Abstract: A home automation system comprises a number of sub-systems for controlling various aspects of a house, such as a security sub-system, an HVAC sub-system, a lighting control sub-system, and an entertainment sub-system. The network comprises a host computer connected through a host interface to a plurality of nodes. The network is in a free form topology and employ asynchronous communication. The host computer polls each node on the network to determine system configuration and to perform a diagnostic check on the system. The messages that are transmitted between the nodes are comprised of a source address, a destination address that uniquely identifies the location of each piece of hardware on the system, a message type field, and a data length segment. Each hardware device has a mirror image software object in the host computer to which messages are directed. The user interfaces for the various sub-systems share a common interfacing method whereby use of the system is greatly simplified.

Abstract: In a data processing system formed of a plurality of nodes each connected to networks, each node operates either as a manager or as an agent. The manager supervises information included in the agents which are managed by the manager itself. A super manager is connected to the network for recognizing the node which operates as the manager which performs double supervision of the information in the agents with the manager. The super manager has a receiving unit for receiving information to be supervised by the node which operates as the manager, a detecting unit for detecting a failure of the node which operates as the manager, and a supervising unit for specifying information to be supervised by the faulty manager in accordance with information received by the receiving unit when the detecting unit detects the failure. The super manager supervises the object information to be supervised instead of the manager when the manager fails.

Abstract: A system for authenticating a user located at a requesting node to a resource such as a host application located at an authenticating node using one-time passwords that change pseudorandomly with each request for authentication. At the requesting node a non-time-dependent value is generated from nonsecret information identifying the user and the host application, using a secret encryption key shared with the authenticating node. The non-time-dependent value is combined with a time-dependent value to generate a composite value that is encrypted to produce an authentication parameter. The authentication parameter is reversibly transformed into an alphanumeric character string that is transmitted as a one-time password to the authenticating node. At the authenticating node the received password is transformed back into the corresponding authentication parameter, which is decrypted to regenerate the composite value. The non-time-dependent value is replicated at the authenticating node using the same nonsecret information and encryption key shared with the requesting node. The locally generated non-time-dependent value is combined with the regenerated composite value to regenerate the time-dependent value. The user is authenticated if the regenerated time-dependent value is within a predetermined range of a time-dependent value that is locally generated at the authenticating node.

Abstract: Object-oriented client-server facility (CSF) and networking service facility (NSF) interfaces implement communication between application programs residing in client and server nodes at a distributed services network. The CSF interface includes remote procedure call (RPC) objects for invoking and responding to service requests at the nodes and application programming interface (API) objects for transporting those requests between the nodes. However, the API objects only provide communication transports within a node. Accordingly, the API and RPC objects interact with dynamically-configurable protocol stacks within the NSF interfaces to complete the transport mechanism needed by an application program on the client node when accessing services on a remote server node.

Abstract: An interactive video system employs Motion Picture Expert Group (MPEG) video compression to transfer images from a remote server to a television. The images correspond to dialog frames in a graphical user interface. During an authoring process, the dialog frames are created by first creating a background image and then adding foreground elements, such as buttons. A set of MPEG video frames is created by encoding the resulting images according to the MPEG algorithm. The MPEG video frames are delivered to the television in sequence, where an MPEG decoder uses them to reconstruct the dialog images that are subsequently displayed. The system also contains an object-oriented database that maintains the necessary MPEG file ordering and also carries out menu navigation commands received from the user. The object classes include NODE, BRANCH, and DISPLAY. NODE objects correspond to dialog frames, and BRANCH objects correspond to user-selectable features such as buttons. DISPLAY objects correspond to either complete or partial images, as described in corresponding MPEG files. Data and function elements within the objects allow the system to track the user's navigation commands, and to highlight and unhighlight selectable features as navigation proceeds in order to provide visual feedback to the user.

