Abstract: A transmit and receive system for transmitting data between a transmit site and a receive site. The system includes a tunnel source, router and modulator for dividing a transmit data stream having a first bit rate into multiple data streams with each of the multiple data streams having a bit rate which is lower than the first bit rate, transmitting each of the multiple data streams over a plurality of RF channels. The system further includes a demodulator and destination source for recombining the multiple data streams at the receive site to provide a receive data stream having a bit rate equal to the first bit rate.

Abstract: This invention provides a new architecture for a communication system between head-ends and end-users which expands bandwidth and reliability of the communication system. A mux-node receives communication signals from a head-end and forwards the received communication signals to one or more mini-fiber nodes. The connection to the head-end is via a small number of optical fibers and the connections to each of the mini-fiber nodes may be via one or more optical fibers that may provide full duplex communication. The head-end may communicate with the mux-node using digital or digital and analog signals. The mini-fiber nodes may combine the signals received from the head-end with loop-back signals used for local media access control prior to forwarding the signals to the end-users. Upstream data are received by the mini-fiber nodes and transmitted to the mux-node.

Abstract: A method and system for generating and transmitting optical signals with only one sideband. Single-sideband optical signal transmission reduces the signal impairment effects associated with dispersion. Such transmission also increases the spectral efficiency of optical transmission systems. Single-sideband modulation also makes possible electrical compensation for optical link dispersion during transmission. Single-sideband modulation is generated using the modulating data signal and its Hilbert transform, which is approximated by a tapped-delay time filter. Line coding is used to remove the low-frequency content in the modulating data signal, avoiding the inefficiencies of tapped-delay-line filter approximated Hilbert transformers at low frequencies. Line coding can also help optical single side band signal generation and transmission using a simple optical filter instead of Hilbert transformers.

Abstract: A communication system between head-ends and end-users is provided which expands bandwidth and reliability. A concentrator receives communication signals from a head-end and forwards the received communication signals to one or more fiber nodes and/or one or more mini-fiber nodes. The concentrator demultiplexes/splits received signals for the mini-fiber nodes and the fiber nodes and forwards demultiplexed/split signals respectively. The mini-fiber nodes may combine signals received from the head-end with loop-back signals used for local medium access control prior to forwarding the signals to the end-users. Upstream data are received by the mini-fiber nodes and/or fiber node and transmitted to the concentrator. The concentrator multiplexes/couples the mini-fiber node and the fiber node upstream signals and forwards multiplexed/coupled signals to the head-end.

Abstract: The optical device is located at a node connected of an optical network. The optical device receives optical signals, each received signal having a different wavelength. The optical device comprises a wavelength-selective optical tap that selectively drops a first portion of the optical power of a received optical signal having a specific wavelength. The optical device also optically conveys the optical signal having the specific wavelength to a next node, the conveyed optical signal having a second portion of the optical power of the received optical signal having the specific wavelength.

Abstract: A communication network uses intermediate nodes to resolve local traffic contention. Intermediate nodes receive upstream signals from end users, derive traffic information signals from the upstream signals, and transmit the traffic information signals to end users. By listening to the traffic information signals from the intermediate node, the end users know whether the upstream transmission channels are idle or busy, or whether a collision has occurred. The intermediate nodes derive and transmit the traffic information signals with or without the assistance of the central office or head end.

Abstract: A method for sending data from a transmit site to a receive site which includes dividing a transmit data stream having a first bit rate into multiple data streams with each of the multiple data streams having a bit rate which is lower than the first bit rate, transmitting each of the multiple data streams over a plurality of RF channels and recombining the multiple data streams at the receive site to provide a receive data stream having a bit rate equal to the first bit rate.

Abstract: A method and apparatus for sending data from a transmit site to a receive site which includes dividing a transmit data stream having a first bit rate into multiple data streams with each of the multiple data streams having a bit rate which is lower than the first bit rate, transmitting each of the multiple data streams over a plurality of RF channels and recombining the multiple data streams at the receive site to provide a receive data stream having a bit rate equal to the first bit rate.

Abstract: A transmit and receive system for transmitting data between a transmit site and a receive site. The system includes a tunnel source, router and modulator for dividing a transmit data stream having a first bit rate into multiple data streams with each of the multiple data streams having a bit rate which is lower than the first bit rate, transmitting each of the multiple data streams over a plurality of RF channels. The system further includes a demodulator and destination source for recombining the multiple data streams at the receive site to provide a receive data stream having a bit rate equal to the first bit rate.

Abstract: A bi-directional optical transmission system provides communications between at least two locations over a single optical fiber. The transmitters at the respective locations are defined to have different optical spectra characteristics to avoid production of optical beat interference.

Abstract: A semiconductor optical amplifier includes an optical signal input and an active section surrounded by two mirrors. A current is applied to the second mirror, for example by a current generator. Thus, the central wavelength of the reflection range of the second mirror is modifiable, the loss of the semiconductor-optical amplifier is changeable and the gain of the amplifier is adjustable.

