Showing papers on "Broadcast communication network published in 1995"

Broadcast disks: data management for asymmetric communication environments

Abstract: This paper proposes the use of repetitive broadcast as a way of augmenting the memory hierarchy of clients in an asymmetric communication environment. We describe a new technique called "Broadcast Disks" for structuring the broadcast in a way that provides improved performance for non-uniformly accessed data. The Broadcast Disk superimposes multiple disks spinning at different speeds on a single broadcast channel--in effect creating an arbitrarily fine-grained memory hierarchy. In addition to proposing and defining the mechanism, a main result of this work is that exploiting the potential of the broadcast structure requires a re-evaluation of basic cache management policies. We examine several "pure" cache management policies and develop and measure implementable approximations to these policies. These results and others are presented in a set of simulation studies that substantiates the basic idea and develops some of the intuitions required to design a particular broadcast program.

Apparatus and method for transparent wireless communication between a remote device and a host system

Abstract: An apparatus and method is provided for transparent communication between a remote or mobile device and a fixed communication host network. The apparatus and method may include a remote network controller that logically resides between the host network and the existing infrastructure(s) that are used to provide communications network contact with one or more remote devices. The remote network controller is connected to the host communication network as a protocol-appropriate communications controller so that remote devices are indistinguishable to the host network from the locally-attached devices. Each remote device may be provided with an asynchronous serial data interface to communicate with a mobile data controller. The mobile data controller, in combination with the remote network controller, provides end-to-end data communication such that incompatible protocols are transparent to the remote device and host communication network. A router may be provided which selects a communications network in accordance with user configured parameters. The router communicates over a plurality of incompatible networks and is capable of using a variety of different protocols. Switching between the plurality of incompatible networks is transparent to the remote device and host communication network.

Atomic broadcast: from simple message diffusion to byzantine agreement

Abstract: In loosely coupled distributed systems subject to random communication delays and component failures, atomic brocrdcart protocols can be used to implement the abstraction of a A-common sfomge, a replicated storage that displays at any clock time the same contents to every correct processor and that requires A time units to complete replicated updates. We term a broadcast protocol atomic if (1) it delivers every message broadcast by a correct sender to all correct receivers within some known time bound (ferminution), (2) it ensures that every message whose broadcast is initiated by a sender is either delivered to all correct receivers or to none of them (ofomicify), and (3) it guarantees that all delivered messages from all senders are delivered in the same order at all receiving nodes (order). This paper presents a famib of atomic broadcast protocols that are tolerant of increasingly general fault classes: ommm fuulfs, which cause a component (processor or communication link) never to deliver a requested service, riming fuulfs, which cause a component to deliver a requested service either too early or too late, and Byanfine fuults, which lead to the delivery of a service other 'than the one requested. The protocols work for arbitrary point-to-point network topologies, can tolerate any number of faults up to network partitioning, use a small number of messages, and achieve in many wes the best possible termination times.

Performance and status monitoring in a computer network

Abstract: Provided is a method and a system for computer network monitoring, implemented in a network in which processes communicate using message queuing. Each node of the network has a network management program installed thereon which includes two independent components: a Point Of Control (POC) program for initiating network tests by injecting a test message into the network and for receiving responses from all the nodes of the network; and a Network Test Program (NTP) for sending a reply message to the single POC for a particular test when the NTP receives test messages within that test, and for propagating the test by forwarding a message to all of the current node's adjacent nodes. Test results are analyzed at the POC for display to the network administrator. Injected test messages propagate throughout the network in a self-exploring manner, exploiting the parallelism of the network. The individual nodes are not required to know the network topology other than to know their nearest neighbor nodes.

Representing and executing agent-based systems

Abstract: In this paper we describe an approach to the representation and implementation of agent-based systems where the behaviour of an individual agent is represented by a set of logical rules in a particular form. This not only provides a logical specification of the agent, but also allows us to directly execute the rules in order to implement the agent's behaviour. Agents communicate with each other through a simple, and logically well-founded, broadcast communication mechanism. In addition, agents can be grouped together. This not only restricts the extent of broadcast messages, but also provides a structuring mechanism within the agent space.

Expandable telecommunications system

Abstract: An open, high speed, high bandwidth digital communication network for connecting multiple programmable telecommunications switches to form a large capacity, non-blocking switching system. Each network switching node includes circuitry for transmitting and receiving variable-length, packetized information over the network, thus enabling each node to receive information from or transmit information to all other nodes. The network may carry any type of information present in the system including voice, data, video, multimedia, control, configuration and maintenance, and the bandwith of the network may be divided or shared across various information types. Devices such as voice processing resources may also interface with the network, thereby gaining direct access to all information passing through the network. Also provided are methods and packet structures for communicating information over the network. Multiple networks may be interconnected to provide even greater switching capacity or voice processing capacity.

