System, device and method of expanding the operational bandwidth of a communication infrastructure

Embodiments of the invention include a method, device an/or system of expanding the operational bandwidth of a communication infrastructure. An optical gathering box may include, according to some demonstrative embodiments of the invention, an optical connector to optically connect the apparatus to an optic fiber; and at least one interface including first and second radio-frequency connectors; an optical to radio-frequency converter to convert a downstream optical signal received via the optical connection into an extended downstream radio-frequency signal in an extended downstream frequency band; and a triplexer to route the extended downstream signal to the first radio-frequency connector; to route a legacy downstream radio-frequency signal in a legacy frequency band from the second radio-frequency connector to the first radio-frequency connector; and to route a legacy upstream radio-frequency signal in the legacy frequency band from the first radio-frequency connector to the second radio-frequency connector. Other embodiments are described and claimed.

FIELD OF THE INVENTION

The present invention generally relates to communication systems and methods and, more particularly, to devices, systems and methods of expanding the effective frequency range of broadband communication, for example, over a cable television network.

BACKGROUND OF THE INVENTION

Cable television (CATV) is a form of broadcasting that transmits programs to paying subscribers via a physical land based infrastructure of coaxial (“coax”) cables or via a combination of fiber-optic and coaxial cables (HFC).

CATV networks provide a direct link from a transmission center, such as a head-end, to a plurality of subscribers at various remote locations, such as homes and businesses, which are usually stationary and uniquely addressable. The head-end may be connected to the subscribers via local hubs, commonly referred to as “nodes”, which route the flow of data to and/or from a predefined group of subscribers, e.g., hundreds of subscribers, in a defined geographical area, for example, a small neighborhood or an apartment complex. The typical distances between the local nodes and the subscribers are relatively short, for example, up to a few thousand feet. Therefore, the communication between nodes and their subscribers is commonly referred to as “last mile” communication.

Existing CATV networks utilize a signal distribution service to communicate over multiple channels using various formats, for example, analog and/or digital formats for multi-channel TV programs, a high definition TV (HDTV) format, providing interactive services such as “video on demand”, and other multimedia services, such as Internet access, telephony and more.

A number of elements are involved in maintaining a desired flow of data through coaxial conductors or through a combination of fiber optics and coaxial cables from the head-end to the subscribers of a CATV system. In a conventional HFC cable TV system, the head end is connected to the local nodes via dedicated optical fibers. In the last mile system, each local node converts the optical signals received from the head-end into corresponding electrical signals, which may be modulated over a radio frequency (RF) carrier, to be routed to the local subscribers via coax cables.

The head-end is the central transmission center of the CATV system, providing content (e.g., programs) as well as controlling and distributing other information, e.g., billing information, related to customer subscribers.

The downstream signals, which are limited to designated channels within a standard frequency range (band) of 48 MHz to 860 MHz (or up to 1,000 MHz by recently introduced Stretching technology) are modulated on a light beam, e.g., at a standard wavelength of 1550 nm, and sent to the local node via a fiber-optical cable. An optical converter at the local node detects the optical signals and converts them into corresponding electrical signals to be routed to the subscribers.

In the reverse direction, the local optical node receives upstream data from all the local subscribers in the last mile section. These are carried by RF electrical signals at a standard frequency band of 5 MHz to 42 MHz, which does not overlap with the downstream band. A converter in the local optical node converts the upstream data into corresponding optical signals by modulating the data on an optical carrier beam, e.g., at a wavelength of 1310 nm, to be transmitted back to the head-end.

The electrical last mile system usually includes low-loss coax cables, which feed a plurality of serially-connected active elements, for example, line extension amplifiers and, if necessary, bridge trunk amplifiers (e.g., in case of splitting paths). In addition, many passive devices of various types may be fed by tapping from the main coaxial line in between the active amplifiers. These passive devices may be designed to equalize the energies fed to different subscriber allocations such that signals allocated to subscribers closer to the local node and/or to one or more of the active devices may be attenuated more than signals allocated to subscribers further away from the node or active devices.

In conventional systems, each passive device can feed a small group of subscribers, usually up to 8 subscribers, via drop cables having a predetermined resistance (e.g., 75Ω), feeding designated CATV outlets at the subscriber end. The drop cables are flexible and differ in attenuation parameters from the coaxial cables that feed the passive devices. The hierarchy of commonly used coaxial drop cables includes the RG-11 coaxial cable, which has the lowest loss and thus the highest performance, then the intermediate quality RG6-cable, and finally the basic quality RG-59 cable. All drop cables used in the industry are usually connected using standard “F type” connectors.

