Abstract: Communication system having a multiprocessor system serving the purpose of central control. Multiprocessor systems are used in communication systems for the purpose of central control. Care must thereby be exercised to ensure that the jobs/messages arriving from a periphery according to the FIFO principle are in turn deposited in the original sequence after being handled by processes being executed on the processors. A coordination procedure required for this purpose thereby uses a holding table. The logical sequence of jobs/messages is thus assured during the processing in the multiprocessor system.

Abstract: A system and method for creating and modifying intelligent telephone network call processing logic trees which can be customized for individual customers and created in a user-friendly visual environment (10, 15, FIG. 3-5). Service primitives are defined as logical graph nodes (20, FIG. 2, FIG. 3) which can be visually assembled into logic trees (FIG. 5) which represent the service logic flow and which provide default values for all service options. Higher level nodes, assembled from a plurality of service primitives, can likewise be defined and stored (12, 13, 19) for later use as entities in defining yet further call processing logic trees. These call processing logic trees are interpreted to allow the service control point computers (17) to implement the services in the switched telephone network (18) by sequentially executing the specified call processing primitives.

Abstract: A user-programmable telephone switch which resides within a commercially available personal computer. The switch is controllable by either the personal computer's microprocessor or a separate, external host connected to an interface provided within the switch. The switch includes a CPU/matrix card that contains a time slot interchange and a CPU running under a real time operating system. The CPU/matrix card controls the overall operation of the switch in accordance with messages received from the operative host. In general, those tasks or functions which must be performed in real time are the responsibility of the switch, as opposed to the internal or external host. Within the switch, certain tasks or functions may be delegated by the CPU/matrix card to intelligent line cards which contain their own microprocessors having substantial call processing capability.

Abstract: An adjunct processor (100) is embedded in a telecommunications switching system (10) wherein port circuits (106-108) are interconnected with each other and with a control processor (101) by a TDM bus (105). The adjunct processor is physically incorporated into the switching system, is connected directly to the TDM bus, and communicates with the control processor exclusively via the TDM bus. The adjunct processor is made up of a telecommunications feature module such as a conventional voice-mail system (200), an arrangement (210, 220, 240) for interfacing the feature module to the TDM bus whereby the adjunct processor emulates a port circuit in its connection to the TDM bus, and an arrangement (203) for interfacing the feature module to the control processor whereby the adjunct processor emulates a telephone in its interactions with the control processor.

Abstract: In a reconfigurable communications system, circuit status bits are stored in a first matrix of rows associated respectively with predefined network configurations and columns associated, respectively, with predefined circuit configurations. Destination status codes are stored in a second matrix of rows associated respectively with the circuit configurations and columns associated, respectively, with switching nodes of the system. Each circuit configuration comprises one or more transmission links, and each circuit status bit stored in each column of the first matrix pattern indicates the presence or absence of the circuit configuration associated with that column. Each destination status code indicates the presence or absence of transmission links from each switching node to possible destination nodes.

Abstract: A device which enables two or more users of outside lines to converse on equal terms with each other. The connection method provides a distributed form of processing. The outside lines are connected to corresponding voice signal lines which intersect with two-party conference lines which serve as connectors for two voice signal lines, and multiple party conference lines which serve as connectors for three or more voice signal lines. Connection is possible at any intersection point. The device is also fitted with a conference line selection signal decoder to enable connection of a voice signal line with a specific conference line as specified by an incoming signal. Exclusion control lines are fitted to prevent the connection of more than two voice signal lines to the same two-party conference line. The voice signal lines are connected to a voice processor to enable the output of voice signals to an outside line.

Abstract: A main processor assigns originated-call processings to each of a plurality of call processors in the sequence of call originations according to the first principle of this invention. A switching state controller collects usage information about a plurality of buffers composing the switching network in the ATM exchanger. The call processors to which call processings are assigned perform the call processings based on the content of switching state controller a main processor assigns a call processing for an originated call to one of a plurality of call processors by referring to the call processing assignment table memory with the virtual channel identifier corresponding to an originated call according to the second principle of this invention thus, call processing loads are distributed among call processors.

