WO2001082581A1

WO2001082581A1 - Method and system for power line communication with set top boxes

Info

Publication number: WO2001082581A1
Application number: PCT/US2001/012444
Authority: WO
Inventors: Scott R. Bullock; John Knab; Scott Smith
Original assignee: Phonex Broadband Corporation
Priority date: 2000-04-19
Filing date: 2001-04-17
Publication date: 2001-11-01
Also published as: AU2001253585A1

Abstract

A power line communication system, which uses the AC power line (112) to provide a communication channel between a Set Top Box (106) and a Central Office (101) or telephone line communication. In particular, this invention provides the extension unit circuitry (105), required to interface to the AC power line (112), internal to the Set Top Box (106), thereby providing a system of Set Top Box communication that avoids the need for dedicated telephone lines to communicate with the Central Office (101), while having the communication extension unit (105) embedded in the Set Top Box (106) to simplify the connection requirement of the Set Top Box (106). This invention uses the power supply (104b) in the Set Top Box to power the Box, the extension unit (105) to provide the communication interface to the AC channel (104a, 104b, 112).

Description

METHOD AND SYSTEM FOR POWER LINE

COMMUNICATION WITH SET TOP BOXES

Background of the Invention Field of the Invention. This invention relates to communication systems. More specifically, in its preferred embodiment, this invention relates to power line communication systems adapted to use with set top boxes.

Description of the Related Art. A variety of power line communication systems have been proposed, as have a number of set top box designs and configurations. Generally, these prior systems do not describe a power line communication system that is incorporated into a set top box to provide telephone access to the set top box, without requiring standard telephone connection, thereby communicating billing information, internet access and other functions related to the telephone connection of a set top box to a central office. The reader is referred to the following U.S. patent documents for general background material. Each of these patents is hereby incorporated by reference in its entirety for the material contained therein.

U.S. Patent No. 2,516,763 describes a telephone communication system that includes subscriber stations arranged for carrier current operation over a power transmission line. U.S. Patent No. 2,828,363 describes a system for carrier current communication over power lines and in particular relates to a system, which performs the dual function of voice communication and remote control of power equipment.

U.S. Patent No. 3,334,185 describes a system for transmitting signals by means of carrier currents on a power line.

U.S. Patent No. 3,399,397 describes an apparatus for sending and receiving a sawtooth waveform signal through an A-C power line.

U.S. Patent No. 3,659,280 describes a communication system adapted for use with a building's alternating current voltage electrical distribution system, wherein a high frequency signal can be transmitted over the electrical distribution system to a remotely disposed receiver electrically connected to the electrical distribution system.

U.S. Patent No. 3,846,638 describes a power line carrier system that is coupled to two or more phase wires of an electrical power transmission line by transformers and coaxial transmission lines. U.S. Patent No. 3,876,984 describes a system for interfacing a telephone party line extending from a central computer with a number of remote inquiry terminals.

U.S. Patent No. 3,942,168 describes a distribution network power line communication system that includes a central communication terminal at a distribution substation in signal communication with a plurality of remote communication terminals via the electrical distribution power lines.

U.S. Patent No. 3,949,172 describes an extension telephone system that communicates with a conventional subscriber telephone line where the subscriber's line telephone is located, through available AC power wires. U.S. Patent No. 3,967,264 describes a distribution network power line communication system, which is divided into addressable communication zones defined by repeaters located at the distribution transformers of the distribution network. U.S. Patent No. 4,013,840 describes a TDM and FDM telephone communication system that provides a plurality of communicating stations that have transmitters, receivers and control means.

U.S. Patent No. 4,254,403 describes a system for transmitting information in an alternating current supply system wherein information is transmitted by reducing the instantaneous value of the supply voltage during a corresponding period in each of a selection of cycles of the supply voltage.

U.S. Patent No. 4,307,380 describes a communication system for transmitting signals over alternating current power networks.

U.S. Patent No. 4,371 ,867 describes a system for transmitting signals over an alternating current power distribution network; the network load parameters are modulated by means of non-linear elements or by varying the characteristics of components by electrical action dependent on a reference signal.

U.S. Patent No. 4,377,804 describes a data transmission system utilizing a power line transmission of a data signal of a plurality of bits in a serial fashion in synchronism with the cycles of the alternating current of a power supply. U.S. Patent No. 4,400,688 describes a method and apparatus for communicating over electric power lines in a direction from load to source. U.S. Patent No. 4,429,299 describes an AC power line communications system that includes a means for transmitting data to and receiving data from a plurality of transceivers over a conventional AC power distribution network.

