Abstract: The present invention is generally directed towards a system and method for providing a high speed switching driver to transmit data information. A first current is switched through a diode or shunted through an alternate path to selectively bias the diode. A second current can also be selectively switched through the diode to modulate a light energy output transmitted from the diode. Based on this configuration, fast bias-switching for generating a modulated laser diode output can be achieved by selectively switching the bias current through the diode or alternate path. Consequently, a solid state device can be controlled to transmit data information after a relatively minimal setup time delay to bias the diode.

Abstract: A method and apparatus for determining a shortest path between a source node and a destination node in an optical network of nodes interconnected with optical transmission links is disclosed. A wavelength graph is used to represent an optical network as a set of electronic nodes and optical channel nodes corresponding to the network nodes with a set of internal links and optical channel links. The electronic node represents the electronic switching fabric that interconnects OEO equipment within a physical node. A single-source shortest path algorithm (e.g., Dijkstra's algorithm) is applied to the wavelength graph to determine a shortest path. The transformation of the network representation to include the electronic node greatly reduces the number of links in the wavelength graph and significantly increases the computational efficiency.

Abstract: Communication between a burst manager and plural remote terminals over a first passive optical network (PON) and a second PON, with each PON having a downstream portion and an upstream portion, includes transmitting a common synchronization signal from the burst manager to the plural remote terminals over both downstream PON portions and transmitting burst data from the plural remote terminals over both upstream PON portions to the burst manager. The burst data for each remote terminal is delayed on the first and second PONs by corresponding first and second delays.

Abstract: An apparatus and method is disclosed for receiving packets having a wide dynamic range of power levels over a shared medium in a communications system. The receiver responds to a packet with a different power level within an inter-packet time and maintains a constant logic level for a long string of ‘ones’ or ‘zeros’ within a packet. An AC-coupled pre-amplifier provides a voltage signal having a slowly decaying power level for a long string of ‘ones’ or ‘zeros’ within the packet. A differential amplifier with hysteresis, ignores the slowly decaying power level of a long string of ‘ones’ or ‘zeros’ within the packet and does not overwrite the power level of the long string until it detects the end of the string.

Abstract: The present invention is generally directed towards a system and method for providing a high speed switching driver to transmit data information. A first current is switched through a diode or shunted through an alternate path to selectively bias the diode. A second current can also be selectively switched through the diode to modulate a light energy output transmitted from the diode. Based on this configuration, fast bias-switching for generating a modulated laser diode output can be achieved by selectively switching the bias current through the diode or alternate path. Consequently, a solid state device can be controlled to transmit data information after a relatively minimal setup time delay to bias the diode.

Abstract: The present invention is generally directed towards a system and method for providing a high speed switching driver to transmit data information. A first current is switched through a diode or shunted through an alternate path to selectively bias the diode. A second current can also be selectively switched through the diode to modulate a light energy output transmitted from the diode. Based on this configuration, fast bias-switching for generating a modulated laser diode output can be achieved by selectively switching the bias current through the diode or alternate path. Consequently, a solid state device can be controlled to transmit data information after a relatively minimal setup time delay to bias the diode.

Abstract: A communications network includes optical network terminations (ONTs) and an optical line termination (OLT) connected to a passive optical network (PON). The OLT measures round trip transmission delay expressed in time slot duration for each of the ONTs, and orders the ONTs in ascending order of respective delay modulo time slot duration. A desired reception time at the OLT is scheduled for each of the OLTs according to the ascending order and each ONT is commanded to transmit at a command time that leads the respective desired reception time by a respective delay integral time slot duration. The scheduling includes leaving a reception interval spare after the last ONT in ascending order. The ascending delay modulo slot protocol becomes more efficient as the number of time slots per frame increases. If the number of time slots per frame is N, then the efficiency of the protocol is (N−1)/N. Unassigned time required per transmission frame is thereby reduced.

Abstract: An apparatus and method is disclosed for protecting access to a shared medium in an optical communications system which has plural remote terminals coupled to a central terminal over the shared medium. According to one aspect, if an optical transmitter for an individual remote terminal is active for a first prescribed time interval when it has not been enabled for such transmission, the optical transmitter is disabled. According to another aspect, the continuous time that an individual terminal is enabled to transmit onto the shared medium is monitored. If the enabled transmission for the individual terminal exceeds a second prescribed time interval, the optical transmitter for the individual terminal is disabled.

Abstract: A method and system for using burst mode transmission on multiple optical wavelengths is disclosed. In a passive optical network, a synchronization signal is transmitted from a central terminal to remote terminals and burst data signals are transmitted from remote terminals to the central terminal. A first group of remote terminals transmits burst data signals in respective timeslots that are synchronized to the received synchronization signal and multiplexed at a first optical wavelength. A second group of remote terminals transmits burst data signals in respective timeslots that are synchronized to the received synchronization signal and multiplexed at a second optical wavelength. The timeslots are synchronized and phase aligned with each other such that optical crosstalk interference between adjacent optical wavelengths is avoided and each wavelength can be spectrally spaced as close as possible to adjacent wavelengths.

