At+t Corp.

At&t Bell Laboratories

Lucent Technologies Inc.

American Telephone & Telegraph Co., At&t Bell Laboratories

American Telephone and Telegraph, Co.

Ronald A Spanke

Alex Lawrence Wierzbicki

John J Stanaway, Jr

Thomas L Hiller

Meyer J Zola

Jayant G Hemmady

Mark A Pashan

Vikram Punj

James M Johnson, Jr

Diana L Lorenz

Neil J Romy

Robert Francis Shaw

Craig P Reilly

Kai Y Eng

Scott C Knauer

Alan Huang

Robert B Dianda

Ronald J Canniff

Jay Henry O'Neill

Sheng Ling Lin

Hsien-Chuen Yu

Gary D Martin

Rolfe E Buhrke

Meyer Joseph Zola

Maurice N Ransom

Douglas H Yano

Charles W Rutledge

Nancy S Stevens

Joseph P Focarile

Thomas Lloyd Hiller

An enhanced Time Slot Interchange (TSI) facility, in addition to serving synchronous channels of communication, decomposes and composes asynchronous data cells to provide real-time communication among and between both synchronous and asynchronous channels served by a network access switch. An asynchronous cell comprises a 5 byte header and a 48 byte payload. The payload comprises voice samples from a temporarily defined set of DSO facilities and/or data from a variety of data facilities. Time slots of the TSI are temporarily assigned to the payload bytes of each incoming asynchronous cell; the payload bytes are stored in memory locations corresponding to those time slots; and the stored data is read out during time slots assigned to the destination channels of communication. The TSI comprises three data rams to accommodate for frame to frame jitter in the time of arrival of payload samples. Asynchronous cells are composed by transferring stored voice samples and data bytes to an asynchronous link during the times slots which are currently assigned to bytes of the composed cell payload. The header for outgoing asynchronous cells is inserted by a message handler.

Communication switch

A high bandwidth gateway comprises a source of packet traffic wherein received packets are stored in a buffer, a destination interface circuit for the packets, a microprocessor and a bus that interconnects the components. The microprocessor, which in the prior art controls data transfers, periodically gives up control to a hardware assist engine. The hardware assist engine detects the presence of packets in the source buffer and causes the source buffer to output one or more packets to the destination directly, thus by-passing the microprocessor completely. By this system, bandwidth is improved by the source and the destination working together directly, without having the overhead associated with microprocessor-based or initiated data transfers.

System and method for increasing throughput of inter-network gateways

Look-ahead control techniques and a variable attenuator are used to solve the known problem of differential attenuation of photonic intensities between time slots are delayed differently in delay paths that have different losses which optical time slot interchangers have. The result of the look-ahead control techniques and variable attenuator is a data frame in which the widely varying photonic intensities are equalized to a substantially similar level, thereby greatly reducing the bit error rate of the downstream receiver/demodulator.

Method and apparatus to compensate for differential attenuation in an

A system and method that controls node congestion in a packet switching network by allowing the congested node to seize control of transmission on the packet switching network and not relinquishing control until it has drained its buffer of the backlog of packets. In response to the node's buffer reaching a predetermined occupancy level, the node requests from the network's arbiter for exclusive transmission rights on the network. When the node receives transmission rights, the node continues to process packets in the buffer. When the occupancy of the buffer reaches a second predetermined threshold, the node releases the transmission right, and thus permits other nodes to transmit packets to it (and to other nodes) again.

Method for avoiding node overload in a packet switching network

Pulse Code Modulation (PCM) signal streams are converted into Asynchronous Transfer Mode (ATM) cells for switching and transmission across a telecommunications network. Each cell carries one PCM sample of up to 48 different voice connections, the voice connections being selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual paths, each path transmitting one cell every 125 .mu.s. The ATM signals are switched by units for switching cells (cell switching), while keeping their payload contents intact, and by units for switching the signals for individual voice connections between cells of an ATM signal (cell remapping). Advantageously, ATM transmission systems interface with PCM systems without adding appreciable delay and without requiring additional buffering. Advantageously, new voice paths can be established most of the time by using available slots in the cells of existing virtual paths. Advantageously, large telecommunication networks can be implemented using a small number of switching units. Advantageously, an access switch comprising a cell mapping or distribution stage for assembling cells comprising PCM samples headed for a common output of the access switch are switched in a cell switch to a cell remap unit for collecting PCM samples headed for a common destination into individual cells of an ATM output stream, provides output signals that can be readily and efficiently switched by a transit network for distribution to other access switches of a large network.

Access switches for large ATM networks

A system for relaying CDMA packetized data from a cell site or sites to a destination speech processor. The CDMA packetized data, is received at the cell site and is sent in its packetized form along with a destination address to a packet switch. A packet handler at the packet switch receives the CDMA data packets and forwards them on a packet bus. If the destination speech processor assigned to that call is connected to the packet bus, it recognizes its own address and processes the data packet.

Packet switch to provide code division, multiple access cellular service

Soft handoff is provided in a mobile-to-mobile call in a cellular communication system, wherein a first mobile is moving from a first cell to a second cell, and the second mobile is in a third cell. The first mobile requests a handoff from the first cell to the second cell. In response, information regarding the call handoff is sent to the second and third cells. During handoff, the first and second cells receive radio transmission from the first mobile, and they both translate the transmissions into electronic data, packetize the data, and send the packetized data to the third cell. The third cell sends packetized data from the second mobile to both the first and second cells. Further, the second mobile may also move from the third cell to a fourth cell. The second mobile requests a handoff from the third cell to the fourth cell. Call data is sent to the fourth cell identifying the first and second cells. Call data is sent to the first and second cells identifying the fourth cell. The first and second cells thereafter transmit packetized data to the third and fourth cells, and the third and fourth cells send packetized data to the first and second cells.

