog lock detector in the MPEG encoder for detecting an analog signal lock condition;
control logic circuitry responsive to the digital lock detector and the analog lock detector with an output to the selector to select an active MPEG stream from the stream indicating a lock condition; and
a modulator and transmitter for producing an RF signal to transmit the selected MPEG stream;
a receiving unit comprising:
a receiver for receiving the RF signal; and
an MPEG demultiplexer/decoder for demultiplexing the desired program and converting the MPEG program to a signal suitable for driving a television receiver.
2. The wireless extension of claim 1 further comprising:
in the sending unit a means for encryption of the selected MPEG program; and
in the receiving unit a means for decryption of the received signal.
3. The wireless extension of claim 2 further comprising:
a public key exchange wherein a public key is transmitted from the receiving unit to the sending unit.
4. The wireless extension of claim 1 further comprising:
in the receiving unit a conditional access unit that receives information to enable decoding of the MPEG program.
5. The wireless extension of claim 1 further comprising:
in the sending unit a programmable transmit power level circuit responsive to power level commands from the remote control.