Abstract: The present invention is generally directed towards a system and method for providing a high speed switching driver to transmit data information. A first current is switched through a diode or shunted through an alternate path to selectively bias the diode. A second current can also be selectively switched through the diode to modulate a light energy output transmitted from the diode. Based on this configuration, fast bias-switching for generating a modulated laser diode output can be achieved by selectively switching the bias current through the diode or alternate path. Consequently, a solid state device can be controlled to transmit data information after a relatively minimal setup time delay to bias the diode.

Abstract: A method and apparatus for determining a shortest path between a source node and a destination node in an optical network of nodes interconnected with optical transmission links is disclosed. A wavelength graph is used to represent an optical network as a set of electronic nodes and optical channel nodes corresponding to the network nodes with a set of internal links and optical channel links. The electronic node represents the electronic switching fabric that interconnects OEO equipment within a physical node. A single-source shortest path algorithm (e.g., Dijkstra's algorithm) is applied to the wavelength graph to determine a shortest path. The transformation of the network representation to include the electronic node greatly reduces the number of links in the wavelength graph and significantly increases the computational efficiency.

Abstract: A method and system provide an approach to support the aggregation of multiple broadband services including voice, high speed data, video and image through the transmission of packets and cells simultaneously over a passive optical network. The method of communication between a central terminal and plural remote terminals over a passive optical network includes transmitting downstream data from the central terminal to the plural remote terminals in successive downstream frames over a downstream network portion and transmitting upstream data from the plural remote terminals to the central terminal in respective upstream timeslots over an upstream network portion, the upstream timeslots forming successive upstream frames. The downstream data includes downstream packet data and downstream ATM cell data and the upstream data including upstream packet data and upstream ATM cell data.

Abstract: A communications network includes a passive optical network (PON), plural user terminals and a central terminal coupled to the PON. Each user terminal includes an optical transmitter for transmitting an upstream signal in an optical channel dedicated to the user terminal and an optical receiver for receiving a shared downstream signal in a shared optical channel. The central terminal includes an optical transmitter for transmitting the shared downstream signal and plural optical receivers each receiving one of the dedicated upstream signals. The central terminal optical transmitter transmits the shared downstream signal in a shared optical channel at wavelength &lgr;0 and the user terminal optical transmitters transmit the upstream signals in dedicated optical channels at dedicated wavelengths &lgr;1 to &lgr;N, respectively.

Abstract: An AC-coupled pre-amplifier is provided for amplifying a signal received in a packet transmitted in burst mode. The pre-amplifier provides a fast time constant for a driven edge of a received signal and a slower time constant for a undriven edge of the received signal. The decay of the undriven edge is faster than the inter-packet time between two received packets. The dual response times, allows for the inter-packet time to be less than the longest string of constant data received in a packet.

Abstract: An electronic chassis or modular rack has elements and methods for reducing emission of electromagnetic waves or interference (EMI) and at the same time ensuring that the components within the chassis or rack are properly cooled. A face plate which attaches to a printed circuit board or blank board for insertion and removal of the board from the chassis and limiting EMI emission while allowing connector and indicator accessibility. The face plate has an elongated frame having at least two planar body portions. The planar body portions are integrally formed to each other with the planes of the two planar body portions at an angle of between 25 and 55 degrees of each other. The elongated frame has a pair of free edges adjacent to the planar surfaces and the pair of side edges. The face plate has a pair of mounting devices. Each mounting device is carried by the elongated frame in proximity to one of the free edges. The pair of mounting devices are offset from each other about the planar body portions.

Abstract: A method of data recovery includes receiving a data stream of data bits and splitting the data stream to N identical input data streams where N is an integer greater than 1. Each of the N input data streams is delayed with respect to the preceding one by a bit time divided by N. Each of the N delayed input data streams is then sampled using a local clock to provide N samples which form an N-bit sample code per clock period. At least two successive sample codes are decoded to select one of the N delayed input data streams most aligned with the local clock. The selected data stream is thereby retimed to the local clock for synchronous processing of the data stream payload. The local system clock is held constant in the presence of multiple asynchronous data streams for improved robustness in overall system performance.

Abstract: A method of data recovery includes receiving a data stream of data bits and splitting the data stream to N identical input data streams where N is an integer greater than 1. Each of the N input data streams is delayed with respect to the preceding one by a bit time divided by N. Each of the N delayed input data streams is then sampled using a local clock to provide N samples which form an N-bit sample code per clock period. At least two successive sample codes are decoded to select one of the N delayed input data streams most aligned with the local clock. The selected data stream is thereby retimed to the local clock for synchronous processing of the data stream payload. The local system clock is held constant in the presence of multiple asynchronous data streams for improved robustness in overall system performance.