Method and apparatus for providing broadcast messages in a communications network

Abstract: The present invention is a novel and improved method for providing broadcast short message services (SMS) in a communication network. It is an objective of the present invention to provide a method and apparatus that insures the successful transmission of the broadcast message while minimizing the impact of providing the short messaging service on overall system capacity. Messages to be broadcast to a group of users are provided by broadcast page generator (20), to a broadcast message buffer (24). The timing of the message transmissions is controlled by a page transmit controller (34), and the message is modulated onto an appropriate channel by modulator (26).

Routing in data communications network

Abstract: The invention provides data communication systems and methods in which information for routing of messages between nodes of a commnunications network is provided by a directory service (300 such as DCE directory service), accessible from all network nodes. The provision of such information by the directory service removes the requirement for routing tables to be set up and maintained at each of the network nodes, which maintenance can involve considerable network traffic in dynamically changing networks or problems of inconsistent data being held at different nodes. The invention also identifies what minimum network configuration information must be held in a directory service for use in message-route determination, providing systems for and methods of route determination which use a directory service storing lists of each node's nearest neighbour nodes only.

Maintaining database integrity throughout a communication network

Abstract: A communication network with a database consistency mechanism is disclosed, wherein a sequence number and a set of routing information for each of a set of virtual circuits of the communication network are maintained in a main database and an auxiliary database in each of a set of communication nodes in the communication network. The sequence numbers in the main database or the auxiliary database in each of the communication nodes are verified if one of the communication nodes switches between the main database and the auxiliary database, and then virtual circuits are rerouted when necessary.

Nationwide communication system

Abstract: A two-way communication system for communication between a system network and a mobile unit. The system network includes a plurality of base transmitters and base receivers included in the network. The base transmitters are divided into zonal assignments and broadcast in simulcast using multi-carrier modulation techniques. The system network controls the base transmitters to broadcast in simulcast during both systemwide and zonal time intervals. The system network dynamically alters zone boundaries to maximize information throughput. The preferred mobile unit includes a noise detector circuit to prevent unwanted transmissions. The system network further provides an adaptive registration feature for mobile units which controls the registration operations by the mobile units to maximize information throughput.

Algorithms for network reliability and connection availability analysis

Abstract: Communications networks used for transmitting and receiving voice or digital data involve copper wire, fiber optics, radio, satellite, and microwave links. In general, these networks are large, diffuse, and complex. Even using modern high-speed computers, exact computations of the network reliability for use as a figure of merit in an interactive network design procedure can take an inordinate amount of time. This paper discusses various exact techniques whose complexity results in run-times short enough for practical network design. We model the network by an undirected probabilistic graph whose vertices represent the nodes and whose edges represent the links. A special feature of our model is that it allows nodes to be imperfect and associates a reliability measure with each node, assumed to succeed or fail independently. Therefore, the network reliability measure is based upon the reliability measures of the individual links and nodes. >

Method for adaptive routing in a communication network

Abstract: The communication network has a plurality of mutually connected network nodes (NR1,...,NK5), in which in each case network data relating to the network topology of the entire communication network are maintained and, depending on said network data, routing tables for connection paths to all remaining network nodes are created. If an event that influences the network topology of the communication network occurs, on the one hand the network data maintained therein are updated by the network node detecting said event. On the other hand a broadcast message corresponding to the event is transmitted to the other network nodes, following the reception of which the respective network nodes update the network data maintained therein. It is provided here that, for the transmission of the broadcast message within the communication network, a connection path network is defined from the plurality of possible connection paths between the individual network nodes, via which network the broadcast message reaches the respective network node via only a defined number of independent connection paths.

Method and apparatus communication handover in a communication system

Abstract: A method of communication handover from a first communication entity (33) to a second communication entity (43) in a communication system (10) where a communication unit (80), communicating with a transceiver (23) associated with the second communication entity, is linked to the first communication entity. The invention provides for establishing a communication link between the communication unit and the second communication entity while maintaining a communication link between the communication unit and the first communication entitiy. Then, communications are substantially simultaneously transfered to the second communication entity while terminated from the first communication entity.