Abstract: Path layer technologies will play a key role in the development of a powerful and failure resilient B-ISDN. So far, they have been based on electrical technologies. This paper highlights WDM/FDM techniques and demonstrates that optical paths can greatly enhance the path layer capability and, therefore, the network performance. It is also shown that effective network failure restoration can be achieved with optical paths. The applicability of the wavelength path (WP) technique to global area networks is revealed by comparing different optical path realization techniques. WPs are applied to the national backbone network example to evaluate the required number of wavelengths, and to identify optical cross-connect node requirements. It then proposes a new optical path concept: the virtual wavelength path (VWP). In the VWP scheme, wavelengths are assigned on a link-by-link basis. In other words, the wavelength assigned to a wavelength path has only local significance. Significant benefits of the VWP such as the simplified path accommodation design within a transmission facility network and the reduced number of wavelengths needed, are elucidated. An optical cross-connect node architecture that enables the VWPs is also proposed. The architecture allows the VWP concept to be realized with commercially available optical technologies. The optical path layer concept proposed exploits and consolidates the layered transport network architecture and optical technologies, and will open up new opportunities for creating a B-ISDN that is bandwidth abundant and has a high degree of integrity. >

Abstract: An apparatus and method for network node identification and network configuration. Prior to physical installation, a first node of a network is communicated with by a dedicated apparatus wherein the first node is requested to transmit a first unique identifier for the node to the apparatus. The apparatus then stores the first unique identifier received from the first node, and generates the first unique identifier on a medium (e.g. a label). This first unique identifier may be represented on the medium in a coded format. In one embodiment, the coded format is a code 39 bar code and the medium is an adhesive label. The labels obtained from querying the nodes prior to physical installation may be affixed to a floor plan of a networking system during installation, indicating each node's physical placement in that system. Each of the identifiers may then later be automatically read by an automated apparatus for network configuration. This apparatus (e.g. a general purpose programmed computer system) displays a physical layout of the networking system. This apparatus automatically reads the labels comprising the unique identifiers of nodes and assigns the identifiers to the respective positions on the physical layout of the networking system according to the position of the nodes on the diagram. Each of the codes, in a preferred embodiment, are associated with the physical placement of node in the networking system by a floor plan displayed on a display device (e.g. a CRT). Then, nodes in the system may be configured (by grouping, network address assignment, etc. . . . ) to communicate with other nodes in the network via the communication medium which is represented on the floor plan.

Abstract: Packets of data, some of which may carry a timestamp value, are transmitted through an Asynchronous Transfer Mode (ATM) network. Prior to transmission, each packet of data is encapsulated in a respective convergence sublayer protocol data unit (CS-PDU) having a header portion and a payload portion. The header portion of each CS-PDU contains a time correction indicator (TCI), which indicates whether the CS-PDU carries a packet of data having a timestamp value that may require correction after the CS-PDU passes through the network, and a time reference correction (TRC) field. Each CS-PDU is then segmented into a plurality of successive segments; a first one of the segments of each CS-PDU contains the CS-PDU header. Each segment is then inserted into the payload section of a respective ATM cell for transmission through the network. At each node in the network, cells are examined to determine if they contain a CS-PDU header. If a cell contains a CS-PDU header, any variable delays imposed upon that cell as it passed through the node are measured and added to the TRC field in the CS-PDU header prior to sending the cell to the next node. At a destination node, the accumulated TRC value may be added to the time stamp value of the packet carried in the CS-PDU in order to compensate for the variable delays imposed upon that packet as the cells carrying the packet traversed the network.

Abstract: In a local network connected to other networks which employ an Internet Protocol, and wherein the local network includes nodes which cannot monitor all other nodes in the local network, an Internet Protocol address of a target node in the local network is translated at a gateway node in the local network to a network-specific local address of the target node without the use of broadcasting. The network specific local address of the target node is the address which is usable within the local network for forwarding a packet to the target node.

Abstract: Disclosed is a server architecture for connecting to a plurality of remote client computers each seeking access to applications resident on the server. The architecture provides (1) a reliable, single point of entry for client users that enforces security and recovers immediately from failures; (2) connection management that monitors the user's level of online activity, terminating inactive connections both to save system resources and to limit unnecessary connection charges to the user; (3) application management that spreads users optimally among active application instances, maintaining a pool of available applications, initiating new instances when the pool is low, and which records a user's utilization of different applications for billing purposes; (4) system integrity, which is achieved through division of transaction-management responsibility among the various interrelated components of the invention; and (5) continuous, uninterrupted operation. The invention distributes tasks to different functional modules in a manner that promotes efficiency and ready accommodation of large numbers of users without processing delays.