SUMMARY OF SOME DEMONSTRATIVE EMBODIMENTS OF THE INVENTION

Some demonstrative embodiments of the present invention may include an improved “last mile” segment of a communication system, such as a Cable Television (CATV) system, in addition or instead of existing last mile segments.

Devices, systems and/or methods according to some demonstrative embodiments of the invention may expand the operational bandwidth of a CATV system, for the downstream and/or upstream paths, e.g., by 2 GHz or more (an improvement of more than 200% compared to the limited ranges of conventional downstream and upstream signals). This may enable communication over multiple channels at exceptionally high data transmission rates, e.g., up to Gigabits per second.

Additionally, some embodiments of the invention may provide Symmetrical data transfer, e.g., expansion of “upstream” throughput such that the “upstream” throughput may be as high as the “downstream” throughput. Furthermore, some embodiments of the invention may provide this expanded bandwidth without compromising quality, and particularly without adversely interrupting and/or interacting with standard legacy services, which may continue to operate in parallel with the system of the invention in some embodiments, e.g., using the coaxial cables, active devices and passive devices of existing last mile CATV infrastructures.

Some demonstrative embodiments of the invention introduce a supplemental and/or alternative method of last mile communication between nodes and subscribers, for example, using a local fiber optical system that may carry expanded broadband signals, e.g., in parallel with an existing local coaxial system, wherein the local coaxial system may continue to transmit legacy signals in an uninterrupted manner.

According to some embodiments of the invention, at least some of the existing Consumer Premises Equipment (CPE), for example, existing Set Top Boxes (STBs) and/or Modems, may continue to operate “as is”, e.g., for transmitting and/or receiving conventional signals and/or expanded broadband signals. The existing CPE may be uninfluenced by the parallel local fiber optical system of the present invention. Accordingly, methods and/or devices according to some embodiments of the invention may be implemented at a reduced cost and/or complexity compared to conventional technologies for extension of bandwidth over CATV networks that may require the use of non-standard and/or proprietary CPE and/or head-end equipment.

According to some demonstrative embodiments of the invention, the local fiber optical system may be used in conjunction with a local coaxial system with an expanded frequency band, for example, a coaxial system employing suitable frequency up-conversion and/or down-conversion schemes, also referred to as Block Division Multiplexing (“BDM”), e.g., as described in U.S. patent application Ser. No. 10/869,578, filed Jun. 16, 2004, entitled “A Wideband Node in a CATV Network” (Reference 1); European Patent Application 04253439, filed Jun. 10, 2004, entitled “A Wideband Node in a CATV Network”, and published Dec. 21, 2005 as EP Publication No. 1608168 (Reference 2); and/or in U.S. patent application Ser. No. 11/041,905, filed Jan. 25, 2005, entitled “DEVICE, SYSTEM AND METHOD FOR CONNECTING A SUBSCRIBER DEVICE TO A WIDEBAND DISTRIBUTION NETWORK”, and published Jul. 14, 2005 as U.S. publication No. 2005/0155082 (Reference 3), the entire disclosures of all of which applications are incorporated herein by reference. This may result in further expansion of the frequency band of the local system. For example, the local fiber optics according to embodiments of the invention may be installed in parallel with existing coaxial system implementing BDM, forming a hybrid system that enables hyper expansion of symmetric bandwidth at a relatively low cost. Additionally or alternatively, the downstream and/or upstream bandwidth may be expanded by DWM and/or Dense Wave Division Multiplexing (DWDM) technologies, e.g., as are known in the art.

Some demonstrative embodiments of the invention may enable expansion of downstream and/or upstream transmission bandwidths of CATV systems, using relatively low-cost optical elements in the local optical system. This may be achieved, for example, by modulating downstream and/or upstream signals to be used by the local optical system on a carrier light beam at a wavelength that may be reproduced by relatively simple optical devices. For example, in some embodiments, visible light beams of two different wavelengths, e.g., corresponding to the red and green spectrums, may be used for upstream and downstream, respectively, in the local system.

According to some demonstrative embodiments of the invention, the local upstream and/or downstream wavelengths may be different from the downstream and upstream wavelengths (e.g., of 1550 nm and 1310 nm, respectively) used for communication between the head-end and the local nodes.

