US20070292136A1 - Transponder for a radio-over-fiber optical fiber cable - Google Patents
Transponder for a radio-over-fiber optical fiber cable Download PDFInfo
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- US20070292136A1 US20070292136A1 US11/454,581 US45458106A US2007292136A1 US 20070292136 A1 US20070292136 A1 US 20070292136A1 US 45458106 A US45458106 A US 45458106A US 2007292136 A1 US2007292136 A1 US 2007292136A1
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- Prior art keywords
- optical fiber
- transponder
- converter
- fiber cable
- optical
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/25—Arrangements specific to fibre transmission
- H04B10/2575—Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier
- H04B10/25752—Optical arrangements for wireless networks
- H04B10/25753—Distribution optical network, e.g. between a base station and a plurality of remote units
- H04B10/25756—Bus network topology
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/16—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole
- H01Q9/28—Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines
- H01Q9/285—Planar dipole
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W24/00—Supervisory, monitoring or testing arrangements
- H04W24/04—Arrangements for maintaining operational condition
Definitions
- the present invention relates generally to radio-over-fiber (RoF) systems, and in particular relates to transponders for a RoF optical fiber cable used in RoF systems.
- RoF radio-over-fiber
- Wireless communication is rapidly growing, with ever-increasing demands for high-speed mobile data communication.
- so-called “wireless fidelity” or “WiFi” systems and wireless local area networks (WLANs) are being deployed in many different types of areas (coffee shops, airports, hospitals, libraries, etc.).
- the typical wireless communication system has a head-end station connected to an access point device via a wire cable.
- the access point device includes a RF transmitter/receiver operably connected to an antenna, and digital information processing electronics.
- the access point device communicates with wireless devices called “clients,” which must reside within the wireless range or a “cell coverage area” in order to communicate with the access point device.
- the size of a given cell is determined by the amount of RF power transmitted by the access point device, the receiver sensitivity, antenna gain and the RF environment, as well as by the RF transmitter/receiver sensitivity of the wireless client device.
- Client devices usually have a fixed RF receive sensitivity, so that the above-mentioned properties of the access point device largely determine the cell size.
- Connecting a number of access point devices to the head-end controller creates an array of cells that cover an area called a “cellular coverage area.”
- picocells are wireless cells having a radius in the range from about a few meters up to about 20 meters. Because a picocell covers a small area, there are typically only a few users (clients) per picocell. A closely packed picocellular array provides high per-user data-throughput over the picocellular coverage area. Picocells also allow for selective wireless coverage in small regions that otherwise would have poor signal strength when covered by larger cells created by conventional base stations.
- Radio over fiber For short.
- RF radio-frequency
- Such systems include a head-end unit optically coupled to a transponder via an optical fiber link. Unlike a conventional access point device, the transponder has no digital information processing capability. Rather, the digital processing capability resides in the head-end unit.
- the transponder is transparent to the RF signals and simply converts incoming optical signals from the optical fiber link to electrical signals, which are then converted to electromagnetic signals via an antenna.
- the antenna also receives electromagnetic signals and converts them to electrical signals.
- the transponder then converts the electrical signals to optical signals, which are then sent to the head-end unit via the optical fiber link.
- the transponders are typically included in an optical fiber cable that includes the optical fiber links for each transponder.
- the picocells associated with the distributed transponders form a picocell coverage area.
- high-directivity transponder antennas can be used. Their use, however, requires additional efforts at the manufacturing and installation stages because proper adjustment and orientation of each antenna is necessary. Installing multiple directive antennas per transponder (e.g., to support both data and voice services in different frequency bands) further complicates installation and imposes tight requirements for integration of antennas with the transponder.
- the size and orientation of the picocells requires direct adjustment of the antennas, which is difficult to do once the antennas are incorporated into the optical fiber cable.
- the transponder for a radio-over-fiber (RoF) optical fiber cable.
- the transponder includes an electrical-to-optical (E/O) converter and an optical-to-electrical (O/E) converter.
- the system also includes a dipole antenna system operably coupled to the E/O converter and the O/E converter.
- the antenna system is arranged relative to the optical fiber cable so as to create an elongate picocell in a direction locally perpendicular to the optical fiber cable when the transponder is addressed.
- the system includes a head-end unit adapted to send and receive optical RF signals.
- the system also includes one or more transponders of the type described immediately above.
- the system further includes one or more optical fiber cables that include the one or more transponders and that optically couple the head-end unit to each transponder.
- Another aspect of the invention is a method of forming an elongate picocell for a RoF system.
- the method includes transmitting optical RF signals to a transponder via a downlink optical fiber in the optical fiber cable, and converting the optical signals to electrical RF signals at the transponder.
- the method also includes converting the electrical signals to electromagnetic RF signals at the transponder using a dipole antenna system to create the elongate picocell in a direction locally perpendicular to the optical fiber cable.
- FIG. 1 is a schematic diagram of a generalized embodiment of a RoF picocellular wireless system according to the present invention
- FIG. 2 is a schematic close-up view of an example embodiment of the RoF system of FIG. 1 , illustrating an example embodiment of the converter unit and dipole antenna system for the transponder of the present invention as arranged in the optical fiber cable;
- FIG. 3 is a close-up schematic diagram of an example embodiment of the configuration of the converter unit and dipole antenna system for the transponder of the present invention, wherein the dipole antenna system includes transmitting and receiving antennas;
- FIG. 4 is a schematic diagram of an example embodiment of the transponder of the present invention similar to that shown in FIG. 3 , but wherein dipole antenna system includes a single antenna that both transmits and receives electromagnetic signals;
- FIG. 5 is a close-up schematic diagram of an example embodiment of an E/O converter in the converter unit that includes a number of amplifiers, with each amplifier adapted to amplify a different frequency in the electrical RF signal created by the photodetector;
- FIG. 6 is a schematic diagram of an example embodiment of the transponder of the present invention, wherein the dipole antenna system includes a power divider and three separate antennas;
- FIG. 7 is a schematic diagram of an example embodiment of the transponder of the present invention similar to that shown in FIG. 6 , wherein the antenna system includes a plurality of power dividers each electrically coupled to an antenna;
- FIG. 8 is a schematic diagram of an example embodiment of the transponder according to the present invention similar to that shown in FIG. 7 , wherein a portion of the antenna system lies outside of the optical fiber cable coating;
- FIG. 9 is a schematic diagram of an example embodiment of the transponder of the present invention similar to that shown in FIG. 8 , wherein the converter unit and dipole antenna system both reside outside of the optical fiber cable coating;
- FIG. 10 is a schematic diagram of an example embodiment of the transponder of the present invention, wherein the antenna system includes two pairs of wire antennas, with each antenna connected to the converter unit via respective RF cable sections;
- FIG. 11 is a schematic diagram of an example embodiment of the RoF picocellular wireless system of FIG. 1 , showing details of an example embodiment of the head-end unit;
- FIG. 12 is a schematic diagram of a typical prior art picocellular coverage area formed by a conventional prior art picocellular wireless system that employs conventional omnidirectional transponders;
- FIG. 13 is a schematic diagram of an example picocellular coverage area formed by the RoF picocellular wireless system of the present invention that utilizes the transponders of the present invention.
- FIG. 14 is a plot of RF power (dBm) emitted by the dipole antenna system of the transponder of the present invention vs. the distance (m) from the antenna system along both the x-direction (i.e., perpendicular to the optical fiber cable) and the y-direction (i.e., along the optical fiber cable).
- FIG. 1 is a schematic diagram of a generalized embodiment of a RoF picocellular wireless system 10 according to the present invention.
- System 10 includes a head-end unit 20 adapted to transmit, receive and/or process RF optical signals.
- head-end unit 20 is operably coupled to an outside network 24 via a network link 25 , and the head-end unit serves as a pass-through for RF signals sent to and from the outside network.
- Transponder 30 also includes one or more transponder units (“transponders”) 30 according to the present invention.
- Each transponder 30 includes a converter unit 31 and a dipole antenna system 32 electrically coupled thereto, wherein the dipole antenna system has a dipole radiation characteristic the same as or substantially similar to that of an ideal dipole antenna.
- Transponder 30 is discussed in greater detail below.
- System 10 includes one or more optical fiber cables 34 each optically coupled to head-end unit 20 .
- Each optical fiber cable 34 includes one or more optical fiber RF transmission links 36 optically coupled to respective one or more transponders 30 .
- each optical fiber RF transmission link 36 includes a downlink optical fiber 36 D and an uplink optical fiber 36 U.
- Example embodiments of system 10 include either single-mode optical fiber or multimode optical fiber for downlink and uplink optical fibers 36 D and 36 U.
- the particular type of optical fiber depends on the application of system 10 , as well as the desired performance and cost considerations. For many in-building deployment applications, maximum transmission distances typically do not exceed 300 meters.
- the maximum length for the intended RoF transmission needs to be taken into account when considering using multi-mode optical fibers for downlink and uplink optical fibers 36 D and 36 U. For example, it has been shown that a 1400 MHz.km multi-mode fiber bandwidth-distance product is sufficient for 5.2 GHz transmission up to 300 meters.
- the present invention employs 50 ⁇ m multi-mode optical fiber for the downlink and uplink optical fibers 36 D and 36 U, and E/O converters (introduced below) that operate at 850 nm using commercially available vertical-cavity surface-emitting lasers (VCSELs) specified for 10 Gb/s data transmission.
- VCSELs vertical-cavity surface-emitting lasers
- RoF picocellular wireless system 10 of the present invention employs a known telecommunications wavelength, such as 850 nm, 1300 nm, or 1550 nm. In another example embodiment, system 10 employs other less common but suitable wavelengths such as 980 nm.
- dipole antenna system 32 is sufficiently stiff so that optical fiber cable 34 is locally straight at the dipole antenna system location.
- dipole antenna system 32 is located relatively far away from converter unit 31 (e.g., 2 meters), while in other example embodiments the dipole antenna system is located relatively close to the converter unit (e.g., a few inches away), or even directly at the converter unit.
- Each transponder 30 is adapted to form a picocell 40 via dipole antenna system 32 via electromagnetic transmission and reception when the transponder is addressed, e.g., receives a downlink optical signal SD′ from head-end unit 20 and/or an uplink electromagnetic signal SU′′ from a client device 46 .
- Client device 46 which is shown in the form of a computer as one example of a client device, includes an antenna 48 (e.g., a wireless card) adapted to electromagnetically communicate with (i.e., address) the transponder and antenna system 32 thereof.
- Dipole antenna system 32 is adapted to form picocell 40 from a dipole radiation pattern 42 oriented perpendicular to optical fiber cable 34 at the location of the dipole antenna system.
- the term “locally perpendicular” is used herein to describe the orientation of picocell 40 and/or the corresponding dipole radiation pattern 42 relative to optical fiber cable 34 at the location of dipole antenna system 32 .
- Dipole radiation pattern 42 is thus centered about the local x-z plane P XZ (viewed edge-on in FIG. 1 and illustrated as a dotted line). In an example embodiment, only a portion of dipole radiation pattern 42 is used for picocell 40 , e.g., the portion below optical fiber cable 34 (i.e., in the -z direction), as shown in FIG. 1 .
- system 10 is powered by a power supply 50 electrically coupled to head-end unit 20 via an electrical power line 52 that carries electrical power signals 54 .
- FIG. 2 is a schematic close-up view of an example embodiment of transponder 30 as incorporated into optical fiber cable 34 .
- optical fiber cable 34 includes an outer coating 58 .
- transponder 30 includes a converter unit 31 .
- Converter unit 31 includes an electrical-to-optical (E/O) converter 60 adapted to convert an electrical signal into a corresponding optical signal, and an optical-to-electrical (O/E) converter 62 that converts an optical signal into a corresponding electrical signal.
- E/O converter 60 is optically coupled to an input end 70 of uplink optical fiber 36 U and O/E converter 62 is optically coupled to an output end 72 of downlink optical fiber 36 D.
- optical fiber cable 34 includes electrical power line 52
- converter unit 31 includes a DC power converter 80 electrically coupled to the electrical power line and to E/O converter 60 and O/E converter 62 .
- DC power converter 80 is adapted to change the voltage levels and provide the power required by the power-consuming components in converter unit 31 .
- DC power converter 80 is either a DC/DC power converter, or an AC/DC power converter, depending on the type of power signal 54 carried by electrical power line 52 .
- electrical power line 52 includes two electrical wires 52 A and 52 B connected to DC power converter 80 .
- dipole antenna system 32 is electrically coupled to converter unit 31 .
- dipole antenna system 32 includes one or more antenna elements (“antennas”) 33 .
- antenna system 32 includes a receiving antenna 33 R electrically coupled to E/O converter 60 via a first RF cable section 90 and a transmitting antenna 33 T electrically coupled to E/O converter 62 via a second RF cable section 90 .
- the one or more antennas 33 is/are made of or include sections of wire.
- One or more RF cable sections 90 are used in example embodiments of the present invention to connect corresponding one or more antennas 33 to the converter unit 31 .
- dipole antenna system 32 supports multiple frequency bands. Additionally, the diversity principle can be used to send the same information through statistically independent channels.
- FIG. 3 is a detailed schematic diagram of an example embodiment of converter unit 31 and dipole antenna system 32 for the transponder 30 of the present invention.
- E/O converter 60 includes a laser 100 optically coupled to an input end 70 of uplink optical fiber 36 U, a bias-T unit 106 electrically coupled to the laser, an amplifier 110 electrically coupled to the bias-T unit, and a RF filter 114 electrically coupled to the amplifier and to the corresponding RF cable section 90 .
- O/E converter 62 includes a photodetector 120 optically coupled to output end 72 of downlink optical fiber 36 D, an amplifier 110 electrically coupled to the photodetector, and a RF filter 114 electrically coupled to the amplifier and to the corresponding RF cable section 90 .
- laser 100 is adapted to deliver sufficient dynamic range for one or more RoF applications. Examples of suitable lasers for E/O converter 60 include laser diodes, distributed feedback (DFB) lasers, Fabry-Perot (FP) lasers, and VCSELs.
- DFB distributed feedback
- FP Fabry-Perot
- Photodetector 120 converts optical signal SD′ into a corresponding electrical signal SD, which is then amplified by amplifier 110 and then filtered by RF filter 114 .
