Abstract: A packet switching arrangement for receiving packets including broadcast addresses and connecting representations of the received packets to any combination of output ports specified in the address is disclosed. The packet routing units of the network both generate packet representations and selectively connect the representations to downstream routing units or network outputs. Packets for use with the network comprise an address portion encoded in a broadcast format or in a shorter point-to-point format and an address type character identifying the type of address in the address portion. The nodes of the network respond to the address type character of a received packet by selecting the appropriate decoding format for the packet address portion. A packet select unit decodes the address portion in accordance with the selected decoding format and selectively connects the packet to the network outputs.

Abstract: Flow control of data packets through a packet switching network to reduce congestion is controlled by an adaptive preferential permit packet (APP) processing from an orginating data terminal through each packet switch node of the network to a destination data terminal. APP requires less buffer storage capacity at each switch node, and enables data packets to enter the network only when there is a permit packet indication that the data packets are likely to reach, and be accepted by, their destination. The permit packet is sent node to node (16-19, 25, 28) prior to a transmission of a bulk of data packets. Each node is equipped to queue buffer (12-15, 21-24) a permit packet on a preferential basis ahead of data packets. The node discards the permit packet if the number of packets awaiting transmission from that node exceeds a prescribed threshold. This is throttling process, since the originating port times out and resends a permit packet if a permit-return packet is not received within a predetermined time.

Abstract: A microcomputer controlled circuit arrangement for sensing fire and burglar alarms in the presence of undesired fault conditions, such as opens or shorts, on monitored communication lines. The arrangement includes transistor-resistor sensing circuitry which is shared by a plurality of monitored communication lines, each of which comprises a first pair of conductors connected to a first contact of an alarm sensor and a second pair of conductors connected to a second alarm sensor contact. The sensing circuitry is connected through a multiplexer to each one of the lines one at a time under control of the microcomputer to detect any fault thereon and any alarm provided by the sensor contacts. The sensing circuitry is responsive to impedance conditions on the four conductors furnishing a plurality of output voltages which are examined by comparators that, in turn, generate combinational logic voltages signifying the alarm-fault state of a monitored line.

Abstract: A hardware and algorithm synchronizing arrangement comprising a subsystem synchronization interface circuit is disclosed for controlling the testing of multiple interconnected processors. The circuit permits the pausing of one processor to cause the other interconnected processors to pause as well. The circuit enables a synchronized resumption of the interconnected processors operations. Logic circuitry and signaling interconnections control individual and multiple simultaneous pauses and full duplex operation of a plurality of central control facilities.

Abstract: A communication method and packet switching system in which packets comprising logical addresses and voice/data information are communicated through the system by packet switching networks which are interconnected by high-speed digital trunks with each of the latter being directly terminated on both ends by trunk controllers. During initial call setup of a particular call, central processors associated with each network in the desired route store the necessary logical to physical address information in the controllers which perform all logical to physical address translations on packets of the call. Each network comprises stages of switching nodes which are responsive to the physical address associated with a packet by a controller to communicate this packet to a designated subsequent node. The nodes provide for variable packet buffering, packet address rotation techniques, and intranode and internode signaling protocols.

Abstract: A communication method and packet switching system in which packets comprising logical addresses and voice/data information are communicated through the system by packet switching networks which are interconnected by high-speed digital trunks with each of the latter being directly terminated on both ends by trunk controllers. During initial call setup of a particular call, central processors associated with each network in the desired route store the necessary logical to physical address information in the controllers which perform all logical to physical address translations on packets of the call. Each network comprises stages of switching nodes which are responsive to the physical address associated with a packet by a controller to communicate this packet to a designated subsequent node. The nodes provide for variable packet buffering, packet address rotation techniques, and intranode and internode signaling protocols.

Abstract: A control word generation method and a structural arrangement of a control word source for use in a time division switching system for serving multirate data stations. The control word source includes a first memory that stores a first plurality of path-definition words defining communication paths for nonsubrate channels and a plurality of storage reference words. The control word source also includes a second memory that stores a second plurality of path-definition words defining communication paths for subrate channels. The first memory is read sequentially and control words are derived from each of the read path-definition words. A location generator responds to timing pulses generated by a network clock and to each of the plurality of read storage reference words by generating a location signal defining a storage location of the second memory. The second memory is read in response to this location signal and a control word is derived from the path-definition word thus read.

