Abstract: By using a LAN emulation in an ATM environment, end systems such as workstations etc. can connect to the ATM network while software applications interact as if they are attached to a traditional LAN. The invention is a simple technique for emulating a LAN on an ATM network. According to the invention, each end system is identified by hub and port identifiers which represent a hub and a port of the hub to which the end system is connected. By labelling each ATM cell, and proper label translation at hubs, a LAN can be emulated without using network servers which would introduce cumbersome extra procedures.

Abstract: The invention relates to automated testing of equipment items of the electronic, electrical, and optical type over a range of environmental conditions. A testing apparatus operates to vary an operating environment of an item of test equipment between a lower extreme and an upper extreme, and iteratively searches each test parameter for a peak response. The peak response is compared with a response limit specified in a customer specification or an international standard. The apparatus assesses a design robustness of the equipment item by comparing a set of measured responses with a maximum range of responses specified in the customer specification or international standard. The apparatus produces a data output for each performance parameter tested, identifying performance parameters which are outside the customer specification, or which have insufficient design robustness.

Abstract: Process for selectively depositing a refractory metal silicide on a surface of a monocrystalline or polycrystalline silicon wafer, comprising: a step of preparing said surface, consisting in forming a silicon oxide or silicon oxynitride layer having a thickness e.ltoreq.1 nm on this surface; and, on the silicon oxide or oxynitride layer formed, a step of selective vapor deposition of a refractory metal silicide.

Abstract: The invention resides in the field of transferring data and other information from multiple asynchronous TDM channels across a synchronous interface in digital blocks of a preset length. Presently, transfer of data and timing information requires serial transmission of frame payload, qualified with clock and frame pulse indications. A separate set of these signals is required in both directions for each port or physical link. An interface of the invention permits data transfer in blocks which are uniquely identified for a specific port or links and the position of the block within the frame (if the transfer is one of framed data). The invention greatly reduces the number of required signals, thus enabling reduction of pin count requirements and an increase in the number of serviced ports.

Abstract: This invention relates to a method and protocol to enable a simple, reliable and highly scaleable data transfer facility in a digital data network. A connectionless, unacknowledged data transfer protocol minimizes resource utilization at a data server and is combined with source rate control to reduce congestion in the intervening network. The data transfer server implementing the protocol, operates by defining a circular ordering of individual scheduling timeslots having zero or more download records. The server selects in sequence, at a predetermined rate, the individual scheduling timeslots, and services, responsive to the selected timeslot having at least one download record, each record therein according to parameters in that record.

Abstract: Novel techniques are disclosed for continuously monitoring parameters of delay between two nodes in a telecommunication network such as an ATM or frame relay network. The techniques use measurement cells, i.e. test cells, test frames, performance management ATM OAM cells, or performance management frame relay frames. These cells or frames contain a timestamp indicating the time a cell or frame is sent and a delay value indicating a difference between reception and transmission times of the cell or frame.

Abstract: An electronic switching system (ESS) analyzes charge data automatically. The ESS comprises a generator for generating the charge data for a call; a recorder coupled with the generator for receiving the charge data from the generator and assembling a data block having a block header, a plurality of charge data and checksum value; a first memory for storing a multiplicity of the data blocks; an analyzer coupled with the first memory for checking the charge data of the data block to detect any erroneous charge data and search for a long call; a controller coupled with the analyzer for generating and transmitting a predetermined message for erroneous charge data to an operator and determining to verify the charge data for a subscriber of the long call; a verifier coupled with the generator for receiving from the generator and displaying the charge data; and a second memory coupled with the verifier for storing the verified charge data.

Abstract: A loopback mechanism uses frame relay OAM loopback frames which eliminate the need for location identifiers and reduces overhead and complexity. The frames replace source and destination loopback location identifiers by a loopback indicator field, a send node count field and a return node count field. The originating node of the loopback procedure sets the number of intermediate frame relay nodes to be traversed. The intermediate frame relay nodes simply increment or decrement the node count, depending on the direction of the loopback frame.

Abstract: A signal transfer point distributes a plurality of messages to a plurality of service control points in accordance with a distribution plan. The distribution plan includes each of the service control points. Each of the plurality of messages from the signal transfer point is distributed to a corresponding one of the plurality of service control points in accordance with the distribution plan.

Abstract: A communication management system and method of operation includes a structure registration interface, a user registration, a submission interface, a communication server and an access interface. The structure registration interface receives structure data and establishes a communication thread structure having a plurality of interconnected threads based upon the structure data. The user registration interface receives user data and establishes user information based upon the user data, the user information linking a user with at least one thread of the plurality of interconnected threads. The submission interface receives communications and at least one desired thread of the plurality of interconnected threads and links the communications with at least some of the plurality of interconnected threads. The communication server establishes links between communications and user information based upon threads of the plurality of interconnected threads.

