Lucent Technologies Inc.

At+t Corp.

At&t Bell Laboratories

Alcatel-lucent USA Inc.

Ender Ayanoglu

Richard Dennis Gitlin

Kai Y Eng

Krishan Kumar Sabnani

Mark John Karol

James E Mazo

Sanjoy Paul

Thomas F La Porta

Chih-Lin I

Pramod Pancha

Malathi Veeraraghavan

Glenn David Golden

Jack Harriman Winters

Israel Bar-David

Nuri Ruhi Dagdeviren

Clark B Woodworth

Burton R Saltzberg

David G Shaw

Raymond K Jones

Murat Alanyali

Kai Yin Eng

Methods for provisioning optical communications networks employing wavelength division multiplexing (WDM) technology provide for routing and wave-length assignment of a set of connection requests. Avoiding many of the pitfalls of exactly optimum solutions, the present heuristic methods provide much shorter execution times while providing near-optimum performance. Adaptations of the basic solutions provide design of restorable networks capable of handling a specified set of failures. This approach advantageously is based on considering all failures simultaneously, and performs better than solutions in which independent designs are developed for each failure. Networks designed using these methods store configuration information for primary network configurations and for one or more restoration networks. Upon startup or upon network failures, predetermined configuration directions are applied to wavelength selective cross-connects (WSXC) at each network node to establish (or reestablish) desired network node interconnections.

WDM optical communications networks and methods for provisioning

The present invention is a restoration scheme for an ad-hoc ATM LAN wherein ATM cells are transported over a wireless point-to-point link. A method for restoring communications in the ATM network includes the steps of: generating a failure message indicative of a failure of a network element, the failure message including an identification of said network element and a predetermined VPI/VCI reserved for failure reporting; communicating the failure message to all said switching nodes in said network; and referencing updated routing tables at said switching nodes, wherein said network element indicated in said failure message is eliminated from routes in said network. Each of the switching nodes is included in a network tree spanning all said switching nodes in the network, wherein each of the switching nodes is included as a root in a specific network tree, each said network tree having a tree identification, the failure message further including a tree identification field containing the tree identification. The method also includes the step of routing the failure message in the switching nodes of the network based on the tree identification. The failure message includes a time stamp indicative of the time said failure message was generated, and the referencing of the updated routing tables is delayed a predetermined time period from the time of said time stamp before referencing said updated routing tables.

Method and apparatus for restoration of an ATM network

A facility is provided for establishing a relatively low-speed path from a user desiring to access the well-known Internet and establishing a high-speed path from the Internet to the user so that the data speed accommodates both the user's requests and a response from an Internet web/host site. Moreover, a user may be mobile, in which case the low-speed path is a conventional wireless path. In most cases, a predetermined spectrum of frequencies, such as one or more television channels, is used as the high-speed path from Internet.

Wireless internet access system

A telecommunications system capable of transmitting an N byte packet over a common communications channel by: temporally dividing the common communications channel into time slots that have a duration equal to ##EQU1## seconds, where i is a natural number greater than one, C is a constant and R is the transmission rate of the common communications channel in bytes per second; splitting the N byte packet into i p-packets; preparing an M byte training sequence; and transmitting the M byte training sequence and the p-packets over the common communications channel in consecutive time slots.

Method and apparatus for transmitting packetized data over a common

The present invention is a signaling and control architecture for establishing a connection between mobile users in a wireless ATM LAN. The ATM LAN includes a plurality of portable base station (PBS) switching nodes coupled together to enable communication between said nodes, wherein the nodes are configurable in an arbitrary topology to form an ad-hoc network. The present invention includes network management techniques for configuration of data tables used for connection control. Mobility management techniques are disclosed to handle mobile sign-ons and idle handoffs, locate mobile users during connection and setup and perform handoffs when a mobile is actively involved in a connection. Connection control procedures are also included for setting up and releasing connections on demand.

Signaling and control architecture for an ad-hoc ATM LAN

Increased numbers of multipath transmission errors, that are detected by the performance of cyclic redundancy checking (CRC) over time and frequency on the words of a multitone transmission block that include mapped information bits, are correctable by forward error control as a result of the iterative performance of CRC over frequency on subblocks of the transmission block using retransmitted parity checking bits. A continuous record is maintained of the frequency channels that are detected as experiencing transmission errors in order to maximize the rate of data bit transmission on frequency channels that are likely to experience a reduced number of transmission errors.

Adaptive ARQ/FEC technique for multitone transmission

The present invention is a reliable data link layer protocol to transport ATM cells over a wireless point-to-point link. The protocol ensures that the cells are transported reliably by use of a sliding window transport mechanism with selective repeat automatic repeat request (ARQ) and forward error correction (FEC). The protocol minimizes ATM header overhead by means of header compression and provides per-cell FEC whose size can be changed adaptively. The protocol also provides parity cells for recovery from errors that cannot be corrected using the per-cell FEC field. The number of these cells as well as the size of a window or frame can also be adaptively changed. In addition, the window can be terminated to request an immediate acknowledgment.

