Abstract: A synchronization circuit for use in a bridge connecting an emitter bus operating on an emitter clock frequency to a receiver bus operating on a receiver clock frequency is provided. The synchronization circuit is responsive to a control signal generated by memory status means coupled to a memory which temporarily stores data transmitted from the emitter bus to the receiver bus. The control signal representative of the status of the memory is reflecting asynchronous read and write operations within the memory. The resultant signal output from the synchronization circuit is a one clock synchronized signal such that rising and falling transitions are synchronized to the receiver bus clock frequency.

Abstract: A method and apparatus for distribution of electrical signals in a circuit board. Specifically, the circuit board comprises a printed circuit board and a plurality of connectors attached to the circuit board for receiving components such as logic cards which each require a clock input. Each of the connectors may have a plurality of pins. A plurality of electrical conductors associated with the circuit board electrically couple a corresponding pin for a clock input from each connector to a common point by individual one of the plurality of electrical conductors. Each of the plurality of electrical conductors are so arranged that to have approximately the same length.

Abstract: A system and method of controlling the operation of a storage device (a semiconductor latch in its preferred embodiment) to reduce the power consumed by the storage device. The system uses a split clock signal to control the operation of the latch, with an early enable signal and a late enable signal being operable to turn the latch on when needed and to turn it off when it is not needed. More particularly, the present invention logically generates clocking control signals for the latch using the early enable signal and the late enable signal to control the operation of the latch and to reduce power consumption and allow for an increased period of time to make a decision whether to turn off the early enable signal.

Abstract: A communication interface and a design method therefor simultaneously shape a synthesized terminating impedance matching different frequency bands on different connecting communication circuits and a receive path response to prevent frequency roll-off. In some cases, for example based on specified network requirements in a particular country, the terminating impedance presented by the interface must have different frequency characteristics for received signals in different bands of frequencies. A transconductance amplifier and feedback loop provide the terminating impedance for signals received from the communication circuit and serve as a source impedance for signals transmitted by the interface to the telephone line. Signals with different frequencies will generally be received from the telephone line. These different characteristics are realized using different filter networks in the feedback loop.

Abstract: A video frame transmitter for transmitting video frame packets into a communications network includes a traffic smoother for adjusting video frame packet transmission rates; a token bucket for controlling video frame packet entry into the network; and a transmission rate attenuator for adjusting video frame packet transmission rates. The traffic smoother adjusts transmission rates from a video frame source to meet a transmission delay bound of the frame source. Video frame packet transmission rates are attenuated to conform with the state of the token bucket in order to maintain a high percentage of high priority video frame packets entering the network. The rate attenuator allows the traffic smoother and token bucket to work together to reduce the number of low priority packets entering the network.

Abstract: A method and an apparatus to calculate the CRC-32 (Cyclic Redundancy Checking) codes of a bit stream while improving the process time and simple to implement. The CRC-32 calculation is used for FCS (Frame Check Sequence) error checking code of bit stream messages sent over a fixed size packet networks when the high speeds require reducing the processing time in the network access nodes. This CRC-32 calculation is also used for FCS checking in the network equipment receiving said packetized bit stream messages. This invention applies particularly to messages conveyed via AAL5 type cells in ATM networks. The CRC-32 per byte computation of the prior art is replaced by a simple per byte CRC-R computation followed by a one pass CRC-32 computation of the R bit stream, result of the CRC-R computation.

Abstract: Queue processing mechanism in which queued messages are processed based on combination of queue delay and queue priority. A scheduler dequeues the highest priority non-empty Microcode Input Queue (MIQ) to serve the queued messages. If there is no critical queue, meaning that the maximum aging of one or more queues has not been reached, the critical state is not entered. A static weight for each queue is then tested to determine if there is still a message to be processed from the corresponding MIQ. Messages are dequeued from the same MIQ until the static weight is reached. The next MIQ is then served etc., until the queue of the lowest priority level is served. If the critical phase is entered, the status of the normal state is stored for later return and the MIQs in critical state are dequeued according to their critical weights. If other MIQs appear to be critical, they are served in the order of their critical priorities (or weights).

Abstract: A telephone switching center is controlled by a server computer (22) utilizing a Hypertext Transfer Protocol (HTTP), which is connected to a World Wide Web (WWW) network. It is proposed to provide, between a HTTP server (22) and the switching system (23), a control program (20) which enables control of a CTI application by the HTTP server (22). The proposed CTI application (20) provides an interface which uses a Universal Resource Locator (URL) specifying high level communicating functions which are independent of the respective interface (21) to the switching system or the CTI server.

Abstract: A communication interface and a design method therefor provide a synthesized terminating impedance matching different frequency bands on a communication circuit. In some cases, for example based on specified network requirements in a particular country, the terminating impedance presented by the interface must have different frequency characteristics for received signals in different bands of frequencies. A transconductance amplifier and feedback loop provide the terminating impedance for signals received from the communication circuit and serves as a source impedance for signals transmitted by the interface to the telephone line. Signals with different frequencies will generally be received from the telephone line. These different characteristics are realized using different filter networks in the feedback loop. Each network provides a matching terminating impedance to the communication circuit according to the frequency band applied to the circuit.

