Method and apparatus for providing a 10BASE-T compatible home network over a ...

(54) METHOD AND APPARATUS FOR

PROVIDING A 10BASE-T COMPATIBLE
HOME NETWORK OVER A SINGLE
TWISTED-PAIR PHONE LINE

(75) Inventor: Ce Richard Liu, Sugarland, TX (US)

(73) Assignee: Compaq Information Technologies Group, L.P., Houston, TX (US)

3Com Corp. website, Robyn Aber; "XDSL Supercharges Copper"; Mar. 1997; pp. 1-5.

Tut Systems website; "Simply delivering xDSL . . . connecting the local loop to the campus, the high rise and throughout the home."; website update Nov. 3, 1997; pp. 1-6.

Zona Research, Inc.; "Compaq Hits Homerun with Tut"; Aug. 11, 1998; pp. 1-2.

( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.

(21) Appl. No.: 09/182,922

(22) Filed: Oct. 30, 1998

(51) Int. CI.7 H04J 3/16; H04J 3/22

(52) U.S. CI 370/465; 375/244

(58) Field of Search 370/378, 379,

370/282, 283, 284, 461, 462, 463, 465;

375/219, 220, 244

(56) References Cited

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OTHER PUBLICATIONS

Texas Instruments; "Implementing an/4 Shift D-QPSK Baseband Modem Using the TMS320C50"; Sep. 1996; pp. 1-40.

A device for seamlessly providing 10BASE-T compatible data communications over an ordinary single twisted pair home phone line between multiple computers, between computers and peripherals, and between multiple peripherals. Each component that is to communicate over the home phone line will have a 10BASE-T compatible network interface card (NIC) for interfacing with the device. A transmit/receive switch is used to switch the device between a transmit mode and a receive mode. When signal are being transmitted from a component a Manchester coder decodes signals received from the NIC. A differential converter is used to convert the differential signal received from the NIC to a single signal. A modulator is used to modulate the signal to a RF signal using a modulation scheme such as PSK, QPSK, QAM or MCM schemes. A filter is used to limit the bandwidth of the modulated signal and a driver is used to amplify the signal to match the impedance of the phone line. When the device is receiving signal from the phone lines, the signal is filtered with a bandpass filter and amplified with an amplifier. The signal is demodulated with a demodulator using the appropriate demodulation scheme. The demodulated signal is differentially encoded with a differential converter. The Manchester coder will encode the signal and send the signal to the receiving NIC.

6 Claims, 2 Drawing Sheets

1

METHOD AND APPARATUS FOR
PROVIDING A 10BASE-T COMPATIBLE
HOME NETWORK OVER A SINGLE
TWISTED-PAIR PHONE LINE

FIELD OF THE INVENTION

The present invention relates to home network computer systems, and more particularly, but not by way of limitation, to a method and apparatus for providing lOBase-T Ethernet compatible data communications between computers and peripherals over an ordinary single twisted pair phone line without conflicting with other signals, such as POTS and xDSL signals, being transmitted over the same single twisted pair phone lines.

BACKGROUND OF THE INVENTION

As more appliances and items in the home become computer controlled and as more homes obtain multiple computer systems, such as one for the "home office" and one for the family, the importance of having a home network system to allow data communications between the various computer systems and peripherals within a home is ever increasing.

Baseband Ethernet technology is currently being used by many businesses for data interconnection between computers. One common widely used baseband ethernet technology being used is the 10BASE-T network. The 10BASE-T network has an operating rate of 10 Mbps, utilizes CSMA/ CD access protocol, baseband signaling and Manchester data encoding.

A standard 10BASE-T network interface card (NIC) is typically used in the construction of a 10 Mbps Ethernet LANs utilizing unshielded twisted-pair wire. Under the 10BASE-T standard, workstations are cabled using twistedpair wire (one twisted pair for transmission and one twisted pair for reception) to medium access units (MAUs). Each MAU normally has a builtin attachment interface unit (AIU) that can be cabled to a coaxial transceiver attached to coaxial cable.