- Electrical signal SD is then fed via the corresponding RF cable section 90 to transmitting antenna 33 T, which converts electrical signal SD into a corresponding electromagnetic signal SD′′, which then travels to one or more client devices 46 within the corresponding picocell 40 ( FIG. 1 ).
- receiving antenna 33 R receives electromagnetic uplink signal SU′′ from one or more client devices 46 within picocell 40 and converts each such signal to a corresponding electrical signal SU.
- This electrical travels over the corresponding RF cable section 90 and is signal is fed to RF filter 114 , which filters the signal and passes it along to amplifier 110 , which amplifies the signal.
- Electrical signal SU then travels to bias-T unit 106 , which conditions electrical signal SU—i.e., combines a DC signal with the electrical RF signal so it can drive (semiconductor) laser 100 above threshold using a DC current source (not shown) and independently modulate the power around its average value as determined by the provided DC current.
- the conditioned electrical signal SU then travels to laser 100 , which converts the electrical signal to an corresponding optical signal SU′′ that is sent to head-end unit 20 for processing.
- Transponders 30 of the present invention differ from the typical access point device associated with wireless communication systems in that the preferred embodiment of the transponder has just a few signal-conditioning elements and no digital information processing capability. Rather, the information processing capability is located remotely in head-end unit 20 . This allows transponder 30 to be very compact and virtually maintenance free. In addition, the preferred example embodiment of transponder 30 consumes very little power, is transparent to RF signals, and does not require a local power source, as described below. Moreover, if system 10 needs to be changed (e.g., upgraded), the change can be performed at head-end unit 20 without having to change or otherwise alter transponders 30 .
- dipole antenna system 32 includes one or more antennas 33 , such as receiving antenna 33 R and a transmitting antenna 33 T.
- antennas 33 R and 33 T are or include respective wires oriented locally parallel to optical fiber cable 34 (i.e., along the y-axis).
- the ability of dipole antenna system 32 to lie along the direction of optical fiber cable 34 allows for easy integration of the dipole antenna system into the optical fiber cable relative to other types of direction antennas, such as patch antennas.
- dipole antenna system 32 includes a circuit-based dipole antenna, such as available over the Internet from Winizen Co., Ltd., Kyounggi-do 429-250, Korea.
- FIG. 4 is a schematic diagram of an example embodiment of the transponder 30 of the present invention similar to that shown in FIG. 3 , but wherein dipole antenna system 32 includes just a single antenna 33 that both transmits and receives electromagnetic signals.
- converter unit 31 includes a RF signal-directing element 130 , such as a circulator, electrically coupled to single antenna 33 via a third RF cable section 90 .
- FIG. 5 is a schematic diagram of an example embodiment of E/O converter unit 60 in converter unit 31 , wherein the E/O converter includes a number of amplifiers 100 electrically connected to photodetector 120 . Each amplifier 100 is adapted to amplify a different frequency in electrical signal SD. This allows for parallel conditioning of different frequency bands within transponder 30 . A variety of other multi-frequency amplification and antenna system arrangements are also possible for E/O converter 60 , as well as for O/E converter 62 .
- FIG. 6 is a schematic diagram of an example embodiment of transponder 30 with a dipole antenna system 32 that includes three different antennas 33 electrically connected to a power divider 210 via respective RF cable sections 90 .
- Power divider 210 in turn is electrically coupled to converter unit 31 via a corresponding RF cable section 90 .
- FIG. 7 is a schematic diagram of an example embodiment of transponder 30 with a dipole antenna system 32 similar to that shown in FIG. 6 , but that includes a plurality of power dividers 210 arranged along a RF cable section 90 , with each power divider branching off an antenna 33 .
- An advantage of the example embodiment of transponder 30 of FIG. 7 is that if the optical fiber cable is deployed in a building and one antenna 33 is obstructed (say, by an air conditioning duct), another antenna can still send and receive electromagnetic signals.
- FIG. 8 is a schematic diagram of an example embodiment of transponder 30 with a dipole antenna system 32 similar to that shown in FIG. 7 , wherein a portion of the antenna system lies outside of cable coating 58 .
- antenna 33 of antenna system 32 is shown arranged outside of cable coating 58 .
- an external covering 220 such as a shrink wrapper, is applied to cable coating 58 to secure and protect the portion of antenna system 32 that lies outside of the cable coating.
- FIG. 9 is a schematic diagram of an example embodiment of transponder 30 with a dipole antenna system 32 similar to that shown in FIG. 8 , wherein converter unit 31 and dipole antenna system 32 are both outside of cable coating 58 and optionally covered by external covering 220 .
- FIG. 10 is a schematic diagram of an example embodiment of transponder 30 with a dipole antenna system 32 that includes two pairs 234 and 235 of wire antennas 33 , with each antenna connected to converter unit 33 via a corresponding RF cable section 90 .
- Antenna pairs 234 and 235 may be designed, for example, to transmit and receive at the 5.2 GHz and 2.4 GHz frequency bands, respectively (i.e., the IEEE 802 a/b/g standard frequency bands).
- the judicious use of RF cable sections 90 in this example embodiment mitigates fading and shadowing effects that can adversely affect the dipole radiation pattern 42 and thus the size and shape of picocell 40 .
- FIG. 11 is a detailed schematic diagram of an example embodiment of system 10 of FIG. 1 , showing the details of an example embodiment of head-end unit 20 .
- head-end unit 20 includes a controller 250 that provides electrical RF signals SD for a particular wireless service or application.
- controller 250 includes a RF signal modulator/demodulator unit 270 for modulating/demodulating RF signals, a digital signal processor 272 for generating digital signals, a central processing unit (CPU) 274 for processing data and otherwise performing logic and computing operations, and a memory unit 276 for storing data.
- CPU central processing unit
- controller 250 is adapted to provide WLAN signal distribution as specified in the IEEE 802.11 standard, i.e., in the frequency range from 2.4 to 2.5 GHz and from 5.0 to 6.0 GHz.
- controller 250 serves as a pass-through unit that merely coordinates distributing electrical RF signals SD and SU from and to outside network 24 or between picocells 40 .
- Head-end unit 20 includes one or more converter pairs 66 each having an E/O converter 60 and an O/E converter 62 .
- Each converter pair 66 is electrically coupled to controller 250 and is also optically coupled to corresponding one or more transponders 30 .
- Each E/O converter 60 in converter pair 66 is optically coupled to an input end 76 of a downlink optical fiber 36 D, and each O/E converter 62 is optically coupled to an output end 74 of an uplink optical fiber 36 U.
- digital signal processor 272 in controller 250 generates a downlink digital RF signal S 1 .
- This signal is received and modulated by RF signal modulator/demodulator 270 to create a downlink electrical RF signal (“electrical signal”) SD designed to communicate with one or more client devices 46 in picocell(s) 40 .
- Electrical signal SD is received by one or more E/O converters 60 , which converts this electrical signal into a corresponding optical signal SU′, which is then coupled into the corresponding downlink optical fiber 36 D at input end 76 .
- optical signal SD′ is tailored to have a given modulation index.
- the modulation power of E/O converter 60 is controlled (e.g., by one or more gain-control amplifiers, not shown) in order to vary the transmission power from dipole antenna system 32 , which is the main parameter that dictates the size of the associated picocell 40 .
- the amount of power provided to dipole antenna system 32 is varied to define the size of the associated picocell 40 .
- Optical signal SD′ travels over downlink optical fiber 36 D to an output end 72 and is processed as described above in connection with system 10 of FIG. 2 to return an uplink optical signal SU′′.
- Optical signal SU′′ is received at head-end unit 20 , e.g., by O/E converter 62 in the converter pair 66 that sent the corresponding downlink optical signal SD′.
- O/E converter 62 converts optical signal SU′ back into electrical signal SU, which is then processed.
- “processed” includes one or more of the following: storing the signal information in memory unit 276 ; digitally processing or conditioning the signal in controller 250 ; sending the electrical signal SU, whether conditioned or unconditioned, on to one or more outside networks 24 via network links 25 ; and sending the signal to one or more client devices 46 within the same or other picocells 40 .
- the processing of signal SU includes demodulating this electrical signal in RF signal modulator/demodulator unit 270 , and then processing the demodulated signal in digital signal processor 272 .
- FIG. 12 is a schematic diagram illustrating a typical prior art picocellular coverage area 44 P formed by a conventional picocellular wireless system that forms symmetric picocells 40 P. Note that such picocells are traditionally represented as hexagons because they can be shown as tiling a given space without gaps.
- Picocell coverage area 44 P requires seven optical fiber cables 34 P that employ conventional transponders having omnidirectional antennas. The conventional optical fiber cables are optically coupled to a conventional head-end station 20 P.
- the dashed-line outer box B in FIG. 12 represents the approximate boundary for picocell coverage area 44 P.
- FIG. 13 is a schematic diagram of a picocellular coverage area 44 based on the RoF picocellular wireless system 10 of the present invention that includes transponders 30 according to the present invention.
- the number of transponders 30 and thus the number of picocells 40 that form picocellular coverage area 44 are approximately equal to the prior art system 10 P of FIG. 12 .
- Dashed-line outer box B is provided in FIG. 13 to show that the size of picocellular coverage area 44 is about the same as that for picocellular coverage area 44 P of FIG. 12 .
- each transponder 30 of the present invention forms an elongate picocell 40 with a long axis A P perpendicular to the local y-direction of optical fiber cable 34 at the corresponding dipole antenna system 32 .
- Transponders 30 of the present invention thus form a picocellular coverage area 44 made up of elongate picocells 40 by virtue of orienting the dipole radiation pattern locally perpendicular to the optical fiber cable at the location of each dipole antenna system 32 .
- the elongate shape of picocells 40 allows system 10 to cover substantially the same picocellular coverage area as area 44 P but using only three optical fiber cables 34 —a reduction of over 50% as compared to the optical fiber cabling needed for the traditional picocellular coverage area 44 P of FIG. 12 .
- the use of the about the same number of transponders 30 allows for picocells 40 operating at the same frequency to be maximally separated.
- Picocells 40 are elongate because dipole antenna 32 has an asymmetric (elliptical) power distribution in the local x-y plane due to the different power decay rate in the different directions.
- FIG. 14 is a plot of RF power (dBm) emitted by dipole antenna system 32 vs. the distance (m) from the antenna along both the x-direction (curve 300 ) and the y-direction (curve 302 ).
- Curve 302 indicates that along the direction of the optical fiber cable (y-direction), the decay is fast, so that one can pack transponders 30 more densely along the optical fiber cable without increasing the picocell-to-picocell crosstalk.
- Omnidirectional antennas such as vertical dipole antennas, typically have a relatively shallow RF power decay rate similar to curve 300 in FIG. 14 . Consequently, picocells 40 formed from such antennas are prone to cross-talk.
- Directive antennas such as microstrip patches, can have an asymmetric radiation pattern in the x-y plane that can create asymmetric cells. However, these antennas require proper alignment in space.
- the dipole antenna system 32 of the present invention produces predictable radiation patterns without any orientation tuning of individual antennas. This is because the dipole antenna system 32 is incorporated into (or onto) optical fiber cable 34 in a manner that allows for the picocell location and orientation to be determined by orienting optical fiber cable 34 rather than orienting individual antennas per se. This makes optical fiber cable 34 easier to manufacture and deploy relative to using other more complex directional dipole antenna systems.
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Abstract
The invention is a transponder for a radio-over-fiber (RoF) optical fiber cable. The transponder includes a converter unit made up of an electrical-to-optical (E/O) converter and an optical-to-electrical (O/E) converter. The optical fiber cable optically couples the converter unit to a head-end unit that sends and receives optical RF signals. A dipole antenna system is operably coupled to the converter unit and is arranged so as to create elongate picocell in a direction perpendicular to the optical fiber cable when the transponder is in communication with the head-end unit. The asymmetric picocell shape allows for creating a picocellular coverage area using fewer optical fiber cables than is possible with prior art transponders.
Description
- The present invention relates generally to radio-over-fiber (RoF) systems, and in particular relates to transponders for a RoF optical fiber cable used in RoF systems.
- Wireless communication is rapidly growing, with ever-increasing demands for high-speed mobile data communication. As an example, so-called “wireless fidelity” or “WiFi” systems and wireless local area networks (WLANs) are being deployed in many different types of areas (coffee shops, airports, hospitals, libraries, etc.). The typical wireless communication system has a head-end station connected to an access point device via a wire cable. The access point device includes a RF transmitter/receiver operably connected to an antenna, and digital information processing electronics. The access point device communicates with wireless devices called “clients,” which must reside within the wireless range or a “cell coverage area” in order to communicate with the access point device.
- The size of a given cell is determined by the amount of RF power transmitted by the access point device, the receiver sensitivity, antenna gain and the RF environment, as well as by the RF transmitter/receiver sensitivity of the wireless client device. Client devices usually have a fixed RF receive sensitivity, so that the above-mentioned properties of the access point device largely determine the cell size. Connecting a number of access point devices to the head-end controller creates an array of cells that cover an area called a “cellular coverage area.”
- One approach to deploying a wireless communication system involves creating “picocells,” which are wireless cells having a radius in the range from about a few meters up to about 20 meters. Because a picocell covers a small area, there are typically only a few users (clients) per picocell. A closely packed picocellular array provides high per-user data-throughput over the picocellular coverage area. Picocells also allow for selective wireless coverage in small regions that otherwise would have poor signal strength when covered by larger cells created by conventional base stations.
- One type of wireless system for creating picocells utilizes radio-frequency (RF) signals sent over optical fibers—called “radio over fiber” or “RoF” for short. Such systems include a head-end unit optically coupled to a transponder via an optical fiber link. Unlike a conventional access point device, the transponder has no digital information processing capability. Rather, the digital processing capability resides in the head-end unit. The transponder is transparent to the RF signals and simply converts incoming optical signals from the optical fiber link to electrical signals, which are then converted to electromagnetic signals via an antenna. The antenna also receives electromagnetic signals and converts them to electrical signals. The transponder then converts the electrical signals to optical signals, which are then sent to the head-end unit via the optical fiber link.