U.S. Patent No. 4,471 ,399 describes a communication system for transmitting baseband digital signals on an electrical power line.

U.S. Patent No. 4,473,817 describes a circuit for bi-directionally coupling a communication signal around a distribution transformer.

U.S. Patent Nos. 4,479,033 and 4,495,386 describe a power line telephone extension system for carrying electrical signals between a subscriber's telephone line of a conventional telephone communication system and the subscriber's remote transmit-receiver device over the AC electric power wires available to the subscriber

U.S. Patent No. 4,538,136 describes a power line transmission system which generates a narrow band multi-frequency shift keyed signal having a first predetermined frequency representing a first state of information and a second predetermined frequency representing a second state of information.

U.S. Patent No. 4,556,864 describes a carrier current transceiver that includes a transmitter section and a receiver section coupled to an AC power line.

U.S. Patent Nos. 4,556,865 and 4,599,598 describe a data transmission system utilizing a power line that comprises a transmitter, a receiver, and a repeater coupled to a power line.

U.S. Patent No. 4,556,866 describes a frequency shift keyed (FSK) data transmission system that uses existing power lines to transmit data by superimposing a high frequency FSK signal on the power line carrier. U.S. Patent No. 4,611 ,274 describes a data transmission system using the power supply line wherein it is characterized in that it effectively controls branching terminal units connected to the CPU by the power line.

U.S. Patent No. 4,633,218 describes an apparatus for transmitting digital data over AC power lines at typically a 300-baud rate and at a frequency of 130 kilohertz representing a binary ONE and 131 kilohertz representing a binary ZERO.

U.S. Patent No. 4,641 ,322 describes a communication system for carrying out communication between a plurality of stations through an electric power line operating in a commercial power frequency band. U.S. Patent No. 4,642,607 describes a power line carrier communications system transformer bridge/repeater for receiving on a power line communications network a series of original message bit streams.

U.S. Patent No. 4,644,321 describes a field configuration terminal that does not require physical or electrical connection to a remote device of a power line communication system.

U.S. Patent No. 4,675,648 describes a passive signal coupler that transfers data signals over AC power lines from a first AC power distribution system to a second AC power distribution system.

U.S. Patent No. 4,701 ,945 describes a carrier current telephone system for use in buildings.

U.S. Patent No. 4,745,391 describes a method for transmission of information, received at a transmitter of a power distribution system, over at least one conductor of that distribution system. U.S. Patent No. 4,745,392 describes a signal transmission system over building or house wiring that includes a noise reduction circuit to reduce noise including asynchronous noise and synchronous noise.

U.S. Patent No. 4,746,897 describes an apparatus for transmitting and receiving on a power line, where the transmitter provides a relatively constant output voltage form its linear amplifier by providing both current and voltage feedback to its operational amplifier.

U.S. Patent No. 4,763,103 describes a process and method for wide band transmission, where each bit for transmission is coded as a function of its state by producing a particular coding frequency combination.

U.S. Patent No. 4,772,870 describes a low-level, low-power radio frequency (RF) communications system designed to operate as a point-to-point power line communications system (PLC) using frequencies from 50 to 600 MegaHertz (MHz) superimposed onto the AC power signal in a building. U.S. Patent No. 4,864,589 describes a spread spectrum power line communications system.

U.S. Patent No. 4,962,496 describes a method for transmitting data in the form of a sequence of data words according to PLBus communications protocol in a channel. U.S. Patent No. 4,968,970 describes a method and system for power line carrier communications, where the transmitter applies to the power line encoded logical-one and logical-zero bit signals consisting of signals formed respectively of predetermined different sequences of frequencies. U.S. Patent No. 4,988,972 describes a transmission signal sending and receiving method that uses the steps of setting the reference channel and data channels in each cycle of the AC voltage wave for transmission in the sending and receiving means, superimposing the reference transmission signal onto the reference channel and the modulated data transmission signals onto the data channels in the sending means, receiving the reference transmission signal and data transmission signal and data transmission signals by being separated from the AC voltage wave for transmission in the receiving means, and monitoring data transmission signals.

U.S. Patent No. 5,003,457 describes a data and power transmitting / receiving system applicable to a home automation system.