Abstract: A PBX communications device is disclosed. The PBX communications device permits communication between a PBX and an adjunct processor. The present invention uses direct communications with a PBX line card as the source of information for the adjunct processor and translates the information to a form usable by the adjunct processor.

Abstract: A telephone network with distributed processing capabilities. A local controller is provided for monitoring status of a plurality of users. A primary controller performs circular polls of the local controllers to determine status changes. The system operates in a time division multiplexed fashion, and the primary controller assigns during which time slot each particular conversation will occur. A synchronizer for synchronizing between the primary and the secondary controller is also provided. In addition, the ring timing for the subscriber premise can be performed in the microprocessor at the subscriber premise.

Abstract: A switching architecture interconnecting remote switches to a central processor via standard links which may be set up through any number of intervening switching systems utilizing standard switching procedures. The standard links are ISDN links that may be set up dynamically via switching networks within the switching system or via the public switching network. The fact that an ISDN goes through a portion of the switching system or the public switching network is transparent to both the central processor and remote switch. Upon detecting that a primary central processor is no longer in control, each remote switch attempts to obtain an alternate path to the primary central processor. If a remote switch is unable to obtain an alternate path to the primary central processor, the remote switch switches to an alternate central processor on the assumption that the primary central processor has failed.

Abstract: A site architecture for a trunked radio frequency communications system provides better fault tolerance capabilities than are available from architectures including redundant hardware. During normal system operations, a primary site controller performs most or all system control functions while signal processing functions are performed in a distributed manner by trunking cards associated with individual repeater channel receivers and transmitters. In the event the site controller fails, the trunking cards also begin performing trunking and other control functions. The trunking cards cease attempting to communicate with the failed site controller, and begin communicating directly with one another via a high speed backup serial link.

Abstract: A programmable universal signaling circuit for use in a universal channeling unit of a telephone network. The programmable universal signaling circuit uses a line converter and decoder circuit which under control of a microprocessor generates a unique set of configuration signals for configuring the universal signaling circuit into one of a plurality of standard signaling telephone circuits. The universal signaling circuit can be reconfigured either at the location of the universal channel unit or remotely.

Abstract: The present invention provides a duplex structure signal transfer point system for common channel signaling system No. 7, which includes a serial duplexed interconnection device; a duplexed network interface connected to the serial duplexed interconnection device, for performing an interconnection between signal message processing submodules; a parallel duplexed interconnection device connected to the duplexed network interface, for performing a parallel duplexed interconnection between unit level 2s and a duplexed unit level 3, wherein the duplexed unit level 3 is connected to the parallel duplexed interconnection device, for performing a protocol level 3 of a message transfer protocol in the common channel signalling system No. 7; and wherein the unit level 2s are connected to the parallel duplexed interconnection device, for performing a protocol level 2 of the message transfer protocol in the common channel signalling system No. 7.

Abstract: A crosspoint for a switching matrix constituted by enhanced P-channel and N-channel MOS transistors. Each input line conductor (Ii1 and Ii2) is connected to an input of a first differential amplifier (M3, M4), each leg of which is associated by a current mirror circuit to a first current source (M9, M10, M11) enabled by a selection input (Sij) of the crosspoint. The outputs of the first differential amplifier are connected to a second differential amplifier (M1, M2) fed by a second current source (I) common to all the crosspoints of a same column. The outputs of the second differential amplifier are connected to the pair of conductors (Oj1, Oj2) of an output column, an extremity of this column being connected to the high voltage source (Vdd) through a resistor (R).

Abstract: An illustrative method and structural arrangement for reconfiguration of switching system functional units where although the distributed control entities and the distributed switch units of a switching system are in fixed association, the association between peripheral circuits and the control and switch units is not fixed. Rather a group of peripheral circuits is connectable to at least first and second ones of the distributed switch units. When the group of peripheral circuits is connected to the first distributed switch unit, the control unit associated with the first distributed switch unit processes calls to and from the group of peripheral circuits. When the group of peripheral circuits is connected to the second distributed switch unit in response to a reconfiguration signal, the control unit associated with the second distributed switch unit processes calls to and from the group.

