Variable low frequency offset, differential, OOK, high-speed twisted pair communication

• US 6,449,318 B1
• Filed: 08/28/2000
• Issued: 09/10/2002
• Est. Priority Date: 08/28/2000
• Status: Expired due to Fees

• Current Assignee: Sofaer Capital, Inc.
• Original Assignee: Telenetwork Incorporated
• Inventors: Rumbaugh, Stephen Roy
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Nguyen, Dung X.
• Application Number:
  US09/649,309
• Time in Patent Office: 743 Days
• Field of Search: 340/853.7, 340/855.4, 340/855.5, 340/286.02, 340/288, 340/307, 340/825, 340/825.25, 340/310.01, 340/310.02, 375/308, 375/309, 375/222, 375/303, 375/295, 375/257, 379/93.01, 370/480, 370/484
• US Class Current: 375/309
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence

Abstract

A method and system for transmitting data over twisted pair copper wires using a low frequency offset, differential voltage, on-off keying (OOK) transmission technique are described. According to one embodiment, an analog or digital signal is sent or received and converted, if necessary, into or from serial format onto or out of a twisted pair. The signal uses an OOK modulated sinusoidal offset signal with an associated differential voltage. A floating reference ground set positive or negative for the differential nature of the transmission may be required. The OOK modulated offset low frequency is being keyed to the floating ground reference that is set to a minimum signal to noise ratio (SNR) level. The SNR level may be set by adjusting the voltage separation between floating ground and the offset of the sinusoidal low frequency wave. The amplitude of the sinusoidal wave may be adjusted to provide increased transmission distance and better SNR. In addition, an encoding scheme may be used to incorporate all signaling and control information within the serial transmission. Next, the transmitted signal is input into a coupler that interfaces it to the twisted pair network. At the far end, a decoupler receives the transmission and sends the OOK sinusoidal signal out to designated amplifiers to provide voltages needed for activating an OOK detection system. The OOK detection system may use current detection that is activated every time the designated OOK signal frequency is received. Clocking may be recovered using a digital phase lock loop. Further, the OOK signal is decoded and information split off to designated leads. Afterwards, the recreated square wave transmission serial bit stream is converted to compatible signaling voltages and sent to a digital computer interface.

Claims

1. A method for transmitting data over a twisted pair network using a differential voltage, frequency offset, OOK transmission, the method comprising:

receiving a data signal from a data source device;

providing a base frequency carrier;

controlling states of the base frequency carrier, the carrier states including an on state and an off state;

transmitting the data signal, using the base frequency carrier, to a twisted pair wire via a twisted pair coupler;

receiving the transmitted data signal from the twisted pair wire by a twisted pair decoupler; and

sending the data signal to a data receiving device.

2. The method of claim 1 further comprising transferring the data signal to a POTS analog connection for emergency services when power in the twisted pair network is turned off.

3. The method of claim 1 further comprising transmitting control and timing information within a serial bit stream.

4. The method of claim 1 wherein the data signal is transmitted from the data source device to the data receiving device over the twisted pair network at a rate equal to an output rate of the data source device plus a transmission control overhead.

5. The method of claim 1 wherein a frequency of the base frequency carrier is set according to a minimum signal to noise ratio.

6. The method of claim 1 wherein the data signal is transmitted using the base frequency carrier as a forward biased low frequency wave.

7. A transmission system for transmitting data from a data source device to a data receiving device over a twisted pair network using a differential voltage, frequency offset, OOK transmission, the system comprising:

a transmitter to receive a data signal from the data source device, to provide a base frequency carrier, to control states of the base frequency carrier, the carrier states including an on state and an off state, and to transmit the data signal, using the base frequency carrier, to a twisted pair wire via a twisted pair coupler; and

a receiver, coupled to the transmitter, to receive the transmitted data signal from the twisted pair wire by a twisted pair decoupler and to send the data signal to a data receiving device.

8. The system of claim 7 wherein the transmitter is configured to transfer the data signal to a POTS analog connection for emergency services using an AC relay when power in the twisted pair network is turned off.

9. The system of claim 7 wherein the transmitter is configured to transmit control and timing information within a serial bit stream.

10. The system of claim 7 wherein the transmitter is configured to transmit the data signal to the data receiving device over the twisted pair network at a rate equal to an output rate of the data source device plus a transmission control overhead.

11. The system of claim 7 wherein a frequency of the base frequency carrier is set according to a minimum signal to noise ratio.

12. The system of claim 7 wherein the data signal is transmitted using the base frequency carrier as a forward biased low frequency wave.