Two-way broadcast system and receiving system

Abstract: A two-way broadcasting system and a receiving system which can be realized at a low cost and is not required to newly connect the connecting cables and extended wiring layout. A multiplexed broadcast signal is transmitted from the broadcasting side under the condition that the two-way broadcast program information can be separated from the principal audio signal of the broadcast program and the two-way broadcast program information can be reproduced as the audible sound in the receiving side. In the receiving side, such broadcast signal is received and the reproduced voice signal including the two-way broadcast program information is reproduced from a loud speaker system. The two-way broadcast program information is extracted from the collected voice signal and is then decoded in a decoding means. Using this decoded information, the response information to the two-way broadcast program can be transmitted to the predetermined response sending destination through the communication line.

On-vehicle data communication system and method

Abstract: An on-vehicle data communication system is provided with at least one master unit, a plurality of slave units and a communication bus. Each of the slave units is provided with: a first receiving device for receiving broadcast communication data through the communication bus; a first judgement device for judging whether or not the first receiving device failed to normally receive the broadcast communication data; and a first transmission device for transmitting acknowledge data to indicate a failure in reception of the first receiving device, if the first judgement device judges that the first receiving device failed to normally receive. The master unit is provided with: a second transmission device for transmitting the broadcast communication data to the slave units; a second receiving device for receiving the transmitted acknowledge data; a second judgement device for judging whether or not the acknowledge data corresponding to the transmitted broadcast communication data are received by the second receiving device; and a process control device for performing a predetermined process to cope with the failure of the first receiving device.

Distributed bidirectional communication network structure in which a host station connected to a plurality of user stations initially assists only in setting up communication directly between user stations without going through the host station

Abstract: In a communication network structure, a communication network system using the communication network structure and a communication method for the communication network system, a plurality of user stations which are connected to one another through bidirectional communication means, and at least one host station which is connected to each of the user stations through bidirectional communication means. The host station holds a data base containing consciousness information in which only each user station's intention of entering the communication network is collected, and communication connection in formation which is required for each user station to directly or indirectly select another user station without going through host station to perform a direct communication therebetween, and each user station holds knowledge information to be delivered between the user stations without going through the host station by the direct communication therebetween.

Parallel processor system with a broadcast message serializing circuit provided within a network

Abstract: In a parallel processor system comprising a plurality of processor elements constituting a network, a source processor element wishing to broadcast data to a plurality of destination processor elements sends a broadcast request message containing the target data to a broadcast exchanger. The broadcast exchanger converts the received message into a broadcast message and sends it over the network to the destinations. A plurality of broadcast request messages, if transmitted parallelly to the broadcast exchanger, are serialized thereby so that only one broadcast message will be transmitted at a time over the network. This prevents deadlock from occurring between different broadcast messages. The routes for transmitting broadcast request messages and those for transmitting broadcast messages are arranged so as not to overlap with one another. This suppresses deadlock between any broadcast request message and broadcast message. The broadcast exchanger is replaced alternatively with one of the partial networks. These schemes all apply where long messages are transmitted through worm-hole routing.

Implementing sequentially consistent shared objects using broadcast and point-to-point communication

Abstract: A distributed algorithm that implements a sequentially consistent collection of shared read/update objects using a combination of broadcast and point-to-point communication is presented and proved correct. This algorithm is a generalization of one used in the Orca shared object system. The algorithm caches objects in the local memory of processors according to application needs; each read operation accesses a single copy of the object, while each update accesses all copies. Copies of all the objects are kept consistent using a strategy based on sequence numbers for broadcasts. The algorithm is presented in two layers. The lower layer uses the given broadcast and point-to-point communication services, plus sequence numbers, to provide a new communication service called a context multicast channel. The higher layer uses a context multicast channel to manage the object replication in a consistent fashion. Both layers and their combination are described and verified formally, using the I/O automaton model for asynchronous concurrent systems.

System for call forwarding from a first communication network to a second remote communication network and a system for virtual extension of a mobile communication network by at least a second, remote mobile communication network

Abstract: Disclosed is a system for call forwarding from a first communication network to a second remote communication network, whereby the second communication network is one of several GSM-type mobile-communication network. The system comprises a bridgehead located in the area of the first communication network, the bridgehead serving as an internetwork junction between the first communication network and the second communication networks (transition network). Calling numbers of the first communication network are assigned to the bridgehead to which calling numbers of the first communication network are assignable by call forwarding, the calling numbers being converted to GSM-type calling numbers in the bridgehead. The bridgehead is connected to a Mobile Services Switching Center (MSC) of the transition network via signalling and intelligence signal channels and provides the basic services of subscribers of a GSM-type mobile-communication network.

