Abstract: In order to reduce messaging within a wireless communication system an emulator (137) is provided that receives multicast packet data from a router (138). The multicast packet data is transmitted from a server (120) and destined to at least one remote unit (113-117). The emulator (137) additionally receives control data for the current multicast session from the router (138). The first set of data is transmitted to the remote unit (113-117) and the emulator (137) responds to the control data (via a response message (134)) without transmitting the control messages to the remote unit (113-117).

Abstract: Systems and methods for providing multiple users with access to a public network like the Internet are provided. A single high bandwidth connection (e.g., fast Ethernet) allows the users to communicate with the public network. Each user is allocated a specific bandwidth and can freely communicate with the public network up to the allocated bandwidth. Additionally, the invention may be remotely configured to change bandwidth allocations.

Abstract: A communication circuit includes a dual-channel coder having an unencoded data communication port, a first encoded data communication port, and a second encoded data communication port. The dual-channel coder is operative to translate between unencoded data at the unencoded communication port and corresponding encoded data at both the first encoded data port and at the second encoded data port The circuit further includes a real-time channel interface for connection to a real-time communication channel and operatively connected to the first encoded data tort of the coder. The real-time communication channel has a first latency of a guaranteed maximum for a data element to travel between ends of the real-time communication channel. The circuit further includes a best-efforts channel interface for connection to a best-efforts communication channel and operatively connected to the second encoded data port of the coder.

Abstract: A network system for providing efficient transmission of real-time data and non-real-time data between a plurality of network devices, including an arbitration mechanism that provides a low cost and high performance mechanism for delivery of quality of service guarantees for time-sensitive data sharing a local area with non-time-sensitive data. Device adapters are placed at all access points to a local network. The device adapters limit admission rates and control the timing of all packets entering the network. An X-Hub placed at the center of the network provides for transparent, concurrent transport of signals transmitted by device adapters. Collisions may therefore be eliminated for time-sensitive traffic, thereby guaranteeing timely delivery. A common time reference is established for the device adapters and the X-Hub. The time reference defines a frame with a plurality of phases. Each of the phases defines a state of the X-Hub, and a state for each of the device adapters.

Abstract: Alternative routing schemes in high-speed networks ensure fault tolerance in the event of a link failure. An heuristic algorithm, based on maximal-flow algorithm, is first used to partition the network into parts: one part carries regular or primary traffic and another part is reserved to carry re-routed traffic in the event of a link failure. The result of applying the algorithm is used to find alternative routes for a given call at the time of call setup. The scheme can be modified to accommodate hop-court limitations and loop avoidance.

Abstract: A wireless communication system 200 comprises a connectionless packet network 201 coupled to a plurality of sites 203-208 that are in wireless communication with a plurality of subscriber units 210-217 logically arranged into a plurality of talk groups having corresponding talk group identifications. In one embodiment, each site maintains mappings 220-225 of at least one multicast address to at least one talk group identification. In another embodiment, individual subscriber units maintain such mappings 320. When a subscriber unit affiliates with a given site and talk group (501, 601), the site identifies a multicast address corresponding to the talk group. Based on the multicast address, the site can participate in traffic targeted for the multicast address and, consequently, for the talk group. In this manner, mobility Processing is decentralized, system calability is improved and call setup delays are minimized.

Abstract: The system separates the common administrative functions from the supervisory host applications. Each administrative function is performed by a separate administrative process that is dedicated to that function and is accessible by all the supervisory application. Thus when a supervisory process requires performance of an administrative function, it invokes operation of the corresponding administrative process. With this arrangement, only a single copy of each administrative process needs to be maintained. All communications between the administrative processes, the switching platform and/or the supervisory applications are routed through a gateway process. The gateway process then forwards the message to the appropriate process or switch and later returns the any reply results to the requesting process or application.

Abstract: According to the present invention, a video signal recording apparatus for recording a digital video signal on a plurality of tracks on a magnetic medium is provided. Each of the tracks has a video data region and an auxiliary data region. In the video signal recording apparatus, the digital video signal is recorded on at least a part of the auxiliary data region.

Abstract: In a local area network, a system and a method to detect transmit underruns and retransmit frames between a sending station and a receiving station using a Media Access Control (MAC) device in lieu of a sending processor. The MAC device includes a MAC processor for transmitting data in blocks from a host buffer to a storage device, e.g., RAM for retransmission to the network via a Media Independent Interface (MII) unit. The MAC device includes a transmit logic unit which uses a control word set by the MAC processor to transmit data by frames from the storage device to the network. The transmit logic unit includes pointer control logic to identify the start address of the data and to track the data as read from the storage device to the network. When a transmit underrun occurs, the transmit logic recognizes the condition and resets the pointer logic to the start of the first frame for retransmission to the receiving station.

Abstract: The invention relates to a implementing signalling in a telecommunications network, particularly in a mobile network. In the method, one network element (BSC) serves as a master element and several other network elements serve as slave elements (BTS1 . . . BTS4) sending a transmission request for signalling information to the master element which assigns transmission turns in accordance with received transmission requests. The signalling is implemented on a signalling channel common to the slave network elements, comprising at least one time slot of the transmission frame, or part of such a time slot.