U.S. Patent No. 5,065,133 describes a method and apparatus for enhancing digital signal transmission which converts a digital signal to an enhanced analog signal, transmits that enhanced analog signal from one electronic component to another electrical component, and converts the enhanced analog signal back to a reconstituted digital signal.

U.S. Patent No. 5,066,939 describes a power line carrier communication system operating on a conventional three-wire power line that uses more than one of the several RF transmission lines that are defined by the three-wire power line to improve communication between units of the PLC system. U.S. Patent No. 5,068,890 describes a combined telephone and electric power distribution system, wherein both telephone signals and electric power are distributed by way of a common distribution system. U.S. Patent Nos. 5,187,865 and 5,192,231 describe a coupler for coupling power line communications between the power lines carrying different phases of the power.

U.S. Patent No. 5,241 ,283 describes a power line communication amplifier circuit for providing a signal transmission across a power line medium when operating in a transmit mode, and for providing a relatively high input impedance to the power line when in the receive mode.

U.S. Patent No. 5,257,006 describes a method and apparatus for power line communications, which utilizes common mode transmission and reception of communication signals over power lines.

U.S. Patent No. 5,319,634 describes a method and system for conducting multiple access simultaneous telephone communications in full duplex either over the power lines of a building or using RF transmission.

U.S. Patent No. 5,351 ,272 describes an improved electrical communication apparatus, which communicates high speed data / information over existing AC wiring, providing a phase linear environment for electrical transmission and reception of information on electrical wiring

U.S. Patent No. 5,410,292 describes a method for communicating information and commands within a dwelling or a property between several items of electrical equipment connected to an electrical distribution equipping the dwelling, by injecting onto said distribution circuit carrier currents conveying said information and commands. U.S. Patent No. 5,452,344 describes an FSK carrier communication system for transmitting and receiving data on an electric utility line even in the presence of extreme noise.

U.S. Patent No. 5,530,737 describes a method and system for conducting secure power line carrier communications in full duplex over the power lines of a building.

U.S. Patent No. 5,554,968 describes an apparatus that uses electric power lines to send and receive command, control and data signal structures.

U.S. Patent 5,559,377 describes an apparatus for electrical line communication that includes a coupler at each of two or more locations along a pair of lines, the coupler having capacitive circuits serially connected with an air-core transformer.

U.S. Patent No. 5,630,204 describes a system and method for providing interactive multimedia services to subscriber premises utilizing wireless and power line distribution within the subscriber premise. U.S. Patent No. 5,896,556 describes an apparatus that is adapted to provide a telephone line connection over a coax cable distributions system.

U.S. Patent No. 5,924,486 describes an environmental condition control and energy management system and method.

U.K Patent No. 553,225 describes an electric wave transmission system, which uses the power line for telephone communications.

U.K Patent No. 544,243 describes a means for communicating verbal instructions to a remote point, by means of superimposing on a polyphase power supply. Australian Patent No. 509,005 describes a power line telephone extension system in a subscriber's premises wired with AC power wires that comprises a subscriber's telephone line entering the premises from a conventional telephone system. PCT patent application number PCT US90/02291 describes an apparatus for power system communications that includes a coupler at each of two or more locations along a pair of power-lines, the coupler having a pair of serial LC circuits with an air coil.

Canadian Patent no. 1 ,057,436 describes a telephone extension system that provides portable or mobile extension telephone communication over the AC power lines.

PCT application number PCT/US95/00354 describes a communication network and method that includes an information signal line that carries a plurality of selectable information signals. PCT application number PCT/US94/031 10 describes a method and system for conducting secure power line carrier communications in full duplex over the power lines of a building.

Summary of the Invention It is desirable to provide a communication system that does not require a dedicated wired channel between a set top box and a the central office in order to provide billing information, internet access and other functions related to the use of the set top box. It is particularly desirable to provide a power line carrier base unit interfaced to the central office, a power line communication channel connecting the base unit to an extension unit, which in turn is installed in or in close proximity to the set top box In its preferred embodiment this invention makes use of the A C power line as the communication channel In alternative embodiments of this invention, the communication channel is can be an RF over-the-air wireless channel For the purposes of this disclosure, "wireless" shall be interpreted to mean RF over-the-air, AC power line or other equivalent communication means that does not require a dedicated wired connection

Accordingly, it is the primary object of this invention to provide a wireless channel for communication between a set top box and a central office Another object of this invention is to provide a base unit connected to the central office, which couples the communication signals to and from the central office on the wireless channel

A further object of this invention is to provide an extension unit connected to a set top box, which couples the communication signals to and from the set top box on the wireless channel

A still further object of this invention is to provide an extension unit that is installed within the set top box to provide the means for connecting the set top box signals through a wireless communication channel

It is another object of this invention to provide a wireless communication channel between the set top box and the central office that permits a user to connect through the set top box to billing information, internet access and entertainment services It is a further object of this invention to provide a wireless communication system that provides the set top box with a direct connection to a telephone line without requiring the use of dedicated telephone wires.