- The transponders are typically included in an optical fiber cable that includes the optical fiber links for each transponder. The picocells associated with the distributed transponders form a picocell coverage area. To reduce picocell cross-talk, high-directivity transponder antennas can be used. Their use, however, requires additional efforts at the manufacturing and installation stages because proper adjustment and orientation of each antenna is necessary. Installing multiple directive antennas per transponder (e.g., to support both data and voice services in different frequency bands) further complicates installation and imposes tight requirements for integration of antennas with the transponder. In addition, the size and orientation of the picocells requires direct adjustment of the antennas, which is difficult to do once the antennas are incorporated into the optical fiber cable.
- One aspect of the invention is a transponder for a radio-over-fiber (RoF) optical fiber cable. The transponder includes an electrical-to-optical (E/O) converter and an optical-to-electrical (O/E) converter. The system also includes a dipole antenna system operably coupled to the E/O converter and the O/E converter. The antenna system is arranged relative to the optical fiber cable so as to create an elongate picocell in a direction locally perpendicular to the optical fiber cable when the transponder is addressed.
- Another aspect of the invention is a RoF picocellular wireless system. The system includes a head-end unit adapted to send and receive optical RF signals. The system also includes one or more transponders of the type described immediately above. The system further includes one or more optical fiber cables that include the one or more transponders and that optically couple the head-end unit to each transponder.
- Another aspect of the invention is a method of forming an elongate picocell for a RoF system. The method includes transmitting optical RF signals to a transponder via a downlink optical fiber in the optical fiber cable, and converting the optical signals to electrical RF signals at the transponder. The method also includes converting the electrical signals to electromagnetic RF signals at the transponder using a dipole antenna system to create the elongate picocell in a direction locally perpendicular to the optical fiber cable.
- Additional features and advantages of the invention are set forth in the detailed description that follows, and will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description that follows, the claims, as well as the appended drawings.
- It is to be understood that both the foregoing general description and the following detailed description present embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and, together with the description, serve to explain the principles and operations of the invention.
- Accordingly, various basic electronic circuit elements and signal-conditioning components, such as bias tees, RF filters, amplifiers, power dividers, etc., are not all shown in the Figures for ease of explanation and illustration. The application of such basic electronic circuit elements and components to the present invention will be apparent to one skilled in the art.
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FIG. 1 is a schematic diagram of a generalized embodiment of a RoF picocellular wireless system according to the present invention; -
FIG. 2 is a schematic close-up view of an example embodiment of the RoF system ofFIG. 1 , illustrating an example embodiment of the converter unit and dipole antenna system for the transponder of the present invention as arranged in the optical fiber cable; -
FIG. 3 is a close-up schematic diagram of an example embodiment of the configuration of the converter unit and dipole antenna system for the transponder of the present invention, wherein the dipole antenna system includes transmitting and receiving antennas; -
FIG. 4 is a schematic diagram of an example embodiment of the transponder of the present invention similar to that shown inFIG. 3 , but wherein dipole antenna system includes a single antenna that both transmits and receives electromagnetic signals; -
FIG. 5 is a close-up schematic diagram of an example embodiment of an E/O converter in the converter unit that includes a number of amplifiers, with each amplifier adapted to amplify a different frequency in the electrical RF signal created by the photodetector; -
FIG. 6 is a schematic diagram of an example embodiment of the transponder of the present invention, wherein the dipole antenna system includes a power divider and three separate antennas; -
FIG. 7 is a schematic diagram of an example embodiment of the transponder of the present invention similar to that shown inFIG. 6 , wherein the antenna system includes a plurality of power dividers each electrically coupled to an antenna; -
FIG. 8 is a schematic diagram of an example embodiment of the transponder according to the present invention similar to that shown inFIG. 7 , wherein a portion of the antenna system lies outside of the optical fiber cable coating; -
FIG. 9 is a schematic diagram of an example embodiment of the transponder of the present invention similar to that shown inFIG. 8 , wherein the converter unit and dipole antenna system both reside outside of the optical fiber cable coating; -
FIG. 10 is a schematic diagram of an example embodiment of the transponder of the present invention, wherein the antenna system includes two pairs of wire antennas, with each antenna connected to the converter unit via respective RF cable sections; -
FIG. 11 is a schematic diagram of an example embodiment of the RoF picocellular wireless system ofFIG. 1 , showing details of an example embodiment of the head-end unit; -
FIG. 12 is a schematic diagram of a typical prior art picocellular coverage area formed by a conventional prior art picocellular wireless system that employs conventional omnidirectional transponders; -
FIG. 13 is a schematic diagram of an example picocellular coverage area formed by the RoF picocellular wireless system of the present invention that utilizes the transponders of the present invention; and -
FIG. 14 is a plot of RF power (dBm) emitted by the dipole antenna system of the transponder of the present invention vs. the distance (m) from the antenna system along both the x-direction (i.e., perpendicular to the optical fiber cable) and the y-direction (i.e., along the optical fiber cable). - Reference is now made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same or analogous reference numbers are used throughout the drawings to refer to the same or like parts.
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FIG. 1 is a schematic diagram of a generalized embodiment of a RoFpicocellular wireless system 10 according to the present invention.System 10 includes a head-end unit 20 adapted to transmit, receive and/or process RF optical signals. In an example embodiment, head-end unit 20 is operably coupled to anoutside network 24 via anetwork link 25, and the head-end unit serves as a pass-through for RF signals sent to and from the outside network. -
System 10 also includes one or more transponder units (“transponders”) 30 according to the present invention. Eachtransponder 30 includes aconverter unit 31 and adipole antenna system 32 electrically coupled thereto, wherein the dipole antenna system has a dipole radiation characteristic the same as or substantially similar to that of an ideal dipole antenna.Transponder 30 is discussed in greater detail below. -
System 10 includes one or moreoptical fiber cables 34 each optically coupled to head-end unit 20. Eachoptical fiber cable 34 includes one or more optical fiber RF transmission links 36 optically coupled to respective one ormore transponders 30. In an example embodiment, each optical fiberRF transmission link 36 includes a downlinkoptical fiber 36D and an uplinkoptical fiber 36U. Example embodiments ofsystem 10 include either single-mode optical fiber or multimode optical fiber for downlink and uplinkoptical fibers system 10, as well as the desired performance and cost considerations. For many in-building deployment applications, maximum transmission distances typically do not exceed 300 meters. The maximum length for the intended RoF transmission needs to be taken into account when considering using multi-mode optical fibers for downlink and uplinkoptical fibers optical fibers - In an example embodiment, RoF
picocellular wireless system 10 of the present invention employs a known telecommunications wavelength, such as 850 nm, 1300 nm, or 1550 nm. In another example embodiment,system 10 employs other less common but suitable wavelengths such as 980 nm. - Also shown in
FIG. 1 is a local x-y-z Cartesian coordinate system C at eachdipole antenna system 32 for the sake of reference, where the x-direction is into the paper and locally perpendicular tooptical fiber cable 34. In an example embodiment,dipole antenna system 32 is sufficiently stiff so thatoptical fiber cable 34 is locally straight at the dipole antenna system location. In an example embodiment,dipole antenna system 32 is located relatively far away from converter unit 31 (e.g., 2 meters), while in other example embodiments the dipole antenna system is located relatively close to the converter unit (e.g., a few inches away), or even directly at the converter unit. - Each
transponder 30 is adapted to form apicocell 40 viadipole antenna system 32 via electromagnetic transmission and reception when the transponder is addressed, e.g., receives a downlink optical signal SD′ from head-end unit 20 and/or an uplink electromagnetic signal SU″ from aclient device 46.Client device 46, which is shown in the form of a computer as one example of a client device, includes an antenna 48 (e.g., a wireless card) adapted to electromagnetically communicate with (i.e., address) the transponder andantenna system 32 thereof. -
Dipole antenna system 32 is adapted to formpicocell 40 from adipole radiation pattern 42 oriented perpendicular tooptical fiber cable 34 at the location of the dipole antenna system. The term “locally perpendicular” is used herein to describe the orientation ofpicocell 40 and/or the correspondingdipole radiation pattern 42 relative tooptical fiber cable 34 at the location ofdipole antenna system 32.Dipole radiation pattern 42 is thus centered about the local x-z plane PXZ (viewed edge-on inFIG. 1 and illustrated as a dotted line). In an example embodiment, only a portion ofdipole radiation pattern 42 is used forpicocell 40, e.g., the portion below optical fiber cable 34 (i.e., in the -z direction), as shown inFIG. 1 . - In an example embodiment,
system 10 is powered by apower supply 50 electrically coupled to head-end unit 20 via anelectrical power line 52 that carries electrical power signals 54. -
FIG. 2 is a schematic close-up view of an example embodiment oftransponder 30 as incorporated intooptical fiber cable 34. In an example embodiment,optical fiber cable 34 includes anouter coating 58. As mentioned above,transponder 30 includes aconverter unit 31.Converter unit 31 includes an electrical-to-optical (E/O)converter 60 adapted to convert an electrical signal into a corresponding optical signal, and an optical-to-electrical (O/E)converter 62 that converts an optical signal into a corresponding electrical signal. E/O converter 60 is optically coupled to aninput end 70 of uplinkoptical fiber 36U and O/E converter 62 is optically coupled to anoutput end 72 of downlinkoptical fiber 36D. - In an example embodiment,
optical fiber cable 34 includeselectrical power line 52, andconverter unit 31 includes aDC power converter 80 electrically coupled to the electrical power line and to E/O converter 60 and O/E converter 62.DC power converter 80 is adapted to change the voltage levels and provide the power required by the power-consuming components inconverter unit 31. In an example embodiment,DC power converter 80 is either a DC/DC power converter, or an AC/DC power converter, depending on the type ofpower signal 54 carried byelectrical power line 52. In an example embodiment,electrical power line 52 includes twoelectrical wires DC power converter 80. - As discussed above,
dipole antenna system 32 is electrically coupled toconverter unit 31. In an example embodiment,dipole antenna system 32 includes one or more antenna elements (“antennas”) 33. In the example embodiment shown inFIG. 2 ,antenna system 32 includes a receivingantenna 33R electrically coupled to E/O converter 60 via a firstRF cable section 90 and a transmittingantenna 33T electrically coupled to E/O converter 62 via a secondRF cable section 90. In an example embodiment, the one ormore antennas 33 is/are made of or include sections of wire. One or moreRF cable sections 90 are used in example embodiments of the present invention to connect corresponding one ormore antennas 33 to theconverter unit 31. In an example embodiment,dipole antenna system 32 supports multiple frequency bands. Additionally, the diversity principle can be used to send the same information through statistically independent channels. -
FIG. 3 is a detailed schematic diagram of an example embodiment ofconverter unit 31 anddipole antenna system 32 for thetransponder 30 of the present invention. In the example embodiment ofFIG. 3 , E/O converter 60 includes alaser 100 optically coupled to aninput end 70 of uplinkoptical fiber 36U, a bias-T unit 106 electrically coupled to the laser, anamplifier 110 electrically coupled to the bias-T unit, and aRF filter 114 electrically coupled to the amplifier and to the correspondingRF cable section 90. Also in an example embodiment, O/E converter 62 includes aphotodetector 120 optically coupled to output end 72 of downlinkoptical fiber 36D, anamplifier 110 electrically coupled to the photodetector, and aRF filter 114 electrically coupled to the amplifier and to the correspondingRF cable section 90. In an example embodiment,laser 100 is adapted to deliver sufficient dynamic range for one or more RoF applications. Examples of suitable lasers for E/O converter 60 include laser diodes, distributed feedback (DFB) lasers, Fabry-Perot (FP) lasers, and VCSELs. - In the operation of
transponder 30 ofFIG. 3 , a downlink optical signal SD′ traveling in downlinkoptical fiber 36D exits this optical fiber atoutput end 72 and is received byphotodetector 120.Photodetector 120 converts optical signal SD′ into a corresponding electrical signal SD, which is then amplified byamplifier 110 and then filtered byRF filter 114. Electrical signal SD is then fed via the correspondingRF cable section 90 to transmittingantenna 33T, which converts electrical signal SD into a corresponding electromagnetic signal SD″, which then travels to one ormore client devices 46 within the corresponding picocell 40 (FIG. 1 ). - Similarly, receiving
antenna 33R receives electromagnetic uplink signal SU″ from one ormore client devices 46 withinpicocell 40 and converts each such signal to a corresponding electrical signal SU. This electrical travels over the correspondingRF cable section 90 and is signal is fed toRF filter 114, which filters the signal and passes it along toamplifier 110, which amplifies the signal. Electrical signal SU then travels to bias-T unit 106, which conditions electrical signal SU—i.e., combines a DC signal with the electrical RF signal so it can drive (semiconductor)laser 100 above threshold using a DC current source (not shown) and independently modulate the power around its average value as determined by the provided DC current. The conditioned electrical signal SU then travels tolaser 100, which converts the electrical signal to an corresponding optical signal SU″ that is sent to head-end unit 20 for processing. -
Transponders 30 of the present invention differ from the typical access point device associated with wireless communication systems in that the preferred embodiment of the transponder has just a few signal-conditioning elements and no digital information processing capability. Rather, the information processing capability is located remotely in head-end unit 20. This allowstransponder 30 to be very compact and virtually maintenance free. In addition, the preferred example embodiment oftransponder 30 consumes very little power, is transparent to RF signals, and does not require a local power source, as described below. Moreover, ifsystem 10 needs to be changed (e.g., upgraded), the change can be performed at head-end unit 20 without having to change or otherwise altertransponders 30. - In an example embodiment of