Abstract: A system and method for the efficient compression and identification of non frame relay data packets allows the transport of non frame relay data packets over a frame relay network. Generic, non frame relay data is segmented into a plurality of data packets and encapsulated for transparent transport over a frame relay communication network.

Abstract: Operations in a cellular system are controlled based on cost values that are generated using neighbor association. In neighbor association, each cost value corresponds to a cost of assigning a candidate channel to a first cell in the cellular system, assuming that the candidate channel is already assigned to a second cell in the cellular system and each cost value is based on an average power attenuation for all of the cells in the cellular system that share the same tier as the second cell with respect to the first cell, wherein the average power attenuation is based on the reuse distances between the first cell and the cells in the same tier. In one embodiment, the cost values are used in a cost-function-based dynamic channel assignment (DCA) algorithm that is, but does not have to be, applied to a list of candidate channels generated using a measurement-based DCA algorithm.

Abstract: In an asynchronous transfer mode (ATM) switching system, a generating section generates test cells at a generation rate, and stops the generation of the test cells in response to a generation stopping instruction. Input and output buffer section stores normal cells and the test cells. Each of the normal cells is used for transferring speech or data Each of the input and output buffer sections issues a congestion notice in accordance with a storage state in the buffer section. An ATM switch receives the normal cells outputted from the input buffer section to transfer to an output port. A test section tests the test cells to determine whether cell conductivity is established. A control section issues the generation stopping instruction to the generating section in response to the congestion notice from the input or output buffer.

Abstract: An echo canceler is connected to an ISDN Primary Rate Interface. The echo canceler is provided with an activation processor for monitoring call control messages on the D-channel and for selectively enabling or disabling echo cancellation on any of the B-channels in response to information contained within the call control messages. In particular, the activation processor decides whether to enable cancellation depending upon the Information Transfer Capability and Protocol Identification fields of the Bearer Capability portion of a call SETUP message. Additionally, the Channel Identification field of the SETUP message is used to identify the B-channel or channels affected by the SETUP message. When a channel is released, the activation processor maintains enabled echo cancellation as the default condition of the released channel. Other signal processing functions can be controlled by the activation processor in a similar manner.

Abstract: Provided is a system which automatically determines and assigns an appropriate address for each chip in a repeater system. All the ASICs in a system are chained together on a serial data ring for address allocation purposes. A "First On" ASIC in a system initializes the chip address map, and assigns itself the first address. The First On ASIC then updates the address map by setting the next address and sends it down the chain to the next ASIC in the system. The second ASIC allocates the incoming address to itself, sets the address for the next ASIC, and passes the address signal on. The process repeats itself until the last ASIC in the chain has an address allocated. The last ASIC then notifies the First On ASIC of its address to close the loop.

Abstract: Methods and apparatuses for processing media data for transmission in a data communication medium. A set of data indicates how to transmit a time related sequence of media data according to a transmission protocol. The set of data, includes a time related sequence of data which is associated with the time related sequence of media data. The set of data may be utilized by a digital processing system to transmit the time related sequence of media data (e.g., by packets generated according to the transmission protocol and the set of data).

Abstract: A network interface device includes a random access memory used as a transmit and receive buffer for transmission and reception of data frames between a host computer bus and a packet switched network. The network interface device includes read and write controllers for each of the transmit and receive buffers, where each write controller operates in a clock domain separate from the corresponding read controller. The memory management unit also includes a synchronization circuit that controls arbitration for accessing the random access memory between the read and write controllers. The synchronization circuit determines the presence of a stored frame in the random access memory by asynchronously comparing write counter and read counter values stored in gray code counters, where each counter is configured for changing a single bit of a counter value in response to an increment signal.

Abstract: A system which uses redundant storage and redundant communication to provide a robust distributed server system.

Abstract: A synchronous serial protocol is used to transfer data from a host processor (102) to multiple CODECs (112) operating at differing speeds and from such CODECs (112) back to the host processor (102) across a bidirectional pair of serial links (134, 136). A link speed fast enough to accommodate all operating CODECs (112) is utilized. Frames are transmitted across the bidirectional pair of serial links (134, 136) controlled by frame sync (132) and bit clock (130) signals. Each frame has a control word of validity bits followed by one data word for each active CODEC (112). The validity bits determine whether the corresponding data word contains valid data for or from the corresponding CODEC (112).

Abstract: A switching system comprising a switching structure for routing cells from a set of M input ports towards a set of M output ports. The system includes a set of distributed individual Switch Core Access layer elements which communicate with one input and output port of the switching structure by means of a set of serial communication links. Each SCAL element provides attachment to at least one Protocol Adapter and comprises a set of circuits. The receive part of each circuit includes means for introducing at least one extra byte to every cell. The extra byte is reserved for carrying a routing header for controlling the switching structure in a first step, and then for use by the PINT circuit when the cell will be received by the transmit part in a second step. The transmit part of each PINT circuit comprises a control module that receives all the cells generated at the corresponding output port and controls whether to discard the cell based on the value of the extra byte.