Abstract: An optical network comprising a broad band optical source having a temporal characteristic and an optical wavelength conversion apparatus. The optical wavelength conversion apparatus comprising a laser means for producing a narrow band optical spectrum signal, a means for receiving a broad band optical signal having a temporal characteristic, and a spectral compactor means. The spectral compactor means is responsive to the narrow band optical spectrum signal and the broad band optical signal, for modulating the narrow band optical signal with the temporal characteristic of the broad band optical signal.

Abstract: A control circuit for an injection laser provides a pre-bias current which prevents clipping induced errors in the laser output. An analog modulating signal is provided directly to the laser which receives the sum of a feedback current (Ifb) and a current source (Io) as the pre-bias current (Ipb). A monitor diode detects the laser light output and provides a current (Idet). A feedback circuit operates in a limited dynamic range, e.g. I.sub.l +/-40 mA or is incapable of outputting a negative current (Ifb>0). The feedback circuit responds to changes in Idet and adjusts the laser pre-bias current to hold Idet equal to a preset value, which effectively holds the laser's average output power constant. If the pre-bias current necessary to hold Idet fixed falls below some minimum level, Imin, the feedback circuit will run out of dynamic range and the laser's average power will increase. By preventing Ipb from falling below Imin clipping induced errors and distortion are avoided.

Abstract: A communication network and method is provided to communicate between a central office/head end and a plurality of end-units (EUs). A first transmission medium is connected between the central office and an intermediate node. A plurality of second transmission mediums are connected between the central office and a plurality of mini-fiber nodes. The intermediate node is also associated with each of the mini-fiber nodes such that an analog broadcast service may be sent over the first transmission medium to each of the mini-fiber nodes. Further, switched digital services and digital broadcast services are also sent over the second transmission mediums to each of the mini-fiber nodes. The mini-fiber nodes combine the signals and send the combined signals to a corresponding subset of EUs.

Abstract: A transmission system for backhauling CDMA signals from remote antennas to the centralized base station of a wireless communication system includes a laser transmitter and an optical receiver coupled to an optical fiber. Wireless signals are backhauled to the central base station without degrading signal quality, and with minimal signal processing performed at the remote antenna site. The RF drive current driving the laser transmitter is kept above a predetermined level to prevent noise caused by optical feedback into the laser transmitter caused by Rayleigh backscatter in the optical fiber. A method of testing the optical link is presented which avoids the expense of using a real CDMA system to test each link. The testing method enables the dynamic range of inexpensive, unisolated, uncooled lasers in the optical link to be increased so the optical link can cost-effectively backhaul the CDMA signals.

Abstract: A Wavelength-Division-Multiplexed (WDM) network provides delivery of both switched services and broadcast analog video over optical facilities through an intermediate optical apparatus (e.g., Passive Optical Network (PON)) splitter to a plurality of remote optical apparatuses (e.g., optical-network units (ONUs)). The broadcast signal is provided to only a selected ONU, together with the switched service signal for that selected ONU, the selected ONU then distributes the broadcast signal to other ONUs over a separate distribution facility interconnecting the ONUs.

Abstract: A converter apparatus (Mini Fiber Node MFN) for use in a communication network (e.g., a coax network) includes a signal distribution unit (e.g., fiber node FN) for transmitting frequency-division multiplexed communication signals downstream over a coax cable to a node apparatus (amplifier) and via an access path to a plurality of end unit apparatuses connected thereto. The converter apparatus connects to the access path and receives downstream second FDM signals directly from the central office over an optical communication path and sends the second FDM signals to at least one end unit apparatus over the access path. The converter apparatus also receives upstream FDM signals from the at least one end unit apparatus over the access path and transmits the upstream FDM signals to the central office over the optical path. In another embodiment, the converter apparatus connects directly to the primary path to provide service to an end user apparatus connected in a "tapped-bus" arrangement.

Abstract: At a central facility, information for a user is converted to a carrierless AM/PM (CAP) signal, upconverted, combined with other upconverted signals destined for other users and transmitted via an analog optical fiber optic line to an optical network unit (ONU) which downconverts the CAP signals without changing their modulation format and places them on the appropriate unshielded twisted line pairs for respective users. If the user is able to receive the optical fiber directly, the ONU can be eliminated. Information may also be transmitted from the users to the central facility using the same transmission lines. Additionally, voiceband channels may be carried on the same transmission lines.

Abstract: A method and apparatus for reducing noise in optical communication systems, wherein the frequency of light output from a signal laser is modulated or dithered to broaden the optical spectrum of the signal laser. The broadening allows error-free data transmission within signal bands, despite the presence of optical beat interference. Different dithering tones are emitted by each laser in the network. The dithering tone for each signal laser in an optical network is chosen so that distortion resulting from the dithering tone falls outside the signal bands.

Abstract: The present invention provides a local access network, having a switching node, a passive remote node connected to an optical network unit, a first optical fiber that provides a dedicated connection between the switching node and the passive remote node, and a second optical fiber that provides a dedicated connection between the switching node and the passive remote node. A first portion of a first fiber-optic cable containing the first optical fiber does not contain any part of the second optical fiber, such that there are independent paths from the switching node to the passive remote node.