According to some demonstrative embodiments of the invention, expanded downstream data from the head-end may be detected at the local node and converted into corresponding electrical signals, which may then be further converted electrically to a standard bandwidth to be routed to the subscribers via the local coaxial system. Expanded upstream data from the subscribers may be detected at the local node and converted into electrical signals in a standard upstream bandwidth, and then converted into corresponding optical signals to be sent back to the head-end. This electrical-to-optical and optical-to-electrical conversion may be performed by suitable converters at the head-end and/or at the local node, e.g., according to frequency up-conversion and/or down-conversion schemes, as are described in detail in References 1, 2 and/or 3. The local fiber optical system of the present invention, which may be laid in parallel with the existing coaxial cables, may be used to communicate the expanded bandwidth between the subscribers and the local node.

According to some demonstrative embodiments of the invention, the local optical system may include an optical adapter (“gathering box”), which may be installed, for example, in parallel with the passive elements of the local coaxial system.

According to some demonstrative embodiments of the invention, the optical adapter may include an optical connector to optically connect the adapter to the local optic fiber; and at least one interface. The interface may include first and second radio-frequency connectors; and an optical to radio-frequency converter to convert a downstream optical signal received via the optical connection into an extended downstream radio-frequency signal in an extended downstream frequency band. The optical connector may also include triplexer to route the extended downstream signal to the first radio-frequency connector; to route a legacy downstream radio-frequency signal in a legacy frequency band from the second radio-frequency connector to the first radio-frequency connector; and/or to route a legacy upstream radio-frequency signal in the legacy frequency band from the first radio-frequency connector to the second radio-frequency connector. The triplexer may include, for example, a three or four section filter.

According to some demonstrative embodiments of the invention, the interface may also include a radio-frequency to optical converter to convert an extended upstream radio-frequency signal in an extended upstream frequency band into an upstream optical signal. The triplexer may also be able to route the extended upstream signal from the first radio-frequency connector to the radio-frequency to optical converter.

According to some demonstrative embodiments of the invention, the optical adapter may include two or more interfaces. In these embodiments, the optical adapter may also include an optical splitter/combiner to split the downstream optical signal into two or more optical downstream signals; to direct the two or more optical downstream signals to the optical to radio-frequency converters of the two or more interfaces, respectively; and to direct two or more upstream optical signals received from the two or more interfaces to the optical connector.

Some demonstrative embodiments of the invention may be used in conjunction with a Wideband Subscriber Interface Unit (also referred to as an XTB) at the subscriber end, e.g., as described in References A and/or B, enabling use of existing CPE in conjunction with equipment according to the invention. The XTB may receive from the subscribers standard CATV data, e.g., 48 MHz to 1000 MHz downstream and 5 MHz to 42 MHz (OR 85 MHz) upstream, and provide the expanded, e.g., BDM multiplexed, data in higher downstream and upstream frequency ranges, which may be converted to respective new ranges within the legacy upstream and downstream bands. For example, a 1250 MHz to 1950 MHz expanded downstream band may be converted to a 160 to 860 MHz new downstream legacy band, and a 2250 to 2750 MHz expanded upstream band may be converted to multiples of 5-42 MHz (or 10 to 85 MHz) in the upstream band.

It will be appreciated that this aspect of the invention is not limited to any specific expanded frequency ranges, and that any other desired ranges may also be suitable for use in conjunction with embodiments of the invention; for example, some embodiments of the invention may use a 1100-1900 MHz expanded downstream range and/or a 2100-2900 MHz expanded upstream range.

It will be appreciated that for simplicity and clarity of illustration, elements shown in the drawings have not necessarily been drawn accurately or to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity or several physical components included in one functional block or element. Further, where considered appropriate, reference numerals may be repeated among the drawings to indicate corresponding or analogous elements. Moreover, some of the blocks depicted in the drawings may be combined into a single function.

DETAILED DESCRIPTION OF SOME DEMONSTRATIVE EMBODIMENTS OF THE INVENTION

Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining,” or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulate and/or transform data represented as physical, such as electronic, quantities within the computing system's registers and/or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices. In addition, the term “plurality” may be used throughout the specification to describe two or more components, devices, elements, parameters and the like.