Abstract: An electrical switch (116) is disclosed having multiple inputs (214) and binary switches (312) operable to switch a signal from an input (214) via respective amplifiers (310). Amplifiers (310) are continuously operable and are provided with an auxiliary switching circuit (412) which provides the amplifier with a fixed voltage input signal when the associated input (214) is not selected. Response time upon selection of an amplifier (310) and crosstalk from any non-selected amplifier is minimised.

Abstract: Two T1 signals are mapped onto a subscriber bus (26) in a subscriber loop equipment (10) for transport between a bank control unit (20) and channel units (22), for example. The data channels and the signaling and control channels of the first T1 signal are mapped onto a first data stream, and the data channels and the signaling and control channels of the second T1 signal are mapped onto a second data stream. The data streams are bit-interleaved for transport on the subscriber bus (26).

Abstract: A configurable connection fabric between a switching fabric and a backplane allows any of the ports of the backplane to be connected to any of the ports of the switching fabric. The connection fabric receives bandwidth load requirements from modules connected to the backplane and uses these load requirements to determine the number of ports required to make a particular connection.

Abstract: A digital signal to be received by a plurality of receivers, particularly restricted-range receivers, and divided into signal frames of which at least some include both a main data channel consisting of sub-channels, and a data transport path including at least one data channel consisting of separate data blocks dedicated to a single service and known as containers. Each container includes a header (41) consisting of a selection sub-header (44) containing, inter alia, data (46) for identifying a group of at least one container destination receiver, and a service sub-header (45) containing, inter alia, dedicated service data; a separately convolutionally coded working data field (42) containing source data for a given service; and an error detection and/or correction data field 943).

Abstract: In a cellular mobile access communications system each mobile terminal registers its location at intervals. From the registration history of each mobile, a probable group of cells within which a mobile terminal may be located is predicted. When a mobile is to be paged, the paging message is transmitted to the predicted cell group. If no response is received from the terminal, the page message is then broadcast to further system cells. This reduces the overall paging load on the system.

Abstract: The gain provided by an erbium amplifier is stabilised by spectrally selective optical feedback to make the amplifier lase. The resulting laser emission is extracted from the amplifier output using a Mach Zehnder with matched Bragg reflectors in its two interference arms. The extracted light may be used for supervisory purposes. Part of the laser cavity defining feedback may be provided by the Mach Zehnder by arranging one of its Bragg reflectors to be displaced with respect to the other.

Abstract: To decode an attenuated multi-level signal (42) in a receive interface (120) of communication apparatus, first (134) and second (150) diode pumps co-operate with a biasing chain to ensure that threshold reference levels used by respective positive (52) and negative (54) data comparators are dynamically adjusted to a level dependent upon the attenuated multi-level signal (42) applied to the diode pumps. Particularly, a voltage divider (138-144) acts dynamically to bias differential inputs to the respective positive (52) and negative (54) data comparators, with a ratio between a biasing chain of resistors (138-144) and a common input resistor 128 determining the threshold reference levels used to assign logical levels for the reconstruction of symbols encoded within the multi-level signal (42).

Abstract: An apparatus for receiving messages defined by data packets having respective header and payload portions where each header portion includes a channel representation regarding a channel associated with the data packet and an end of message representation representing whether or not the data packet is a final data packet in the message and where each payload portion includes information pertaining to the message. The apparatus includes data memory for storing the payload portions of the data packets, list memory, a header processor for receiving the header portion of the data packet and for providing status signals indicative of the channel representation and the end of message representation, and a reassembly processor programmed to maintain in the list memory a pointer list of address pointers to unused blocks of data memory and a link list of address pointers associated with each channel.

Abstract: A switch that includes inputs for receiving cells connected to a first storage means for storing the cells received at the inputs. The first storage means includes a plurality of portions in which each portion is associated with an input. Additionally, each portion has a number of segments in which a cell may be stored. Additionally, the switch includes an address translation means for assigning a destination from a plurality of destinations to each cell received at the inputs. A second storage means is included in the switch. This second storage means has a number of sections in which each section is associated with a destination within the plurality of destinations and each section includes a number of segments. For each cell assigned a destination, the second storage means stores information identifying the location of the cell within the first storage means. This information is stored in a segment in the section associated with the destination assigned to the cell.

Abstract: A method of etching of indium phosphide (InP) semiconductor materials using methyl chloride CH.sub.3 Cl and phosphine PH.sub.3 in a low pressure MOCVD reactor is provided. Etching of InP using CH.sub.3 Cl as an etchant and PH.sub.3 to prevent thermal decomposition of the etched surface gives excellent etching morphology, and a maximum etching rate of 0.75 mm/hr for the CH.sub.3 Cl flow rates studied. A PH.sub.3 flow rate.ltoreq.40 SCCM and etching temperature.gtoreq.610.degree. C. provided excellent etch morphology, without formation of pits, independent of the CH.sub.3 Cl flow rate. A controllable etching rate was obtained for a coated susceptor when deposits are primarily InP. Thus this method of CH.sub.3 Cl etching is suitable for multiple growth and etching steps using an MOCVD reactor. By controlling the PH.sub.