Ethernet passive optical network over coaxial (EPOC)
View Patent ↗Embodiments of the present invention exploit the existing capabilities of the Ethernet Passive Optical Network (EPON) MAC layer, designed for fiber optics communications, to provide a low cost MAC layer with upper layer connectivity over a hybrid fiber coaxial (HFC) network. In particular, embodiments allow for the EPON MAC to be used end-to-end (i.e., from an optical line terminal (OLT) to a coaxial network unit (CNU)) in a HFC network, thereby fully leveraging the packet processing capabilities, QoS functions, and management features of the EPON MAC. Furthermore, embodiments enable unified provisioning and management for both fiber and coaxial network units in a HFC network.
1. A media converter, comprising:
a first interface configured to receive a first optical signal sent from an optical line terminal (OLT) and generate a first bitstream having a first physical layer (PHY) encoding;
a PHY conversion module, coupled to the first interface, configured to perform PHY layer conversion of the first bitstream to generate a second bitstream having a second PHY encoding; and
a second interface, coupled to the PHY conversion module, configured to generate a first radio frequency (RF) signal from the second bitstream and to transmit the first RF signal to a coaxial network unit (CNU).
2. The media converter of claim 1 , wherein the second interface is further configured to receive a second RF signal from the CNU and generate a third bitstream therefrom having the second PHY encoding, wherein the PHY conversion module is further configured to perform PHY layer conversion of the third bitstream to generate a fourth bitstream therefrom having the first PHY encoding, and wherein the first interface is further configured to generate a second optical signal from the fourth bitstream and to transmit the second optical signal to the OLT.
3. The media converter of claim 2 , wherein the first interface includes a digital optical receiver to receive the first optical signal from the OLT, and a digital optical laser to transmit the second optical signal to the OLT.
4. The media converter of claim 1 , wherein the first interface includes an optical burst transceiver.
5. The media converter of claim 1 , wherein the second interface includes an RF transceiver.
6. The media converter of claim 1 , wherein the first PHY encoding is Ethernet Passive Optical Network (EPON) PHY encoding, and wherein the second PHY encoding is Ethernet Passive Optical Network Over Coax (EPOC) PHY encoding.
7. The media converter of claim 1 , wherein data packets contained in the first bitstream and in the second bitstream have a same Media Access Control (MAC) layer.
8. The media converter of claim 7 , wherein the MAC layer is of an Ethernet Passive Optical Network (EPON) MAC layer.
9. The media converter of claim 7 , wherein the MAC layer is that of an IEEE 802.3ah MAC layer.
10. The media converter of claim 1 , wherein the OLT and the CNU both are configured to operate an Ethernet Passive Optical Network (EPON) MAC layer.
11. The media converter of claim 1 , wherein the media converter enables end-to-end provisioning, management, and Quality of Service (QoS) functions between the OLT and the CNU.
12. The media converter of claim 1 , wherein the media converter is coupled to the OLT by only a fiber optic hue.
13. The media converter of claim 1 , wherein the media converter is integrated within an optical network unit (ONU) located between the OLT and the CNU.
14. The media converter of claim 1 , wherein the media converter is integrated within a network node or amplifier located between the OLT and the CNU.
15. The media converter of claim 1 , wherein the PHY conversion module comprises:
a first module configured to replace a first line encoding of the first bitstream with a second line encoding, and to add inner and outer forward error correction (FEC) bits and framing bits to generate the second bitstream; and
a second module that divides the second bitstream into a plurality of sub-bands.
16. The media converter of claim 15 , wherein the second module performs one of Sub-band Division Multiplexing (SDM), wavelet Orthogonal Frequency Division Multiplexing (OFDM), and Discrete Wavelet Multitone (DWMT).
17. The media converter of claim 15 , wherein the second interface is configured to Pulse Amplitude Modulation (PAM) encode the plurality of sub-bands to generate the first RF signal.
18. The media converter of claim 15 , wherein the PHY conversion module further comprises:
a controller chip, coupled to the first interface, configured to provide software configuration, management, and control of the first module and second module.
19. The media converter of claim 15 , wherein the second bitstream is shorter than the first bitstream.
20. The media converter of claim 19 , wherein the controller chip registers the media converter with the OLT.
21. A method, comprising:
receiving a first optical signal;
generating a first bitstream having a first physical layer (PHY) encoding from the first optical signal;
performing PHY layer conversion of the first bitstream to generate a second bitstream having a second PHY encoding;
generating a first radio frequency (RF) signal from the second bitstream; and
transmitting the first RF signal.
22. The method of claim 21 , further comprising:
receiving a second RF signal;
generating a third bitstream having the second PHY encoding from the second RF signal;
performing PHY layer conversion of the third bitstream to generate a fourth bitstream having the first PHY encoding;
generating a second optical signal from the fourth bitstream; and
transmitting the second optical signal.
23. The method of claim 21 , wherein the first PHY encoding is Ethernet Passive Optical Network (EPON) PHY encoding, and wherein the second PHY encoding is Ethernet Passive Optical Network Over Coax (EPOC) PHY encoding.
24. The method of claim 21 , wherein data packets contained in the first bitstream and in the second bitstream have same Media Access Control (MAC) layer.
25. The method of claim 24 , wherein the MAC layer is of an Ethernet Passive Optical Network (EPON) MAC layer.
26. The method of claim 24 , wherein the MAC layer is that of an IEEE 802.3ah MAC layer.
27. The method of claim 21 , wherein performing PHY layer conversion comprises:
replacing a first line encoding of the first bitstream with a second line encoding;
adding inner and outer forward error correction (FEC) bits; and
adding framing bits to generate the second bitstream.
28. The method of claim 27 , wherein performing PHY layer conversion further comprises:
dividing the second bitstream into a plurality of sub-bands.
29. The method of claim 28 , wherein dividing the second bitstream into the plurality of sub-bands includes performing one of Sub-band Division Multiplexing (SDM), wavelet Orthogonal Frequency Division Multiplexing (OFDM), and Discrete Wavelet Multitone (DWMT).
30. The method of claim 28 , wherein generating the first RF signal from the second bitstream comprises Pulse Amplitude Modulation (PAM) encoding the plurality of sub-bands.
31. The method of claim 21 , wherein the second bitstream is shorter than the first bitstream.