Fiber-to-coax conversion unit and method of using same

A fiber-to-coax optical network unit for converting one or more Gigabit or Ethernet Passive Optical Network (GPON or EPON) fibers to one or more coaxial cable lines to connect a subscriber's premises to a Community Access Television (CATV) system.

TECHNICAL FIELD

The present disclosure relates generally to fiber and coax cable technologies for transmitting and receiving Internet Protocol (IP) content and, more specifically, to devices for transmitting and receiving digital content to a subscriber's premises.

BACKGROUND

In hybrid fiber coax (hereinafter sometimes HFC) and radio frequency (RF) over glass (hereinafter sometimes RFOG) and passive optical network (hereinafter sometimes PON) CATV (hereinafter sometimes cable) plant designs, there is a forward path (from the cable company's transmission point to the subscriber's premises) and a return path (from the subscriber's premises back to the cable company's receiving point). The goals of all of these technologies are to provide a communication infrastructure for video, audio, and data. With the advent of the Internet Protocols (hereinafter sometimes called IP), it is the ultimate goal for cable companies to move to an IP-based communication network with fiber leading the way on maximum data capacity. The leading technologies are PON-based systems. Either GPON (Gigabit Passive Optical Network) and EPON (Ethernet Passive Optical Network) along with their 10 Gigabit newer specifications (10G PON/10G EPON).

Because it is extremely capital cost and labor expensive to replace all of the coaxial cable in the world with fiber, cable companies have been moving in stages. The first stage (S1) was moving from all coax to an HFC network where the fiber reached part way out into the system; usually the node. The second stage (S2) is to reach fiber out to the pedestal or aerial mounted TAP which typically feeds 4 or 8 homes. The last and most expensive stage (S3) would be to take fiber all the way to the home. New subdivision developments today start with this final stage (S3) of fiber directly to the home.

With each step taken by the cable companies, the speed and quality of the network improves because fiber is inherently lower in noise content and a more efficient medium of transferring information. It should be noted that after each step is taken, a time period usually exists for the cable companies to recoup their investment. This disclosure focuses on extending the useful life of stage S2.

In some Stage S2systems, fiber reaches the pedestal or aerial Tap and allows the cable company to use RFOG to get data from the Tap into the customers home. RFOG still requires DOCSIS standards for data transport.

Due to the increasing demand of higher Internet speed to support digitized video, voice, and data applications, legacy HFC networks face the challenge of catching the competition from regular Fiber-To-The-Home (FTTH) and Wireless (4G, 5G LTE) service providers to serve every subscriber to reach at least 1 Gbps downlink speed without upgrading the existing equipment to support the latest but more expensive DOCSIS standard.

SUMMARY

According to one aspect, an apparatus comprising a housing and an optical network unit and an adaptor positioned in the housing. The optical network unit is configured to convert a fiber optical signal into a second signal type, and the adaptor is configured to convert the second signal type into an RF signal. The adaptor includes a port configured to receive a coaxial cable connector.

In some embodiments, the optical network unit may include a plurality of optical network units operable to utilize at least one of GPON, EPON, 10G-PON, and 10G-EPON. In some embodiments, the adaptor may include a plurality of adaptors.

In some embodiments, the apparatus further may comprise a switch configured to selectively connect each adaptor to the optical network unit.

In some embodiments, the apparatus may further comprise a splitter positioned in the housing and connected to the optical network unit. The splitter may be configured to convert a single fiber optical signal into multiple fiber optical signals. The optical network unit may be operable to convert each of the multiple optical signals into a second signal type. Additionally, in some embodiments, the adaptor may include a plurality of adaptors configured to separately receive one of the second signal types based on the multiple optical signals.

According to another aspect, a system comprising a signal conversion unit positioned at a pedestal remote from a plurality of subscriber's premises is disclosed. The signal conversion unit comprises an optical network unit positioned in a housing that is configured to convert a fiber optical signal into a second signal type, and an adaptor positioned in the housing. The adaptor is configured to convert the second signal type into an Ethernet-based RF signal and includes at least one port coupled to a coaxial cable. The system also includes an Ethernet over Coax (EoC) converter device positioned in each subscriber's premises that is coupled to at least one coaxial cable coupled to the signal conversion unit.

In some embodiments, the system may further comprise a switch configured to selectively connect each adaptor to the optical network unit. In some embodiments, the system may further comprise a splitter positioned in the housing and connected to the optical network unit. The splitter may be configured to convert a single fiber optical signal into multiple fiber optical signals. The optical network unit may be operable to convert each of the multiple optical signals into a second signal type. Additionally, in some embodiments, the adaptor may include a plurality of adaptors configured to separately receive one of the second signal types based on the multiple optical signals.

