Abstract: An Ethernet ADSL adapter controls data communication between an Ethernet port and an ADSL modem connected to an ADSL channel. The adapter includes a first buffer for storing data packets received at the Ethernet port, a second buffer for storing data packets received from the ADSL modem and a controller. When the first buffer contains a first predetermined number of data packets and data packets are not available for transmission to the Ethernet port, a jamming signal is transmitted from the Ethernet port. The jamming signal inhibits transmission of additional data packets to the Ethernet port by other Ethernet nodes until space is available in the first buffer. When the second buffer contains a second predetermined number of data packets, a pause signal is transmitted to the ADSL modem. The pause signal inhibits further transmission of data packets to the ADSL modem on the ADSL channel until space is available in the second+ buffer.

Abstract: A communication service with a computer application is presented. The application provides an advertising dashboard to a subscriber engaged in a session of a service. The advertising dashboard includes an advertisement. The advertising dashboard may also include personalized information such as hotlinks to customized web pages.

Abstract: A system subsidizes telephone calls over a network. The system includes a service provider 120 that establishes a telephone call between a calling party terminal 130 and a called party terminal 140 over the network 110. During the telephone call, the service provider causes at least one advertisement 312 to be displayed at the calling, or called party terminal. At any time during, or after, the telephone call, the service provider generates a bill based on a subsidized billing rate related to the display of the at least one advertisement.

Abstract: A data communication network includes a network access unit for coupling one or more computer devices to the network. The network typically has asymmetric upstream and downstream data transmission rates. The network access device implements a method for acknowledging data packets. When a new packet is received by the network access unit from one of the computer devices, the new packet is placed in an outbound queue in the network access unit. When the new packet contains an acknowledgment, previous acknowledgment packets in the outbound queue that have the same source and destination addresses as the new packet are identified and discarded. Remaining packets are transmitted from the outbound queue in the network access unit. By discarding acknowledgment packets in the network access unit, throughput is increased.

Abstract: A data link layer switch includes a switching mechanism coupled to several port interface controllers. The port interface controllers include an address table, an address learner, and an address matcher. The address table stores multicast addresses for hosts attached to the port interface controller. The address learner compares a destination address in an incoming packet to a target address, and stores a multicast address from the incoming packet in the address table when the destination address matches the target address. The address matcher compares a destination address in an outgoing packet to the multicast addresses stored in the address table, and transmits the outgoing packet when the destination address matches one of the multicast addresses.

Abstract: An Ethernet ADSL adapter controls data communication between an Ethernet port and an ADSL modem connected to an ADSL channel. The adapter includes a first buffer for storing data packets received at the Ethernet port, a second buffer for storing data packets received from the ADSL modem and a controller. When the first buffer contains a first predetermined number of data packets and data packets are not available for transmission to the Ethernet port, a jamming signal is transmitted from the Ethernet port. The jamming signal inhibits transmission of additional data packets to the Ethernet port by other Ethernet nodes until space is available in the first buffer. When the second buffer contains a second predetermined number of data packets, a pause signal is transmitted to the ADSL modem. The pause signal inhibits further transmission of data packets to the ADSL modem on the ADSL channel until space is available in the second+buffer.

Abstract: A data communication network includes a network access unit for coupling one or more computer devices to the network. The network typically has asymmetric upstream and downstream data transmission rates. The network access device implements a method for acknowledging data packets. When a new packet is received by the network access unit from one of the computer devices, the new packet is placed in an outbound queue in the network access unit. When the new packet contains an acknowledgment, previous acknowledgment packets in the outbound queue that have the same source and destination addresses as the new packet are identified and discarded. Remaining packets are transmitted from the outbound queue in the network access unit. By discarding acknowledgment packets in the network access unit, throughput is increased.

Abstract: In a wavelength division multiplexed network having a plurality of nodes and having optical channels at wavelengths .lambda.i, where i=1 . . . N, for transmission of optical signals over optical interconnection means, control for informing the network of which nodes are transmitting at which frequencies and for token holding. Control is provided without the need for a second transmitter at each node and another control channel. Data signals are provided at baseband by keying the optical signal at a data repetition rate. Control signals are imposed on a wavelength .lambda.t of a transmitting node as a subcarrier. Receiver means at each node respond to a .lambda.t from another channel to receive information. The node also includes means for all wavelengths .lambda.i and demodulating the subcarrier therefrom to derive control information.

Abstract: Subcarrier multiplexed acknowledgment tones are used for contention recovery in multiple-access WDM networks with basedband data packets and subcarrier multiplexed control headers. Upon receiving a data message from another node, the receiving node sends a subcarrier acknowledgement tone to the transmitter thus informing the transmitting node that the message has been received. The thoughput of the network is significantly improved. In an alternative embodiment, an acknowledgement is sent from the receiver by impressing a data message on a subcarrier.

Abstract: An optical communication system includes a transmitter for generating a subcarrier multiplexed optical signal from a pilot tone, a receiver and an optical fiber for coupling the optical signal from the transmitter to the receiver. At the transmitter, an optical carrier is modulated with a composite modulation signal including a plurality of modulated microwave subcarriers to provide the optical signal and pilot tone for carrier and clock recovery. The receiver includes a local oscillator for generating a local light beam, a detector responsive to the received optical signal and the local light beam for providing a detected signal at an intermediate frequency, and a microwave receiver for receiving the detected pilot tone for simultaneously generating the subcarrier frequencies for demodulating the microwave subcarriers from the detected signal, an automatic frequency control signal for controlling the local oscillator, and the clock signal.