Various systems, methods and devices for expanding the effective bandwidth of conventional Cable Television (CATV) networks beyond the limited ranges of conventional downstream and upstream signals, e.g., by 200 percent or more, are described in References 1, 2 and/or 3. As described in these applications, the expansion of bandwidth may be achieved by introducing new active electronic devices, as well as new passive elements, along the last-mile coaxial portion of an existing HFC or other CATV network.

In some demonstrative embodiments of the invention described herein, the term “wide frequency band” may refer to an exemplary frequency band of, e.g., 5-3000 MHz; the term “extended upstream frequency band” may refer to an exemplary frequency band of 2250-2750 MHz; the term “extended downstream frequency band” may refer to an exemplary frequency band of 1250-1950 MHz; the term “legacy upstream frequency band” may refer to an exemplary frequency band of 5-42 MHz or 5-60 MHz; the term “legacy downstream frequency band” may refer to an exemplary frequency band of 54-860 MHz; and the term “legacy frequency band” may refer to an exemplary frequency band of 5-860 MHZ. However, it will be appreciated by those skilled in the art that in other embodiments of the invention, these exemplary frequency bands may be replaced with any other suitable wide frequency band, extended upstream frequency band, extended downstream frequency band, legacy downstream frequency band, legacy upstream frequency band, and/or any desired frequency band. For example, the systems, devices and/or methods of some embodiments of the invention may be adapted for a wide frequency band of between 5 MHz and more than 3000 MHz, e.g., 4000 MHz, and/or a legacy band of 5-1000 MHz.

FIG. 1schematically illustrates a hybrid optical-coaxial communication system according to some demonstrative embodiments of the present invention, showing the signal flow throughout the system.

According to some demonstrative embodiments of the invention, system100may include a head-unit102able to communicate with a node104via optical fibers106, e.g., as is known in the art. Downstream signals may be modulated on a carrier light beam having a wavelength of, for example, 1,550 nm or any other suitable wavelength, and upstream signals may be modulated on a carrier light beam having a wavelength of, for example, 1,310 nm or any other suitable wavelength.

Node104may include any suitable configuration, e.g., as is known in the art, for converting downstream optical signals received via fibers106into legacy downstream RF signals for transmission via a coaxial cable (coax)110, and/or for converting legacy upstream RF signals received via coax110into optical signals suitable for transmission via fibers106.

According to some demonstrative embodiments of the invention, system100may also include one or more taps132to distribute legacy downstream signals received from node104via coax110to one or more users (subscribers), and/or to provide node104via coax110with legacy upstream signals received from one or more subscribers, e.g., as is known in the art.

According to demonstrative embodiments of the invention, the downstream and/or upstream signals may include an expanded bandwidth enabled by block division multiplexing, e.g., as described in Appendix A and Appendix B. Additionally or alternatively, expanded downstream and/or upstream bandwidth between head-end102and node104may be achieved by DWM and/or DWDM technologies as are known in the art.

According to demonstrative embodiments of the invention, node104may include an Optical Hub (OHUB)107, which may include a modulator111able to detect expanded downstream data optically received via fibers106, and to modulate the expanded downstream data on a light beam of a wide bandwidth at a first wavelength, e.g., corresponding to a red spectrum, to be sent to the subscribers via a local fiber-optical cable108. OHUB107may also include a demodulator114able to detect expanded upstream data modulated on a light beam of a second wavelength, e.g., corresponding to a green spectrum, optically received via local fiber108, and to demodulate the received expanded upstream data into expanded upstream data in a standard legacy format which may be transferred over fibers106. Node104may also include, for example, an optical duplexer112to selectively transfer to local fiber108the light beam of the first wavelength received from modulator111, and/or to demodulator114the light beam of the second wavelength received from fiber108. It will be appreciated by persons skilled in the art that the invention is not limited to the specific demonstrative wavelengths described above, e.g., red and green wavelengths, and that any other suitable wavelengths may be used to carry the local upstream and/or downstream optical signals according to embodiments of the invention. OHUB107may include any suitable configuration, e.g., as described in References 1 and/or 2.

According to demonstrative embodiments of the invention, system100may include one or more optical adapters (“Optical Gathering Boxes (OGBs)”)130to selectively transfer expanded upstream and/or expanded downstream data to/from one or more subscribers via local fiber108; and upstream and/or downstream data via tap132and coax110, as described in detail below.

OGB130may be connected to local fiber108through an optical coupler131, which may have, for example, very low pass attenuation. This may enable serially connecting a large number of OGBs130, e.g. one hundred OGBs, with relatively low optical path loss.