Abstract: In a distributed processing system having a least an originating node and a responding node connected through a communication path, the responding node comprising a plurality of processors and a memory device and where each of these processors is capable of accessing information from a corresponding database residing within the memory device, the inventive method involves: storing context information for an associated conversational transaction using a first processor situated within the responding node wherein the context information is stored at a pre-defined address in a first database residing within the memory device and associated with the first processor; producing a first message using the first processor for transmission from the responding node over the communication path to the originating node wherein the first message contains a first transaction identifier field having a value that corresponds to the pre-defined address; generating within the originating node a second message for transmission fr

Abstract: The present invention is a novel technique in the automatic control of the size of a network of remote attendants in accordance with varying incoming call traffic patterns. The remote attendants are on the public switched telephone network. The system routes incoming calls via outgoing lines to the attendants. The remote attendants can receive a "stream" of incoming calls within one outgoing call to an attendant. The remote attendants are kept on-line, that is, "off-hook" as long as the amount of waiting time between incoming calls does not exceed a maximum waiting interval set by the supervisor. When the attendant has to wait for the next incoming call for longer than a maximum waiting interval set by a supervisor, then the attendant can be automatically disconnected from the system. As call traffic increases, the system can automatically redial the remote attendant to be re-networked so as to receive another "stream" of incoming calls.

Abstract: A computer connected to an ISDN central office switch via an ISDN digital subscriber line, provides management information regarding activities of a plurality of telephone agents. The computer has shared call appearances with a number of telephone agent stations and receives shared call appearance associated messages from the switch reflecting call handling messages exchanged between the ISDN and each of the agent stations. The messages are interpreted by the computer, which generates station status information and management information such as the number of calls handled, average holding time per call, etc. The computer may be connected simultaneously to several central offices via ISDN subscriber lines and generate management information for a group of geographically separated agents, such as home telemarketing agents operating out of their individual homes and connected to different central offices.

Abstract: In a circuit arrangement for telecommunications exchanges, including PCM time division multiplex telephone exchanges with a central switching array and connected subordinate switching arrays, line terminal groups connected to a central switching network by way of link connections where each line terminal group has its own subordinate switching array and a group control unit are arranged in pairs. Within each line terminal group, there is terminal equipment for connection of outside lines on the one hand, and on the other hand link terminating circuits for the link connections to the central switching array can also be switched from the subordinate switching array of the respective line terminal group to that of the partner line terminal group. Terminal equipment and link terminating circuits as well a subordinate control units with subordinate switching arrays are equipped with three internal power supply systems and three internal clock pulse supply systems per line terminal group.

Abstract: The present invention provides a distributed architecture that includes multiple voice processing unit each designated as a home unit for a subscriber's messages. An incoming call is preferentially switched to the home VPU by a digital switching system under the control of a master control unit. If a master control unit determines that all lines to the home unit are busy or the home unit is otherwise unavailable, the master unit causes the digital system to switch the call to another or remote voice processing unit. The remote unit then handles the call by either locally storing a message or retrieving a message from the home unit storage over an internal message bus.

Abstract: A modular switching system for terminating and originating calls between central office subscriber lines and local stations provides the appearance of a business environment to an establishment served by one or more central office lines and as few as one local station. Central office lines may comprise standard subscriber lines or PBX trunks. The switching system includes one or more master switching units (102, 112) equal in number to the central office lines which are seved by the system; and a plurality of station switching subsystems (120, 130) corresponding in number to the local stations served by the switching system. Each master switching unit includes a main port for connection to a telephone answering device (TAD). A TAD comprises a manual attendant's module and/or an automatic telephone answering set to provide a recorded audio announcement (OGM) which advises a calling party how to proceed to complete a call to a particular local station served by the called central office number.

Abstract: The establishment of connections between two subscriber or trunk locations or line terminating groups (TG1 . . . TGm) in a communication switching system in which the individual subscriber or trunk locations or line terminating groups are interconnected on a ring-shaped bus arrangement (BUS 0, BUS 1) are carried out through the application of two computers (SB1 . . . SBn) one of which interacts with or serves the calling subscriber location or line terminating group while the second computer interacts with or serves the subscriber location or line terminating group being called. The transmission of communications signals between subscriber locations or line terminating groups occurs through only one of the two computers.