System and method for providing soft handoff of a cellular

A system and method for delivering packetized data representing radio signals to and from cell sites, and to and from a destination point via a fast packet network. Each cell site includes an interface for packetizing the radio signals and transmitting the packetized data to its destination. The destination could be a delivery point at a switch connected to the telephone network, which then converts the packetized data into a form usable by the telephone network. Alternatively, the destination point could be another cell site, which then depacketizes the radio signal and retransmits the radio signal to another wireless communication device without connecting to the telephone network.

System for communicating digital cellular data between a cell site and a

Pulse Code Modulation (PCM) signal streams are converted into Asynchronous Transfer Mode (ATM) cells for switching and transmission across a telecommunications network. Each cell carries one PCM sample of up to 48 different voice connections, the voice connections being selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual paths, each path transmitting one cell every 125 .mu.s. The ATM signals are switched by units for switching cells (cell switching), while keeping their payload contents intact, and by units for switching the signals for individual voice connections between cells of an ATM signal (cell remapping). Advantageously, ATM transmission systems interface with PCM systems without adding appreciable delay and without requiring additional buffering. Advantageously, new voice paths can be established most of the time by using available slots in the cells of existing virtual paths. Advantageously, large telecommunication networks can be implemented using a small number of switching units. For use with PCM switches, it is desirable to provide supervisory signals accompanying the PCM data. Advantageously, this arrangement permits supervisory signals to be passed within an access switch thus simplifying compatibility with existing switching systems.

Intra-switch communications in narrow band ATM networks

A data stream is converted from a synchronous transfer mode (STM) to an asynchronous transfer mode (ATM) by extracting data of a number of payload signals from the data stream, writing data of the payload signal into a random access memory (RAM), separately recording address locations of the data of each of the payload signals in separate buffers, directing the RAM to separately read the data of the payload signals, and attaching a cell header to the data read from the RAM to form ATM cells.

STM-to-ATM converters

Pulse Code Modulation (PCM) signal streams are converted into Asynchronous Transfer Mode (ATM) cells for switching and transmission across a telecommunications network. Each cell carries one PCM sample of up to 48 different voice connections, the voice connections being selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual paths, each path transmitting one cell every 125 .mu.s. The ATM signals are switched by units for switching cells (cell switching), while keeping their payload contents intact, and by units for switching the signals for individual voice connections between cells of an ATM signal (cell remapping). Advantageously, ATM transmission systems interface with PCM systems without adding appreciable delay and without requiring additional buffering. Advantageously, new voice paths can be established most of the time by using available slots in the cells of existing virtual paths. Advantageously, large telecommunication networks can be implemented using a small number of switching units. Advantageously, a central communications network comprising stages of cell remapping interconnected by one or more stages of cell switching provides flexibility for interconnecting large access switches; the cell remapping stage may be made part of the access switch.

ATM distribution networks for narrow band communications

Pulse Code Modulation (PCM) signal streams are converted into Asynchronous Transfer Mode (ATM) cells for switching and transmission across a telecommunications network. Each cell carries one PCM sample of up to 48 different voice connections, the voice connections being selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual paths, each path transmitting one cell every 125 .mu.s. The ATM signals are switched by units for switching cells (cell switching), while keeping their payload contents intact, and by units for switching the signals for individual voice connections between cells of an ATM signal (cell remapping). Advantageously, ATM transmission systems interface with PCM systems without adding appreciable delay and without requiring additional buffering. Advantageously, new voice paths can be established most of the time by using available slots in the cells of existing virtual paths. Advantageously, large telecommunication networks can be implemented using a small number of switching units.

ATM networks for narrow band communications

An Optical Time Slot Interchange (OTSI) Apparatus that has relatively low optical fiber requirements and good attenuation and signal-to-noise characteristics. This OTSI uses parallel feedback (PFB) to provide the delays. This PFB OTSI can be implemented with an n.times.n optical crossbar switch. The PFB OTSI is conditionally, i.e., rearrangeably, non-blocking for 16.times.16 crossbar switch implementations if a controller using the control method of the invention is also included.

Optical time slot interchanger apparatus and method of operation

Pulse Code Modulation (PCM) signal streams are converted into Asynchronous Transfer Mode (ATM) cells for switching and transmission across a telecommunications network. Each cell carries one PCM sample of up to 48 different voice connections, the voice connections being selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual paths, each path transmitting one cell every 125 .mu.s. The ATM signals are switched by units for switching cells (cell switching), while keeping their payload contents intact, and by units for switching the signals for individual voice connections between cells of an ATM signal (cell remapping). Advantageously, ATM transmission systems interface with PCM systems without adding appreciable delay and without requiring additional buffering. Advantageously, new voice paths can be established most of the time by using available slots in the cells of existing virtual paths. Advantageously, large telecommunication networks can be implemented using a small number of switching units. Advantageously, such a cell remap unit provides a key element to the implementation of an efficient large ATM voice network.

Inter-cell switching unit for narrow band ATM networks

A system for delivering packetized data in a network comprising a plurality of packet switch communities, wherein each of the packet switch communities has a plurality of endpoints connected to a common packet switch and having a unique address, and wherein each of the endpoints has addresses unique to their respective packet switch community. The endpoints in this system add a two-part destination address to the packetized data to be sent, wherein the first field represents a packet switch community and the second represents a destination endpoint. Each packet switch community is responsive to the first field being different from its own address for delivering the packetized data to a switch. The switch is responsive to the first field for delivering the packetized data to a packet switch community identified by the first field. Finally, each endpoint in the destination packet switch community is responsive to the first and second address fields for accepting packetized data.

Growing community of inventors

Wheaton, IL, United States of America

Ronald A Spanke