transponder 30 such as shown inFIG. 3 ,dipole antenna system 32 includes one ormore antennas 33, such as receivingantenna 33R and a transmittingantenna 33T. In an example embodiment,antennas dipole antenna system 32 to lie along the direction ofoptical fiber cable 34 allows for easy integration of the dipole antenna system into the optical fiber cable relative to other types of direction antennas, such as patch antennas. In an example embodiment,dipole antenna system 32 includes a circuit-based dipole antenna, such as available over the Internet from Winizen Co., Ltd., Kyounggi-do 429-250, Korea. -
FIG. 4 is a schematic diagram of an example embodiment of thetransponder 30 of the present invention similar to that shown inFIG. 3 , but whereindipole antenna system 32 includes just asingle antenna 33 that both transmits and receives electromagnetic signals. Intransponder 30 ofFIG. 4 ,converter unit 31 includes a RF signal-directingelement 130, such as a circulator, electrically coupled tosingle antenna 33 via a thirdRF cable section 90. -
FIG. 5 is a schematic diagram of an example embodiment of E/O converter unit 60 inconverter unit 31, wherein the E/O converter includes a number ofamplifiers 100 electrically connected tophotodetector 120. Eachamplifier 100 is adapted to amplify a different frequency in electrical signal SD. This allows for parallel conditioning of different frequency bands withintransponder 30. A variety of other multi-frequency amplification and antenna system arrangements are also possible for E/O converter 60, as well as for O/E converter 62. - The
transponder 30 of the present invention is capable of supporting numerous configurations ofdipole antenna system 32.FIG. 6 is a schematic diagram of an example embodiment oftransponder 30 with adipole antenna system 32 that includes threedifferent antennas 33 electrically connected to apower divider 210 via respectiveRF cable sections 90.Power divider 210 in turn is electrically coupled toconverter unit 31 via a correspondingRF cable section 90. -
FIG. 7 is a schematic diagram of an example embodiment oftransponder 30 with adipole antenna system 32 similar to that shown inFIG. 6 , but that includes a plurality ofpower dividers 210 arranged along aRF cable section 90, with each power divider branching off anantenna 33. An advantage of the example embodiment oftransponder 30 ofFIG. 7 is that if the optical fiber cable is deployed in a building and oneantenna 33 is obstructed (say, by an air conditioning duct), another antenna can still send and receive electromagnetic signals. -
FIG. 8 is a schematic diagram of an example embodiment oftransponder 30 with adipole antenna system 32 similar to that shown inFIG. 7 , wherein a portion of the antenna system lies outside ofcable coating 58. InFIG. 8 ,antenna 33 ofantenna system 32 is shown arranged outside ofcable coating 58. In an example embodiment, anexternal covering 220, such as a shrink wrapper, is applied tocable coating 58 to secure and protect the portion ofantenna system 32 that lies outside of the cable coating. -
FIG. 9 is a schematic diagram of an example embodiment oftransponder 30 with adipole antenna system 32 similar to that shown inFIG. 8 , whereinconverter unit 31 anddipole antenna system 32 are both outside ofcable coating 58 and optionally covered byexternal covering 220. -
FIG. 10 is a schematic diagram of an example embodiment oftransponder 30 with adipole antenna system 32 that includes twopairs wire antennas 33, with each antenna connected toconverter unit 33 via a correspondingRF cable section 90. Antenna pairs 234 and 235 may be designed, for example, to transmit and receive at the 5.2 GHz and 2.4 GHz frequency bands, respectively (i.e., the IEEE 802 a/b/g standard frequency bands). The judicious use ofRF cable sections 90 in this example embodiment mitigates fading and shadowing effects that can adversely affect thedipole radiation pattern 42 and thus the size and shape ofpicocell 40. -
FIG. 11 is a detailed schematic diagram of an example embodiment ofsystem 10 ofFIG. 1 , showing the details of an example embodiment of head-end unit 20. In an example embodiment, head-end unit 20 includes acontroller 250 that provides electrical RF signals SD for a particular wireless service or application. In an example embodiment,controller 250 includes a RF signal modulator/demodulator unit 270 for modulating/demodulating RF signals, adigital signal processor 272 for generating digital signals, a central processing unit (CPU) 274 for processing data and otherwise performing logic and computing operations, and amemory unit 276 for storing data. In an example embodiment,controller 250 is adapted to provide WLAN signal distribution as specified in the IEEE 802.11 standard, i.e., in the frequency range from 2.4 to 2.5 GHz and from 5.0 to 6.0 GHz. In an example embodiment,controller 250 serves as a pass-through unit that merely coordinates distributing electrical RF signals SD and SU from and tooutside network 24 or betweenpicocells 40. - Head-
end unit 20 includes one or more converter pairs 66 each having an E/O converter 60 and an O/E converter 62. Eachconverter pair 66 is electrically coupled tocontroller 250 and is also optically coupled to corresponding one ormore transponders 30. Each E/O converter 60 inconverter pair 66 is optically coupled to aninput end 76 of a downlinkoptical fiber 36D, and each O/E converter 62 is optically coupled to anoutput end 74 of an uplinkoptical fiber 36U. - In an example embodiment of the operation of
system 10 ofFIG. 11 ,digital signal processor 272 incontroller 250 generates a downlink digital RF signal S1. This signal is received and modulated by RF signal modulator/demodulator 270 to create a downlink electrical RF signal (“electrical signal”) SD designed to communicate with one ormore client devices 46 in picocell(s) 40. Electrical signal SD is received by one or more E/O converters 60, which converts this electrical signal into a corresponding optical signal SU′, which is then coupled into the corresponding downlinkoptical fiber 36D atinput end 76. It is noted here that in an example embodiment optical signal SD′ is tailored to have a given modulation index. Further, in an example embodiment the modulation power of E/O converter 60 is controlled (e.g., by one or more gain-control amplifiers, not shown) in order to vary the transmission power fromdipole antenna system 32, which is the main parameter that dictates the size of the associatedpicocell 40. In an example embodiment, the amount of power provided todipole antenna system 32 is varied to define the size of the associatedpicocell 40. - Optical signal SD′ travels over downlink
optical fiber 36D to anoutput end 72 and is processed as described above in connection withsystem 10 ofFIG. 2 to return an uplink optical signal SU″. Optical signal SU″ is received at head-end unit 20, e.g., by O/E converter 62 in theconverter pair 66 that sent the corresponding downlink optical signal SD′. O/E converter 62 converts optical signal SU′ back into electrical signal SU, which is then processed. Here, in an example embodiment “processed” includes one or more of the following: storing the signal information inmemory unit 276; digitally processing or conditioning the signal incontroller 250; sending the electrical signal SU, whether conditioned or unconditioned, on to one or moreoutside networks 24 via network links 25; and sending the signal to one ormore client devices 46 within the same orother picocells 40. In an example embodiment, the processing of signal SU includes demodulating this electrical signal in RF signal modulator/demodulator unit 270, and then processing the demodulated signal indigital signal processor 272. -
FIG. 12 is a schematic diagram illustrating a typical prior artpicocellular coverage area 44P formed by a conventional picocellular wireless system that formssymmetric picocells 40P. Note that such picocells are traditionally represented as hexagons because they can be shown as tiling a given space without gaps.Picocell coverage area 44P requires sevenoptical fiber cables 34P that employ conventional transponders having omnidirectional antennas. The conventional optical fiber cables are optically coupled to a conventional head-end station 20P. The dashed-line outer box B inFIG. 12 represents the approximate boundary forpicocell coverage area 44P. -
FIG. 13 is a schematic diagram of apicocellular coverage area 44 based on the RoFpicocellular wireless system 10 of the present invention that includestransponders 30 according to the present invention. The number oftransponders 30 and thus the number ofpicocells 40 that formpicocellular coverage area 44 are approximately equal to theprior art system 10P ofFIG. 12 . Dashed-line outer box B is provided inFIG. 13 to show that the size ofpicocellular coverage area 44 is about the same as that forpicocellular coverage area 44P ofFIG. 12 . However, eachtransponder 30 of the present invention forms anelongate picocell 40 with a long axis AP perpendicular to the local y-direction ofoptical fiber cable 34 at the correspondingdipole antenna system 32.Transponders 30 of the present invention thus form apicocellular coverage area 44 made up ofelongate picocells 40 by virtue of orienting the dipole radiation pattern locally perpendicular to the optical fiber cable at the location of eachdipole antenna system 32. The elongate shape ofpicocells 40 allowssystem 10 to cover substantially the same picocellular coverage area asarea 44P but using only threeoptical fiber cables 34—a reduction of over 50% as compared to the optical fiber cabling needed for the traditionalpicocellular coverage area 44P ofFIG. 12 . The use of the about the same number oftransponders 30 allows forpicocells 40 operating at the same frequency to be maximally separated. - Picocells 40 are elongate because
dipole antenna 32 has an asymmetric (elliptical) power distribution in the local x-y plane due to the different power decay rate in the different directions.FIG. 14 is a plot of RF power (dBm) emitted bydipole antenna system 32 vs. the distance (m) from the antenna along both the x-direction (curve 300) and the y-direction (curve 302).Curve 302 indicates that along the direction of the optical fiber cable (y-direction), the decay is fast, so that one can packtransponders 30 more densely along the optical fiber cable without increasing the picocell-to-picocell crosstalk. - Omnidirectional antennas, such as vertical dipole antennas, typically have a relatively shallow RF power decay rate similar to
curve 300 inFIG. 14 . Consequently,picocells 40 formed from such antennas are prone to cross-talk. Directive antennas, such as microstrip patches, can have an asymmetric radiation pattern in the x-y plane that can create asymmetric cells. However, these antennas require proper alignment in space. Thedipole antenna system 32 of the present invention produces predictable radiation patterns without any orientation tuning of individual antennas. This is because thedipole antenna system 32 is incorporated into (or onto)optical fiber cable 34 in a manner that allows for the picocell location and orientation to be determined by orientingoptical fiber cable 34 rather than orienting individual antennas per se. This makesoptical fiber cable 34 easier to manufacture and deploy relative to using other more complex directional dipole antenna systems. - It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
Claims (20)
1. A transponder for a radio-over-fiber (RoF) optical fiber cable, comprising:
an electrical-to-optical (E/O) converter;
an optical-to-electrical (O/E) converter; and
a dipole antenna system operably coupled to the E/O converter and the O/E converter and arranged relative to the optical fiber cable so as to create an elongate picocell in a direction locally perpendicular to the optical fiber cable when the transponder is addressed.
2. The transponder of claim 1 , wherein the dipole antenna includes a transmitting antenna formed from a first wire electrically coupled to the O/E converter, and a receiving antenna formed from a second wire electrically coupled to the E/O converter, wherein the first and second wires are arranged locally parallel to the optical fiber cable.
3. The transponder of claim 1 , wherein the optical fiber cable has an outer coating, and wherein at least a portion of the transponder resides outside of the outer coating.
4. The transponder of claim 1 , wherein the dipole antenna system has includes one or more power dividers and corresponding one or more antenna elements electrically coupled to respective power dividers.
5. The transponder of claim 1 , wherein the E/O converter and the O/E converter constitute a converter unit, and wherein the dipole antenna system includes one or more wires electrically coupled to the converter unit via respective one or more radio-frequency (RF) cable sections.
6. A radio-over-fiber (RoF) picocellular wireless system, comprising:
a head-end unit adapted to send and receive optical RF signals;
one or more transponders according to claim 1 ; and
one or more optical fiber cables that include the one or more transponders and that optically couple the head-end unit to each transponder.
7. The system of claim 6 , wherein each optical fiber cable includes, for each transponder:
a downlink optical fiber optically coupled to the head-end unit and to the transponder O/E converter; and
an uplink optical fiber optically coupled to the head-end unit and to the transponder E/O converter.
8. The system of claim 7 , wherein each optical fiber cable includes an electrical power line adapted to provide electrical power to each transponder in the corresponding optical fiber cable.
9. A transponder for forming a picocell as part of a radio-over-fiber (RoF) system having an optical fiber cable optically connected to a head-end unit, comprising:
a converter unit adapted to convert electrical signals to optical signals and vice versa; and
a dipole antenna system arranged relative to the optical fiber cable so as to create a picocell formed by creating a dipole radiation field directed perpendicular to the optical fiber cable at the dipole antenna system location.
10. The transponder of claim 9 , wherein the dipole antenna system includes one or more antenna elements each electrically coupled to the converter unit via corresponding one or more radio-frequency (RF) cable sections.
11. The transponder of claim 9 , wherein the optical fiber cable includes an outer coating, and wherein at least a portion of the transponder resides outside of the outer coating.
12. The transponder of claim 11 , wherein some or all of the dipole antenna system resides outside of the outer coating.
13. A radio-over-fiber (RoF) picocellular wireless system, comprising:
one or more transponders according to claim 9 ;
a head-end unit adapted to send and receive optical RF signals;
one or more optical fiber cables each having at least one transponder and corresponding one or more optical fiber RF communication links that optically couple the one or more transponders to the head-end unit; and
wherein the one or more transponders form a picocellular coverage area made up of elongate picocells formed by each transponder.
14. The system of claim 13 , wherein the head-end unit is adapted to send and transmit optical RF signals having different frequencies, and the dipole antenna system is adapted to transmit and receive electromagnetic signals having the different frequencies.
15. The system of claim 13 , further including:
a power supply operably connected to the head-end unit via an electrical power line that runs through the one or more optical fiber cables so as to provide electrical power to each transponder.
16. The system of claim 13 , wherein each optical fiber cable has an outer coating, and at least a portion of some or all of the one or more transponders reside outside of the outer coating.
17. A method of forming an elongate picocell for a radio-over fiber (RoF) system that includes an optical fiber cable, comprising:
transmitting optical RF signals to a transponder via an optical fiber RF communication link in the optical fiber cable;
converting the optical signals to electrical RF signals at the transponder;
converting the electrical signals to electromagnetic RF signals at the transponder using a dipole antenna system that creates the elongate picocell in a direction locally perpendicular to the optical fiber cable.
18. The method of claim 17 , wherein the optical fiber cable has an outer coating and including providing at least a portion of the dipole antenna system outside of the outer coating.
19. The method of claim 17 , including performing the acts therein for multiple transponders so as to form a picocellular coverage area made up of multiple elongate picocells.