Method of establishing access to secondary communication resources in a communication system

Abstract: In a radio communication system, a method of establishing access to a secondary communication resource includes the steps of identifying a need for such a resource, and requesting access to that resource while still engaged in a first communication. In particular, a first communication unit, being presently engaged in a first communication on a primary communication resource, allows the user to identify a present need for a secondary communication resource for the secondary communication resource. The communication unit is further made capable of requesting, during the first communication, access to the secondary communication resource.

Bridging apparatus for traffic filtering in communication networks

Abstract: A bridging apparatus for receiving and transmitting broadcast and non-broadcast frames from a first communication network to a second communication network in a network system, is provided. The bridging apparatus includes storage memory for storing the broadcast frames and the non-broadcast frames, and filtering arrangement for controlling and balancing the transmission of the frames to the second communication network. The filtering is performed by alternatively reading and sending a first number of broadcast frames and a second number of non-broadcast frames to the second communication network. The number of broadcast frames and non-broadcast frames being read and send alternatively is based upon the characteristics of the communication networks. The bridging system of the invention further permits to discard either broadcast frames or non-broadcast frames that are received from a first network, when the capacity of the memory in which each type of frame is stored is reached. The system disclosed also permits that a broadcast frame received from a same station may be discarded if it is received within a variable delay. This delay may be defined with respect to the characteristics of the networks, or may be dynamically computed with respect to the time at which the last broadcast frame received from the same station has not been successfully transmitted to the second network.

DUET: an agent-based personal communications network

Abstract: The authors propose a network architecture that provides access to resources on different networks in a manner that is transparent to the user They named this network distributed user-assistant for easy telecommunications (DUET) Personal agents manage resources for the users and allow each user to customize his/her communication services This architecture is especially suitable to advanced personal communications integrating real-time voice and non-real-time messaging services >

Optical communication system having loop-back function for informing congestion state of receiving node

Abstract: An optical communication scheme is carried out by using a network having a plurality of nodes, a first network medium connected to a first group of the nodes, and a second network medium for transmitting control signals and connected to a second group of nodes When initiating data transmission, any of the nodes transmits a transmission signal to the first network medium, and a receiving node that has received the signal loops-back the same signal to the second network medium thereby communicating information as to a state of congestion at the receiving node A network for large volume data transmission can be realized by simple hardware and the state of congestion can be controlled using a simple method

Communication process in a telecommunications network

Abstract: A communication process in a telecommunications network between a processing member and at least one terminal (11) remote therefrom allows a subscriber equipped with a multi-user terminal or an identification module to choose at least one access area (21) to the network in which he benefits from special conditions.

Communication network system in which an unregistered terminal being used by a party can be located for starting a session

Abstract: An object of the present invention is to offer a communication network system in which it is possible to connect a logical channel for performing information exchange or information communication between terminals connected to the communication network without inputting an address of a terminal to communicate with. In the communication network according to the present invention in which a logical channel is connected between desired terminals connected to the communication network to perform information exchange or information communication between the desired terminals, a connection controller for a network and communication is provided which specifies a terminal which can be used by a person to communicate with through the communication network by inputting information excluding the address of the terminal to which a connection request is issued to connect the logical channel to the specified terminal.

Internet message communicator with direct output to a hard copy device

Abstract: This invention discloses an apparatus for a global network communicator including an application-specific communications device suitable substantially only for global network communications and including a global network application specific user interface, network protocol processing circuitry operative for communication with the global network and for formatting data to a required protocol employed by the global network and for translating data received from the global network to a format acceptable to the user interface, a communication line interface interconnecting the network protocol processing circuitry to the global network and including logical and physical interface apparatus and modulation and demodulation apparatus for information transmitted to the global network and information received from the global network respectively and network access activation circuitry for initiating communication between the communicator and the global network.

Radio communication network system

Abstract: PURPOSE: To improve the reliability of a network and the communication efficiency of the whole of the network by properly judging the service providing status of a server and the status of the communication route to the server and suppressing the generation of wasteful traffic. CONSTITUTION: A BCD reception processing part 31 receives the broadcast communication data (BCD) transmitted from a server by a prescribed time interval via an antenna 6. The service providing status on a server side which is contained in the BCD is stored in a server information table 32. Further, when the service request is received from an operator, a client AP 30 refers to this server information table 32. When the server judges the status as the one in which the processing of service is impossible within prescribed response time, the transmission of the service request to the server is not performed. By this constitution, the reliability of the network and the communication efficiency of the whole of the network are improved.