Abstract: A theatrical lighting control network is disclosed which incorporates a local area network for communication among a number of node controllers and control consoles or devices employed in establishing lighting or other effects levels in a theater, film production stage or other performance environment. Use of the network eliminates the requirements for the majority of hardwiring for interconnection of consoles and other controller or monitoring devices to effects controller racks and provides great flexibility in location and relocation of various components of the system.

Abstract: In a connection-oriented communications network, a source node selects one of first and second routing mode flags and a first route to a destination node in response to a connection request, and establishes a connection to a first intermediate node located along the first route. The first intermediate node is responsive to the first flag for extending the connection along the first route if there is an acceptable link in the first route. If there is no acceptable link, it finds a first route section therefrom to the destination node and extends the connection along the first route section if a total cost of links from the source node to the destination node using the first route section is less than a cost threshold, or cranks the connection back to an upstream node if there is none of such route sections. The upstream node then finds a second route section if a total cost of links from the source node to the destination node using the second route section is less than the cost threshold and extends the connection from the upstream node to a second intermediate node along the second route section, or clears the connection if there is none of the such route sections. On clearing the connection, the source node may or may not select the other flag. In either case, it selects a second, alternate route to the destination node and establishes a connection to a third intermediate node along the second route. If the flag is set to the first mode, the third intermediate node operates in the same manner as the first intermediate node does, and if the flag is set to the second mode, it extends the connection along the second route if there is an acceptable link. Otherwise, it clears the connection if there is no acceptable link and communicates this fact to the source node.

Abstract: A distributed digital communications network (10) has an originating node (12) and a multiplicity of destination nodes (18, 20, 22, 24, 26). The various nodes are interconnected by links (28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54) and at least some of the nodes are accessible to other nodes only by multiple links. To save time in establishing the least cost path from an originating node to a destination node, the attributes of the various links are stored in memory (14) at the originating node, a least cost path from the originating node to a destination node is calculated in response to a connection request and stored in memory. Then, when a subsequent connection request to the destination node requires the same link attributes as the least cost path already stored in memory, that same least cost path is used if it is still operational. Significant time saving is achieved in that no new least cost calculation need be made.

Abstract: A method for providing files to a remote node including the steps of determining whether bandwidth is available for transmitting across a communications link a file requested by a remote node, reserving bandwidth for the requested file if bandwidth is determined to be available, and opening the requested file for transmission only if bandwidth is reserved. In addition, an apparatus for providing files to a remote node including apparatus for determining whether bandwidth is available for transmitting across a communications link a file requested by a remote node, apparatus for reserving bandwidth for the requested file if bandwidth is determined to be available, and apparatus for opening the requested file for transmission only if bandwidth is reserved.

Abstract: We provide a model and a set of solution techniques for an important problem arising in the design of survivable telecommunication networks utilizing fiber-optics-based technologies. The emergence of a synchronous standard for optical signaling called "SONET" allows for an economic implementation of ring designs that provides protection for high capacity services. An objective is to choose a loading of the demands onto a ring design that minimizes associated equipment and facility costs while providing capacity for alternative routing should some link or node fail. After the computational complexity of the problem has been determined, three approximation heuristics, including a mathematical programming dual-ascent solution technique, are described and compared. The heuristics are being successfully applied to actual network design problems arising in Bell operating companies and other telecommunication providers.

