Abstract: 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.

Abstract: An Asynchronous Transfer Mode-Local Area Network (ATM-LAN) connection apparatus is connected between an ATM terminal of a LAN emulation protocol and an ATM switch connected to ATM terminals of an Internet Protocol (IP) over ATM protocol. The ATM-LAN connection apparatus includes ATM physical layer sections for transmission and reception of an ATM cell, AAL5-SAR sections for reassembly and segmentation of an AAL5 packet, a LAN emulation protocol processing section for performing minimum LAN emulation protocol processing with respect to the specific ATM terminal, an IP over ATM protocol processing section, and a bridging section for frame format conversion between both the protocols.

Abstract: A method determines the signal usability of an adjacent channel in a multi-cell communication system without the aid of synchronization symbols. In general, a three step search is used to arrive at the adjacent channel signal quality. The first step is a coarse timing phase search. This is accomplished through a signal quality estimates (606). The second step arrives at the optimum time phase by first interpolating (608) the received signal around the time phase selected in the first step to generate additional samples. After the interpolation (608), signal quality estimates are calculated (610) for the time phases immediately surrounding the time phase found in the first step. The optimum time phase corresponds to the maximum of these quality estimates. Finally, in the third step, the signal quality estimate is calculated for the optimum time phase. This provides the adjacent channel signal quality estimate desired.

Abstract: The invention provides a system for dynamic distribution of processing time during a frame in a station operating in time-division multiple access mode. The system comprises a set of N independent configurable processing resources respectively associated with N time windows in the frame, where N is a predetermined integer greater than 1. The N configurable processing resources can be configured to yield N respective configured processing resources each of which is activated for a respective particular processing operation for which it has been configured. Each of the N previously configured configurable processing resources is activated so that the respective particular processing operations are effected during the frame.

Abstract: An apparatus an method for adaptive time slot scheduling of communications traffic generated by end-point host in ATM network. The scheduler includes a time slot ring including an array of time slots, wherein each of said time slots includes a virtual channel identifier (VCID) of a virtual channel (VC) to be serviced; a VC table including an array of VC descriptors, wherein the VCID stored in said time slot ring points to a VC descriptor in the VC table; and processor for scheduling the VCs in said time slots of said time slot ring, wherein the time slots ring are circularly processed in a continuous fashion thereby enabling scheduled transmission of ATM cells in the network. The processor is operable to queue the VCID of a newly calculated target slot in an already occupied time slot if the newly calculated target slot is occupied, thereby creating a linked list of VCs, and the processor is operable to service all VCs at a single time slot before proceeding to a next time slot.

Abstract: A method for controlling a conditional connection in a synchronous digital telecommunications system, in which a signal has a frame structure has a predetermined number of bytes of fixed length and includes a pointer indicating the phase of the payload within the frame structure. Condition information relating to a useful signal is transmitted, on the basis of which information the connection is made. In order to enable control of conditional connections in a synchronous digital telecommunications network without using the effective capacity of the network, the condition information is transmitted at least in one byte belonging to the overhead section of the frame structure.

Abstract: Switches connected via transmission lines, wherein one switch has a bidirectional mode, while the other switch has a unidirectional mode. To realize line switching when a failure occurs, the switches function to switch signals from a working transmission line to a protection transmission line. The switch having the bidirectional mode switches concurrently both first and second direction paths from a working transmission line to a protection transmission line. The switch having the unidirectional mode switches either one of the first and second direction paths from the working transmission line to the protection path. When the second switch switches to send signals via the first direction path of the protection transmission, the first switch notifies the second switch as if a fault occurred in the second direction path of the working transmission line.

Abstract: Apparatus and a method for establishing voice band telecommunications connections using a cross connect/switching system (CCSS) for establishing all or part of the connection setments required for individual calls. The CCSS contains bundles of provisioned paths and also has facilities for establishing individual per call paths which do not use these bundles. When a call is received, the CCSS switches the call through a combination of provisioned and unprovisioned paths. In the preferred embodiment, the CCSS is an asynchronous transfer mode (ATM) switch enhanced with converters to communicate with pulse code modulation (PCM) facilities for communicating with other switches and with associated PCM switches. Terminal adapters are provided in either the CCSS or the associated switches or both for processing voice signals to perform functions such as echo cancellation or speech quality enhancement.

Abstract: The ATM communication equipment (KE) serves the purpose of forwarding message cells supplied via at least one offering trunk (E1, . . . , En) during to course of virtual connections with a serving trunk arrangement (A1, . . . , An) coming into consideration for the respective virtual connection. Characteristic parameters as well as at least two different priorities are thereby defined for the respective virtual connection during the course of the call set up. The respective serving trunk arrangement has a handling device (BHE) allocated to it that has a central cell memory (CM) in which call-associated cell waiting lists are established for storing message cells. A control device (STE) in which an allocation table (LUT) is kept is connected to the cell memory. This allocation table allocates a waiting list identifier as well as a priority identifier to the call information (VPA/VCI) carried in the message cells.

Abstract: Simultaneous and temporal masking of digital speech data is applied to an MBE-based speech coding technique to achieve additional, substantial compression of coded speech over existing coding techniques, while enabling synthesis of coded speech with minimal perceptual degradation relative to the human auditory system. A real-time perceptual coder and decoder is disclosed in which speech may be sampled at 10 kHz, coded at an average rate of less than 2 bits/sample, and reproduced in a manner that is perceptually transparent to a human listener. The coder compresses speech segments that are inaudible due to simultaneous or temporal masking, while audible speech segments are not compressed.

