Abstract: An optical transmitter of a subscriber optical interface and an optical receiver of a laser transceiver node can be designed to a frequency of data that is formatted according to a predetermined network protocol, that is encoded with a predetermined coding scheme, and that is transmitted according to a predetermined data transmit timing scheme. The frequency of data is an occupied frequency of a protocol when the data comprises a maximum number of like bits permitted by the protocol. An optical transmitter and optical receiver can be designed to a lowest occupied frequency of data that is encoded with 8B/10B encoding, and that is propagated upstream according to time division multiple access (TDMA). In this way, upstream optical communications can be maximized for speed.

Abstract: An optical fiber network can include an outdoor laser transceiver node that can be positioned in close proximity to the subscribers of an optical fiber network. The outdoor laser transceiver node does not require active cooling and heating devices that control the temperature surrounding the laser transceiver node. The laser transceiver node can adjust a subscriber's bandwidth on a subscription basis or on an as-needed basis. The laser transceiver node can also offer data bandwidth to the subscriber in preassigned increments. Additionally, the laser transceiver node lends itself to efficient upgrading that can be performed entirely on the network side. The laser transceiver node can also provide high speed symmetrical data transmission. Further, the laser transceiver node can utilize off-the-shelf hardware to generate optical signals such as Fabry-Perot (F-P) laser transmitters, distributed feed back lasers (DFB), or vertical cavity surface emitting lasers (VCSELs).

Abstract: An optical receiver circuit receives analog optical signals and outputs corresponding electrical signals. The circuit's amplifier can amplify a modulated signal from a photodiode. Gain control can adjust the amplifier's gain to compensate for power fluctuation in the optical signals. Linear compensation can enhance the linearity of the gain adjustment in response to optical power fluctuation and can facilitate feedforward gain control. A digital controller can implement the linear compensation. The circuit can operate with an impedance mismatch in the coupling between the photodiode and the amplifier, thereby avoiding the need for an impedance matching transformer in that coupling.

Abstract: Analog video signals are communicated from multiple service providers to subscribers by using analcg optical carriers. Unlike digital optical carriers that typically support data services or IP TV, analog optical carriers that can be demodulated or translated back into the analog radio-frequency (RF) signals do not require additional and costly hardware for reception by a RF receiving device such as a television (TV) set. With the present invention, a TV set does not need significant digital hardware such as a digital set top box to allow the TV set to view video signals from a desired service provider. The present invention can allow a plurality of competing service providers to offer video services to a subscriber through a single optical network.

Abstract: An optical transmitter of a subscriber optical interface and an optical receiver of a laser transceiver node can be designed to a frequency of data that is formatted according to a predetermined network protocol, that is encoded with a predetermined coding scheme, and that is transmitted according to a predetermined data transmit timing scheme. The frequency of data is an occupied frequency of a protocol when the data comprises a maximum number of like bits permitted by the protocol. An optical transmitter and optical receiver can be designed to a lowest occupied frequency of data that is encoded with 8B/10B encoding, and that is propagated upstream according to time division multiple access (TDMA). In this way, upstream optical communications can be maximized for speed.

Abstract: An optical transmitter of a subscriber optical interface and an optical receiver of a laser transceiver node can be designed to a frequency of data that is formatted according to a predetermined network protocol, that is encoded with a predetermined coding scheme, and that is transmitted according to a predetermined data transmit timing scheme. The frequency of data is an occupied frequency of a protocol when the data comprises a maximum number of like bits permitted by the protocol. An optical transmitter and optical receiver can be designed to a lowest occupied frequency of data that is encoded with 8B/10B encoding, and that is propagated upstream according to time division multiple access (TDMA). In this way, upstream optical communications can be maximized for speed.

Abstract: An apparatus (7) for switching from a first pilot signal and a second pilot signal on a system transporting a plurality of signals. A tuner (30) receives the signals and provides an output signal to a loop compensation circuit (26). The tuner includes a bandpass filter (22) for removing signals other than the selected pilot signal from the output of the tuner. The output of the bandpass filter is provided to a detector circuit (24, 25). The output of the detector is compared with a reference signal (28) by the loop compensation circuit (28). A microcontroller (39) sends a tuning command to the tuner which causes the tuner to switch from tuning to the first pilot signal to tuning to the second pilot signal and also sends a new reference voltage to the loop compensation circuit. Thus, if the input signal changes from analog to digital modulation on the pilot channel, the set-point, or target level of the reference signal, will automatically change to provide the correct value for operation of the circuit.

Abstract: Unlike the conventional art which polices data at the entry points of a network, a transceiver node can police or monitor downstream bandwidths for quality of service at exit portions of an optical network. That is, the transceiver node can police downstream communication traffic near the outer edges of an optical network that are physically close to the subscribers of the optical network. In this way, a network provider can control the volume or content (or both) of downstream communications that are received by subscribers of the optical network. In addition to controlling the volume of communications that can be received by a subscriber, the transceiver node employs a plurality of priority assignment values for communication traffic. Some priority assignment values are part of a weighted random early discard algorithm that enables an output buffer to determine whether to drop data packets that are destined for a particular subscriber.

Abstract: A protocol for an optical network can control the time at which subscriber optical interfaces of an optical network are permitted to transmit data to a transceiver node. The protocol can prevent collisions of upstream transmissions between the subscriber optical interfaces of a particular subscriber group. With the protocol, a transceiver node close to the subscriber can allocate additional or reduced upstream bandwidth based upon the demand of one or more subscribers. That is, a transceiver node close to a subscriber can monitor (or police) and adjust a subscriber's upstream bandwidth on a subscription basis or on an as-needed basis. The protocol can account for aggregates of packets rather than individual packets. By performing calculation on aggregates of packets, the algorithm can execute less frequently which, in turn, permits its implementation in lower performance and lower cost devices, such as software executing in a general purpose microprocessor.