According to some demonstrative embodiments of the invention, OGB130may include at least one interface, which may include first and second radio-frequency connectors. The first connector may be coupled to a subscriber, and/or the second connector may be coupled to tap132, e.g., as described in detail with reference toFIGS. 2A-3B.

According to some demonstrative embodiments of the invention, OGB130may also include an optical to radio-frequency converter to convert a downstream optical signal received via coupler131into an extended downstream radio-frequency signal in an extended downstream frequency band, e.g., as described in detail with reference toFIG. 4Aand/orFIG. 4B.

According to some demonstrative embodiments of the invention, OGB130may also include a triplexer to route the extended downstream signal to the first radio-frequency connector; to route a legacy downstream radio-frequency signal in a legacy frequency band from the second radio-frequency connector to the first radio-frequency connector; and to route a legacy upstream radio-frequency signal in the legacy frequency band from the first radio-frequency connector to the second radio-frequency connector, e.g., as described in detail with reference toFIG. 4Aand/orFIG. 4B.

According to some demonstrative embodiments of the invention, OGB130may also include, a radio-frequency to optical converter to convert an extended upstream radio-frequency signal in an extended upstream frequency band into an upstream optical signal; and the triplexer may route the extended upstream, signal from the first radio-frequency connector to the radio-frequency to optical converter, e.g., as described in detail with reference toFIG. 4Aand/orFIG. 4B.

Reference is made toFIGS. 2A and 2B, which schematically illustrate a 4-tap OGB200and an 8-tap OGB230, respectively, in accordance with some demonstrative embodiments of the invention. Although the invention is not limited in this respect, OGB200and/or OGB230may perform the functionality of at least one of OGBs130(FIG. 1).

According to some demonstrative embodiments of the invention, OGB200may include an optical input202and an optical output204connectable to a local optical fiber, e.g., local fiber108(FIG. 1).

According to some demonstrative embodiments of the invention, OGB200may also include four subscriber connectors, e.g., connectors207,209,211and213, which may be connected to CATV wall outlets of four subscribers, respectively. Connectors207,209,211and/or213may include, for example, female “F type” connectors, e.g., adapted for passing 3 GHZ signals, as are known in the art.

According to some demonstrative embodiments of the invention, OGB200may also include four RF tap connectors, e.g., connectors206,208,210and212, which may be connected with four, respective, subscriber inputs of a legacy coax “F type” tap, e.g., tap132. Connectors206,208,210and/or212may include, for example, “F type” taps adapted for passing 750 MHZ, 860 MHz, or 1000 MHZ, e.g., in accordance with legacy CATV specifications as known in the art.

According to some demonstrative embodiments of the invention, OGB230may include a configuration of eight subscriber connectors and eight tap connectors, e.g., analogous to the 4-tap configuration of OGB200.

According to demonstrative embodiments of the invention, OGB200and/or230may be closed, e.g., hermetically, and may be configured to withstand environmental conditions, e.g., as are specified for CATV out-door apparatuses.

Reference is made toFIGS. 3A and 3B, which schematically illustrate an OGB300according to demonstrative embodiments installed in two, respective, service configurations310and350.

According to demonstrative embodiments of the invention, OGB300may be connected between one or more subscribers and a coax tap332. OGB300may be located, for example, as near as possible to a passive element, which may feed a CATV wall outlet of a subscriber, e.g., through the “F type” connector.

According to the demonstrative embodiments ofFIG. 3A, configuration310may enable connection of four subscribers, denoted S1, S2, S3and S4, respectively, to a local fiber308. According to these embodiments, an optical input302and an optical output304of OGB300may each be connected to local fiber308. Subscribers S1, S2, S3and/or S4may be connected, e.g., via four drop lines (drops)315,316,317, and/or318, to four subscriber connectors of OGB300, respectively. Four tap connectors of OGB300corresponding to the four subscriber connectors may be connected, e.g., via four short lines (shorts)321,322,323and324, to four subscriber connectors of tap332, respectively. Tap332may be connected to a coax line309, e.g., as is known in the art.

OGB300may be able to modulate expanded upstream data received from a subscriber, e.g., subscriber S1, S2, S3or S4, over a light beam, e.g., of the second wavelength, to be transferred over local fiber308, as described below. OGB300may also be able to transfer upstream data received from the subscriber to tap332, e.g., if no expanded upstream data is detected.