Abstract: A communication method and switching system in which voice and data signals are communicated through the system by a programmed controlled switching processor. The switching processor reads these signals from an input memory where they were transferred from telephone stations and data terminals by a scanner. The voice and data signals are transmitted to telephone stations and data terminals by the switching processor storing these signals in an output memory from which they are retransmitted by a distributor to the telephone stations and data terminals. The intelligent processor reads data signals from the input memory and assembles these signals into data packets which are temporarily stored in the data memory. Subsequently, the intelligent processor transmits these data packets by storing the data signals in the output memory.

Abstract: A communication method and wideband switching network in which wideband signals are communicated through the network with minimal crosstalk between the wideband signals. Minimal crosstalk is achieved by a network architecture and by grounding both ends of all unused video paths. Each stage of the network has a plurality of switching input and output arrays. Each input array has one input terminal and each output array has one output terminal. Output and input terminals of the input and output arrays, respectively, are interconnected to form a nonblocking stage. Each array is one integrated circuit (IC), and crosstalk is reduced by allowing only one wideband signal to be present in an IC at any one time and by grounding all unused output and inputs in the arrays.

Abstract: A digital multifrequency (MF) receiver for use in telephone switching systems is disclosed. Input MF signals in a PCM (pulse code modulation) format are detected by simultaneously computing the convolution of the digital input signal with discrete portions of the impulse response of a narrow bandpass filter. The convolution functions are performed by multiplication or log addition circuitry with adder and accumulator apparatus. A 10-millisecond PCM sample comprising 80 discrete samples of an input signal is simultaneously applied to four convolution circuits, each of which applies a different portion of the impulse response of a bandpass filter, also comprising 80 samples, to the input signal as it is received. The complete impulse response signals are applied to the convolution circuits but out-of-phase with impulse response signals as applied to the remainder of the convolution circuits. When four such circuits are used, a quadrature is established and the amplitude of the desired signal is computed at 2.

Abstract: Each power diode in an ORed direct-current power distribution system has connected thereacross, between the respective load and source terminals of the power diode, a series connection of respective first and second light-emitting diodes (LEDs) with the LEDs being similarly poled with respect to their common connection, with the power diode and the first LED being oppositely poled with respect to the power diode load terminal, with a resistance connected between the common LED connection and the power supply return. A resistance-LED arrangement is also provided in parallel with each nonindicating fuse. The ON (fully conducting--showing detectable visible light) and OFF (not fully conducting--not showing detectable visible light) patterns of the LEDs, both under the condition of normal voltage on each power bus and under the condition where the relative voltage between buses is varied slightly, can be used for circuit failure diagnostics.

Abstract: A time division multiplex loop communication system for voice and data is disclosed with multiaccess time slot seizure and data transmission capability from all station nodes without changing the idle, nonreserved, status of the seized time slot. A method and station node apparatus sends bursty data packets from a node when a time slot is not busy serving a longer duration voice telephone call. The apparatus eliminates the need for inefficient time slot request, acknowledgement and reservation procedures which require several TDM frames to complete and which are typically longer in duration than the bursty data packet to be transmitted. All stations have access to all time slots for bursty data transmission under control of loop interface circuitry which statistically ensures the successful data transmission from all sending nodes.

Abstract: A method is disclosed for automatically detecting a trunk that is likely to be defective even though it passes operational tests incident to switching it into service. In a telephone system, such a trunk might, for example, be so noisy or ineffective for transmission that customers cannot communicate over that trunk. Resultingly, the trunk is likely to handle a much higher than normal number of calls with short holding times since the customers quickly discover that they cannot communicate and terminate the calls. The method is implemented via telephone call processing, memory lists, and a program routine integrated into the call disconnect sequences. It allows such defective trunks to be identified by the steps of: detecting all calls with short holding times, successively processing trunk identities which have a repetition of such short holding-time calls, and alerting the maintenance force when such trunks have been processed through several memory lists.