20. The method of claim 17 , including orienting the picocell by orienting the optical fiber cable.
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US11/454,581 US20070292136A1 (en) | 2006-06-16 | 2006-06-16 | Transponder for a radio-over-fiber optical fiber cable |
US11/505,772 US7590354B2 (en) | 2006-06-16 | 2006-08-17 | Redundant transponder array for a radio-over-fiber optical fiber cable |
PCT/US2007/014094 WO2007146428A2 (en) | 2006-06-16 | 2007-06-14 | Transponder for a radio-over-fiber optical fiber cable |
CNA2007800224532A CN101473568A (en) | 2006-06-16 | 2007-06-14 | Transponder for a radio-over-fiber optical fiber cable |
EP07809595A EP2033343A2 (en) | 2006-06-16 | 2007-06-14 | Transponder for a radio-over-fiber optical fiber cable |
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US11/454,581 US20070292136A1 (en) | 2006-06-16 | 2006-06-16 | Transponder for a radio-over-fiber optical fiber cable |
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---|---|
US (2) | US20070292136A1 (en) |
EP (1) | EP2033343A2 (en) |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130004176A1 (en) * | 2010-04-16 | 2013-01-03 | Panasonic Corporation | Communication system, main unit, radio access unit and communication method |
Families Citing this family (71)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7787823B2 (en) | 2006-09-15 | 2010-08-31 | Corning Cable Systems Llc | Radio-over-fiber (RoF) optical fiber cable system with transponder diversity and RoF wireless picocellular system using same |
US7848654B2 (en) * | 2006-09-28 | 2010-12-07 | Corning Cable Systems Llc | Radio-over-fiber (RoF) wireless picocellular system with combined picocells |
US8873585B2 (en) | 2006-12-19 | 2014-10-28 | Corning Optical Communications Wireless Ltd | Distributed antenna system for MIMO technologies |
US8111998B2 (en) | 2007-02-06 | 2012-02-07 | Corning Cable Systems Llc | Transponder systems and methods for radio-over-fiber (RoF) wireless picocellular systems |
US7920764B2 (en) * | 2007-05-04 | 2011-04-05 | Anthony Stephen Kewitsch | Electrically traceable and identifiable fiber optic cables and connectors |
US20100054746A1 (en) | 2007-07-24 | 2010-03-04 | Eric Raymond Logan | Multi-port accumulator for radio-over-fiber (RoF) wireless picocellular systems |
US8175459B2 (en) | 2007-10-12 | 2012-05-08 | Corning Cable Systems Llc | Hybrid wireless/wired RoF transponder and hybrid RoF communication system using same |
WO2009081376A2 (en) | 2007-12-20 | 2009-07-02 | Mobileaccess Networks Ltd. | Extending outdoor location based services and applications into enclosed areas |
WO2009114738A2 (en) | 2008-03-12 | 2009-09-17 | Hypres, Inc. | Digital radio-frequency tranceiver system and method |
EP2394379B1 (en) | 2009-02-03 | 2016-12-28 | Corning Optical Communications LLC | Optical fiber-based distributed antenna systems, components, and related methods for calibration thereof |
AU2010210766A1 (en) | 2009-02-03 | 2011-09-15 | Corning Cable Systems Llc | Optical fiber-based distributed antenna systems, components, and related methods for monitoring and configuring thereof |
US9673904B2 (en) | 2009-02-03 | 2017-06-06 | Corning Optical Communications LLC | Optical fiber-based distributed antenna systems, components, and related methods for calibration thereof |
TWI385958B (en) * | 2009-03-20 | 2013-02-11 | Ind Tech Res Inst | System for providing wireless communication over a passive optical network (pon) |
US9590733B2 (en) * | 2009-07-24 | 2017-03-07 | Corning Optical Communications LLC | Location tracking using fiber optic array cables and related systems and methods |
US8548330B2 (en) | 2009-07-31 | 2013-10-01 | Corning Cable Systems Llc | Sectorization in distributed antenna systems, and related components and methods |
US8280259B2 (en) | 2009-11-13 | 2012-10-02 | Corning Cable Systems Llc | Radio-over-fiber (RoF) system for protocol-independent wired and/or wireless communication |
US8275265B2 (en) | 2010-02-15 | 2012-09-25 | Corning Cable Systems Llc | Dynamic cell bonding (DCB) for radio-over-fiber (RoF)-based networks and communication systems and related methods |
EP2553839A1 (en) | 2010-03-31 | 2013-02-06 | Corning Cable Systems LLC | Localization services in optical fiber-based distributed communications components and systems, and related methods |
US20110268446A1 (en) | 2010-05-02 | 2011-11-03 | Cune William P | Providing digital data services in optical fiber-based distributed radio frequency (rf) communications systems, and related components and methods |
US9525488B2 (en) | 2010-05-02 | 2016-12-20 | Corning Optical Communications LLC | Digital data services and/or power distribution in optical fiber-based distributed communications systems providing digital data and radio frequency (RF) communications services, and related components and methods |
US8509850B2 (en) * | 2010-06-14 | 2013-08-13 | Adc Telecommunications, Inc. | Systems and methods for distributed antenna system reverse path summation using signal-to-noise ratio optimization |
US8570914B2 (en) | 2010-08-09 | 2013-10-29 | Corning Cable Systems Llc | Apparatuses, systems, and methods for determining location of a mobile device(s) in a distributed antenna system(s) |
WO2012024247A1 (en) | 2010-08-16 | 2012-02-23 | Corning Cable Systems Llc | Remote antenna clusters and related systems, components, and methods supporting digital data signal propagation between remote antenna units |
US9252874B2 (en) | 2010-10-13 | 2016-02-02 | Ccs Technology, Inc | Power management for remote antenna units in distributed antenna systems |
CN203504582U (en) | 2011-02-21 | 2014-03-26 | 康宁光缆系统有限责任公司 | Distributed antenna system and power supply apparatus for distributing electric power thereof |
CN103548290B (en) | 2011-04-29 | 2016-08-31 | 康宁光缆系统有限责任公司 | Judge the communication propagation delays in distributing antenna system and associated component, System and method for |
CN103609146B (en) | 2011-04-29 | 2017-05-31 | 康宁光缆系统有限责任公司 | For increasing the radio frequency in distributing antenna system(RF)The system of power, method and apparatus |
MX2013012927A (en) | 2011-05-17 | 2013-12-16 | 3M Innovative Properties Co | Converged in-building network. |
EP2710691B1 (en) | 2011-05-17 | 2016-02-24 | 3M Innovative Properties Company | Remote socket apparatus |
EA036943B1 (en) * | 2011-11-07 | 2021-01-19 | Дали Системз Ко., Лтд. | Soft hand-off and routing data in a virtualized distributed antenna system |
WO2013148986A1 (en) | 2012-03-30 | 2013-10-03 | Corning Cable Systems Llc | Reducing location-dependent interference in distributed antenna systems operating in multiple-input, multiple-output (mimo) configuration, and related components, systems, and methods |
US9781553B2 (en) | 2012-04-24 | 2017-10-03 | Corning Optical Communications LLC | Location based services in a distributed communication system, and related components and methods |
WO2013162988A1 (en) | 2012-04-25 | 2013-10-31 | Corning Cable Systems Llc | Distributed antenna system architectures |
EP2862304A4 (en) | 2012-05-16 | 2016-03-09 | Oe Solutions America Inc | Wavelength tunable array for data communications |
WO2013181247A1 (en) | 2012-05-29 | 2013-12-05 | Corning Cable Systems Llc | Ultrasound-based localization of client devices with inertial navigation supplement in distributed communication systems and related devices and methods |
WO2014024192A1 (en) | 2012-08-07 | 2014-02-13 | Corning Mobile Access Ltd. | Distribution of time-division multiplexed (tdm) management services in a distributed antenna system, and related components, systems, and methods |
US9455784B2 (en) | 2012-10-31 | 2016-09-27 | Corning Optical Communications Wireless Ltd | Deployable wireless infrastructures and methods of deploying wireless infrastructures |
WO2014085115A1 (en) | 2012-11-29 | 2014-06-05 | Corning Cable Systems Llc | HYBRID INTRA-CELL / INTER-CELL REMOTE UNIT ANTENNA BONDING IN MULTIPLE-INPUT, MULTIPLE-OUTPUT (MIMO) DISTRIBUTED ANTENNA SYSTEMS (DASs) |
US9647758B2 (en) | 2012-11-30 | 2017-05-09 | Corning Optical Communications Wireless Ltd | Cabling connectivity monitoring and verification |
US9158864B2 (en) | 2012-12-21 | 2015-10-13 | Corning Optical Communications Wireless Ltd | Systems, methods, and devices for documenting a location of installed equipment |
US9383427B2 (en) * | 2013-01-08 | 2016-07-05 | Dura-Line Corporation | Duct system including information modules configured to emit positional information and method of the same |
EP3008515A1 (en) | 2013-06-12 | 2016-04-20 | Corning Optical Communications Wireless, Ltd | Voltage controlled optical directional coupler |
EP3008828B1 (en) | 2013-06-12 | 2017-08-09 | Corning Optical Communications Wireless Ltd. | Time-division duplexing (tdd) in distributed communications systems, including distributed antenna systems (dass) |
US9247543B2 (en) | 2013-07-23 | 2016-01-26 | Corning Optical Communications Wireless Ltd | Monitoring non-supported wireless spectrum within coverage areas of distributed antenna systems (DASs) |
US9661781B2 (en) | 2013-07-31 | 2017-05-23 | Corning Optical Communications Wireless Ltd | Remote units for distributed communication systems and related installation methods and apparatuses |
US9385810B2 (en) | 2013-09-30 | 2016-07-05 | Corning Optical Communications Wireless Ltd | Connection mapping in distributed communication systems |
US9750082B2 (en) | 2013-10-07 | 2017-08-29 | Commscope Technologies Llc | Systems and methods for noise floor optimization in distributed antenna system with direct digital interface to base station |
US20170250927A1 (en) | 2013-12-23 | 2017-08-31 | Dali Systems Co. Ltd. | Virtual radio access network using software-defined network of remotes and digital multiplexing switches |
US9178635B2 (en) | 2014-01-03 | 2015-11-03 | Corning Optical Communications Wireless Ltd | Separation of communication signal sub-bands in distributed antenna systems (DASs) to reduce interference |
US9775123B2 (en) | 2014-03-28 | 2017-09-26 | Corning Optical Communications Wireless Ltd. | Individualized gain control of uplink paths in remote units in a distributed antenna system (DAS) based on individual remote unit contribution to combined uplink power |
US9357551B2 (en) | 2014-05-30 | 2016-05-31 | Corning Optical Communications Wireless Ltd | Systems and methods for simultaneous sampling of serial digital data streams from multiple analog-to-digital converters (ADCS), including in distributed antenna systems |
US9525472B2 (en) | 2014-07-30 | 2016-12-20 | Corning Incorporated | Reducing location-dependent destructive interference in distributed antenna systems (DASS) operating in multiple-input, multiple-output (MIMO) configuration, and related components, systems, and methods |
US9730228B2 (en) | 2014-08-29 | 2017-08-08 | Corning Optical Communications Wireless Ltd | Individualized gain control of remote uplink band paths in a remote unit in a distributed antenna system (DAS), based on combined uplink power level in the remote unit |
US9602210B2 (en) | 2014-09-24 | 2017-03-21 | Corning Optical Communications Wireless Ltd | Flexible head-end chassis supporting automatic identification and interconnection of radio interface modules and optical interface modules in an optical fiber-based distributed antenna system (DAS) |
US10659163B2 (en) | 2014-09-25 | 2020-05-19 | Corning Optical Communications LLC | Supporting analog remote antenna units (RAUs) in digital distributed antenna systems (DASs) using analog RAU digital adaptors |
US9420542B2 (en) | 2014-09-25 | 2016-08-16 | Corning Optical Communications Wireless Ltd | System-wide uplink band gain control in a distributed antenna system (DAS), based on per band gain control of remote uplink paths in remote units |
WO2016071902A1 (en) | 2014-11-03 | 2016-05-12 | Corning Optical Communications Wireless Ltd. | Multi-band monopole planar antennas configured to facilitate improved radio frequency (rf) isolation in multiple-input multiple-output (mimo) antenna arrangement |
WO2016075696A1 (en) | 2014-11-13 | 2016-05-19 | Corning Optical Communications Wireless Ltd. | Analog distributed antenna systems (dass) supporting distribution of digital communications signals interfaced from a digital signal source and analog radio frequency (rf) communications signals |
US9729267B2 (en) | 2014-12-11 | 2017-08-08 | Corning Optical Communications Wireless Ltd | Multiplexing two separate optical links with the same wavelength using asymmetric combining and splitting |
WO2016098109A1 (en) | 2014-12-18 | 2016-06-23 | Corning Optical Communications Wireless Ltd. | Digital interface modules (dims) for flexibly distributing digital and/or analog communications signals in wide-area analog distributed antenna systems (dass) |
WO2016098111A1 (en) | 2014-12-18 | 2016-06-23 | Corning Optical Communications Wireless Ltd. | Digital- analog interface modules (da!ms) for flexibly.distributing digital and/or analog communications signals in wide-area analog distributed antenna systems (dass) |
US10334572B2 (en) | 2015-02-05 | 2019-06-25 | Commscope Technologies Llc | Systems and methods for emulating uplink diversity signals |
