Interactive video distribution systems – Local video distribution system – Multiunit or multiroom structure
Reexamination Certificate
1999-01-28
2001-02-13
Faile, Andrew (Department: 2611)
Interactive video distribution systems
Local video distribution system
Multiunit or multiroom structure
C725S148000
Reexamination Certificate
active
06189148
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the field of communications in general and more particularly to serial data transmission.
BACKGROUND OF THE INVENTION
As the popularity of cable television services increases, new consumer devices may become available for home use. For example, new types of consumer devices such as cable ready televisions, cable tuners, and video cassette recorders may be connected to cabling which carries the transmission of the cable television services for use by consumers in their homes. As the number of consumer devices used in the home increases, the cabling needed inside the home may also increase and become unwieldy. As a result, the cabling may be integrated into the structure of the home, for example in the walls and floors. It is known to use coaxial cable having an impedance of 75 ohms in some cable systems for the transmission of the cable television services.
The cabling may conduct television signals and other signals which include the cable television services, and Direct Current (DC) voltages or Alternating Current (AC) voltages for controlling the consumer devices. For example, a television signal and a DC voltage may be transmitted over the cabling to provide a video signal and a DC voltage for controlling a cable tuner.
Other devices, such as Personal Computers (PCs), are also used in consumers' homes. Some of these devices may be capable of communicating with other devices, such as the consumer devices described above. Unfortunately, separate wiring may be needed to provide the communications between the devices. For example, a serial data cable may be needed to connect two PCs. Unfortunately, if the PCs are located in different areas of the home, the serial data cable may need to be long which may make the serial data cable expensive and unwieldy. Therefore, a need exists to further improve communications between devices such as consumer devices and PCs.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to allow an improvement in the transfer of data between devices within a building.
It is another object of the present invention to allow improvement in transferring data over transmission lines which conduct television signals.
These and other objects of the present invention are provided by transferring data using frequency shift keying modulation in a frequency range that is not within a television signal frequency range used to conduct the television signal over the transmission line. The present invention may thereby allow the same cabling to be used to transfer data between devices. In one embodiment, the devices are located in the same building, such as a home. Consequently, the present invention may provide a less expensive and convenient way to transfer data between devices using the same cable used to conduct the television signal. According to conventional systems, the transfer may be performed over separate cabling which may be unwieldy and expensive.
The frequency shift keying modulation is provided by generating a modulated data signal based on information included in the data. For example, the frequency shift keying modulation generates a modulated data signal at a first frequency when the data is equal to a logical 0 and at a second frequency when the data is equal to a logical 1. In one embodiment, the first frequency is about 800 KHz and the second frequency is about 1 MHz.
Frequency shift keying modulation may provide a reduction in the cost of transferring the data. In particular, the frequency shift keying modulation may be embodied using relatively few components. In contrast, some conventional data transfers are performed using phase shift keying modulation which may be more expensive than a system according to the present invention.
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International Search Report, dated Jul. 13, 2000.
Clark Jerry R.
Cutler Todd D.
Monaco Lawrence D.
Schultheiss Christopher J.
Brown Douglas G.
Faile Andrew
Myers Bigel & Sibley & Sajovec
Srivastava Vivek
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