Abstract: A telecommunications network service overcomes the annoying effects of transmitted noise by signal processing which filters out the noise using a model-based iterative signal estimator. The estimator is provided with a current estimate of the noise power spectral density, using signal frame samples determined by a voice activity detector to be noise-only frames. The signal estimator makes intra-frame iterations of the current frame while using smoothing across LSP parameters of adjacent frames, recent past frames, and up to two contiguous future frames. Non-stationary noise created by the iterative filtering is further reduced in one or more post-filtering stages that use knowledge of the nature of the low level non-stationary noise events.

Abstract: The present invention telecommunications system provides validation of authorization codes input by a user for placing a call from a service area of a first telecommunications service provider with a calling card issued by another telecommunications service provider. The present invention allows the subscriber to place a special service call irrespective of whether the signaling protocol of the first service provider is different from the service provider to which the subscriber is a customer of. If the protocol of one telecommunications service provider is indeed different from the other service provider, a gateway residing in an intelligent service network node would convert the signaling protocol of the first service provider into a signaling protocol that is compatible with the other service provider.

Abstract: In a congestion control method for a system having a first network of one congestion control unit representing a subset of a switching network constituted by a set of switching nodes connected to each other and a second network which serves as a subset of the switching network and does not have a switching node common to the first network, thereby controlling congestion of the first and second networks, the traffic is classified into first traffic generated in the first network and reaching a target switching node of the first network through a switching node in the first network, second traffic having the switching node of the first network as a start point and directed toward the second network, third traffic having a switching node in the second network as a start point and transmitted through a switching node in the second network and a switching node in the first network, and fourth traffic which does not correspond to any one of the first traffic, the second traffic, and the third traffic.

Abstract: A connectionless server for an ATM network carries out routing so that connectionless data generated in a local area network or a terminal is delivered to the appropriate destination. The connectionless server includes a cell header processor for delivering a destination address and an HCT (Header Conversion Table) write address to a destination address processor whenever a BOM or SSM cell is received, and for delivering the cell and an HCT read address to a header conversion processor whenever any cell is received. The destination address processor performs searching and delivers header conversion information (VPIo/VCIo/MIDo) generated from the destination address. The header conversion processor stores the header conversion information from the destination address process and converts the header value of the cell input from the cell header processor using header conversion information stored in a header conversion table.

Abstract: A personal communication network distribution system includes a predetermined number of node devices, a controller, and a network connecting the controller to each of the node devices. The network carries a time division multiplexed signal having a plurality of channels for carrying digital communication information signals between the controller and the respective node devices. Each respective node device is assigned a respective predetermined number of the plurality of channels for receiving digital communication information signals from and/or for inserting digital communication information signals into the time division multiplexed signal. The time division multiplexed signal also includes a second predetermined number of non-assigned channels.

Abstract: A system for routing packets in a network environment having a connection-oriented subnetwork, a plurality of routers coupled to said connection-oriented subnetwork, and a plurality of established virtual circuits. A packet is received by a router for forwarding toward a packet destination. A best existing virtual circuit across said connection-oriented subnetwork is identified from said plurality of established virtual circuits. The best existing virtual circuit is analyzed to determine whether it is both feasible and efficient for forwarding the packet toward the packet destination. If the best existing virtual circuit is both feasible and efficient, then the packet is forwarded using the best existing virtual circuit. If the best existing virtual circuit is either not feasible or inefficient, then a new virtual circuit is established to an optimal next hop router and the packet is forwarded using the new virtual circuit.

Abstract: A high-speed bit assignment method for audio signal is disclosed. The Method is usable by various systems using encoding and decoding, capable of reducing bit assignment time in a compressing method using a psychological acoustic model, increasing a bit assignment ratio by using a maximum possible bit, and facilitating high-speed processing.

Abstract: Packet based telecommunications networks are being developed to carry Constant Bit Rate (CBR) data streams between source and destination exchanges in the form of multiplexed packets, which are recombined at the destination exchange into a CBR stream. In such a network it is desirable to synchronise the frequency and maintain the phase relation of the recombined CBR stream with those of a source CBR stream arriving at the source exchange. The described synchronising circuit for use in such a network comprises a local oscillator (46), a local Residual Time Stamp (RTS) generator (50) arranged to determine a local RTS value (51) from the local oscillator frequency, a comparator (52) to determine the difference between the local RTS value (51) and a source RTS value (41) extracted from packets received at a destination exchange (10), and an oscillator controller (54) responsive to the difference to adjust the frequency and phase of the local oscillator to maintain the difference constant.

Abstract: A hardware timing system for a cellular telephone comprises a master counter and a slave counter. The slave counter controls timing window generators in synchronism with the time frame of the local base station. The phases of timing frames of other base stations are monitored using the master counter.

Abstract: A programmable data link module (32) for use in a time division multiplexing control system (30) having a plurality of modules interconnected by a bus (40) for passing control signals between data link modules on a serial multiplex basis. Each module includes an integrated circuit (80) having signal conditioning circuits (180, 186 and 188) including a programmable hysteresis circuit (126), a power on reset delay circuit (190), a safety input inhibit circuit (220), a clock loss detect circuit (240), a safety output protection circuit (262), a data verifier (260), a polarity selector for a third output terminal (350), an input synchronizer (182 and 184), a combined mode/sync output terminal (110), a multiplex clock output terminal (108), a programing circuit (232) for accepting programing over the clock bus (44) and data bus (46), input/output word extender circuits (104, 106), a high voltage protection circuit (420) including a transistor (600) and a data bus integrity checker (630).