Optical line terminal (OLT) optical module adapted to perform optical unit network (ONU) functionality
View Patent ↗An optical line terminal (OLT) is operable in a passive optical network (PON). The OLT comprises a plurality of optical network units (ONUs), an electrical module for generating continuous downstream signal and processing received upstream burst signals according to a communication protocol of the PON and an optical module for transmitting continuous optical signals over a first wavelength and receiving burst optical signals over a second wavelength. The optical module further includes an ONU traffic processing module is electrically coupled to the optical module and the electrical module. The ONU traffic processing module is configured to emulate one of the ONUs of the PON. An interface is used for interfacing between the electrical module and the optical module.
1. An optical line terminal (OLT) comprises:
an electrical module configured to generate continuous downstream signals and to process received upstream burst signals according to a communication protocol of a passive optical network (PON);
an optical module configured to transmit continuous optical signals over a first wavelength and to receive upstream optical burst signals over a second wavelength,
wherein the optical module comprises:
an optical network unit (ONU) traffic processing module configured to:
perform as an ONU of the PON,
transmit the upstream electrical signals to the electrical module,
test performance of the OLT,
test performance of the PON,
detect optical failures in the PON, or
measure a round trip time (RTT) of the PON; and
a signal splitter configured to split the downstream electrical signals into first downstream electrical signals and second downstream electrical signals, the first downstream electrical signals being provided to the ONU traffic processing module; and
an interface between the electrical module and the optical module.
2. The OLT of claim 1 , wherein the electrical module is further configured to assign the ONU traffic processing module with an ONU identification utilized to filter information sent in the first downstream electrical signals.
3. The OLT of claim 1 , wherein the electrical module is further configured to allocate upstream time slots for transmission of the upstream electrical signals by the ONU traffic processing module.
4. The OLT of claim 1 , wherein the ONU traffic processing module is further configured to generate an upstream test signal including a test pattern,
wherein the optical module further comprises an optical sub assembly module that comprises a first laser diode operable at the first wavelength and a first photodiode operable at the second wavelength, the optical sub-assembly being configured to transmit the upstream test signal to the PON network, to receive a response from the upstream test signal from the PON, and to provide the response to the ONU traffic processing module, and
wherein the ONU traffic processing module is further configured to process the response.
5. The OLT of claim 1 , wherein the ONU traffic processing module includes at least a network processor, a microprocessor, and a medium access control adapter.
6. The OLT of claim 1 , wherein the ONU traffic processing module provides a communication channel between the optical module and the electrical module that is compliant with the communication protocol.
7. The OLT of claim 6 , wherein the interface is a small form-factor pluggable (SFP) interface.
8. The OLT of claim 7 , wherein the PON is one of: an Ethernet PON (EPON), a ten Gigabit-Ethernet PON ( 10 G-EPON), a Gigabit PON (GPON), and a ten Gigabit PON (XG-PON).
9. An optical line terminal (OLT), comprising:
an electrical module configured to generate downstream electrical signals and to process upstream electrical signals according to a communication protocol of a passive optical network (PON); and
an optical module configured to transmit downstream optical signals over a first wavelength and to receive upstream optical signals over a second wavelength,
wherein the optical module comprises:
an optical network unit (ONU) traffic processing module configured to perform as an ONU of the PON and to transmit the upstream electrical signals to the electrical module,
an optical sub assembly module that comprises a first laser diode operable at the first wavelength and a first photodiode operable at the second wavelength;
a laser driver coupled to the first laser diode;
a limiter amplifier coupled to the first photodiode;
a controller coupled to an interface between the electrical module and the optical module; and
a signal splitter, coupled to the interface, configured to split the downstream electrical signals into first downstream electrical signals for the ONU traffic processing module and second downstream electrical signals for the laser driver.
10. The OLT of claim 9 , wherein the ONU traffic processing module is coupled to an output of the limiter amplifier and further configured to receive the upstream electrical signals.
11. The OLT of claim 9 , wherein the optical sub assembly module further comprises:
a second laser diode operable at the second wavelength.
12. The OLT of claim 11 , wherein the second wavelength is a wavelength utilized by at least one of a plurality of ONUs of the PON for upstream communication.
13. The OLT of claim 9 , wherein the optical sub assembly module further comprises:
a second laser diode configured to transmit the downstream optical signals based on analysis signals generated by the ONU traffic processing module over a third wavelength; and
a second photodiode configured to receive the upstream optical signals based on the analysis signals over the third wavelength.
14. The OLT of claim 13 , wherein the third wavelength is a dedicated wavelength utilized for transmission and reception of optical signals based on the analysis signals generated by the ONU traffic processing module.
15. The OLT of claim 9 , wherein the first and second wavelengths are wavelengths defined for OLT communication by the communication protocol.
16. The OLT of claim 9 , wherein the optical module further comprises:
a signal switching unit configured to recieve the upstream electrical signals from the ONU traffic processing module and from the limiter amplifier and to provide either the upstream electrical signals received from the ONU traffic processing module or the upstream electrical signals received from the limiter amplifier to the interface.
17. An optical module apparatus, comprising:
an optical sub assembly module comprising a laser diode, operable at a first wavelength, configured to transmit first optical signals over the first wavelength and a photodiode, operable at a second wavelength, configured to receive second optical signals over the second wavelength;
an optical network unit (ONU) traffic processing module configured to perform as an ONU of a passive optical network (PON), to transmit electrical signals to an electrical module, and to test performance of an optical line terminal (OLT), test performance of the PON, detect optical failures in the PON, or measure a round trip time (RTT) of the PON; and
a signal splitter configured to split the downstream electrical signals into first downstream electrical signals and second downstream electrical signals, the first downstream electrical signals being provided to the ONU traffic processing module.
18. The optical module apparatus of claim 17 , wherein the electrical module is implemented as part of the OLT, and
wherein the ONU traffic processing module is coupled to the electrical module.
19. The optical module apparatus of claim 18 , further comprising:
a laser driver coupled to the laser diode;
a limiter amplifier coupled to the photodiode;
a controller coupled to an interface; and
a signal splitter, coupled to the interface, configured to split the electrical signals into first electrical signals for the ONU traffic processing module and second electrical signals for the laser driver.
20. The optical module apparatus of claim 19 , wherein the ONU traffic processing module is further coupled to an output of the limiter amplifier and configured to receive the first electrical signals.
21. The optical module apparatus of claim 20 , wherein the optical sub assembly module further comprises:
a second laser diode operable at the second wavelength.
22. The optical module apparatus of claim 21 , wherein the second wavelength is a wavelength utilized by at least one of a plurality of ONUs of the PON for upstream communication.