US20160249365A1 (en) | 2015-02-19 | 2016-08-25 | Corning Optical Communications Wireless Ltd. | Offsetting unwanted downlink interference signals in an uplink path in a distributed antenna system (das) |
US9681313B2 (en) | 2015-04-15 | 2017-06-13 | Corning Optical Communications Wireless Ltd | Optimizing remote antenna unit performance using an alternative data channel |
US10064143B2 (en) * | 2015-05-08 | 2018-08-28 | Comba Telecom Technology (Guangzhou) Co., Ltd. | System and method for signal backup of active DAS master unit |
US9948349B2 (en) | 2015-07-17 | 2018-04-17 | Corning Optical Communications Wireless Ltd | IOT automation and data collection system |
US10560214B2 (en) | 2015-09-28 | 2020-02-11 | Corning Optical Communications LLC | Downlink and uplink communication path switching in a time-division duplex (TDD) distributed antenna system (DAS) |
CA3015253A1 (en) | 2016-01-18 | 2017-07-27 | Viavi Solutions Inc. | Method and apparatus for the detection of distortion or corruption of cellular communication signals |
US9648580B1 (en) | 2016-03-23 | 2017-05-09 | Corning Optical Communications Wireless Ltd | Identifying remote units in a wireless distribution system (WDS) based on assigned unique temporal delay patterns |
US10236924B2 (en) | 2016-03-31 | 2019-03-19 | Corning Optical Communications Wireless Ltd | Reducing out-of-channel noise in a wireless distribution system (WDS) |
CN107196707B (en) * | 2017-05-24 | 2020-01-31 | 重庆三峡学院 | Distributed radio over fiber-WiFi-ZigBee network |
Citations (93)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4896939A (en) * | 1987-10-30 | 1990-01-30 | D. G. O'brien, Inc. | Hybrid fiber optic/electrical cable and connector |
US4916460A (en) * | 1988-01-29 | 1990-04-10 | Decibel Products, Incorporated | Distributed antenna system |
US5301056A (en) * | 1991-12-16 | 1994-04-05 | Motorola, Inc. | Optical distribution system |
US5339058A (en) * | 1992-10-22 | 1994-08-16 | Trilogy Communications, Inc. | Radiating coaxial cable |
US5339184A (en) * | 1992-06-15 | 1994-08-16 | Gte Laboratories Incorporated | Fiber optic antenna remoting for multi-sector cell sites |
US5400391A (en) * | 1990-09-17 | 1995-03-21 | Nec Corporation | Mobile communication system |
US5424864A (en) * | 1991-10-24 | 1995-06-13 | Nec Corporation | Microcellular mobile communication system |
US5444564A (en) * | 1994-02-09 | 1995-08-22 | Hughes Aircraft Company | Optoelectronic controlled RF matching circuit |
US5627879A (en) * | 1992-09-17 | 1997-05-06 | Adc Telecommunications, Inc. | Cellular communications system with centralized base stations and distributed antenna units |
US5640678A (en) * | 1992-12-10 | 1997-06-17 | Kokusai Denshin Denwa Kabushiki Kaisha | Macrocell-microcell communication system with minimal mobile channel hand-off |
US5648961A (en) * | 1994-11-21 | 1997-07-15 | Meisei Electric Co., Ltd. | Radio telephone system and antenna device and base station for the same |
US5867485A (en) * | 1996-06-14 | 1999-02-02 | Bellsouth Corporation | Low power microcellular wireless drop interactive network |
US5881200A (en) * | 1994-09-29 | 1999-03-09 | British Telecommunications Public Limited Company | Optical fibre with quantum dots |
US5883882A (en) * | 1997-01-30 | 1999-03-16 | Lgc Wireless | Fault detection in a frequency duplexed system |
US5910776A (en) * | 1994-10-24 | 1999-06-08 | Id Technologies, Inc. | Method and apparatus for identifying locating or monitoring equipment or other objects |
US5930682A (en) * | 1996-04-19 | 1999-07-27 | Lgc Wireless, Inc. | Centralized channel selection in a distributed RF antenna system |
US5936754A (en) * | 1996-12-02 | 1999-08-10 | At&T Corp. | Transmission of CDMA signals over an analog optical link |
US5943372A (en) * | 1993-11-30 | 1999-08-24 | Lucent Technologies, Inc. | Orthogonal polarization and time varying offsetting of signals for digital data transmission or reception |
US5946622A (en) * | 1996-11-19 | 1999-08-31 | Ericsson Inc. | Method and apparatus for providing cellular telephone service to a macro-cell and pico-cell within a building using shared equipment |
US6014546A (en) * | 1996-04-19 | 2000-01-11 | Lgc Wireless, Inc. | Method and system providing RF distribution for fixed wireless local loop service |
US6016426A (en) * | 1996-10-10 | 2000-01-18 | Mvs, Incorporated | Method and system for cellular communication with centralized control and signal processing |
US6232870B1 (en) * | 1998-08-14 | 2001-05-15 | 3M Innovative Properties Company | Applications for radio frequency identification systems |
US6268946B1 (en) * | 1998-07-01 | 2001-07-31 | Radio Frequency Systems, Inc. | Apparatus for communicating diversity signals over a transmission medium |
US6337754B1 (en) * | 1997-11-20 | 2002-01-08 | Kokusai Electric Co., Ltd. | Optical conversion relay amplification system |
US20020003645A1 (en) * | 2000-07-10 | 2002-01-10 | Samsung Electronic Co., Ltd | Mobile communication network system using digital optical link |
US6353406B1 (en) * | 1996-10-17 | 2002-03-05 | R.F. Technologies, Inc. | Dual mode tracking system |
US6353600B1 (en) * | 2000-04-29 | 2002-03-05 | Lgc Wireless, Inc. | Dynamic sectorization in a CDMA cellular system employing centralized base-station architecture |
US6374124B1 (en) * | 1997-12-24 | 2002-04-16 | Transcept, Inc. | Dynamic reallocation of transceivers used to interconnect wireless telephones to a broadband network |
US20020048071A1 (en) * | 2000-10-25 | 2002-04-25 | Ntt Docomo, Inc. | Communication system using optical fibers |
US6405018B1 (en) * | 1999-01-11 | 2002-06-11 | Metawave Communications Corporation | Indoor distributed microcell |
US6405308B1 (en) * | 1996-09-03 | 2002-06-11 | Trilogy Software, Inc. | Method and apparatus for maintaining and configuring systems |
US6405058B2 (en) * | 2000-05-16 | 2002-06-11 | Idigi Labs, Llc | Wireless high-speed internet access system allowing multiple radio base stations in close confinement |
US20020075906A1 (en) * | 2000-12-15 | 2002-06-20 | Cole Steven R. | Signal transmission systems |
US20020092347A1 (en) * | 2001-01-17 | 2002-07-18 | Niekerk Jan Van | Radio frequency identification tag tire inflation pressure monitoring and location determining method and apparatus |
US6504636B1 (en) * | 1998-06-11 | 2003-01-07 | Kabushiki Kaisha Toshiba | Optical communication system |
US20030007214A1 (en) * | 2000-05-10 | 2003-01-09 | Yuji Aburakawa | Wireless base station network system, contorl station, base station switching method, signal processing method, and handover control method |
US20030016418A1 (en) * | 1996-07-19 | 2003-01-23 | British Telecommunications Public Limited Company | Telecommunications system |
US6512478B1 (en) * | 1999-12-22 | 2003-01-28 | Rockwell Technologies, Llc | Location position system for relay assisted tracking |
US6519395B1 (en) * | 2000-05-04 | 2003-02-11 | Northrop Grumman Corporation | Fiber optic array harness |
US20030045284A1 (en) * | 2001-09-05 | 2003-03-06 | Copley Richard T. | Wireless communication system, apparatus and method for providing communication service using an additional frequency band through an in-building communication infrastructure |
US20030078074A1 (en) * | 2001-06-28 | 2003-04-24 | Sesay Abu Bakarr | Optical fiber based on wireless scheme for wideband multimedia access |
US6556551B1 (en) * | 1999-05-27 | 2003-04-29 | Lgc Wireless, Inc. | Multi-frequency pilot beacon for CDMA systems |
US6577801B2 (en) * | 1999-05-20 | 2003-06-10 | University Of Southampton | Holey optical fibers |
US6594496B2 (en) * | 2000-04-27 | 2003-07-15 | Lgc Wireless Inc. | Adaptive capacity management in a centralized basestation architecture |
US20030141962A1 (en) * | 2002-01-25 | 2003-07-31 | Bernard Barink | RFID systems - antenna system and software method to spatially locate transponders |
US20040001719A1 (en) * | 2002-06-26 | 2004-01-01 | Kensuke Sasaki | Optical transmission system of radio signal over optical fiber link |
US20040008114A1 (en) * | 2002-07-09 | 2004-01-15 | Fred Sawyer | Method and apparatus for tracking objects and people |
US20040017785A1 (en) * | 2002-07-16 | 2004-01-29 | Zelst Allert Van | System for transporting multiple radio frequency signals of a multiple input, multiple output wireless communication system to/from a central processing base station |
US20040041714A1 (en) * | 2002-05-07 | 2004-03-04 | Forster Ian J. | RFID temperature device and method |
US20040043764A1 (en) * | 2000-04-12 | 2004-03-04 | John Bigham | Intelligent control of radio resources in a wireless network |
US20040047313A1 (en) * | 2002-09-10 | 2004-03-11 | Harris Corporation | Communication system providing hybrid optical/wireless communications and related methods |
US6710366B1 (en) * | 2001-08-02 | 2004-03-23 | Ultradots, Inc. | Nanocomposite materials with engineered properties |
US20040078151A1 (en) * | 2002-10-18 | 2004-04-22 | Daniel Aljadeff | Wireless local area network (WLAN) channel radio-frequency identification (RFID) tag system and method therefor |
US6758913B1 (en) * | 2000-10-12 | 2004-07-06 | General Electric Company | Method of cleaning pressurized containers containing anhydrous ammonia |
US6847856B1 (en) * | 2003-08-29 | 2005-01-25 | Lucent Technologies Inc. | Method for determining juxtaposition of physical components with use of RFID tags |
US6865390B2 (en) * | 2001-06-25 | 2005-03-08 | Lucent Technologies Inc. | Cellular communications system featuring a central radio pool/traffic router |
US20050052287A1 (en) * | 2001-09-13 | 2005-03-10 | Whitesmith Howard William | Wireless communication system |
US20050058451A1 (en) * | 2003-08-12 | 2005-03-17 | Barrett Ross | Enhanced fiber infrastructure for building interiors |
US6873823B2 (en) * | 2002-06-20 | 2005-03-29 | Dekolink Wireless Ltd. | Repeater with digital channelizer |
US20050068179A1 (en) * | 2003-09-30 | 2005-03-31 | Roesner Bruce B. | Distributed RF coupled system |
US6879290B1 (en) * | 2000-12-26 | 2005-04-12 | France Telecom | Compact printed “patch” antenna |
US20050076982A1 (en) * | 2003-10-09 | 2005-04-14 | Metcalf Arthur Richard | Post patch assembly for mounting devices in a tire interior |
US20050078006A1 (en) * | 2001-11-20 | 2005-04-14 | Hutchins J. Marc | Facilities management system |
US6883710B2 (en) * | 2000-10-11 | 2005-04-26 | Amerasia International Technology, Inc. | Article tracking system and method |
US6885846B1 (en) * | 1997-03-31 | 2005-04-26 | Texas Instruments Incorporated | Low power wireless network |
US20050093679A1 (en) * | 2003-10-31 | 2005-05-05 | Zai Li-Cheng R. | Method and system of using active RFID tags to provide a reliable and secure RFID system |
US20050099343A1 (en) * | 2003-11-10 | 2005-05-12 | Asrani Vijay L. | Antenna system for a communication device |
US20050116821A1 (en) * | 2003-12-01 | 2005-06-02 | Clifton Labs, Inc. | Optical asset tracking system |
US6909399B1 (en) * | 2003-12-31 | 2005-06-21 | Symbol Technologies, Inc. | Location system with calibration monitoring |
US20050141545A1 (en) * | 2003-11-10 | 2005-06-30 | Yaron Fein | Performance of a wireless communication system |
US20050143077A1 (en) * | 2003-12-24 | 2005-06-30 | Hugo Charbonneau | System and method for designing a communications network |
US6915058B2 (en) * | 2003-02-28 | 2005-07-05 | Corning Cable Systems Llc | Retractable optical fiber assembly |
US20050148306A1 (en) * | 2004-01-05 | 2005-07-07 | Hiddink Gerrit W. | Predictive method and apparatus for antenna selection in a wireless communication system |
US6920330B2 (en) * | 2002-03-26 | 2005-07-19 | Sun Microsystems, Inc. | Apparatus and method for the use of position information in wireless applications |
US20050159108A1 (en) * | 2002-03-16 | 2005-07-21 | Qinetiq Limited | Signal processing system and method |
US20060002326A1 (en) * | 2004-06-30 | 2006-01-05 | Sarosh Vesuna | Reconfigureable arrays of wireless access points |
US20060017633A1 (en) * | 2002-12-04 | 2006-01-26 | Koninklijke Philips Electronics N.V. | Method and apparatus for true diversity reception with single antenna |
US7020473B2 (en) * | 2003-02-07 | 2006-03-28 | Siemens Aktiengesellschaft | Method for finding the position of a subscriber in a radio communications system |
US7039399B2 (en) * | 2002-03-11 | 2006-05-02 | Adc Telecommunications, Inc. | Distribution of wireless telephony and data signals in a substantially closed environment |
US20060094470A1 (en) * | 2004-11-01 | 2006-05-04 | Microwave Photonics, Inc. | Communications system and method |
US7054513B2 (en) * | 2003-06-09 | 2006-05-30 | Virginia Tech Intellectual Properties, Inc. | Optical fiber with quantum dots |
US7072586B2 (en) * | 1999-12-28 | 2006-07-04 | Ntt Docomo, Inc. | Radio base station system and central control station with unified transmission format |
US20070009266A1 (en) * | 2005-07-07 | 2007-01-11 | Andrew Bothwell | Multimode optical fibre communication system |
US20070058978A1 (en) * | 2005-09-12 | 2007-03-15 | Samsung Electronics Co., Ltd. | Wireless remote access base station and pico-cell system using the same |
US20070149250A1 (en) * | 2003-10-23 | 2007-06-28 | Telecom Italia S.P.A | Antenna system and method for configuring a radiating pattern |
US20070166042A1 (en) * | 2003-12-23 | 2007-07-19 | Seeds Alwyn J | Multiservice optical communication |