Abstract: A communication system for implementing remote operations between a PABX and a host computer, conforming to Open Systems Interconnect (OSI) communication protocol. Circuitry is provided in each of the PABX and host computer for generating and encoding invoke, return result, error and reject operation protocol data unit signals, for transmission between application layer entities of the PABX and host computer. In order to support invoking of asynchronous telephony operations, invoke address and server address fields are incorporated within the argument sequence and the result sequence of the invoke and return result operation protocol data unit signals, respectively.

Abstract: The switch units of a distributed switching system are connected by a central switch for advancing connections between the switch units and also by inter-switch unit trunks. To save switch unit resources, trunk services such as scanning and signaling are not provided to the inter-switch unit trunks while the central switch is available for advancing connections. When the central switch becomes unavailable for advancing connections, as detected by control units in the switch units, the inter-switch unit trunks are connected to the trunk serving circuitry of the switch units and connections are advanced between switch units over the inter-switch unit trunks. Serving the inter-switch units trunks while the central switch is unavailable requires additional switch unit resources but provides for continuity of service which would to otherwise be lost due to the unavailability of the central switch.

Abstract: A switched telephone exchange that comprises a plurality of modules designed to use a connection network of the "mesh" type to implement medium--low potential exchanges (i.e. 20,000 users) or a connection network of the centralized type--by means of adaption circuits--to implement high potential exchanges (i.e. 100,000 users). This characteristic permits the installation of medium to low capacity exchanges, which have low costs as they do not have any centralized organs, and their subsequent "conversion" into high potential exchanges when there is a large increase in user traffic. The adaption circuits comprise parallel to serial conversion facilities(IFT) for the voice signals, line facilities (ULL), signalling processing facilities (USI) for the signalling exchanged between the individual modules of the switched exchange, serial to parallel conversion facilities (IFR) for the voice signals.

Abstract: This invention relates to a method of allocating new telecommunications cells to one of a plurality of processors, and to control acceptance of new calls when in overload. The method is based on measuring the real time occupancy of each processor periodically, and allocating new calls for the following period in such a way as to attempt to make each processor's occupancy approach the average occupancy of all the processors. An overload state is detected when the average occupancy of the processors in one period exceeds a predetermined threshold, e.g., 90%. When this happens, load is shed in an amount calculated to restore the average occupancy to the threshold value over a number of periods of time. Advantageously, this method optimizes the call processing capacity of the processors.

Abstract: An integrated telecommunication system for multiple telephone line response and processing having a plurality of interface circuits, each of which is adapted to control the physical connection to a plurality of telephone line channels, control communication on a group of telephone line channels connected thereto. Each interface circuit includes a high speed interface microprocessor and a first data storage associated therewith. A first bus system interconnects the plurality of interface processor circuits to signal processor circuits. Each signal processor module includes a cross-point switch and a high speed digital signal microprocessor for analyzing the incoming signals and compressing the data therein, a second data storage associated therewith, and one or more of a plurality of telecommunication function circuits controlled thereby.

Abstract: A method provides error protection in a multiprocessor central control unit of a switching system wherein a number of central processors (CP, IOC) as well as a central memory (CMY) are connected in parallel to a central bus system (B:CMY0/B:CMY1). The processors include dual highly-synchronous parallel driven processor units (PU) --apart from a possible tolerable positive timing slip--and integral error detection circuits (V), as well as an integral local memory (LMY), in the ROM-area of which test program sections are stored for testing the respective processors (CP, IOC). Upon the detection of an error by at least one of the error detection circuits (V) of a processor (for example CPx), in the respective processor (CPx), at least if the error is not immediately correctable, the error detection circuit (V in CPx) starts isolating the respective processor (CPx) from the bus system (B:CMY).

Abstract: A method and apparatus for operating a multiprocessor control computer provides that at least one part of the central processors may be connected through switches to each half of a duplicated central bus system and through switches to each half of duplicated memory banks of a common memory. With the duplication and selectable switching, the multiprocessor control computer may be normally operated while the remainder of the computer may be connected to a special computer for modification of the normal operating program. Data already in one memory bank can also be stored in another memory bank under the same address so that after the special operating time of both memory banks, the memory banks contain the same information at the same addresses. Two specific processors are provided for operating and security functions, while the remainder of the processors carry out exchange functions.