Additionally or alternatively, OGB300may be able to provide the subscriber with expanded downstream data received via local fiber308, and/or downstream data received via coax309and tap332, as described in detail below.

According to the demonstrative embodiments ofFIG. 3B, service configuration350may enable connection of only some of the subscribers, e.g., subscribers S1and S2, respectively, to local fiber308. According to these embodiments, optical input302and optical output304may each be connected to local fiber308. Subscribers S1and S2may be connected, e.g., via two drop lines,315and316, respectively, to two respective subscriber connectors of OGB300. Two tap connectors of OGB300, corresponding to the two connected subscribers, may be connected to two subscriber connectors of tap332, e.g., via two shorts321and322, respectively. According to the demonstrative embodiments ofFIG. 3B, the subscribers not subscribed to use optical fiber308, e.g., subscribers S3and S4, may be connected directly to tap332, e.g., for upstream and/or downstream communication via coax309.

It will be appreciated that the configuration described above may enable downstream and/or upstream flow of legacy data via coax309, for example, without interference from the flow of the expanded bandwidth of upstream and/or downstream data via optical fiber308.

Reference is made toFIG. 4A, which schematically illustrates OGB configuration400according to one demonstrative embodiment of the invention. Although the invention is not limited in this respect, configuration400may be implemented, for example, by 4-tap OGB200.

According to demonstrative embodiments of the invention, OGB configuration400may include an optical coupler402to couple/decouple optical signals to/from a local optical fiber, e.g., fiber108(FIG. 1). This may enable efficiently connecting a large number of OGBs along the optical fiber, e.g., without generally affecting a signal to noise level of optical signals transferred via the local fiber. The optical signals may include, for example, an optical downstream signal, e.g., having a wavelength of between 400 and 560 nm, and/or an optical upstream signal, e.g., having a wavelength of between 660 and 1550 nm.

According to some demonstrative embodiments of the invention, OGB200may include at least one interface, e.g., four OGB interfaces401,403,405and407. At least one of interfaces401,403,405and407may include a triplexer406, a downstream amplifier408, an optical-to-RF converter410, a power source412, an upstream amplifier414, and/or a RF-to-optical converter416, as are described below.

According to some demonstrative embodiments of the invention, triplexer406may be connected, e.g., on one side, to subscriber connector207and to tap connector206; and to amplifier408, amplifier414and power source412, e.g., on another side. Triplexer406may be able to provide subscriber connector207with expanded downstream signals received via amplifier408; to provide subscriber connector207with downstream signals received from tap connector206; to provide upstream amplifier414with expanded upstream signals received from subscriber connector207; and/or to provide tap connector206with upstream signals received from subscriber connector207.

According to some demonstrative embodiments, triplexer406may enable only legacy CATV signals to pass, e.g., if no subscriber is connected to connector207.

According to some demonstrative embodiments of the invention, triplexer406may be constructed, for example, with SMD lamped elements, e.g., as illustrated inFIG. 5, and/or using any other suitable technologies, e.g., including CMOS integration.

Power source412may include any suitable configuration, for example, able to convert a power input, e.g., a 15 volt 22 KHZ AC power input, into electrical power in a form suitable for triplexer406of each of the OGB interfaces, e.g., as described below.

According to some demonstrative embodiments of the invention, optical-to-RF converter410may include any suitable converter, e.g., a diode. For example, optical-to-RF converter410may include a diode corresponding to the first wavelength, e.g., a red diode, implemented for expanded downstream signals. RF-to-optical converter416may include any suitable converter, e.g., a diode. For example, RF-to-optical converter416may include a diode corresponding to the second wavelength, e.g., a green diode, implemented for expanded upstream signals.

According to some demonstrative embodiments of the invention, OGB200may also include two optical splitters404, and421able to pass, combine, or separate a light beam according to the wavelength of the light beam. For example, splitter404may be able to split a light beam from coupler202to one or more optical-to-RF converters410; and/or to combine one or more light beams from one or more RF-to-optical converters416into a combined light beam to be provided to coupler202. Optical splitter may include, for example, a doublet dichoric mirror with built-in wavelength filters, e.g., as is known-in-the art.

It will be appreciated that the configuration ofFIG. 4may allow substantially no transfer of signals (“signal theft”) between one or more subscribers connected to one or more of connectors207,209,211and213, since each subscriber is connected via a different triplexer406.

