Integrated electrical/optical hybrid communication system with revertive hitless switch

• US 7,805,078 B1
• Filed: 08/23/2007
• Issued: 09/28/2010
• Est. Priority Date: 06/06/2002
• Status: Expired due to Fees

• Current Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Inventors: Okoro, Jeremiah, Gerszberg, Irwin
• Primary Examiner(s): Liu; Li
• Application Number:
  US11/843,908
• Time in Patent Office: 1,132 Days
• Field of Search: 398/17, 398/19, 398/23, 398/24, 398/52, 398115-120, 398/128, 359/145, 340/825, 250/205
• US Class Current: 398/115
• CPC Class Codes: H04B 10/1123 Bidirectional transmission

Abstract

A system according to embodiments of the invention may include a first communication path that converts an optically-modulated source signal to a radio signal based on a detected degradation in a quality of a received optical signal, and a second communication path that converts a radio-modulated source signal to an optical signal based on a detected degradation in a quality of a received radio signal. The system has the ability to automatically adapt to diverse weather conditions to improve the reliability of a communication link without user intervention while supporting multiple modulation schemes.

Claims

1. A method of increasing reliability of a communication system comprising:

comparing a value of a characteristic associated with an optical receive signal to a first threshold value, the optical receive signal being received following exposure to climatic conditions;

comparing a value of a characteristic associated with an electrical receive signal to a second threshold value, the electrical receive signal being received following exposure to climatic conditions;

transmitting an input signal to a first signal path and a second signal path;

coupling operatively the first signal path to an optical switch associated with an optical path, the optical path being configured to output an optical output signal based on the input signal;

coupling operatively the second signal path to electrical switch associated with an electrical path, the electrical path being configured to output an electrical output signal based on the input signal;

controlling, without user intervention, the optical switch based on a result of comparing the value of the characteristic associated with the electrical receive signal to the second threshold value using a second control circuit; and

controlling, without user intervention, the electrical switch based on a result of comparing the value of the characteristic associated with the optical receive signal to the first threshold value using a first control circuit.

2. A method of increasing reliability of a communication system defined by claim 1, wherein the value of the optical characteristic associated with the optical receive signal depends on a climatic condition.

3. A method of increasing reliability of a communication system defined by claim 1, further comprising directing the input signal through the optical path without user intervention as a result of a decrease in fog.

4. A method of increasing reliability of a communication system defined by claim 1, further comprising directing the input signal through the electrical path without user intervention as a result of a decrease in rain.

5. A method of increasing reliability of a communication system defined by claim 1, further comprising directing the input signal through the electrical path without user intervention as a result of an increase in fog.

6. A method of increasing reliability of a communication system defined by claim 1, further comprising directing the input signal through the optical path without user intervention as a result of an increase in rain.

7. A method of increasing reliability of a communication system defined by claim 1, wherein the characteristic associated with the received signal comprises a carrier-to-noise ratio (CNR).

8. A communication system comprising:

an optical communication path comprising;

an optical switch operatively coupled to an optical transceiver, the optical switch being controlled to connect the optical transceiver to the optical communication path or to a first hybrid optical-radio communication path, the optical switch receiving an optical receive signal from the optical transceiver,

an optical modulator/demodulator for demodulating the optical receive signal when the optical switch is connected to the optical communication path,

a first control circuit coupled to the optical receive signal by a first coupler after demodulation of the optical receive signal, the first control circuit including a first comparator adapted to compare a value of an optical characteristic associated with the optical receive signal to a first threshold value, the optical receive signal being exposed to climatic conditions before receipt; and

a electrical communication path comprising;

an electrical switch operatively coupled to a radio transceiver, the electrical switch being controlled to connect the radio transceiver to the electrical communication path or to a second hybrid optical-radio communication path,

an electrical modulator/demodulator for demodulating an electrical receive signal when the electric switch is connected to the electrical communication path,

a second control circuit coupled to the electrical receive signal by a second coupler after demodulation of the electrical receive signal, the second control circuit including a second comparator adapted to compare a value of an electrical characteristic associated with the electrical receive signal to a second threshold value,

wherein the first control circuit of the optical communication path generates a first control signal that is sent to the electrical switch of the electrical communication path to control whether the electrical switch connects the radio transceiver to the electrical communication path or the second hybrid optical-radio communication path and the second control circuit generates a second control signal that is sent to the optical switch to control whether the optical switch connects the optical transceiver to the optical communication path or to the first hybrid optical-radio communication path.

9. A communication system defined by claim 8, wherein the value of the optical characteristic associated with the optical receive signal depends on a climatic condition.

10. A communication system defined by claim 8, wherein the optical switch is adapted to direct the optical transmit signal or the electrical transmit signal to the optical transceiver without user intervention as a result of a decrease in fog.

11. A communication system defined by claim 8, wherein the electrical switch is adapted to direct the electrical transmit signal or the optical transmit signal to the radio transceiver without user intervention as a result of a decrease in rain.

12. A communication system defined by claim 8, wherein the electrical switch is adapted to direct the electrical transmit signal or the optical transmit signal to the radio transceiver without user intervention as a result of an increase in fog.

13. A communication system defined by claim 8, wherein the optical switch is adapted to direct the optical transmit signal or the electrical transmit signal to the optical transceiver without user intervention as a result of an increase in rain.

14. A communication system defined by claim 8, wherein the characteristic associated with the optical receive signal comprises a carrier-to-noise ratio (CNR).