Abstract: The invention relates to a network comprising a plurality of switches which are combined to respective sub-networks and coupled to fixed terminals or, via base stations, to mobile terminals. Each switch comprises for the connection setup from a terminal to a mobile terminal at least a table which contains an assignment of the home address of a mobile terminal to its visitor's address and to the sub-network of the switch assigned to the mobile terminal.

Abstract: Centrally controlled wireless networks require reliable communications between the central controller and each of the stations within the wireless networks. The structure of a wireless network is often dynamic, or ad-hoc, as stations enter and exit the network, or are physically relocated. The selection of the central controller for the network may also be dynamic, either because the current central controller desires to exit the network, or because the communication between the current central controller and one or more of the stations is poor. This invention discloses a method and apparatus for assessing the quality of the communication paths among all stations in the network. This assessment is useful as a continual monitor of the quality of the network, and can be utilized to select an alternative central control station based upon the quality of communication paths to and from this station. Additionally, the quality assessment can be utilized to establish relay communication paths, as required.

Abstract: The invention relates to a local area network operating in the asynchronous transfer mode (ATM) for transmitting cells, comprising a plurality of network interfaces (1 to 8) coupled to a ring by ring connections (29 to 32), each network interface including a switch (24). For providing a more flexible local area network, at least one network interface (1 to 8) includes a radio device (33) for exchanging data with at least one terminal (9 to 21) located in the radio coverage area of the network interface (1 to 8). For controlling the cell transport within a network interface, a switch (24) is provided.

Abstract: The invention relates to a local area network operating in the asynchronous transfer mode (ATM) for transmitting cells, comprising a plurality of network interfaces (1 to 8) coupled to a ring by ring connections (29 to 32), each network interface including a switch (24). For providing a more flexible local area network, at least one network interface (1 to 8) includes a radio device (33) for exchanging data with at least one terminal (9 to 21) located in the radio coverage area of the network interface (1 to 8). For controlling the cell transport within a network interface, a switch (24) is provided.

Abstract: A local area network with a plurality of nodes for transmitting cells in the asynchronous transfer mode over a ring system having two opposite direction rings. In the event of a defect in a transmitting line from a node, or a defect in a neighboring node, a loop is formed in this node to reroute messages from one ring to the other. First, a node detecting a defect transmits a message of a first type to all other involved nodes, identifying the location of the detected defect. This information is entered in a respective status table in each node. After evaluating the information in its status table, a node which should form a loop does so, and sends a message of a second type identifying the loop to any nodes which do not already have this information.

Abstract: In a communication environment with a number of radio systems a radio station in one of the radio systems seizes a sub-frequency range in a predetermined frequency range. Prior to each transmission of a useful signal, the one radio station checks whether a given sub-frequency range in the predetermined frequency range is free for a selected size of a propagation area. If the given sub-frequency range is free, the radio station transmits at random instants at least two pulses with a transmission range that is substantially restricted to the given sub-frequency range and avoids collisions with another radio system belonging to the communication environment by detecting whether the other radio system has seized the sub-frequency range in an overlapping radio propagation area at the same time.

Abstract: A protocol, method, and apparatus for managing network communications which are particularly well suited for ATM communications across a wireless medium. Contiguous time slots within a frame are allocated to each node having traffic to send. Each node is assured a nominal bandwidth, and excess bandwidth is distributed by demand. The allocation of excess bandwidth can be dependent upon the size of the buffer at each node, as well as the time-criticality of each message. Nodes communicate their requests for allocation by appending such control information to the first of their transmitted packets. The allocation, of each node's transmit and receive time slots, is transmitted to all the nodes at the beginning of each frame. Thereafter, each node need not participate on the network until their allocated time periods, thereby allowing portable devices to enter inactive states to conserve power.

Abstract: The invention relates to a system for the wireless transmission of a frame-synchronized signal between a base radio station (1) and at least one mobile terminal (2), which base radio station is provided for defining, prior to the transmission of data of a synchronous service, the periodically occurring frames which are to be used and a constant number of synchronous channels for the duration of the connection. The base radio station (1) and at least one mobile terminal (2) are provided for transmitting packets containing data of an asynchronous service in the frame-synchronized signal. The base radio station (1) is provided for defining for each respective frame a number of asynchronous channels used for transmitting the packets.