Data link layer protocol for transport of ATM cells over a wireless link

A navigation system for an automotive vehicle designed to display a road map image around the vehicle in correlation with the current position of the automotive vehicle. The navigation system is adapted to determine a best navigation route to a selected destination on the basis on the approximated time necessary to travel such a navigation route in correspondence to its travel length and speed rate.

Navigation system for an automotive vehicle

A forward error correction system adaptively changes the number of parity bits, bytes or packets transmitted to a receiver, based on previous error patterns experienced recently in the reception of original and parity bits, bytes or packets by that receiver.

Adaptive forward error correction system

A wireless communications system is arranged to provide data communications services, including error recovery, between at least one wireless end-user device and at least one one base station. The wireless end user device(s) receives(s) from the base station(s) unsolicited messages indicative of the status of data packets received by the base station(s). The wireless end-user device(s) transmit acknowledgement and request for retransmission messages only upon request, or when all the packets within a block of such packets have been received.

Asymmetric protocol for wireless communications

The present invention is a quantization-level-sampling (QLS) modem which includes means for separately equalizing each loop of an end-to-end digital telephone system network connection by employing a plurality of transmitter filters and a plurality of receiver filters in such a way that, in the direction of transmission from modem to central office, the voltage samples seen by the coder/decoder stations are equivalent to the network quantization levels transmitted by the modem, and in the direction of transmission from central office to modem, the voltage samples seen by the modem are equivalent to the network quantization levels encoded by the coder/decoder stations. The invention also includes a QLS modem communications system which includes the aforesaid digital telephone system network and a plurality of QLS modems. In preferred embodiments, an adaptation service unit within the telephone system network assists in the determination of the settings of the transmitter and receiver filters.

High speed quantization-level-sampling modem with equalization

A modem that operates reliably at a symbol rate that corresponds to twice its bandwidth even when it is coupled to a receiving A/D converter that operates under control of a clock is realized by synchronizing the modem's operation to the A/D's clock. The superior operation of this modem advantageously extends to A/D clock frequencies beyond the frequency of twice the modem's bandwidth. To minimize quantization noise, the modem's output is conditioned to minimize intersymbol interference by adjusting the modem's output to the A/D converter's sampling times and slicing levels. When the A/D's clock is higher than twice the bandwidth of the modem's output signal, some intersymbol interference cannot be avoided. In accordance with this invention, the position and value of this interference is computed at the receiver and subtracted from the received signal.

High-speed modem synchronized to a remote CODEC

Ghosts are canceled in received analog TV (for IDTV, EDTV, and HDTV) signals by utilizing the fact that there are short periods of time without the analog signals (the horizontal flyback interval between the lines) to process the received signal on a line-to-line basis using a finite impulse response (FIR) or an infinite impulse response (IIR) equalizer. This line-by-line processing (which can be implemented by periodic cleansing of the equalizer) overcomes the limitations of standard equalizers to allow for 40-50 dB of suppression of ghosts, even with nulls in the spectrum, as long as the ghost delay is less than the period of time without the analog signal. Furthermore, by using time inversion in combination with line-by-line processing, the stability problem of the conventional IIR equalizer is eliminated. The IIR equalizer may be implemented on a single digital integrated circuit. Alternatively, an FIR equalizer can be used which, although it may require multiple chips (i.e., more taps), can acquire and adapt to the ghosted channel more rapidly than an IIR equalizer. With line-by-line processing, FIR and IIR equalizers can eliminate any ghost with delays up to 11 .mu.sec in IDTV or EDTV. For larger delays, a standard IIR or FIR equalizer can be used as a preprocessor to eliminate small ghosts and an adaptive antenna can be used to eliminate large ghosts. Thus, with these techniques, the ghosting problem can be eliminated in all TV receivers.

Ghost cancellation of analog TV signals

This invention is a technique for the substantially instantaneous self-healing of digital communications networks. Digital data streams from each of N nearby sources are combined and encoded to produce N+M coded data streams using a coding algorithm. The N+M coded data streams are then each transmitted over a separate long haul communications link to a decoder where any N of the N+M coded data streams can be decoded uniquely to produce the original N data streams. The orginal N data streams are then distributed to their respective separate end destinations. If any M or less of the N+M long haul communications links fails, i.e. as in a telephone line that gets cut or a long distance switch that fails, no rerouting of traffic need be done. Rather, the receiver detects loss of carrier on the failed link(s), and immediately supplies the missing data by decoding the data from the at least N remaining links. The technique overcomes a long felt problem of trying to reroute traffic by using sophisticated resource allocation techniques when a communications link fails.

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Red Bank, NJ, United States of America

Ender Ayanoglu