It is a still further object of this invention to provide a wireless communication channel that provides a communication channel over the A.C. power plug.

A further object of this invention is to provide a wireless communication channel that communicates between a set top box and a central office without requiring the use of an additional interface, antenna or dedicated wiring.

A still further object of this invention is to provide a wireless communication system that makes use of existing set top box power supplies, phone connections and interface circuitry, thereby reducing the cost of the combined set top box - extension unit.

Additional objects, advantages, and other novel features of this invention will be set forth in part in the description that follows and in part will be apparent to those of ordinary skill in the art upon examination of the following or may be learned with the practice of the invention. The objects and advantages of this invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. Still other objects of the present invention will become readily apparent to those skilled in the art from the following description wherein there is shown and described the preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out this invention. As it will be realized, this invention is capable of other different embodiments, and its several details, and specific electronic circuits, are capable of modification in various aspects without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not as restrictive.

Brief Description of the Drawings The accompanying drawings incorporated in and forming a part of the specification, illustrate a preferred embodiment of the present invention. Some, although not all, alternative embodiments are described in the following description. In the drawings:

Figure 1 is a top-level block diagram of the preferred power line communication system of this invention.

Figure 2 is a detailed block diagram of the preferred components of the preferred base unit of the invention.

Figure 3 is a detailed block diagram of the preferred components of the preferred extension unit of the invention. Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Detailed Description of the Invention This invention is a power line telephone connection system for use with set top boxes and which uses the AC power line as the communication channel. By providing a direct connection communication channel for a set top box that does not require dedicated telephone wiring, this invention provides telephone access to for set top boxes where dedicated telephone wiring is unavailable or inconvenient. Referring now to figure 1 , which is a top-level block diagram of the communication channel of this invention. The Central Office 101 is electrically connected to a base unit 102. Within the base unit 102 is a power line interface 103 for connection 1 1 1 to the AC power line, via a standard AC power outlet 104a. The AC power line includes the AC wiring 112 within a building or facility and including the standard AC outlets. Connected into the AC wiring is a second AC power outlet 104b. Connected into the second AC power outlet 104b is an OEM extension unit 105, which is embedded into the set top box 106, thereby, removing the necessity for additional external modules and/or wiring. This embedded OEM extension unit 105 uses power line carrier (PLC) interface circuitry well known in the art. By simply plugging in the set top box 106 into an AC power outlet, the communication channel between the set top box 106 and the base unit 102 is established, providing an AC power line communication channel to the Central Office 101. This channel provides set top box 106 access to the telephone line or Central Office 101 for accumulating billing information or other transmitting other information. The preferred set top box 106 is provided with electronic connections to external communication signal sources, such as a satellite receiver 109, a cable television signal 108, a television antenna or receiver 107, and other similar signal sources 1 10.