Abstract: The present invention is a telecommunications control system for accepting a plurality of multi-purpose stations for use as attendant stations in an attendant-service complex. Calls directed to the system from originating stations are received by a line connection subsystem having a plurality of connection controllers. Each connection controller in this first plurality of connection controllers provides for cooperating with a respective one of the plurality of multi-purpose stations defining opposite ends of a call connection path. Each of these connection controllers has a controllable switch for opening the call connection path and releasing the respective multi-purpose station. The line connection subsystem further includes a second plurality of connection controllers, each connection controller provides for cooperation with a respective one of the plurality of originating stations in defining opposite ends of a call connection path.

Abstract: A circuit for a central control TDM PCM telecommunications exchange with groups of terminals connected to a switching network is disclosed in which the terminal groups which are each connected to the duplicated switching network over TDM lines and which each include a subsidiary switching network and a decentral control unit are assigned to one another in pairs. In preparation for the stand-by substitution of the central switching network and associated central processor, in the two terminal groups, assigned to one another in pairs, the subscriber lines and/or connection lines connected to the first of said terminal groups can be switched-over from the subsidiary switching network of the first terminal group to the subsidiary switching network of the partner terminal group, whereupon the decentral control unit additionally undertakes all the control functions for the decentral control unit of the first terminal group.

Abstract: In a telecommunications exchange system, consisting of a central section comprising a central switching network and a central coordination processor, and consisting of line trunk groups which are connected to the switching network via allocatable connection paths and which each comprise a subsidiary switching network and a subsidiary control unit, between the coordination processor on the one hand and each of the subsidiary control units on the other hand, a control channel exists via which the former at all times has access to each of the latter. With the start-up of an entire exchange system or only of individual line trunk groups, the coordination processor loads the subsidiary control units with items of switching orientated program information and with items of connection state data individually assigned to the individual subsidiary switching network terminals, which can consist of subscriber terminals and connection line terminals.

Abstract: A distributed digital data processing system including a host and at least one node interconnected by a communications link. In response to a boot command, the node requests its boot image from the host over the communications link. The host then provides pointers to portions of the boot image to the node. The node then retrieves the portions of the boot image identified by the pointers. These operations are repeated until node retrieves the entire boot image. By having the host supply pointers to the boot image and the node perform the retrieval operations in response to the pointers, the host is freed to perform other operations while the node is actually performing the retrieval operations.

Abstract: Enhanced telephone services are provided through a multi-service telephone switching system that contains a programmable adjunct connected to a telephone switching system. Specifically, this system includes a telephone switch that serves at least one subscriber and an adjunct connected both through one or more distinct paths, such as a number of hunt group lines, and through a datalink, such as a simplified message desk datalink, to the telephone switch. The telephone switch routes a telephone call involving this subscriber to the adjunct through an available hunt group line and provides a message to the adjunct over the datalink specifying a condition under which the call was routed. In response to this message, the adjunct takes complete control of the call substantially throughout the remainder of its duration and provides a desired enhanced service that has been pre-defined by a service script stored within the adjunct.

Abstract: The present invention relates to a technique for providing phone management (PM) services to personal computers (PCs) which are end users of a PC-only Local Area Network (LAN) by logically associating voice terminals of a separate voice and data Network, e.g., a Private Branch Exchange (PBX), with the PCs. To provide the PM services, a PM server device is provided as an interface between the PC and PBX Networks onto which are bridged appearances of the logically associated voice terminals. The PM server device includes hardware and PM server application software that perform routing and translations between (1) PM messages of the PC-LAN which use a first PM signaling protocol, and (2) PM messages of the PBX which use a second signaling protocol. Each end user PC of the PC-LAN that is logically associated with a voice terminal on a PBX network includes PM user application software that provides a PM user interface and terminates the first PM signaling protocol.

Abstract: There is disclosed a message formatting arrangement which allows messages from a central processor to be distributed over a bus to a plurality of remote processors using a single address presentation for any message without regard to the byte length of the message. Each message consists of a variable number of sub-messages each having a 3-bit qualifier which specifies the sub-message type. Each remote processor is capable of determining the length of each sub-message depending jointly upon the value of the qualifier and upon the context byte which precedes each group of sub-messages. The remote processors having the capability of skipping over a variable number of idle frames without beginning to process a new message.