Abstract: A first data processing device (node I) is coupled to a private network which is in turn coupled to the Internet. A second data processing device (node J) is coupled to the same, or to a different network, which is also coupled to the Internet, such that node I communicates to node J using the Internet protocol. Node I is provided with a secret value i, and a public value ∝i mod p. Node J is provided with a secret value j, and a public value ∝j mod p. Data packets (referred to as "datagrams") are encrypted using the teachings of the present invention to enhance network security. A source node I obtains a Diffie-Helman (DH) certificate for node J, (either from a local cache, from a directory service, or directly from node J), and obtains node J's public value ∝j mod p from the DH certificate. Node I then computes the value of ∝ij mod p, and derives a key Kij from the value ∝ij mod p. A transient key Kp is then generated at random, and Kp is used to encrypt the datagram to be sent by node I. Kp is then encrypted with key Kij. Upon receipt of the encrypted datagram by the receiving node J, the node J obtains a DH certificate for node I, (either from a local cache, from a directory service, or directly from node J), and obtains the public value ∝i mod p. Node J then computes the value of ∝ij mod p and derives the key Kij. Node J utilizes the key Kij to decrypt the transient key Kp, and using the decrypted transient key Kp, node J decrypts the datagram packet, thereby resulting in the original data in unencrypted form.

Abstract: The timed-token protocol is a token-passing protocol in which each node receives a guaranteed share of the network bandwidth. Partly because of this property, the timed-token protocol has been incorporated into a number of network standards, including the IEEE 802.4 token bus, the Fiber Distributed Data Interface (FDDI), and the Survivable Adaptable Fiber Optic Embedded Network (Safenet). Networks based on these standards are becoming increasingly popular in new generation real-time systems. In particular, the IEEE 802.4 standard is included in the Manufacturing Automation Protocol (MAP), which has been widely used in computer-integrated manufacturing and industrial applications. Meeting message deadlines requires proper control of medium access. In the timed-token protocol, access to the communication medium is controlled by a token that is passed among the nodes in a circular fashion. Messages are segregated into two separate classes: synchronous and asynchronous. Synchronous messages, used for real-time communication, can have deadline constraints and thus are given a guaranteed share of the network bandwidth. The authors focus on meeting the deadlines of synchronous messages. >

Abstract: Efficient routing of messages is the key to the performance of multicomputers. Multicast communication refers to the delivery of the same message from a source node to an arbitrary number of destination nodes. Wormhole routing is the most promising switching technique used in new generation multicomputers. In this paper, we present multicast wormhole routing methods for multicomputers adopting 2D-mesh and hypercube topologies. The dual-path routing algorithm requires less system resource, while the multipath routing algorithm creates less traffic. More import antly, both routing algorithms are deadlock-free, which is essential to wormhole networks.

Abstract: The present device provides for a dynamically configurable communication network having a multi-processor parallel processing system having a serial communication network and a high speed parallel communication network. The serial communication network is used to disseminate commands from a master processor (100) to a plurality of slave processors (200) to effect communication protocol, to control transmission of high density data among nodes and to monitor each slave processor's status. The high speed parallel processing network is used to effect the transmission of high density data among nodes in the parallel processing system. Each node comprises a transputer (104), a digital signal processor (114), a parallel transfer controller (106), and two three-port memory devices. A communication switch (108) within each node (100) connects it to a fast parallel hardware channel (70) through which all high density data arrives or leaves the node.

Abstract: The present invention relates to a borehole acoustic communication system. The apparatus of the invention comprises a first transceiver at a first communication node and a second transceiver at a second communication node. The data is transmitted in a wellbore between the first transceiver and the second transceiver through a communication channel.

Abstract: A plurality of telecommunication switches are coupled to agent communication terminals (ACTs) which are used by agents for handling incoming calls. An integrated control system is coupled to the ACTs and controls the distribution of incoming calls among the ACTs. An intelligent node in the system can access an agent queue that stores data indicating availability of ACTs to handle the call and a call queue which stores data concerning calls waiting for ACD service. A database stores processing instructions for the handling of incoming calls based on data contained in the agent and call queues, and subscriber specified instructions.

Abstract: In a distributed data processing system, the authentication of a process at one node for the use of a service at another node is performed in a facility that is separate from the requestor and service process. The separate facility is also replaceable, thereby allowing different authentication policies to be implemented within the distributed data processing system. The requesting process and the service process merely pass the authentication information between themselves without attempting to interpret the work of the separate authentication facility. In addition to authenticating the requestor to the service, the service is also authenticated to the requestor.