Figure 2 shows a block diagram of the preferred components of the base unit 102 of this invention. The base unit 102 is provided with a communication link 206 with the Central Office 101. Typically the communication link 206 is a standard telephone connection. A Central Office Interface circuit 201 is provided within the base unit 102 to buffer and isolate the base unit 102 from the Central Office 101. An electronic connection 207 is provided between the Central Office Interface circuit 201 and a digital processor 202. The digital processor 202 receives data from the Central Office Interface circuit 201 and formats and processes the received data to be sent over the power line data link 112 to the extension unit 105 in the set top box 106. For incoming data from the Central Office Interface circuit 201 , the processor utilizes a transmitter 203 to modulate the data to be sent over the power lines to the extension unit 105 in the set top box 106. For data received from the extension unit 105 in the set top box 106 a receiver 204 is employed. This data link invention can employ a wide variety of different methods of transmission, including but not limited to straight data transmissions using simple A/D conversions, frequency translations, FDMA, TDMA, and/or CDMA methods. In order to improve the reliability of the data transmission, the link may use forward error correction (FEC) as well as spread spectrum methods well known in the art for improvements in the signal-to-noise ratio of the data link. The transmitter 203 sends the desired modulated data signal to the power supply / line interface 205. The receiver 204 demodulates and the received data link signal from the extension unit 105 in the set top box 106 via the power supply / line interface 205 and sends this data to the digital processor 202 to be processed and reformatted for transmission to the Central Office 101 via the Central Office interface circuit 201. The power supply / line interface 205 provides electrical power for the base unit 102 components as well as the connection for the received and transmitted carrier signals to and from the transmitter 203 or the receiver 204 and the extension unit 105 in the set top box 106. Typically, the connection between the power supply / line interface 205 and the AC power line data link 1 12 is made through the use of a power cord with a standard two or three prong AC power plug connected into a standard wall outlet, although alternative connections are envisioned, including direct power connection wiring and connections from the power supply / line interface 205 to a power breaker box. Typically, the AC power lines 1 1 1 provide 110 VAC power, however alternative power systems are compatible with the concept of this invention.

Figure 3 shows the detailed block diagram of the preferred embodiment of the extension unit 105 of the invention. The power supply / line interface 301 , in the extension unit 105, provides the power for the extension unit 105 and its components as well as the connections for the received and transmitted carrier signals to and from the transmitter 303 and the receiver 302 interfacing with the AC power lines 1 12, via a standard two or three-prong AC plug, wall outlet, and power cord. Typically, the AC power lines 112 provide 110 VAC power, however alternative power systems are compatible with the concept of this invention. The data link receiver 302 receives and demodulates the data, sending it to the extension digital processor 304. The extension digital processor 304 processes the data received from the receiver 302 and decodes, processes and retrieves this data and sends the data to the device interface unit 305. The device interface unit 305 conditions and processes the data and provides the interface to the set top box 106. The device interface 305 also receives data from the set top box 106 and sends this received data to the extension digital processor 304, which then processes and conditions the data to be sent out to the extension transmitter 303. The extension digital processor 304 uses the transmitter 303 to modulate the data to be sent over the power line data link 1 12 to the base unit 102. This data link can make use of a variety of different methods of transmission, including but not limited to straight data transmissions using simple A/D conversions, frequency translations, FDMA, TDMA, and/or CDMA methods of transmission. In order to improve the reliability of the data transmission and its signal-to-noise ratio, the link of this invention may use forward error correction (FEC) and spread spectrum techniques. The transmitter 303 sends the desired modulated signal to the extension power supply / line interface 301.

The foregoing description is of a preferred embodiment of the invention and has been presented for the purposes of illustration and to describe the best mode of the invention currently known to the inventors. For example, alternative embodiments replacing the AC power line communication channel with a wireless RF over-the-air channel, although not preferred, are foreseeable. This disclosure is not intended to be exhaustive or to limit the invention to the precise form, connections, or choice of components disclosed. Obvious modifications and/or variations are possible and foreseeable in light of the above teachings. This embodiment of the invention was chosen and is described to provide the best illustration of the principles of the invention and its practical application and to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when they are interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.

Claims

ClaimsWe claim:

1. A power line communication system, comprising:

(A) a base unit connected to a standard telephone line; (B) a set top box connected to one or more signal sources; and

(C) an AC power line communication channel connecting said base unit to said set top box.

2. A power line communication system, as recited in claim 1 , wherein said base unit further comprises: (1) a central office interface circuit;

(2) a digital processor electrically connected to said central office interface circuit;

(3) a transmitter controlled electronically by said digital processor;

(4) a receiver controlled electronically by said digital processor; and

(5) a power supply / line interface electrically connected to said transmitter, said receiver and said AC power line communication channel.

3. A power line communication system, as recited in claim 1 , wherein said set top box further comprises an extension unit contained within said set top box.

4. A power line communication system, as recited in claim 3, wherein said extension unit, further comprises: (a) a device interface connecting said extension unit to said set top box;

(b) an extension digital processor electrically connected to said device interface;

5 (c) an extension transmitter controlled electrically by said extension digital processor;

(d) an extension receiver controlled electrically by said extension digital processor; and

(e) an extension power supply / line interface electrically 10 connected to said extension transmitter, said extension receiver, and said AC power line communication channel.