Optical telecommunications devices, systems, and methods

Patent metadata

Field	Value
Publication number	US-10079645-B2
Application number	US-201615383175-A
Country	US
Kind code	B2
Filing date	Dec 19, 2016
Priority date	Dec 31, 2015
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

Optical telecommunications devices, systems, and methods. In some implementations, an optical networking unit (ONU) includes a multi-rate receiver having an operating bandwidth that is selected operationally based on physical layer characteristics of received signals and information received from a MAC. The ONU can also include an upstream laser circuit having an output impedance that differs from a characteristic impedance of a system in which the laser circuit is implemented. The ONU can also include a decision feedback equalizer (DFE) having at least one tap weight that is fixed to facilitate convergence of the DFE when signals received by the DFE would otherwise fail to meet characteristics required for DFE convergence.

First claim

What is claimed is:

1. An ONU, comprising:
a multi-rate receiver having an operating bandwidth that is selected operationally based on physical layer characteristics of received signals and information received from a MAC, the multi-rate receiver configured to:
obtain the physical layer characteristics of the received signals, wherein the received signals are input to a DFE or output from the DFE;
obtain the information from the MAC, wherein the information from the MAC is quality of service information from the MAC;
determine a data rate of received communications based on the physical layer characteristics and the quality of service information; and
automatically connect one of multiple different feedback resistors across a TIA based on the determination;

an upstream laser circuit; and
the DFE having at least one tap weight that is fixed.

2. The ONU of claim 1 , wherein the DFE is configured to have at least one tap weight that is pre-set to ensure convergence of the DFE when characteristics of signals received from the TIA fail to meet required characteristics for DFE convergence.

3. The ONU of claim 1 , wherein the multi-rate receiver comprises the TIA, and performance of the multi-rate receiver at each of two or more rates is optimized by switching between two or more different feedback resistors that are connected across the TIA.

4. The ONU of claim 3 , further comprising a processor configured to select which of the two or more different feedback resistors are connected across the TIA based on the physical layer characteristics of the received signals and the information received from the MAC.

5. The ONU of claim 4 , wherein circuitry connected to the DFE is configured to provide the physical layer characteristics to the processor.

6. A multi-rate receiver comprising:
a TIA;
a set of selectable feedback resistors connected across the TIA; and
a microprocessor that selects a feedback resistor from the set based on physical layer characteristics of received signals and information received from a MAC, the microprocessor configured to:
obtain the physical layer characteristics of the received signals, wherein the received signals are input to a DFE or output from the DFE;
obtain the information from the MAC, wherein the information from the MAC is quality of service information from the MAC;
determine a data rate of received communications based on the physical layer characteristics and the quality of service information; and
automatically connect the feedback resistor from the set across the TIA based on the determination.

7. The multi-rate receiver of claim 6 , wherein the set of selectable feedback resistors includes a narrow-band feedback resistor and a wide-band feedback resistor.

8. The multi-rate receiver of claim 6 , wherein the microprocessor receives the physical layer characteristics from circuitry connected to an input of the DFE.

9. The multi-rate receiver of claim 6 , wherein the physical layer characteristics includes an eye-opening measure.

10. A receiver having an improved operating bandwidth, comprising:
a TIA; and
a DFE having at least one tap weight that is pre-set to ensure convergence of the DFE when characteristics of signals received from the TIA fail to meet required characteristics for DFE convergence, wherein the at least one tap weight is associated with a second tap, and the second tap is pre-set and fixed at a maximum weight.

11. The receiver of claim 10 , wherein the at least one tap weight is pre-set to facilitate convergence of the DFE when signals received from the TIA have less than a specified eye opening.

12. A method, comprising
obtaining physical layer characteristics from signals input to a DFE or output from the DFE;
obtaining quality of service information from a MAC;
determining a data rate of received communications based on the physical layer characteristics and the quality of service information; and
automatically connecting one of multiple different feedback resistors across a TIA based on the determination.

13. The method of claim 12 , wherein connecting one of multiple different feedback resistors across the TIA comprises:
connecting a narrow-band feedback resistor across the TIA when the data rate is determined to be less than a higher supported data rate; and
connecting a wide-band feedback resistor across the TIA when the data rate is determined to be at the higher supported data rate.

14. The method of claim 12 , wherein the physical layer characteristics include one or more of a measure of an eye opening of signals received at the DFE, an amount of time between signal transitions, a number of signal transitions detected over a given amount of time, or a signal to noise measure for signals received at the DFE.

15. The method of claim 12 , wherein the quality of service information includes one or more of a dropped packets count, a dropped packets rate, a frame error rate, or a bit error rate.

Assignees

• Adtran Inc

Inventors

• Joffe Daniel M

Classifications

• H04L25/03057

  with a recursive structure (H04L25/03031 takes precedence) · CPC title

• H04B10/272 Primary

  Star-type networks {or tree-type networks} · CPC title

• H04B10/07953

  Monitoring or measuring OSNR, BER or Q · CPC title

• H04B10/69

  Electrical arrangements in the receiver · CPC title

• H03F3/04

  with semiconductor devices only · CPC title