Abstract: A method and apparatus for accessing data in a data base that provides for a minimum of unused storage while preserving easy expandability. A group of accessing keys are used to identify the attributes data that is being sought in a data base. In accordance with the invention, subkeys are extracted from members of the group of data accessing keys and these subkeys are advantageously rearranged to form derived accessing keys. Subkeys are densely populataed if most values of a subkey are used in most systems. One of the derived accessing keys, derived from densely populated subkeys is used for accessing the tables of data attributes that are therefore advantageously densely populated. Another derived accessing key, derived from sparsely populated subkeys, is used for accessing a sparsely populated head table. Derived keys of intermediate population density are used for accessing tables intermediate between the head tables and the tables of data attributes.

Abstract: The present invention is a telecommunications control system for accepting a plurality of multi-purpose stations for use as attendant stations in an attendant service complex to service calls directed to the system from originating stations. This system comprises a first plurality of connection controllers. Each connection controller in this first plurality of connection controllers provides for cooperating with a respective one of a plurality of multi-purpose stations in defining opposite ends of a call connection path. Each of these connection controllers has controllable switching means for opening the call connection path and releasing the respective multi-purpose station. The system provides for security against use of any of the multi-purpose stations within the attendant service complex by an unauthorized person. This system further includes a second plurality of connection controllers.

Abstract: A method and apparatus for controlling calls in in a distributed processing communications switching system. A call is assigned to any one of a plurality of call control processors. The assigned processor thereafter directs the establishment of communications connections for that call. In the exemplary embodiment, the control of a cellular mobile communications switching system, a high speed data ring is used to communicate among a switching network, the call control processors, and call assignment processors of the system. Advantageously, each of the call control processors can be fully utilized since each may be flexibly assigned to any set of communications ports or terminals. New calls to a terminal which is already on an existing call are assigned to the call control processor assigned to control the existing call. Advantageously, call data for all calls to that terminal are therefore under the control of a single processor.

Abstract: The invention provides a communications system comprising a plurality of functional units including a switching network and peripheral units, and a message switch comprising a processor and data port circuits for interfacing with respective ones of the functional units. The message switch is adapted for interconnecting any one of the functional units with any other of the functional units. The data point circuits are connected to a transaction bus internal to the message switch and are respectively addressable by a physical address contained in the header of each message to be routed. The routing header of each message comprises a physical address and a logical address. The message switch also comprises a mapper circuit addressable by a predetermined physical address for translating the logical address to a physical address and for replacing the predetermined physical address with the translated physical address while the message data is retained in a source port message buffer.

Abstract: A method of distributing the processing load among components of a multiprocessor system, such as a switching system, avoids having two different processors (CP9) simultaneously handling different jobs for the same connection. A plurality of central processors (BP,CP,IOC) and a central main memory (CMY) are connected in parallel to a central bus system (B:CMY). As soon as they are free, each processor fetches a job for handling a switching task from a job registering means (AR), and then fetches data about the appertaining connections from the main memory (CMY). Each processor stores a protective code corresponding to its address at a location associated with the job as soon as and as long as it is handling the job. However, it does not store its code in case a different processor (CP9) has already entered its protective code there. Every central processor has its own job memory (AS).

Abstract: A circuit arrangement for telecommunication installations, in particular, telephone exchange installations is disclosed in which type information is sent ahead of each communication to be transmitted. In bidirectional communication transmission with different possible communication types, type information announcing the respective communication type is sent ahead. In the receiving equipment the beginning of the arrival of type information is recognized and immediately, that is, almost simultaneously, an assortment of type-specific message corresponding to each of the possible communication types is transmitted in the opposite direction, of which each indicates the readiness or non-readiness for receiving a communication of the respective type.

Abstract: In an electronic telephone exchange and a method of connecting ports of the exchange, highways connected to a time switch is divided into extension highways and office line highways and thus highways are connected to discrete terminals of a connector formed with extension interface circuits and office line interface circuits. Input and output terminals are provided at positions corresponding to the discrete terminals so as to connect the extension interface circuits and the office line interface circuits to corresponding highways through the input and output terminals thereby effecting exchange of communication signals through the highways.