Abstract: A method is implemented to enable networks employing source-route bridging to participate in route switched, Asynchronous Transfer Mode (ATM), networks. Such source-routed networks, for example, Token-Ring LANs, incorporate an end-to-end route description in the data packets transmitted by the source station. The end-to-end route description is contained in a Route Information Field (RIF). The method implemented herein associates an RIF with the ATM address corresponding to a destination station. This permits the source-route bridged network to exploit the efficiencies of layer-2 connections and the high-speed switching characteristics of the ATM network.

Abstract: Asynchronous Transfer Mode (ATM) network Quality of Service (QoS) guarantees are extended to Token Ring LAN stations. A LAN station originating a request for a connection through an ATM network to either a remote ATM station or a remote LAN station sends a frame having an encoded priority value to a LAN/ATM interface device. The device maps the priority value to one of the standard ATM traffic classes; namely, CBR, VBR, ABR and UBR. The LAN/ATM interface device attempts to set up a connection through the ATM network conforming to the mapped class or QoS. If the connection destination is another LAN station, a destination LAN/ATM interface device attempts to set up the final ATM-LAN phase of the connection.

Abstract: Information providers act as sources of information consisting of a plurality of variable length messages and issue control packets, enabling/disabling packets and data packets. Each data receiver has a unique address as a permanent attribute. The enabling/disabling packets selectively enable or disable a specific data receiver or a specific group of data receivers. Therefore to avoid that the loss of the enabling/disabling packet leads to the loss of the corresponding whole set of packets, each data receiver stores data packets for later use in the re-establishment of the entire set of transmission packets. However, only data packets provided by any FRIEND information provider (i.e. information provider from which the data receiver is authorized to receive information on a selective basis) are managed by the data receiver.

Abstract: The invention relates to a switching device which transports data packets from input ports to selected output ports. The payload of the packets is stored in a storage means. A switching means is arranged which has more switch outputs than switch inputs and which switches sequentially between one switch input and several switch outputs while storing the payloads. Furthermore, the invention relates to a storing method which uses switching means to store payloads in a sequential order and to a switching apparatus comprising several switching devices. Furthermore, the invention relates to systems using the switching device as a scaleable module.

Abstract: An anti-surveillance device for keyboards, particularly for the keyboards of cash dispensing machines or electronic cash devices, in order to prevent unwanted viewing of the keyboard from the side. The invention comprises at least one anti-surveillance filter (3), preferably exhibiting a lamellar or lamellar-grid structure, where only the lamellae consist of opaque material and where the anti-surveillance filter (3) is disposed above the keyboard (5).

Abstract: A method and system are provided for enabling simultaneous cut-through and store-and-forward transmission of frames in high speed network devices. A Buffer Parameter Vector chains multiple frame buffers together. Frame Parameter Vectors created for each unique version of a frame are used to manage frames as they flow through the network device. Cut-through/store-and-forward decision logic determines whether frames can be transmitted by cut-through or store-and-forward. Multiple unique frames or copies of a frame that are to be transmitted store-and-forward have their Frame Parameter Vectors chained together by pointers. The cut-through/store-and-forward decision logic steps through the chain of Frame Parameter Vectors resulting in the frames associated with each Frame Parameter Vector being transmitted.

Abstract: A method for controlling communications between link stations locally attached to a router and served by the same single thread Logical Link Control (LLC) stack. LLC generates a table for identifying all of the locally attached link stations served by the LLC and upon request from a locally attached source link station to establish a session with another destination link station, the LLC examines the table to determine if the destination link station is locally attached and served by it. If the destination link station is locally attached and served by the same LLC, the LLC deletes all standard LLC protocols normally used to inform a partner LLC concerning the state of the communication.

Abstract: A data transmission method and apparatus, by which, when coded and compressed image data are transmitted in the form of packet composed of a fixed bit length, image data can be desirably transmitted, even though a band width given to image data is dynamically changed. The data transmission method mixes coded and compressed voice data and coded and compressed image data together, and transmits resultant data to a network in the form of packet composed of a fixed bit length.

Abstract: Data communications apparatus is described having a duplex SC connector comprising two parallel connection assemblies integrated into a single component for connecting two optical fiber cables with two optical fiber transceivers and a shielding structure arranged to, at least in part, reduce electromagnetic emissions from the optical fiber transceivers, characterised by a conductive member extending between the parallel connection assemblies, the conductive member being in conductive contact with the shielding structure at both sides of the duplex connector.

Abstract: A control network and a configuration method, therefor, is described wherein sensor and actuator elements are connected to configurable converters. These converters perform (in addition to any other converters which might be necessary to convert physical signals into network data, e.g. A/D conversion etc.) a conversion of sensor data in accordance with conditions provided externally. In a preferred embodiment the range of possible sensor data is compressed to one bit for each condition referring to this sensor element. The conversion is done prior to the transmission of that sensor data to other nodes, thereby reducing the network traffic significantly. The traffic is further reduced as each sensor elements transmits its current state only when the logical value of this state has changed. The described network is especially suitable for low bandwidth media with a high noise level, e.g., power lines and infrared radiation.

Abstract: An information handling apparatus and screen display control method for appropriately controlling a screen display when a changed output destination for a display signal is selected from among a plurality of display devices having different resolutions.