However, because home phone lines are traditionally considered to be narrow band and therefore only permit low data rate signals, bringing Ethernet to the home environment would require new wiring in virtually every home.

Some proposed solutions to home networking include standard modem technology and digital subscriber line (xDSL) technology. One of the problems with standard modem technology is that it is currently limited to data speeds of 56 kbps and requires very complicated circuitry. Although, xDSL technology can transmit data at a much higher rate that standard modem technology, up to 4 Mbps, the cost of implementing such is very high and requires very complicated modulation methods.

Another proposed solution is the wireless solution. Wireless solutions would also be very expensive to implement and do not have the reliability of a wired solution.

One existing home network product is that of TUT Systems, the HR1300T. The HR1300T uses a "time modulation line code" to provide an in-home network over existing phone lines. However, this modulation scheme only provides a slow 1.3 Mbps data rate.

Therefore, as can be appreciated, there is a need to provide an easy-to-install-and-use, low cost home networking solution that can provide high data rates.

SUMMARY OF THE INVENTION

The present invention overcomes the above identified problems as well as other shortcomings and deficiencies of

2

existing technologies by providing a method and apparatus that enables seamless lOBase-T Ethernet compatible data communications between computers and peripherals over an ordinary single twisted pair phone line without conflicting

5 with other signals, such as POTS and xDSL signals, being transmitted over the same single twisted pair phone lines.

The present invention further provides a device for seamlessly providing 10BASE-T compatible data communications over an ordinary single twisted pair home phone line

1° between multiple computers, between computers and peripherals, and between multiple peripherals. Each component that is to communicate over the home phone line will have a 10BASE-T compatible network interface card (NIC) for interfacing with the device. The device includes a

15 Manchester coder; differential converter; baseband processor; modulator; demodulator; filters; amplifiers, and a transmit/receive switch. The transmit/receive switch is used to switch the device between a transmit mode and a receive mode. When signal are being transmitted from a component

20 the Manchester coder decodes signals received from the NIC. The differential converter is used to convert the differential signal received from the NIC to a single signal. The modulator is used to modulate the signal to a RF signal using a modulation scheme such as one of the PSK, QPSK, QAM

25 or MCM schemes. A filter is used to limit the bandwidth of the modulated signal and a driver is used to amplify the signal to match the impedance of the phone line. When the device is receiving a signal from the phone lines, the signal is filtered with a bandpass filter and amplified with an

30 amplifier. The signal is demodulated using the appropriate demodulation scheme. The demodulated signal is differentially encoded. The Manchester coder will encode the signal and send the signal to the receiving NIC.

35 BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be had by reference to the following Detailed Description and appended claims when taken in conjunction with the accompanying Drawings wherein: 40 FIG. 1 is a block diagram of an exemplary home utilizing the present invention; and

FIG. 2 is a schematic block diagram of an exemplary embodiment of the present invention.

45 DETAILED DESCRIPTION

With reference to FIG. 1, there is shown a block diagram of a home 110 in which an exemplary embodiment the present invention is being utilized to provide a high rate data

5Q communications between multiple computers and peripherals connected to a single twisted pair of home phone lines.

As depicted in FIG. 1, home 110 includes multiple computers, such as computers 112. Each of the computers includes a network interface card (NIC) 114. The NIC of

55 each computer is connected to a converter, such as converter 116. The converter of each computer is connected to the phone lines 118 of the house through a standard phone jack 120.

In this exemplary embodiment of the present invention, 60 each of the NICs are standard 10BASE-T network interface cards. As can be appreciated, a standard 10BASE-T NIC provides that the data communication received and transmitted therefrom occur over two twisted-pair wires. The first twisted pair is for transmission of data (T+, T-) and the 65 second twisted pair is for receiving data (R+, R-).

Still referring to FIG. 1, the converters 116, which are connected between each of the computers and the phone