According to another aspect, a method of using any of the devices or apparatuses described herein is disclosed. In some embodiments, the method may comprise positioning a signal conversion unit at a pedestal remote from a plurality of subscriber's premises, and coupling an Ethernet over Coax (EoC) converter device positioned in each subscriber's premises to at least one coaxial cable that is coupled to the signal conversion unit.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring now toFIG. 1, a portion of a Community Access Television (CATV) system10is shown. The system10includes an optical line terminal12that acts as the endpoint of a passive optical network (PON). In the illustrative embodiment, the passive optical network is a gigabit-capable passive optical network (PON). The optical line terminal12processes signals between the wider internet network14and one or more fiber-to-coax (FTC) conversion units16. As described in greater detail below, each FTC unit16is designed to provide a full Internet Protocol (IP) based network structure to deliver 1 Gpbs home service through the existing HFC network structure for service providers to save capital expenditure, but still build the modern infrastructure to satisfy the uptrend bandwidth requirement of video, voice and data service to the home. Each FTC unit16is connected to the terminal12via one or more fiber optic cable lines18.

The system10also includes one or more subscriber premises20, which are connected to the FTC unit16via coaxial cables22. In the system10, each FTC unit is located on a pedestal, pole, or the like, typically in the vicinity of one or more subscriber premises20. As shown inFIG. 1, each premises20includes a router or other converter device24that is connected to each line22. home gateway/broadband router from EoC (Ethernet over Coax) to regular Ethernet (CAT-5 and above) or Wi-Fi (or WAN). Each router24converts the signals received over the line22into a form for use with one or more devices26such as, for example, televisions, computers, mobile devices, and so forth. The router24may create a local area network and act as a connection point for one or more Ethernet cables such as, for example, CAT-5 cables. The router24may additionally, or alternatively, include electronic circuitry for creating a wireless area network (WAN).

Referring now toFIG. 2, the circuitry of one FTC unit16is shown in greater detail. In the illustrative embodiment, the FTC unit16is designed with a one-to-one connection to convert one GPON fiber connection to one EoC connection to each subscriber premises. As shown inFIGS. 1-2, the FTC unit16serves multiple subscribers and combines 4 or 8 (or multiple) pairs of fiber-EoC lines in an integrated outdoor box to support 1 Gbps downlink and 1 Gbps uplink over Ethernet for each subscriber premises. To do so, the FTC unit16includes a number of optical network units (ONU)30that are positioned in a housing32. Each ONU30is operable to convert optical signal(s) into another signal type (in this case, an electrical signal suitable for transmission via an Ethernet cable). The ONU may utilize GPON, EPON, 10G-PON, and 10G-EPON to convert the signals. In the illustrative embodiment, the FTC unit16includes four ONUs. Each ONU30includes a 1270-1610 nm wavelength, fiber input port SC/APC optical fiber connector34that connects to a fiber optic cable18. It should be appreciated that other connectors may be used. Each ONU30also includes a CAT-5 Ethernet port36configured to connect to an Ethernet cable38extending between each ONU30and an EoC adaptor40.

As shown inFIG. 2, the FTC unit16includes one EoC adaptor40for each ONU30. Each EoC adaptor40includes a CAT-5 or above Ethernet port42configured to connect to one of the Ethernet cables38. Each adaptor40also includes a RF input/output port44to connect to a coaxial cable22, which, in turn, is connected to a subscriber premises20. In the illustrative embodiment, each port44is a 75 Ω F-connector. It should be appreciated that other connectors may be used. The unit16also includes a power supply50to provide electrical power to the various components included in the housing32.

It should be appreciated that with the conversion unit16, a service provider can convert an existing HFC network to reach 1 Gbps downlink speed over the coaxial cable22to each premises20without changing the existing wiring. The transition and conversion of HFC to GPON service to premises20is completely transparent to the residential customers, and each conversion can simultaneously support four homes. It should be appreciated that in other embodiments the FTC conversion unit may be configured to simultaneously support eight or more homes.

It should also be appreciated that no infrastructure change is needed to deliver high-speed Internet service to each premises20because the FTC unit16uses the existing HFC network in transition to the GPON deployment, thereby saving capital expenditure for the service providers. Additionally, by using Internet Protocol (IP) as the transport layer, the network service deployed to each premises via fiber and coaxial cable can reach 1 Gbps speed and be easily expanded to higher speed with advanced modulation technology developed for data transmission over coaxial cable, thereby creating the opportunity for cable service providers to compete against telecom/DSL and wireless operators in providing high-speed Internet service to the subscriber's premises. As described above, the change is completely transparent to the residential and business subscribers because the subscribers' premises connects to the GPON service via a coaxial cable22. without the subscribers being aware of the difference of existing hardware/software but receiving the benefits of much higher Internet speed. Further, with IPv6 enabled on the addressing plane, Internet of Thing (IoT) applications can be developed to reach every network enabled device at the subscriber's premises for management, security and monitoring purpose.