Some embodiments of the invention are described herein with relation to a system, e.g., system100(FIG. 1), including a local optical fiber, e.g., local fiber108(FIG. 1), for transferring both the upstream and the downstream data. According to these embodiments, the system may include an OGB, e.g., OGB200, able to modulate the downstream data on a red light beam, and the upstream data on a green light beam. However, it will be appreciated by those skilled in the art that according to other embodiments of the invention, any other suitable configuration of one or more local fibers may be used. For example, the system may include a first local fiber for transferring upstream data using a first wavelength, e.g., a red or infrared wavelength, and a second local fiber for transferring downstream data using a second wavelength, e.g., a green wavelength, or any other desired wavelengths. Both these local fibers may be, for example, optically coupled to each OGB.

Reference is made toFIG. 4B, which schematically illustrates OGB configuration900according to another demonstrative embodiment of the invention. Although the invention is not limited in this respect, configuration900may be implemented, for example, by 4-tap OGB200.

According to demonstrative embodiments of the invention, OGB900may be connected to fiber108(FIG. 1), e.g., by an input port902and an output port906. OGB configuration900may include an optical coupler904to couple/decouple optical signals to/from a local optical fiber, e.g., fiber108(FIG. 1). This may enable efficiently connecting a large number of OGBs along the optical fiber, e.g., without generally affecting a signal to noise level of optical signals transferred via the local fiber. The optical signals may include, for example, an optical downstream signal, e.g., having a wavelength of between 400 and 560 nm, and/or an optical upstream signal, e.g., having a wavelength of between 660 and 1550 nm.

According to some demonstrative embodiments of the invention, OGB900may include an interface998. Interface998may include at least one triplexer, e.g., triplexers922,924,926, and928. Interface998may also include a downstream amplifier914, an optical-to-RF converter910, an upstream amplifier916, a combiner918, a splitter920, and/or a RF-to-optical converter908, as are described below.

According to some demonstrative embodiments of the invention, triplexer922may be connected, e.g., on one side, to a subscriber connector930and to a tap connector931; and to combiner918, and splitter920, e.g., on another side. Triplexer922may be able to provide subscriber connector930with expanded downstream signals received via splitter920; to provide subscriber connector930with downstream signals received from tap connector931; to provide combiner918with expanded upstream signals received from subscriber connector930; and/or to provide tap connector931with upstream signals received from subscriber connector930. Triplexer924may be connected, e.g., on one side, to a subscriber connector932and to a tap connector933; and to combiner918, and splitter920, e.g., on another side. Triplexer924may be able to provide subscriber connector932with expanded downstream signals received via splitter920; to provide subscriber connector932with downstream signals received from tap connector933; to provide combiner918with expanded upstream signals received from subscriber connector932; and/or to provide tap connector933with upstream signals received from subscriber connector932. Triplexer926may be connected, e.g., on one side, to a subscriber connector934and to a tap connector935; and to combiner918, and splitter920, e.g., on another side. Triplexer926may be able to provide subscriber connector934with expanded downstream signals received via splitter920; to provide subscriber connector934with downstream signals received from tap connector935; to provide combiner918with expanded upstream signals received from subscriber connector934; and/or to provide tap connector935with upstream signals received from subscriber connector934. Triplexer928may be connected, e.g., on one side, to a subscriber connector936and to a tap connector937; and to combiner918, and splitter920, e.g., on another side. Triplexer928may be able to provide subscriber connector936with expanded downstream signals received via splitter920; to provide subscriber connector936with downstream signals received from tap connector937; to provide combiner918with expanded upstream signals received from subscriber connector936; and/or to provide tap connector937with upstream signals received from subscriber connector936.

According to some demonstrative embodiments, triplexers922,924,926, and/or928may enable only legacy CATV signals to pass, e.g., if no subscriber is connected to connectors930,932,934, and/or936, respectively.

According to some demonstrative embodiments of the invention, triplexers922,924,926and/or928may be constructed, for example, with SMD lamped elements, e.g., as illustrated inFIG. 5, and/or using any other suitable technologies, e.g., including CMOS integration.

According to some demonstrative embodiments of the invention, optical-to-RF converter910may include any suitable converter, e.g., a diode. For example, optical-to-RF converter910may include a diode corresponding to the first wavelength, e.g., a red diode, implemented for expanded downstream signals. RF-to-optical converter908may include any suitable converter, e.g., a diode. For example, RF-to-optical converter908may include a diode corresponding to the second wavelength, e.g., a green diode, implemented for expanded upstream signals.