Abstract: A dedicated debugging facility for tracing hardware and software faults in a distributed digital system. An event data capture circuit is integrated into each processing node in a distributed multinode system for capturing event data within each node under software control. The captured event data is stored in one of a plurality of variable-length trace data buffers in the node processor memory space for analysis or transfer. These dedicated trace data acquisition circuits provide continuously available trace data for the hardware and software functions within each node. Each variable-length trace data entry is stored in the trace data buffers according to a format of this invention that permits collection and assembly of trace data entries from throughout the distributed multinode system to debug local hardware or software and to debug internodal interconnection hardware and software.

Abstract: . During the last thirty years there has been much research effort in regional science devoted to modeling interactions over geographic space. Theoretical approaches for studying these phenomena have been modified considerably. This paper suggests a new modeling approach, based upon a general nested sigmoid neural network model. Its feasibility is illustrated in the context of modeling interregional telecommunication traffic in Austria, and its performance is evaluated in comparison with the classical regression approach of the gravity type. The application of this neural network approach may be viewed as a three-stage process. The first stage refers to the identification of an appropriate network from the family of two-layered feedforward networks with 3 input nodes, one layer of (sigmoidal) intermediate nodes and one (sigmoidal) output node (logistic activation function). There is no general procedure to address this problem. We solved this issue experimentally. The input-output dimensions have been chosen in order to make the comparison with the gravity model as close as possible. The second stage involves the estimation of the network parameters of the selected neural network model. This is performed via the adaptive setting of the network parameters (training, estimation) by means of the application of a least mean squared error goal and the error back propagating technique, a recursive learning procedure using a gradient search to minimize the error goal. Particular emphasis is laid on the sensitivity of the network performance to the choice of the initial network parameters, as well as on the problem of overfitting. The final stage of applying the neural network approach refers to the testing of the interregional teletraffic flows predicted. Prediction quality is analyzed by means of two performance measures, average relative variance and the coefficient of determination, as well as by the use of residual analysis. The analysis shows that the neural network model approach outperforms the classical regression approach to modeling telecommunication traffic in Austria.

Abstract: A method and apparatus for transmitting signals according to the present invention between electrical metering devices and a system control center includes a mobile node. The mobile node communicates with the electrical metering devices operably connected to a distribution transformer and transmits the signals received from the electrical metering devices to the system control center while the mobile node is in the field and removed from the system control center. The mobile node may then be relocated in the field within the electrical power distribution system so as to communicate with the electrical metering devices operably connected to another distribution transformer. Thus, a single mobile node may communicate with the electrical metering devices connected to a number of distribution transformers so as to decrease the number of fixed nodes employed by a communications system of an electrical power distribution system.

Abstract: A distributed file system with dedicated nodes capable of being connected to workstations at their bus. The system uses a complementary client-side and server-side file caching method that increases parallelism by issuing multiple server requests to keep the hardware devices busy simultaneously. Most of the node memory is used for file caching and input/output (I/O) device buffering using dynamic memory organization, reservation and allocation methods for competing memory-intensive activities.

Abstract: An Ethernet network or other CSMA/CD network includes a hub that is modified to generate a jamming signal on a communication line when a packet received over that line is directed to an unavailable destination. The destination may be unavailable due to full transmit buffers, full receive buffers, or congestion in other parts of the hub architecture. Jamming is detected by the source node as a collision and causes retransmission of the packet from the source node. The decision to jam may include a determination of the packet's priority which may be determined based on the packet's destination or source address.

Abstract: Information packets are routed among a constellation of satellite nodes in a communication system in a distributed, yet systematic fashion. Routing tables for each node are generated in advance by a recursive process that considers link usage and anticipated link loading for different times and states of the constellation. Routing tables are generated centrally, distributed to, and maintained in each satellite node. The routing tables are updated regularly to reflect anticipated traffic loading and physical changes in node connectivity within the constellation which occur as a result of satellite motion. The tables are also updated responsively to reflect changes in network connectivity which occur because of failures that may occur in the cross-links or satellite nodes.

Abstract: The imaging pixel according to the present invention includes a floating gate pixel node capable of nondestructive readout and active source follower output circuitry suitable for combination with other like imaging pixels to form an imaging array.