Abstract: A method is disclosed of using the public switched telephone network, including the CCIS (Common Channel Interoffice Signaling) system, to provide nationwide personal locator telephone service for called subscribers. In accordance with the service, a calling party may reach a called subscriber wherever the subscriber may be located by merely keying from a standard push-button telephone set a personal number unique to the subscriber. A telephone office having access to CCIS sends the number to a centralized data base. A telephone number at which the subscriber is located is returned to the access office, and the call is automatically completed to the telephone number. Other information may be returned to the access office to provide enhanced features. Such features include called subscriber unavailability announcements to the calling party, storage of a caller's telephone number, automatic call-back by the subscriber, and paging of the subscriber.

Abstract: A method is disclosed of processing telephone calls with customized services in a telephone system with CCIS (Common Channel Interoffice Signaling) in which all offices are not required to have CCIS capability. The entitlement of a call to customized service is verified by transmitting from an action control point (TSPS 13) via CCIS (15, 16, 17, 19) a data message identifying calling and called entities. The message is transmitted to a data processing facility (19) associated with the terminating office (14). If the call is so entitled, a fictitious number (44) is assigned to the call and returned to the action control point. The fictitious number is stored at the data processing facility with the called entity identification. The call is completed from the action control point using the fictitious number. Upon receipt of the call directed to the fictitious number, the terminating office obtains the identity of the called entity from storage and completes the call with customized service.

Abstract: A method is disclosed illustratively in an emergency call handling system for automatically providing the identity of a calling station to a call terminating facility, such as a call answering bureau. In response to an appropriate call, a data base is accessed where a fictitious telephone number is temporarily assigned to the call. The calling station identity is stored at the data base with the assigned number. The call is completed over conventional facilities to the call terminating facility using the assigned number. In response to the call directed to the fictitious number, the data base is accessed with the fictitious number to obtain the calling station's identity.

Abstract: A network control circuit which allows time division switching systems of different sizes to operate with the same port circuit is disclosed. The time division switching systems utilize a port circuit with a ring counter which controls connection of the circuit to a system bus for establishing telecommunications paths. Each port circuit is provided with a ring counter which has one stage per time slot for the largest size switching system. A network control circuit generates commands which control circuitry associated with the ring counter to write bits into stages of the ring counter causing connection during appropriate time slots. When the port circuit is used with the largest sized switching system, one bit is written into the counter causing one connection per system cycle. In order to use the port circuit with switching systems that have fewer time slots, the network control generates commands to write two or more bits into the ring counter causing the ring counter to appear as if it had fewer stages.

Abstract: In a cable restoration system neon devices and light-emitting diodes are utilized to identify corresponding conductors in a broken cable by an arrangement that does not require the assistance of a lineman at the central office. The apparatus identifies a central office line by means of a neon device and ringing bridge arrangement which replaces the neon indicating bulbs used in prior art systems. After identifying a customer line at a cable break by using indicating devices in a conventional manner, a maintenance man at the break location dials the central office over a spare pair. When ringing is applied to the desired central office line, a glow discharge occurs in the neon device, which discharge heats a bi-metallic strip and causes the strip to move and establish a metallic short across the line. The short trips ringing extinguishing the discharge. The bi-metallic strip cools and the short is removed from the line.

Abstract: Ringing loop-current detectors are shared by groups of telephone set line circuits. A time division switching system is disclosed having a plurality of telephone line circuits and common control circuits for switching calls over a time division communication bus. Ringing loop current detectors are shared by groups of the line circuits for detecting call answer signals during active ringing on a call and for controlling the line circuits to interrupt, or trip, the ringing upon a called party answer. Each group of the line circuits is permanently connected to a ringing current supply via an individual one of the loop current detectors. Each line circuit includes ringing control circuitry operated and released by the common control circuits for connecting ringing current to a called line during an active ringing interval and for disconnecting it during a silent interval of the ringing cycle.

Abstract: Automatic coin telephone station and central office facilities are disclosed for deriving data on the exact numbers and types of coins deposited during initial and overtime periods. Each station is equipped with nickel, dime and quarter binary counter memories and with flip-flop and logic gating control circuitry which is responsive to interrogate, coin collect and return signals received from the central office for sequentially interrogating the memories and frequency shift keying the stored information to the central office. A coin processor and memory, preference and connector, interrogate tone generator, and detectors are integrated into the central office switching system.