Abstract: The invention relates to a local area network operating in the asynchronous transfer mode, with a first transceiver (1 to 8, 54 to 57) which includes a radio device (33, 60) for transmitting cells to a plurality of other transceivers (1 to 21, 54 to 57). For a data exchange between the first and the other transceivers (1 to 21, 54 to 57) without cells being blocked, a radio device (49, 60) includes a first buffer memory (73) assigned to a respective other transceiver (1 to 21, 54 to 57). A first buffer memory (73) is used for storing a cell whose destination is another transceiver (1 to 21, 54 to 57) which is assigned to the respective first buffer memory (73).

Abstract: The invention relates to a local area network operating in the asynchronous transfer mode comprising a plurality of terminals (1 to 4) which are formed each by a station (5), a radio device (7) for transmitting data between the terminals (1 to 4) and a network interface (6) including a controller (8) at least provided for setting up a connection, and comprising a switch unit (9) for switching cells between radio device (7), station (5) and controller (8). To effect a fast data transmission, the terminals (1 to 4) are provided each for a direct data exchange with another terminal (1 to 4). One terminal (1 to 4) then executes management functions in the network and exchanges data by means of at least one virtual link between a local user and a user of another terminal (1 to 4).

Abstract: The invention relates to a local network operating in the asynchronous transfer mode (ATM), comprising a plurality of stations (10) which are each coupled to transmitting and receiving ring lines (16, 19) via a network interface (9) which comprises at least one switch (11) and which stations are provided for transmitting cells. The switch (11) is arranged for relaying a user cell containing information relating to the user from a receiving ring line (16) to the transmitting ring line (19) and/or to the station (10) or from a station (10) to the transmitting ring line (19) in response to status information.

Abstract: A local network for connecting a plurality of stations includes a main ring which is formed by a number of network interfaces coupled via main ring lines, which network interfaces are each coupled to a respective one of the stations, and a first relief ring, which is formed by a number of bridge elements coupled in series via relief ring lines. The relief ring is coupled to the main ring. At least one bridge element is provided for establishing a connection between the first relief ring and the main ring.

Abstract: The application describes a network comprising transceivers (1..6) linked in a network topology. The positions of the transceivers in the network topology are changed in dependence on the loads on the end-to-end connections (VC1..VC5) between the transceivers in the network. A configuration is chosen to give efficient use of the capacity available in the network. Each time that a new end-to-end connection (VC) within the network is set up the positions of the transceivers (1..6) are changed such that the network remains optimized.

Abstract: Local area network operating in the asynchronous transfer mode (ATM) comprising a plurality of stations which are coupled each via a network interface, which interface comprises a coupling device and a control arrangement and transmits cells via the coupling device between send and receive ring lines, to at least one station and at least one control arrangement. A control arrangement comprises an access controller which is arranged for conveying, in dependence on the contents of the header field of a cell received from the coupling device, the cell or first parts of the cell and/or additional information to a bus system and units coupled to the bus system.

Abstract: The invention relates to a local network operating in the asynchronous transfer mode (ATM), comprising a plurality of stations which are coupled, via network interfaces comprising a coupling device and a control arrangement, to sending and receiving ring lines and which are provided for transmitting user cells containing user-oriented information and at least control cells containing signalling information. The control arrangement assigned to a transmitter station is provided for generating at least a control cell to be sent to a receiver station after the control arrangement has received from the transmitter station a control cell with a realisable request for a unicast or multicast connection from a user of the transmitter station to a user of at least one receiver station, which control cell has in its information field at least information about the users, the address of the transmitter station and a user-related identification for a down channel.

Abstract: A local area network comprises a plurality of network interfaces with each network interface coupled to a station, the network interfaces further for exchanging data with each other. The local area network further comprises a distribution station for exchanging data with the network interfaces. The distribution station further receives load information of the network interfaces, and in response to the load information, transmits a channel distribution for the exchange of data between the network interfaces.