Abstract: A packet switch (25.sub.1) contains input port circuits (310) and output port circuits (380) inter-connected through two parallel paths: a multi-slot central queue (350) and a low latency by-pass cross-point switching matrix (360). The central queue has one slot dedicated to each output port to store a message portion ("chunk") destined for only that output port with the remaining slots being shared for all the output ports and dynamically allocated thereamong, as the need arises. Only those chunks which are contending for the same output port are stored in the central queue; otherwise, these chunks are routed to the appropriate output ports through the cross-point switching matrix. Each receiver classifies its resident chunks (as critical or non-critical) based upon both the urgency with which that chunk must be transmitted to its destination output port and by the status of the central queue. A critical chunk, i.e.

Abstract: A communication system with switched hub is disclosed including a set of communication ports that transfer inbound and outbound communication frames over corresponding serial communication links. The communication ports determine a destination port for each incoming communication frame and perform interleaved transfers of the incoming communication frames to a set of virtual transmit first-in first-out (FIFO) memories that buffer communication frames for outbound transfer. The mechanism disclosed enables fast and efficient switching of the inbound frames to corresponding outbound ports.

Abstract: A physically realizable one terabit or more ATM packet switch that has a large number of input interfaces connected to a single stage switching fabric which is in turn connected to a number of output modules, generally according to the growable packet switch architecture. This ATM packet switch is different from other growable packet switches in that it has a single stage switch fabric controlled by an out-of-band controller, yet it has significantly reduced complexity with respect to comparably sized electronic crossbar switches or their isomorphs.

Abstract: A procedure for the transmission of digital data in a control/monitoring system of a building in which a number of room-specific nodes, one of which operates as a central node, are interconnected by cables and used as control units, which form a loop. Data flows in the system in the form of packets including the fields required for data transmission in the system, as well as fields for commands and corresponding data transfer required by the system. The fields for commands having leading and trailing flags indicating the status of such fields. When a receiver releases a field for commands for a following user, this is done by means of a status bit acting as a trailing flag and being the last in the time scale. This status bit is then transferred by the central node so that it becomes a status bit preceding the released field and acting as a leading flag. This method of handling the status information provided by the flags reduces the need for data buffering at the nodes.

Abstract: A secure repeater implementing data packet masking includes a programmable and selective, on a per port basis, multicast response. A multicast controller receives a multicast identifier extracted from a destination address field of a data packet. A plurality of memories, one associated with each port, determines the associated port's response to the multicast identifier. Each memory stores a multicast control code. When the multicast control code for a particular port has a value indicating that the associated port is enabled to receive multicast packets, assertion of the multicast identifier to the multicast controller for the particular port results in disabling the security masking for the port and subsequent transmission of unmodified data from the particular port.

Abstract: Method and apparatus are provided for transmitting a stream of multimedia digital data over a distribution communications network. A multimedia stream server segments the multimedia digital data stream into data blocks on a first boundary and a second boundary. The first boundary is a set number of transport system data packets and the second boundary is a transport system data packet including a timestamp. A scheduler schedules the segmented data blocks for transmission. The multimedia stream server decodes the segmented data blocks to locate the timestamps and matches the transmission of the located timestamp data block with a time value indicated by the timestamp. The set number of transport system data packets can be determined at connection setup and is not a predetermined value for all sessions. At the receiver, batch processing of received multimedia data can be provided.

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.

Abstract: A bidirectional line switched ring network having a path alarm indication signal (AIS) generation function, which is provided with ID writing means for writing, in the path overhead bytes of frames, IDs preassigned to add side nodes, tables for holding the correspondence between the IDs of add side nodes for sending frames to be dropped at drop side nodes and the number of the time slots to be used for the transmission of the frames, comparing means for comparing the IDs of the add side nodes read from the received path overhead bytes and the IDs in the tables corresponding to the number of the time slots used by the received frames, and path alarm indication signal generation means for generating and sending a path alarm indication signal (AIS) when the result of the comparison is that the two IDs do not match. By this, a path alarm indication signal can be generated at a high speed at the time of erroneous channel connection by simple hardware and a simple procedure.

Abstract: A synchronizing system with a simple structure accomplishes synchronous reproduction without complicating a control circuit for synchronizing video and audio signals with each other. The number of unit audio data blocks to be put in one pack is set in such a way that the difference between the presentation start times for the stream of video data and the stream of audio data in one pack in a predetermined pack period becomes a predetermined value, and the pack carries positional information of the pack in the predetermined pack period to the pack.

Abstract: A plurality of digital transmission network analyzers are arranged to analyze and compare the appearance of a data packet on the plurality of ports of a network. Each analyzer has its own internal clock for time stamping of data packets in addition to other internal timing purposes. In order to synchronize the time stamping of the packet as it appears to each analyzer at a each different port, the clock outputs of the several analyzers are connected together; and a controlling CPU commands one of the analyzers to supply the master clock to the others. That master analyzer then commands the other analyzers to disable or disconnect their own clocks, thereby all of the analyzers involved in a given test are under timing control of the clock of the master analyzer. Packet headers and time stamps are transmitted between analyzers for comparison, analysis, and reporting to the controlling CPU.