Referring now toFIG. 3, another embodiment of a FTC unit (hereinafter referred to as FTC unit116) is shown. It should be appreciated that an FTC unit116may be used in the system10as an alternative to an FTC unit16. In the system10, each FTC unit116is located on a pedestal, pole, or the like, typically in the vicinity of one or more subscriber premises20. The FTC unit116, like the FTC unit16, is configured to convert a GPON fiber connection to one EoC connection to each subscriber premises. In the illustrative embodiment, however, the FTC unit116is designed with one-to-many connections to convert one GPON fiber connection to multiple EoC connections. The FTC unit116is configured to split one fiber line18to multiple coaxial cables22in an integrated housing to support sub-1 Gbps downlink and sub-1 Gbps uplink over Ethernet for each subscriber premises.

As shown inFIG. 3, the FTC unit116includes a single ONU30that is positioned in a housing118with a number of EoC adaptors40. The ONU30includes a 1270-1610 nm wavelength, fiber input port SC/APC optical fiber connector34that connects to a fiber optic cable18. It should be appreciated that other connectors may be used. The ONU30also includes a CAT-5 or above Ethernet port36configured to connect to an Ethernet cable38extending between the ONU30and a switch circuit120positioned in the housing118. The unit16also includes a power supply50to provide electrical power to the various components included in the housing118.

As shown inFIG. 3, the switch circuit120is connected to each EoC adaptor40via an Ethernet cable122. In the illustrative embodiment, the switch circuit120is operable to selectively connect each adaptor40(and hence each subscriber premises20) to the ONU30. Each EoC adaptor40includes a CAT-5 or above Ethernet port42configured to connect to one of the Ethernet cables122. Each adaptor40also includes a RF input/output port44to connect to a coaxial cable22, which, in turn, is connected to a subscriber premises20. In the illustrative embodiment, each port44is a 75 Ω F-connector. It should be appreciated that other connectors may be used.

Referring now toFIG. 4, one embodiment of an FTC unit116(hereinafter referred to as FTC unit216) is shown. It should be appreciated that an FTC unit216may be used in the system10as an alternative to an FTC unit16. In the system10, each FTC unit216is located on a pedestal, pole, or the like, typically in the vicinity of one or more subscriber premises20. The FTC unit216, like the FTC units16,116, is configured to convert a GPON fiber connection to one EoC connection to each subscriber premises. In the illustrative embodiment, the FTC unit216is also designed with one-to-many connections to convert one GPON fiber connection to multiple EoC connections. The FTC unit216includes an optical network unit30and an EoC adapter218. The optical network unit30includes a wavelength-division multiplexer (WDM)220and an optical-to-Ethernet converter222. The adaptor218includes an interface switch120and an FPGA226connected to the converter222. The FTC unit216is configured to split one fiber line18to multiple coaxial cables22in an integrated housing118to support sub-1 Gbps downlink and sub-1 Gbps uplink over Ethernet for each subscriber premises. The FTC unit216includes a fiber connector34configured to be coupled to the fiber line18and a number of F-Connectors224configured to be connected to the coaxial cables22. Power is supplied via a power supply50. The FTC unit216also includes another pass through connector228.

As described above, the system10includes one or more subscriber premises20, as shown inFIG. 5. In the illustrative embodiment, an FTC unit16is placed at a pedestal300in the vicinity of the subscriber premises20and is connected to each premises20via a coaxial cable22. As shown inFIGS. 6 and 7, each premises20includes a converter device24, such as for example, an EoC to Ethernet adaptor302(seeFIG. 6) or Wi-Fi gateway304(seeFIG. 7), that is connected to each line22. Each router24is powered via cable306and converts the signals received over the line22into a form for use with one or more devices such as, for example, televisions, computers, mobile devices, and so forth.

As shown inFIGS. 6-7, the FTC unit16is positioned within the pedestal300. In the illustrative embodiment, the FTC unit16is designed with a one-to-one connection to convert one GPON fiber connection to one EoC connection to each subscriber premises. It should be appreciated that in other embodiments the FTC unit116and associated circuitry described in regard toFIG. 3above may also be used. In the illustrative embodiment, power from cable306in the subscriber premises20is supplied from the converter device24over the cable22to the FTC unit16, thereby supplying any power necessary to operate the ONU and other circuitry of the FTC unit16. In some embodiments, the pedestal300or FTC unit16may include a visual indicator to indicate a connection has been made to a subscriber premises20and/or indicate that power is being received.

Referring nowFIGS. 8-9, other configurations of the system10are shown. In these embodiments, the pedestal300also includes a splitter circuit310to divide a single fiber line18into four separate lines312. Each of the lines312are connected within the pedestal300to the FTC unit.