According to some demonstrative embodiments of the invention, combiner may include any suitable RF combiner to provide one or more upstream signals received from triplexers922,924,926, and926to amplifier916. Splitter920may include any suitable RF splitter to the downstream RF signal received from amplifier914into two or more RF signals, e.g., four RF signals, to be provided to two or more triplexers, e.g., triplexers922,924,926, and926, respectively.

According to some demonstrative embodiments of the invention, OGB900may also include a selective optical reflector912to reflect, deflect, transmit or route a light beam according to the wavelength of the light beam. For example, reflector912may be able to direct a light beam from coupler904towards optical-to-RF converter910; and/or to direct a light beams from RF-to-optical converter908towards coupler904. Reflector912may include, for example, a dichoric mirror with built-in wavelength filters, e.g., as is known in the art.

It will be appreciated that the configuration ofFIG. 4may allow substantially no transfer of signals (“signal theft”) between one or more subscribers connected to one or more of connectors930,932,934and936, since each subscriber is connected via a different triplexer.

FIG. 6schematically illustrates OGB power module circuitry600according to demonstrative embodiments of the invention. Although the invention is not limited in this respect, circuitry600may perform the functionality of power source412(FIG. 4).

According to some demonstrative embodiments of the invention, power module600may include a RF separation coil602, a RF damping capacitor604, and a fast high performance diode606, e.g., to rectify a 22 KHZ 15 volt AC into a 10 volt DC, which may be collected at a capacitor, e.g., a Tantalum capacitor608. The output of diode606, e.g., a 10 volts DC signal, may be regulated, for example, to 0.1%, with a regulator610, e.g., a standard T05 ½ watt +5 volt IC regulator. The regulated output may then be filtered using a capacitor612. According to other embodiments of the invention, power circuitry600may include any other suitable configuration.

FIG. 7schematically illustrates an OGB optical splitter according to demonstrative embodiments of the invention. Although the invention is not limited in this respect, the optical splitter ofFIG. 7may perform the functionality of splitter404(FIG. 4). The optical splitter ofFIG. 7may be adapted, for example, to provide one or more outputs having an attenuation factor of, for example, at least 6 dB.

FIG. 8Aschematically illustrates a subscriber Optical Set Top Box (OSTB)800according to demonstrative embodiments of the invention, andFIG. 8Bschematically illustrates OSTB circuitry850that may be used in OSTB800.

According to demonstrative embodiments of the invention, OSTB800may include a housing802to shield circuitry850. OSTB800may operate, for example, with an external UL approved power supply840as is known in the art, which may be connected to a power input803of OSTB800. The over all consumption of OSTB800may be, for example, less than six watts.

According to some demonstrative embodiments of the invention, circuitry850may include, for example, a triplexer,852, e.g., analogous to triplexer406(FIG. 4). Triplexer852may be able to transfer legacy CATV data, e.g., CATV data in the frequency band of 5-860 MHz or 10-1000 MHz, which may be received via a wall outlet connector807, to a legacy CATV outlet connector809. Legacy connector809may include, for example, a legacy out “F type” connector, as is known in the art.

According to some demonstrative embodiments of the invention, circuitry850may also include an oscillator854, e.g., a 22 KHZ 15 volts ½ watt oscillator. Triplexer852may selectively associate oscillator854with outlet connector807, for example, to enable oscillator854to feed, e.g., via triplexer852and wall outlet807, a desired section of the OGB.

A power supply840, for example, a small UL approved power supply rated at 6 Watt max (e.g., 12V at 500 mA), may be used to provide electrical power to one or more VCC's.

Expanded upstream and/or downstream data may be transferred via a connector811. A downstream converter may convert expanded downstream data, which may be received via triplexer852and may have a frequency band of, e.g., 1250 and 1950 MHZ, into data of a frequency of, e.g., 160-860 MHZ.

A splitter858may allow upstream data of a frequency band 5-42 MHz (or 10-85) to pass to an upstream converter860able to convert the upstream data into converted upstream data of a frequency band of, e.g., 2250 to 2750 MHZ. Triplexer852may route the converted upstream data via wall outlet807to the OGB, where it may be modulated onto an optical, signal of a desired wavelength, e.g., as described above with reference toFIGS. 4Aand/or4B.