Abstract: The invention is a communication method with the equipment belonging to it and its aim is to increase the number of users in a network or cell. Data is transmitted by the method by using a combined CDMA/TDMA or TDMA/CDMA multiple use whereby complementary code sets (complete orthogonal codes or non-interacting codes) are used as spreading codes. In the applications of the method to existing or planned TDMA systems, a CDMA part is added to them, by which a spreading coded CDMA multiple access is used in every time slot of the TDMA frame, in said way, to increase the number of users. The described method does not require any power control methods, nor any multiple access interference cancelling methods to increase network or cell capacity.

Abstract: A bandwidth management system manages a plurality of virtual data connections within a communications network. The system includes an input for receiving data cells, wherein each cell is associated with a particular one of the virtual connections. The system also includes a cell pool, coupled to the input for storing the cells, first and second queues for ordering the virtual connections, and an output for transmitting cells from the cell pool. The relative position of a virtual connection in the first queue is determined by an eligibility variable that varies according to an anticipated data rate associated with the particular virtual connection and according to an amount of time that the particular virtual connection has been in the first queue. The relative position of a virtual connection in the second queue varies according to a predetermined quality of service that is assigned to each of the virtual connections.

Abstract: An integrated circuit has an isochronous network port for receiving isochronous information from an isochronous network. To allow the integrated circuit to receive information packaged in accordance with two different packaging protocols (for example, HDLC and ATM), the integrated circuit includes a first framer/deframer circuit for deframing information packaged in accordance with a first packaging protocol (for example, HDLC) and a second framer/deframer circuit for deframing information packaged in accordance with a second packaging protocol (for example, ATM). A circuit switch is provided to cause incoming data to be deframed by the appropriate framer/deframer circuit depending on which slot of the network frame contained the information. Once deframed, a buffer manager controls storing of the information in a circular ring buffer in an external memory.

Abstract: In a communication system utilizing DMT technology to couple a primary site (102) to a plurality of secondary sites (104-108), infrastructure control channels are established in the following manner. Having obtained a plurality of site bit loading tables, the primary site (102) generates a control channel bit loading table from the plurality of site bit loading tables. From the control channel bit loading table, the primary site selects at least one carrier channel to function as the control channel. The selection is based on bandwidth requirements for the control channel.

Abstract: Method and apparatus are provided for transmitting a stream of multimedia digital data over a distribution communications network. A multimedia stream server segments the multimedia digital data stream into data blocks on a first boundary and a second boundary. The first boundary is a set number of transport system data packets and the second boundary is a transport system data packet including a timestamp. A scheduler schedules the segmented data blocks for transmission. The multimedia stream server decodes the segmented data blocks to locate the timestamps and matches the transmission of the located timestamp data block with a time value indicated by the timestamp. The set number of transport system data packets can be determined at connection setup and is not a predetermined value for all sessions. At the receiver, batch processing of received multimedia data can be provided.

Abstract: A method for initializing ISDN adapter cards installed within a workstation having a main processor and an ISDN primary adapter for connecting the ISDN adapter cards to an ISDN primary gateway. Each ISDN adapter card has circuits for handling at least one B-channel, and a first processor associated with memory storage. The ISDN primary adapter includes a second processor associated with a second memory storage. In response to the reception of a specific polling pattern transmitted to each adapter card by the primary adapter, a pattern is transmitted to the workstation processor for requesting the loading of the second memory storage with operational code transferred from the workstation to the ISDN adapter card.

Abstract: An intelligent multistation access unit is provided having a transmission speed detection circuit for determining the data transmission speed of an attached device attempting to gain access to a node of a multiple transmission rate digital data communications network. The intelligent multistation access unit is comprised of a speed detect circuit, which indicates the data transmission speed of the attached device, a switching circuit which directs the attached device to the speed detect circuit until switched to allow the attached device access to the network node, and a processor that controls the switching circuit and which permits the attached device access to the node depending on the data transmission speed indication.

Abstract: The present invention provides a unique access control scheme for assigning a plurality of time slots in a fair manner among subscriber units using a single time slot in a frame and subscriber units using multiple time slots in a frame in a communication system.

Abstract: A communication system (100) provides simultaneous synchronization between a network controller (106) and numerous radio ports (102) using a single signaling channel. The network controller (106) includes a multiframe synchronization generator (208) which generates a multiframe synchronization packet (302) in response to a series of counters (212) and a timing reference (202). Each radio port (102) includes a multiframe synchronization detector (410) which verifies that the multiframe synchronization packet (302) is error free.

Abstract: In a diversity transmission system the problem arises that almost no improvement can be obtained when the signals to be received show frequency selective fading within the band width of the signal to be transmitted. To solve this problem the signal to be received is separated by filter banks into a number of sub-band signals. Corresponding sub-band signals of different filter banks are combined by the combiners into combined sub-band signals. These combined sub-band signals are combined to a broad band signal by a final combiner.