Abstract: A return path system includes inserting RF packets between regular upstream data packets, where the data packets are generated by communication devices such as a computer or internet telephone. The RF packets can be derived from analog RF signals that are produced by legacy video service terminals. In this way, the present invention can provide an RF return path for legacy terminals that shares a return path for regular data packets in an optical network architecture. The invention operates independently of a legacy upstream transmission timing scheme so that the legacy upstream transmission timing scheme can remain effective in preventing data collisions. In other embodiments, the present invention allows for less complex hardware for subscribers that are not taking data services. Further, an optical signal present line in combination with a driver may be employed in order to reduce the amount of hardware in a laser transceiver node.

Abstract: An optical transmitter of a subscriber optical interface and an optical receiver of a laser transceiver node can be designed to a frequency of data that is formatted according to a predetermined network protocol, that is encoded with a predetermined coding scheme, and that is transmitted according to a predetermined data transmit timing scheme. The frequency of data is an occupied frequency of a protocol when the data comprises a maximum number of like bits permitted by the protocol. An optical transmitter and optical receiver can be designed to a lowest occupied frequency of data that is encoded with 8B/10B encoding, and that is propagated upstream according to time division multiple access (TDMA). In this way, upstream optical communications can be maximized for speed.

Abstract: An optical fiber network can include an outdoor bandwidth transforming node that can be positioned in close proximity to the subscribers of an optical fiber network. The outdoor bandwidth transforming node does not require active cooling and heating devices that control the temperature surrounding the bandwidth transforming node. The bandwidth transforming node can adjust a subscriber's bandwidth on a subscription basis or on an as-needed basis. The bandwidth transforming node can also offer data bandwidth to the subscriber in preassigned increments. Additionally, the bandwidth transforming node lends itself to efficient upgrading that can be performed entirely on the network side. The bandwidth transforming node can also provide high speed symmetrical data transmission. Further, the bandwidth transforming node can increase upstream and downstream bandwidth and transmission speed by propagating data signals at different wavelengths.

Abstract: An optical fiber network can include an outdoor laser transceiver node that can be positioned in close proximity to the subscribers of an optical fiber network. The outdoor laser transceiver node does not require active cooling and heating devices that control the temperature surrounding the laser transceiver node. The laser transceiver node can adjust a subscriber's bandwidth on a subscription basis or on an as-needed basis. The laser transceiver node can also offer data bandwidth to the subscriber in preassigned increments. Additionally, the laser transceiver node lends itself to efficient upgrading that can be performed entirely on the network side. The laser transceiver node can also provide high speed symmetrical data transmission. Further, the laser transceiver node can utilize off the shelf hardware to generate optical signals such as Fabry-Perot (F-P) laser transmitters, distributed feed back lasers (DFB), or vertical cavity surface emitting lasers (VCSELs).

Abstract: The invention relates to an explosive charge assembly for cutting tubular members, particularly underwater. The assembly is lowered into the tubular member to a distance where the cut is to be performed. A shaped charge carrier has a pair of parallel circular plates, a casing unitary connected to the plates and a truncated shaped charge liner. An inflatable bladder surrounding the casing expands to create a stand off distance between the wall of the tubular member and the shell of the assembly. A plurality of centralizer members allow to adjust position of the shell in the tubular member prior to detonation.

Abstract: A method and apparatus for severing tubular members below a mud line. The mud is evacuated from the target area of the tubular member and the apparatus is lowered through the inner opening of the tubular member to the target area. A housing of the apparatus carries a plurality of centralizing fins which hinge 90 degrees in relation to their pre-deployed position and centralize the housing in the target area. An explosive material contained in the housing is extruded, by movement of the piston, into a flexible bag secured at a lower portion of the housing, forcing the bag to form a receptacle for the explosive. A sidewall of the bag protector pivots at a right angle to form a support for the receptacle with the explosive.

Abstract: The invention relates to an apparatus for severing tubular members and is provided with a carrier, which carries a sparging assembly and an explosive assembly downwardly into the tubular member to be severed. The outlet of the sparging assembly is below the lower end of the carrier and is at a level adjacent to the level of the explosive charge carried by the explosive assembly. The sparging assembly dislodges and agitates the debris accumulated within the tubular member and evacuates it from the level, wherein it is deployed, simultaneously allowing progression of the explosive assembly downward along the interior of the tubular member.

Abstract: The invention relates to an apparatus for severing tubular members and is provided with a carrier, which carries a sparging assembly and an explosive assembly downwardly into the tubular member to be severed. The outlet of the sparging assembly is below the lower end of the carrier and is at a level adjacent to the level of the explosive charge carried by the explosive assembly. The sparging assembly dislodges and agitates the debris accumulated within the tubular member and evacuates it from the level, wherein it is deployed, simultaneously allowing progression of the explosive assembly downward along the interior of the tubular member.

Abstract: The invention relates to an apparatus for explosively severing tubular members at a pre-designated severance level. The apparatus is designed to deliver a detonation signal to a ring-shaped explosive charge, to an annularly formed detonation signal receiving locations, so that explosion takes place substantially simultaneously about the circumference of the explosive charge about internal periphery of the tubular member at the severance level.