US20080014948A1 (en) * | 2006-07-14 | 2008-01-17 | Lgc Wireless, Inc. | System for and method of for providing dedicated capacity in a cellular network |
US20080047023A1 (en) * | 2006-07-24 | 2008-02-21 | Aplix Corporation | User space virtualization system |
US20080058018A1 (en) * | 2006-08-29 | 2008-03-06 | Lgc Wireless, Inc. | Distributed antenna communications system and methods of implementing thereof |
US7359408B2 (en) * | 2003-01-30 | 2008-04-15 | Samsung Electronics Co., Ltd. | Apparatus and method for measuring and compensating delay between main base station and remote base station interconnected by an optical cable |
US20080124086A1 (en) * | 2006-11-27 | 2008-05-29 | Sbc Knowledge Ventures L.P. | System and method for high speed data communications |
US20080150514A1 (en) * | 2006-12-21 | 2008-06-26 | Nokia Corporation | Communication method and system |
US7496384B2 (en) * | 1999-09-13 | 2009-02-24 | Kabushiki Kaisha Toshiba | Radio communication system |
Family Cites Families (77)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4365865A (en) * | 1981-01-30 | 1982-12-28 | Sea-Log Corporation | Hybrid cable construction |
IT1202720B (en) * | 1987-03-31 | 1989-02-09 | Pirelli Cavi Spa | CABLE FOR THE TRANSPORT OF ELECTRICITY AND THE TRANSMISSION OF OPTICAL SIGNALS |
US4889977A (en) | 1987-12-21 | 1989-12-26 | Southwestern Bell Telephone Company | Method of identifying the disposition of plug-in units at a warehouse |
US5682256A (en) | 1988-11-11 | 1997-10-28 | British Telecommunications Public Limited Company | Communications system |
US5042086A (en) * | 1988-11-16 | 1991-08-20 | Dylor Corporation | Method and means for transmitting large dynamic analog signals in optical fiber systems |
US5001303A (en) * | 1989-05-26 | 1991-03-19 | Coleman Cable Systems, Inc. | Metallic sheath electrical cable |
US5039195A (en) * | 1990-05-29 | 1991-08-13 | At&T Bell Laboratories | Composite cable including portions having controlled flexural rigidities |
US5189718A (en) * | 1991-04-02 | 1993-02-23 | Siecor Corporation | Composite cable containing light waveguides and electrical conductors |
US5268971A (en) * | 1991-11-07 | 1993-12-07 | Alcatel Na Cable Systems, Inc. | Optical fiber/metallic conductor composite cable |
US5260957A (en) | 1992-10-29 | 1993-11-09 | The Charles Stark Draper Laboratory, Inc. | Quantum dot Laser |
US5949564A (en) * | 1993-03-01 | 1999-09-07 | British Telecommunications Public Limited Company | Transducer |
US5377035A (en) | 1993-09-28 | 1994-12-27 | Hughes Aircraft Company | Wavelength division multiplexed fiber optic link for RF polarization diversity receiver |
US5960344A (en) | 1993-12-20 | 1999-09-28 | Norand Corporation | Local area network having multiple channel wireless access |
US5457557A (en) * | 1994-01-21 | 1995-10-10 | Ortel Corporation | Low cost optical fiber RF signal distribution system |
US5469523A (en) * | 1994-06-10 | 1995-11-21 | Commscope, Inc. | Composite fiber optic and electrical cable and associated fabrication method |
US5557698A (en) * | 1994-08-19 | 1996-09-17 | Belden Wire & Cable Company | Coaxial fiber optical cable |
CA2162515C (en) | 1994-12-22 | 2000-03-21 | Leonard George Cohen | Jumper tracing system |
US5854986A (en) | 1995-05-19 | 1998-12-29 | Northern Telecom Limited | Cellular communication system having device coupling distribution of antennas to plurality of transceivers |
IL114176A (en) * | 1995-06-15 | 2000-02-29 | Jolt Ltd | Wireless communication system |
US5598288A (en) * | 1995-07-31 | 1997-01-28 | Northrop Grumman Corporation | RF fiber optic transmission utilizing dither |
US5677974A (en) * | 1995-08-28 | 1997-10-14 | Southern New England Telephone Company | Hybrid communications and power cable and distribution method and network using the same |
US6005884A (en) * | 1995-11-06 | 1999-12-21 | Ems Technologies, Inc. | Distributed architecture for a wireless data communications system |
US6177911B1 (en) * | 1996-02-20 | 2001-01-23 | Matsushita Electric Industrial Co., Ltd. | Mobile radio antenna |
US5668562A (en) | 1996-04-19 | 1997-09-16 | Lgc Wireless, Inc. | Measurement-based method of optimizing the placement of antennas in a RF distribution system |
US5983070A (en) | 1996-04-19 | 1999-11-09 | Lgc Wireless, Inc. | Method and system providing increased antenna functionality in a RF distribution system |
US6157810A (en) | 1996-04-19 | 2000-12-05 | Lgc Wireless, Inc | Distribution of radio-frequency signals through low bandwidth infrastructures |
US5703602A (en) | 1996-06-14 | 1997-12-30 | Metricom, Inc. | Portable RF antenna |
US6128470A (en) * | 1996-07-18 | 2000-10-03 | Ericsson Inc. | System and method for reducing cumulative noise in a distributed antenna network |
KR20000049066A (en) * | 1996-10-17 | 2000-07-25 | 핀포인트 코포레이션 | Article tracking system |
IL119832A (en) * | 1996-12-15 | 2001-01-11 | Foxcom Wireless Ltd | Wireless communications systems employing optical fibers |
US5913003A (en) * | 1997-01-10 | 1999-06-15 | Lucent Technologies Inc. | Composite fiber optic distribution cable |
US6049593A (en) | 1997-01-17 | 2000-04-11 | Acampora; Anthony | Hybrid universal broadband telecommunications using small radio cells interconnected by free-space optical links |
US5914671A (en) * | 1997-02-27 | 1999-06-22 | Micron Communications, Inc. | System and method for locating individuals and equipment, airline reservation system, communication system |
KR100244979B1 (en) * | 1997-08-14 | 2000-02-15 | 서정욱 | The cdma micro-cellular communication system for pcs |
US6323980B1 (en) | 1998-03-05 | 2001-11-27 | Air Fiber, Inc. | Hybrid picocell communication system |
JP2981880B2 (en) * | 1998-04-23 | 1999-11-22 | 郵政省通信総合研究所長 | Multi-mode service wireless communication system |
FR2779022B1 (en) | 1998-05-20 | 2000-07-28 | Nortel Matra Cellular | RADIOCOMMUNICATION BASE STATION |
US5959531A (en) | 1998-07-24 | 1999-09-28 | Checkpoint Systems, Inc. | Optical interface between receiver and tag response signal analyzer in RFID system for detecting low power resonant tags |
JP4063419B2 (en) * | 1998-10-06 | 2008-03-19 | 松下電器産業株式会社 | Optical transmission system |
KR100319298B1 (en) | 1998-11-23 | 2002-04-22 | 윤종용 | ADSS cable and manufacturing method |
US6812905B2 (en) * | 1999-04-26 | 2004-11-02 | Andrew Corporation | Integrated active antenna for multi-carrier applications |
KR100441147B1 (en) * | 1999-05-14 | 2004-07-19 | 가부시키가이샤 히다치 고쿠사이 덴키 | Mobile communication system |
US6438301B1 (en) * | 1999-07-07 | 2002-08-20 | Trw Inc. | Low-torque electro-optical laminated cable and cablewrap |
US6714121B1 (en) * | 1999-08-09 | 2004-03-30 | Micron Technology, Inc. | RFID material tracking method and apparatus |
US6577794B1 (en) * | 1999-09-27 | 2003-06-10 | Robert M. Currie | Compound optical and electrical conductors, and connectors therefor |
US6784802B1 (en) | 1999-11-04 | 2004-08-31 | Nordx/Cdt, Inc. | Real time monitoring of cable patch panel |
US6640103B1 (en) * | 1999-11-23 | 2003-10-28 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and system for cellular system border analysis |
US6634811B1 (en) * | 1999-11-30 | 2003-10-21 | Jds Corporation | High performance optical link |
US6236789B1 (en) * | 1999-12-22 | 2001-05-22 | Pirelli Cables And Systems Llc | Composite cable for access networks |
US6466718B1 (en) * | 1999-12-29 | 2002-10-15 | Emc Corporation | Method and apparatus for transmitting fiber-channel and non-fiber channel signals through common cable |
US6687437B1 (en) * | 2000-06-05 | 2004-02-03 | Essex Group, Inc. | Hybrid data communications cable |
US6788666B1 (en) * | 2000-06-13 | 2004-09-07 | Sprint Communications Company, L.P. | Hybrid fiber wireless communication system |
US6606430B2 (en) | 2000-09-05 | 2003-08-12 | Optical Zonu Corporation | Passive optical network with analog distribution |
US6652158B2 (en) | 2000-09-05 | 2003-11-25 | Optical Zonu Corporation | Optical networking unit employing optimized optical packaging |
US6801767B1 (en) | 2001-01-26 | 2004-10-05 | Lgc Wireless, Inc. | Method and system for distributing multiband wireless communications signals |
US6771933B1 (en) | 2001-03-26 | 2004-08-03 | Lgc Wireless, Inc. | Wireless deployment of bluetooth access points using a distributed antenna architecture |
US20020181668A1 (en) * | 2001-06-01 | 2002-12-05 | Lee Masoian | Method and system for radio frequency/fiber optic antenna interface |
EP1400141B1 (en) * | 2001-06-08 | 2010-03-10 | Nextg Networks | Network and method for connecting antennas to base stations in a wireless communication network using space diversity |
US6771862B2 (en) * | 2001-11-27 | 2004-08-03 | Intel Corporation | Signaling medium and apparatus |
JP2003198464A (en) * | 2001-12-28 | 2003-07-11 | Mitsubishi Electric Corp | Optical transmitter-receiver |
CN101957904B (en) * | 2002-01-09 | 2012-12-05 | 传感电子有限责任公司 | System for detecting radio frequency identification tag |
JP2003324393A (en) * | 2002-02-26 | 2003-11-14 | Matsushita Electric Ind Co Ltd | Bi-directional optical transmission system, and master and slave stations used therefor |
US7263293B2 (en) * | 2002-06-10 | 2007-08-28 | Andrew Corporation | Indoor wireless voice and data distribution system |
US6931813B2 (en) * | 2002-08-02 | 2005-08-23 | Anthony D. Collie | Tornado and hurricane roof tie |
US7280848B2 (en) * | 2002-09-30 | 2007-10-09 | Andrew Corporation | Active array antenna and system for beamforming |
US6785558B1 (en) | 2002-12-06 | 2004-08-31 | Lgc Wireless, Inc. | System and method for distributing wireless communication signals over metropolitan telecommunication networks |
GB0229238D0 (en) * | 2002-12-13 | 2003-01-22 | Univ London | An optical communication system |
JP2004229180A (en) * | 2003-01-27 | 2004-08-12 | Oki Electric Ind Co Ltd | Relay communication system |
EP1623590B1 (en) * | 2003-04-22 | 2007-01-10 | Matsushita Electric Industrial Co., Ltd. | Wireless lan system wherein an access point is connected to remote slave stations via an optical multiplexing system |
KR100547880B1 (en) * | 2003-05-20 | 2006-01-31 | 삼성전자주식회사 | Indoor Short-range Communication Network System Using Ultra-Wideband Communication System |
US20040258105A1 (en) * | 2003-06-19 | 2004-12-23 | Spathas Matthew T. | Building optical network |
US7460829B2 (en) * | 2003-07-25 | 2008-12-02 | Panasonic Corporation | Wireless communication system |
US6965718B2 (en) * | 2004-02-20 | 2005-11-15 | Hewlett-Packard Development Company, L.P. | Apparatus and method for supplying power over an optical link |
US7466925B2 (en) * | 2004-03-19 | 2008-12-16 | Emcore Corporation | Directly modulated laser optical transmission system |
US7469105B2 (en) * | 2004-04-09 | 2008-12-23 | Nextg Networks, Inc. | Optical fiber communications method and system without a remote electrical power supply |
US20060182449A1 (en) * | 2005-02-16 | 2006-08-17 | John Iannelli | Optical transmitter with integrated amplifier and pre-distortion circuit |
KR100640385B1 (en) * | 2005-02-18 | 2006-10-31 | 삼성전자주식회사 | BTS Apparatus with mobile and fixed wireless service distribution function |
-
2006
- 2006-06-16 US US11/454,581 patent/US20070292136A1/en not_active Abandoned
- 2006-08-17 US US11/505,772 patent/US7590354B2/en active Active
-
2007
- 2007-06-14 EP EP07809595A patent/EP2033343A2/en not_active Withdrawn
- 2007-06-14 WO PCT/US2007/014094 patent/WO2007146428A2/en active Application Filing
- 2007-06-14 CN CNA2007800224532A patent/CN101473568A/en active Pending
Patent Citations (99)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4896939A (en) * | 1987-10-30 | 1990-01-30 | D. G. O'brien, Inc. | Hybrid fiber optic/electrical cable and connector |
US4916460A (en) * | 1988-01-29 | 1990-04-10 | Decibel Products, Incorporated | Distributed antenna system |
US5400391A (en) * | 1990-09-17 | 1995-03-21 | Nec Corporation | Mobile communication system |
US5424864A (en) * | 1991-10-24 | 1995-06-13 | Nec Corporation | Microcellular mobile communication system |
US5301056A (en) * | 1991-12-16 | 1994-04-05 | Motorola, Inc. | Optical distribution system |
US5339184A (en) * | 1992-06-15 | 1994-08-16 | Gte Laboratories Incorporated | Fiber optic antenna remoting for multi-sector cell sites |
US5627879A (en) * | 1992-09-17 | 1997-05-06 | Adc Telecommunications, Inc. | Cellular communications system with centralized base stations and distributed antenna units |
US5644622A (en) * | 1992-09-17 | 1997-07-01 | Adc Telecommunications, Inc. | Cellular communications system with centralized base stations and distributed antenna units |
US5543000A (en) * | 1992-10-22 | 1996-08-06 | Trilogy Communications, Inc., | Method of forming radiating coaxial cable |
US5339058A (en) * | 1992-10-22 | 1994-08-16 | Trilogy Communications, Inc. | Radiating coaxial cable |
US5640678A (en) * | 1992-12-10 | 1997-06-17 | Kokusai Denshin Denwa Kabushiki Kaisha | Macrocell-microcell communication system with minimal mobile channel hand-off |
US5943372A (en) * | 1993-11-30 | 1999-08-24 | Lucent Technologies, Inc. | Orthogonal polarization and time varying offsetting of signals for digital data transmission or reception |