Abstract: A line condition data collecting system for a telephone exchange includes an image memory in a central processing unit which stores line condition data to reduce the amount of time the central controller in the central processing unit waits for the line condition data. A signal receiving memory in the telephone exchange stores the line condition data and is sequentially accessed by an image memory controller autonomously from the central controller in the central processing unit. When the central controller requires line condition data, the image memory is checked and if the line condition data stored therein is valid, it is supplied to the central controller. If the line condition data in the image memory is invalid, a conventional access request is made to the signal receiving memory, but this occurs less frequently than in a conventional system.

Abstract: A distributed control switching system where calls, to and from a directory number that is shared by a key-system group of terminals, are processed cooperatiavely by multiple, distributed control units but in response to busy/idle data for the shared directory number stored advantageously by only a lead one of the control units. In addition to processing a call, for example to complete a connection to or from one of the terminals of the group, the multiple control units also cooperate as the call progresses to inform each of the group terminals of the call status as though the terminals were connected in parallel to a central office line as in an electromechanical key system.

Abstract: A method and apparatus is described for providing extended subscriber features, e.g., equal access, to otherwise non-conforming central offices of a telephone switching system. According to the invention, a register module is interposed between the subscriber line and an input of the central office for intercepting digits from the subscriber line intended for the central office and for receiving subscriber information from the central office identifying the subscriber line. The register module includes a memory having a plurality of address locations and a control circuit for analyzing the intercepted digits to determine whether processing of the subscriber call requires an extended subscriber feature. If so, the intercepted digits are processed to generate a coded signal, the coded signal including the address location where the stored digits and the subscriber information resides in the memory.

Abstract: The present invention relates to a communication system which includes a plurality of N communication links coupled to a central office. A plurality of N-1 user devices are coupled to N-1 of the N communication links with each of the N-1 user devices including a memory for storing a translation table relating a device identification code for each of the N-1 user devices to a directory code associated with each of the communication links. An input is situated at each of the N-1 user devices, for allowing a user to supply a device identification code of another user device to be called. A translating circuit is situated at each of the N-1 user devices, for translating the device identification code to it's associated directory code responsive to the input of a device identification code by the user by reading the translation table.

Abstract: In a distributed processing telecommunication switching system comprising a plurality of switching modules, the individual modules control substantially all telephone call control processing actions, including the selection of an available port of a multiport hunt group, without requiring the assistance of a central processor. Each module includes a processor, a plurality of ports connected to customer lines and interoffice trunks, a plurality of outlets for setting up intermodule connections, and a switching network for interconnecting ports and outlets within a module. The module processors communicate with each other by a high speed common data communication facility connected to all processors. This data communication facility is used for communicating intermodule call control messages and port availability data to allow port hunts to be accomplished without using a central processor.

Abstract: A multi-link communication system includes a number of stations and interconnecting audio links under the control of a central computer. Each station is addressable by the computer for connecting selected stations to a selected audio link for establishing audio communication between stations. Each station has at least one corresponding access circuit for establishing an audio connection to a selected or preassigned link, and the connection is maintained by a corresponding memory circuit that is addressable by the computer. A group of output lines from the computer are used as select inputs to an analog multiplexer connecting a bidirectional control line to the selected access circuit for connecting or disconnecting the corresponding station and also for receiving connect or disconnect requests from the corresponding station. In a particular embodiment, the stations include multi-link dial and dialless telephones, single-link dialless telephones, and intercom speakers in an automatic private branch exchange.

Abstract: A private branch exchange includes a common control module and a plurality of line/trunk modules. A plurality of line/trunk cards are contained in a respective line/trunk module and terminals of the same type, such as digital telephones or standard telephones, are connected to the respective cards. For control data transmission, the line/trunk cards of each of the line/trunk modules are coupled to the common control module via a common control data highway. Each line/trunk card includes, for terminal control, a central processor unit (CPU) and random access memory (RAM) for storing a control program in accordance with the type of terminals. To the line/trunk card is allocated an individual address and group address representing a group of line/trunk cards to which are connected terminals of the same type.