Abstract: Apparatus for and method of communicating over a local area network is disclosed. Multiple nodes are connected by an optical fiber in a ring architecture. The cable supports multiple subcarrier multiplexed data communication channels for transmitting and receiving message data between the nodes and a control channel for partitioning nodal access to the individual data channels. Tokens are circulated on the control channel indicating the status of each data channel. A node desiring to send, acquires an open data channel by marking the corresponding control channel token to show that the selected data channel is no longer available, inserts the node destination address into the control channel token, and transmits data on the acquired data channel. A node recognizing its address in the control channel token's destination address field for a particular data channel tunes its receiver to accept data on that channel.

Abstract: Optical communication methods and apparatus are disclosed for transmitting two or more optical signals with different optical carrier frequencies on a single optical fiber with high spectral efficiency. Each optical carrier is typically modulated with multiple modulated subcarriers. In one embodiment, an optical phase modulator provides cancellation of second order intermodulation products in each optical signal, thereby permitting the optical carrier frequencies to be spaced by 2f.sub.max, where f.sub.max is the maximum modulation frequency. In another embodiment, a single sideband optical phase modulator provides cancellation of second order intermodulation products and one signal sideband, thereby permitting the optical carrier frequencies to be spaced by f.sub.max.

Abstract: A semiconductor optical amplifier with a high speed photodetector acting as an optical tap is disclosed. The device functions simultaneously as an in-line optical amplifier and as a high-speed photodetector tap. An in-line an optical amplifier is combined with a waveguiding, high speed (low capacitance) reverse-biased photodetector that absorbs only a percentage of the amplified signal, allowing the remainder to pass through without distortion.

Abstract: An optoelectronic device is disclosed utilizing a semiconductor laser amplifier that provides for simultaneous detection, amplification, and modulation of an input optical signal. In one embodiment, an electronic transmitter and receiver are coupled to the semiconductor laser amplifier through an RF circulator. In an alternative embodiment, the electronic transmitter and receiver are coupled to the semiconductor laser amplifier through an RF power splitter with frequency or phase discriminating circuitry.

Abstract: This invention disclosure describes the application of a polarization insensitive acoustically-tuned optical filter used in a multichannel WDM system to equalize variations in the power level of the WDM channels. The invention also describes a simple means for providing a low frequency control system which enables the equalizer to determine the signal levels of N optical carriers prior to equalizing the signals.

Abstract: A method and apparatus is disclosed for signaling a switch of the target destination of a data packet having a header specifying the destination address and an information frame. The data packet along with a separate instance of the header is subcarrier multiplexed and simultaneously transmitted. The separate header is transmitted at a lower speed than the data packet permitting detection and processing by less expensive receivers.

Abstract: Optical communication methods and apparatus are disclosed for transmitting two or more optical signals with different optical carrier frequencies on a single optical fiber with high spectral efficiency. Each optical carrier is typically modulated with multiple modulated subcarriers. In one embodiment, an optical phase modulator provides cancellation of second order intermodulation products in each optical signal, thereby permitting the optical carrier frequencies to be spaced by 2f.sub.max, where f.sub.max is the maximum modulation frequency. In another embodiment, a single sideband optical phase modulator provides cancellation of second order intermodulation products and one signal sideband, thereby permitting the optical carrier frequencies to be spaced by f.sub.max.

Abstract: A semiconductor optical amplifier is utilized for optical amplification and for detection of an optical signal at the current injection electrode of the optical amplifier. A wide detection bandwidth is provided by utilizing an impedance transformer between the current injection terminal and the detection circuit. The impedance transformer typically has an input impedance of about 1 to 15 ohms. The impedance transformer can be a bipolar junction transistor circuit, a microstrip transmission line impedance transformer or a hybrid impedance transformer. A wide detection bandwidth is also obtained by providing a semiconductor optical amplifier having two current injection electrodes. A bias current is supplied through both current injection electrodes, and both electrodes produce optical gain. However, only one of the electrodes is used for optical signal detection. The detection electrode has a relatively high junction resistance and a relatively high series resistance.

Abstract: A semiconductor optical amplifier is utilized for optical amplification and for detection of an optical signal at the current injection electrode of the optical amplifier. A wide detection bandwidth is provided by utilizing an impedance transformer between the current injection terminal and the detection circuit. The impedance transformer typically has an input impedance of about 1 to 15 ohms. The impedance transformer can be a bipolar junction transistor circuit, a microstrip transmission line impedance transformer or a hybrid impedance transformer. A wide detection bandwidth is also obtained by providing a semiconductor optical amplifier having two current injection electrodes. A bias current is supplied through both current injection electrodes, and both electrodes produce optical gain. However, only one of the electrodes is used for optical signal detection. The detection electrode has a relatively high junction resistance and a relatively high series resistance.

Abstract: This invention disclosure describes the application of a polarization insensitive acoustically-tuned optical filter used in a multichannel WDM system to equalize variations in the power level of the WDM channels. The invention also describes a simple means for providing a low frequency control system which enables the equalizer to determine the signal levels of N optical carriers prior to equalizing the signals.