US5444564A (en) * | 1994-02-09 | 1995-08-22 | Hughes Aircraft Company | Optoelectronic controlled RF matching circuit |
US5881200A (en) * | 1994-09-29 | 1999-03-09 | British Telecommunications Public Limited Company | Optical fibre with quantum dots |
US5910776A (en) * | 1994-10-24 | 1999-06-08 | Id Technologies, Inc. | Method and apparatus for identifying locating or monitoring equipment or other objects |
US5648961A (en) * | 1994-11-21 | 1997-07-15 | Meisei Electric Co., Ltd. | Radio telephone system and antenna device and base station for the same |
US5930682A (en) * | 1996-04-19 | 1999-07-27 | Lgc Wireless, Inc. | Centralized channel selection in a distributed RF antenna system |
US6014546A (en) * | 1996-04-19 | 2000-01-11 | Lgc Wireless, Inc. | Method and system providing RF distribution for fixed wireless local loop service |
US5867485A (en) * | 1996-06-14 | 1999-02-02 | Bellsouth Corporation | Low power microcellular wireless drop interactive network |
US6731880B2 (en) * | 1996-07-19 | 2004-05-04 | Microwave Photonics, Inc. | Telecommunications system |
US20030016418A1 (en) * | 1996-07-19 | 2003-01-23 | British Telecommunications Public Limited Company | Telecommunications system |
US6525855B1 (en) * | 1996-07-19 | 2003-02-25 | British Telecommunications Public Limited Company | Telecommunications system simultaneously receiving and modulating an optical signal |
US6405308B1 (en) * | 1996-09-03 | 2002-06-11 | Trilogy Software, Inc. | Method and apparatus for maintaining and configuring systems |
US6675294B1 (en) * | 1996-09-03 | 2004-01-06 | Trilogy Development Group, Inc. | Method and apparatus for maintaining and configuring systems |
US6016426A (en) * | 1996-10-10 | 2000-01-18 | Mvs, Incorporated | Method and system for cellular communication with centralized control and signal processing |
US6353406B1 (en) * | 1996-10-17 | 2002-03-05 | R.F. Technologies, Inc. | Dual mode tracking system |
US5946622A (en) * | 1996-11-19 | 1999-08-31 | Ericsson Inc. | Method and apparatus for providing cellular telephone service to a macro-cell and pico-cell within a building using shared equipment |
US5936754A (en) * | 1996-12-02 | 1999-08-10 | At&T Corp. | Transmission of CDMA signals over an analog optical link |
US5883882A (en) * | 1997-01-30 | 1999-03-16 | Lgc Wireless | Fault detection in a frequency duplexed system |
US6885846B1 (en) * | 1997-03-31 | 2005-04-26 | Texas Instruments Incorporated | Low power wireless network |
US6337754B1 (en) * | 1997-11-20 | 2002-01-08 | Kokusai Electric Co., Ltd. | Optical conversion relay amplification system |
US6374124B1 (en) * | 1997-12-24 | 2002-04-16 | Transcept, Inc. | Dynamic reallocation of transceivers used to interconnect wireless telephones to a broadband network |
US6504636B1 (en) * | 1998-06-11 | 2003-01-07 | Kabushiki Kaisha Toshiba | Optical communication system |
US6268946B1 (en) * | 1998-07-01 | 2001-07-31 | Radio Frequency Systems, Inc. | Apparatus for communicating diversity signals over a transmission medium |
US6232870B1 (en) * | 1998-08-14 | 2001-05-15 | 3M Innovative Properties Company | Applications for radio frequency identification systems |
US6405018B1 (en) * | 1999-01-11 | 2002-06-11 | Metawave Communications Corporation | Indoor distributed microcell |
US6577801B2 (en) * | 1999-05-20 | 2003-06-10 | University Of Southampton | Holey optical fibers |
US6556551B1 (en) * | 1999-05-27 | 2003-04-29 | Lgc Wireless, Inc. | Multi-frequency pilot beacon for CDMA systems |
US7496384B2 (en) * | 1999-09-13 | 2009-02-24 | Kabushiki Kaisha Toshiba | Radio communication system |
US6512478B1 (en) * | 1999-12-22 | 2003-01-28 | Rockwell Technologies, Llc | Location position system for relay assisted tracking |
US7072586B2 (en) * | 1999-12-28 | 2006-07-04 | Ntt Docomo, Inc. | Radio base station system and central control station with unified transmission format |
US20040043764A1 (en) * | 2000-04-12 | 2004-03-04 | John Bigham | Intelligent control of radio resources in a wireless network |
US6594496B2 (en) * | 2000-04-27 | 2003-07-15 | Lgc Wireless Inc. | Adaptive capacity management in a centralized basestation architecture |
US6353600B1 (en) * | 2000-04-29 | 2002-03-05 | Lgc Wireless, Inc. | Dynamic sectorization in a CDMA cellular system employing centralized base-station architecture |
US6519395B1 (en) * | 2000-05-04 | 2003-02-11 | Northrop Grumman Corporation | Fiber optic array harness |
US20030007214A1 (en) * | 2000-05-10 | 2003-01-09 | Yuji Aburakawa | Wireless base station network system, contorl station, base station switching method, signal processing method, and handover control method |
US6405058B2 (en) * | 2000-05-16 | 2002-06-11 | Idigi Labs, Llc | Wireless high-speed internet access system allowing multiple radio base stations in close confinement |
US20020003645A1 (en) * | 2000-07-10 | 2002-01-10 | Samsung Electronic Co., Ltd | Mobile communication network system using digital optical link |
US6883710B2 (en) * | 2000-10-11 | 2005-04-26 | Amerasia International Technology, Inc. | Article tracking system and method |
US6758913B1 (en) * | 2000-10-12 | 2004-07-06 | General Electric Company | Method of cleaning pressurized containers containing anhydrous ammonia |
US20020048071A1 (en) * | 2000-10-25 | 2002-04-25 | Ntt Docomo, Inc. | Communication system using optical fibers |
US7013087B2 (en) * | 2000-10-25 | 2006-03-14 | Ntt Docomo, Inc. | Communication system using optical fibers |
US20020075906A1 (en) * | 2000-12-15 | 2002-06-20 | Cole Steven R. | Signal transmission systems |
US6879290B1 (en) * | 2000-12-26 | 2005-04-12 | France Telecom | Compact printed “patch” antenna |
US20020092347A1 (en) * | 2001-01-17 | 2002-07-18 | Niekerk Jan Van | Radio frequency identification tag tire inflation pressure monitoring and location determining method and apparatus |
US6865390B2 (en) * | 2001-06-25 | 2005-03-08 | Lucent Technologies Inc. | Cellular communications system featuring a central radio pool/traffic router |
US20030078074A1 (en) * | 2001-06-28 | 2003-04-24 | Sesay Abu Bakarr | Optical fiber based on wireless scheme for wideband multimedia access |
US6710366B1 (en) * | 2001-08-02 | 2004-03-23 | Ultradots, Inc. | Nanocomposite materials with engineered properties |
US20030045284A1 (en) * | 2001-09-05 | 2003-03-06 | Copley Richard T. | Wireless communication system, apparatus and method for providing communication service using an additional frequency band through an in-building communication infrastructure |
US20050052287A1 (en) * | 2001-09-13 | 2005-03-10 | Whitesmith Howard William | Wireless communication system |
US20050078006A1 (en) * | 2001-11-20 | 2005-04-14 | Hutchins J. Marc | Facilities management system |
US20030141962A1 (en) * | 2002-01-25 | 2003-07-31 | Bernard Barink | RFID systems - antenna system and software method to spatially locate transponders |
US7039399B2 (en) * | 2002-03-11 | 2006-05-02 | Adc Telecommunications, Inc. | Distribution of wireless telephony and data signals in a substantially closed environment |
US20050159108A1 (en) * | 2002-03-16 | 2005-07-21 | Qinetiq Limited | Signal processing system and method |
US6920330B2 (en) * | 2002-03-26 | 2005-07-19 | Sun Microsystems, Inc. | Apparatus and method for the use of position information in wireless applications |
US20040041714A1 (en) * | 2002-05-07 | 2004-03-04 | Forster Ian J. | RFID temperature device and method |
US6873823B2 (en) * | 2002-06-20 | 2005-03-29 | Dekolink Wireless Ltd. | Repeater with digital channelizer |
US20040001719A1 (en) * | 2002-06-26 | 2004-01-01 | Kensuke Sasaki | Optical transmission system of radio signal over optical fiber link |
US20040008114A1 (en) * | 2002-07-09 | 2004-01-15 | Fred Sawyer | Method and apparatus for tracking objects and people |
US20040017785A1 (en) * | 2002-07-16 | 2004-01-29 | Zelst Allert Van | System for transporting multiple radio frequency signals of a multiple input, multiple output wireless communication system to/from a central processing base station |
US20040047313A1 (en) * | 2002-09-10 | 2004-03-11 | Harris Corporation | Communication system providing hybrid optical/wireless communications and related methods |
US20040078151A1 (en) * | 2002-10-18 | 2004-04-22 | Daniel Aljadeff | Wireless local area network (WLAN) channel radio-frequency identification (RFID) tag system and method therefor |
US20060017633A1 (en) * | 2002-12-04 | 2006-01-26 | Koninklijke Philips Electronics N.V. | Method and apparatus for true diversity reception with single antenna |
US7359408B2 (en) * | 2003-01-30 | 2008-04-15 | Samsung Electronics Co., Ltd. | Apparatus and method for measuring and compensating delay between main base station and remote base station interconnected by an optical cable |
US7020473B2 (en) * | 2003-02-07 | 2006-03-28 | Siemens Aktiengesellschaft | Method for finding the position of a subscriber in a radio communications system |
US6915058B2 (en) * | 2003-02-28 | 2005-07-05 | Corning Cable Systems Llc | Retractable optical fiber assembly |
US7054513B2 (en) * | 2003-06-09 | 2006-05-30 | Virginia Tech Intellectual Properties, Inc. | Optical fiber with quantum dots |
US20050058451A1 (en) * | 2003-08-12 | 2005-03-17 | Barrett Ross | Enhanced fiber infrastructure for building interiors |
US6847856B1 (en) * | 2003-08-29 | 2005-01-25 | Lucent Technologies Inc. | Method for determining juxtaposition of physical components with use of RFID tags |
US20050068179A1 (en) * | 2003-09-30 | 2005-03-31 | Roesner Bruce B. | Distributed RF coupled system |
US20050076982A1 (en) * | 2003-10-09 | 2005-04-14 | Metcalf Arthur Richard | Post patch assembly for mounting devices in a tire interior |
US20070149250A1 (en) * | 2003-10-23 | 2007-06-28 | Telecom Italia S.P.A | Antenna system and method for configuring a radiating pattern |
US20050093679A1 (en) * | 2003-10-31 | 2005-05-05 | Zai Li-Cheng R. | Method and system of using active RFID tags to provide a reliable and secure RFID system |
US20050141545A1 (en) * | 2003-11-10 | 2005-06-30 | Yaron Fein | Performance of a wireless communication system |
US20050099343A1 (en) * | 2003-11-10 | 2005-05-12 | Asrani Vijay L. | Antenna system for a communication device |
US20050116821A1 (en) * | 2003-12-01 | 2005-06-02 | Clifton Labs, Inc. | Optical asset tracking system |
US20070166042A1 (en) * | 2003-12-23 | 2007-07-19 | Seeds Alwyn J | Multiservice optical communication |
US20050143077A1 (en) * | 2003-12-24 | 2005-06-30 | Hugo Charbonneau | System and method for designing a communications network |
US6909399B1 (en) * | 2003-12-31 | 2005-06-21 | Symbol Technologies, Inc. | Location system with calibration monitoring |
US20050148306A1 (en) * | 2004-01-05 | 2005-07-07 | Hiddink Gerrit W. | Predictive method and apparatus for antenna selection in a wireless communication system |
US20060002326A1 (en) * | 2004-06-30 | 2006-01-05 | Sarosh Vesuna | Reconfigureable arrays of wireless access points |
US20060094470A1 (en) * | 2004-11-01 | 2006-05-04 | Microwave Photonics, Inc. | Communications system and method |
US20070009266A1 (en) * | 2005-07-07 | 2007-01-11 | Andrew Bothwell | Multimode optical fibre communication system |
US20070058978A1 (en) * | 2005-09-12 | 2007-03-15 | Samsung Electronics Co., Ltd. | Wireless remote access base station and pico-cell system using the same |
US20080014948A1 (en) * | 2006-07-14 | 2008-01-17 | Lgc Wireless, Inc. | System for and method of for providing dedicated capacity in a cellular network |
US20080047023A1 (en) * | 2006-07-24 | 2008-02-21 | Aplix Corporation | User space virtualization system |
US20080058018A1 (en) * | 2006-08-29 | 2008-03-06 | Lgc Wireless, Inc. | Distributed antenna communications system and methods of implementing thereof |
US20080124086A1 (en) * | 2006-11-27 | 2008-05-29 | Sbc Knowledge Ventures L.P. | System and method for high speed data communications |
US20080150514A1 (en) * | 2006-12-21 | 2008-06-26 | Nokia Corporation | Communication method and system |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130004176A1 (en) * | 2010-04-16 | 2013-01-03 | Panasonic Corporation | Communication system, main unit, radio access unit and communication method |
US20150236786A1 (en) * | 2010-04-16 | 2015-08-20 | Panasonic Corporation | Communication System, Main Unit, Radio Access Unit And Communication Method |
US9485023B2 (en) * | 2010-04-16 | 2016-11-01 | Nokia Solutions And Networks Oy | Communication system, main unit, radio access unit and communication method |
Also Published As
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EP2033343A2 (en) | 2009-03-11 |
CN101473568A (en) | 2009-07-01 |
WO2007146428A2 (en) | 2007-12-21 |
US7590354B2 (en) | 2009-09-15 |
WO2007146428A3 (en) | 2008-04-24 |
US20070292137A1 (en) | 2007-12-20 |
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Owner name: CORNING CABLE SYSTEMS LLC, NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SAUER, MICHAEL;KOBYAKOV, ANDREY;REEL/FRAME:018151/0111 Effective date: 20060623 |
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AS | Assignment |
Owner name: CORNING CABLE SYSTEMS LLC, NORTH CAROLINA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SAUER, MICHAEL;KOBYAKOV, ANDREY;REEL/FRAME:018289/0694 Effective date: 20060623 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |