Abstract: An asynchronous transfer mode (ATM) digital electronic communication system includes an ATM communication system interconnection and termination unit (ATMCSI/TU). This ATMCSI/TU includes both a programmable microprocessor and several hardware-implemented coprocessors. The hardware-implemented coprocessors are under control of the microprocessor, and are dedicated to the performing of repetitive tasks. Thus, the microprocessor is freed to perform supervisory tasks in the ATM in addition to performing tasks associated with actual communication of digital data packages (i.e., CS-PDU's) in the ATM system. Thus, the APU is freed from doing repetitive data manipulation tasks, while these tasks are performed by one or more hardware-implemented coprocessors using memory mapped data structures and linked lists of data.

Abstract: A switch module for time switching telecommunications data includes an input circuit for selecting data samples from a time slot in an input frame of data samples. The selected data samples are arranged into groups of uniform size, each group consisting of at least two data samples. The groups of selected data samples are stored in an orderly manner, in each of as many storage entities as there are data samples in each group. Thereafter in accordance with a predefined sequence peculiar to each of the storage entities, the data samples are simultaneously read out, group by group. An output circuit selects data samples into a selected group of data samples from among each of the readouts of each of the storage entities and transmits each selected group into an output frame of data samples. Hence a sequence of the data samples appears switched in the output frame with respect to the sequence of the data samples as they were stored from the input frame.

Abstract: A method and apparatus for communicating with a plurality of ground terminals using a plurality of satellites transmitting time-division multiplexed signals are disclosed. First, a first satellite transmits to a first group of ground terminals using a first number of timeslots in a TDM frame period. In addition, the first satellite and a second satellite transmit in alternate TDM frames to a second group of ground terminals using a second number of timeslots in said TDM frame period. Finally, the second satellite transmit to a third group of ground terminals using a third number of timeslots in the TDM frame period.

Abstract: A N input and N output, scalable switching network (80) is implemented with an array of log base x of N rows and N/x columns of routers (40-68); where each router has 2x ports and where the rows of routers are connected to each other via a blocking compensated cyclic group mapping interconnect (49 and 59). A N input and N output, bi-directional scalable switching network (90) is implemented with an array of log base x of (N/2) rows and (N/2)/x columns of routers (40-68); where each router has 2x ports, and where the rows of routers are connected to each other via a blocking compensated cyclic group mapping interconnect (49 and 59). The routers provide destination routing. The levels of blocking compensated cyclic group mapping interconnect provide connectivity between the rows of routers.

Abstract: A satellite broadcast communications system, in which a host station sends packet-multiplexed signals to a plurality of terminal stations via a communications satellite, specifically improving efficiency in data retransmission operations without sacrificing the channel capacity of the satellite communications link. Broadcast schedule transmission means transmits the broadcast schedule, which contains the title and transmission time of each transmission data, to every terminal station via the communications satellite. Based on the broadcast schedule, composite information transmission means broadcasts various data to the terminal stations. Broadcast schedule reception means receives the broadcast schedule, and based on the received broadcast schedule, desired information reception means selectively receives desired information at the scheduled transmission time.

Abstract: A receiver for FM data multiplex broadcasting includes a analog/digital converter for receiving an analog FM demodulation signal and for converting the analog FM demodulation signal into a digital FM demodulation signal; a digital filter for processing the digital FM demodulation signal so as to isolate a digital multiplex signal; and a demodulator for demodulating said digital multiplex signal.

Abstract: In a telecommunication system that uses asynchronous transfer mode (ATM) with the ATM adaption layer (AALm) protocol as a data transfer infrastructure, a method and apparatus for segmenting and reassembling user data packets. The method and apparatus improve the quality and effectiveness of telecommunication data transfer by avoiding the problems associated with excessively long minicells.

Abstract: A repeater for a multibeam communications satellite combines the features of coaxial channel interbeam switching and subchannelization of some of the channels. In one embodiment described, the input radio-frequency signals from the input beams are fed through the input multiplexers to form channels. Some, but not all, channels are subsequently subchannelized for interbeam switching. In another embodiment of the invention, a portion of the incoming radio frequency signals bypasses the input demultiplexer and is filtered for noise-limiting reasons, converted down to an intermediate frequency and then subchannelized using SAW filters. The specification also teaches that digital techniques can be used to obtain the same results.

Abstract: Data sequences correspond to L different parameter sets (effective symbol length, guard interval length, the number of carrier waves) and transformed into parallel data by respective serial/parallel converters, which are allocated to respective carrier waves for OFDM and subjected to inverse discrete Fourier transform by inverse discrete Fourier transformers to produce sampled values for the transmission waveform in the time domain. The sampled values are transformed into serial sequences of sampled values by parallel/serial converters and then into a single temporal sampling sequence by a temporal sampling sequence switching unit. A frame synchronizing symbol is added to the temporal sampling sequence and then transformed into an analog base band OFDM signal before it is converted up to a transmission signal. The frequency bandwidth of the OFDM signal is made smaller than a predetermined value defined by the bandwidth of the available transmission channel.

Abstract: Both call switching communication and packet communication are achieved by one personal communication device. Misreceiving in the personal communication device usable in two communication modes is prevented. The personal communication device has a call switching modem and a packet switching modem. The former is used for AMPS network, and the latter for CDPD network. A telecommunication system includes a transmission/receiving terminal and a telecommunication network. The packet switching modem of the terminal awaits the receiving and initial transmission. In this system, the transmission terminal first sends a CDPD packet to the receiving terminal. The receiving terminal is informed of a request for call switching communication. The receiving terminal sends back a response to the request as a CDPD packet, and then a call in the AMPS network is made. Although the personal communication device is usable in the two modes, misreceiving does not occur because awaiting is in a fixed mode.

Abstract: A method and apparatus for establishing deadlock free routing in a bi-directional, multi-stage, inter-connected, cross-point based packet switch, particularly, though not exclusively employed within a high speed packet network of a massively parallel processing system. Specifically, a group of sets of restricted routes traversing a source, intermediate and destination switch chip are determined by establishing a number of route restrictions from each source switch in the network and determining a number of routes restricted between each source-destination pair of switch chips therein, such that the standard deviation for the number of routes left unrestricted between all source-destination pairs of switch chips for the packet network is minimized.

Abstract: A method and apparatus enabling operation of a dual mode TDMA portable telephone unit is disclosed. The first mode of operation enables synchronous communication up to 75 kilometers. In the second mode of operation, the portable telephone unit operates according to a frame structure enabling synchronization between the portable telephone unit and the base station for ranges greater than 75 kilometers. This increased range is achieved by moving the transmission timeslot within the frame structure of a TDMA transmission in the second mode to a later timeslot then in the frame structure of the first mode.

Abstract: Disclosed are methods for acquiring a forward channel in a point-to-multipoint CDMA system. One method includes the steps of (a) despreading a received CDMA signal with a first pn code that is known to be present in the received CDMA signal and obtaining a first measure of received signal level; (b) despreading the received CDMA signal with a second pn code that is known not to be present in the received CDMA signal and obtaining a second measure of received signal level; and (c) synchronizing to a desired channel using a difference between the first and second signal levels. In this method the first step of despreading despreads a continuously transmitted side-channel, and the step of synchronizing synchronizes to the side-channel. Also, the step of obtaining a first measure of received signal level obtains a correlation peak, and the step of obtaining a second measure of received signal level obtains a correlation null.

Abstract: An adaptive channel allocation system is provided which monitors the actual channel bandwidth used by network sources. Sources which have placed demands for network bandwidth, but not used that bandwidth, have their channel resources down-allocated according to a smoothed exponential function. Sources which are idle are detected by means of an aging function.

Abstract: A sequencer 32 is provided with a plurality of protocol processing circuits for independently carrying out at least a part of processes to respective protocol hierarchies of the protocol in response to sequence selection by a sequence selection circuit 28 according to a result of received protocol type identification in a protocol recognition circuit 26. As a result, processes for the respective protocol hierarchies of the protocol or partial processes thereof can be simply and efficiently performed at the same time, and the data receiving device can be configured by the hardware.

Abstract: The present invention provides a method for achieving alignment of the header fields of a specific layer, such as the transport layer header fields, at a receiving host. The receiving host determines a number of padding bytes that need to be added to the transport layer header for the fields to be properly aligned in the memory of the receiving host. This number is determined dynamically for each connection because different connections require different numbers of padding bytes. The number of padding bytes for a connection is determined by the receiving host from the first packet received for a particular connection. Specifically, the receiving host examines this first packet and determines the position of the first byte of the transport layer protocol header, and therefore, the number of padding bytes required to achieve 32-bit (or 64 bit) alignment. The receiving host communicates the number of padding bytes to the transmitting host.

Abstract: A distributed cycle reset protocol used in a system including a plurality of nodes sharing a single medium, which reduces the reset overhead generated due to an increased medium distance and increased transmission rate in accordance with a reset made by the co-operation between two adjacent nodes. The distributed cycle reset protocol includes a distributed medium connection control unit for controlling each of the nodes in such a manner that a node, in which all quotas thereof have been exhausted, is allocated with new quotas to enter a new cell transmission cycle when it receives a reset signal from a lower-order node after transmitting a reset signal to a higher-order node.

Abstract: A multi-point communications system is set forth. The communications system comprises a primary transmitter disposed at a primary site and a plurality of receivers respectively disposed at a plurality of secondary sites. The primary transmitter generates OFDM/DMT transmissions over a first number of transmission bins to transmit communication data in those bins. A transmission medium is used for transmitting the OFDM/DMT transmissions from the primary transmitter at the primary site to the plurality of receivers disposed at a plurality of secondary sites. Each of the plurality of receivers employs a unique receiver architecture that digitally processes exclusively a reduced subset of the first number of bins transmitted by the primary transmitter to recover communication data that is transmitted in the reduced subset of the first number of bins.

Abstract: A system and method for restoring communication between at least one pair of nodes in a network. Distributed intelligence is provided by messaging between adjacent nodes in the network. The messages in combination with user-configurable timers and rules provide fault isolation, forward flooding, reverse linking and connection.

Abstract: A local area network switch which implements packet segmentation and reassembly for cell-based switching on a backplane cell bus. A plurality of packet processing units are each coupled to a backplane cell bus wherein each packet processing unit hosts a plurality of local area network ports. Each packet processing unit is associated with a single packet buffer memory that is shared by the ports associated with the packet processing unit. The segmentation of local area network packets into fixed-size cells facilitates an efficient local area network switch which provides dedicated bandwidth for each of the ports associated with the switch. There is also provision for coupling the local area network ports to communicate with a high-speed network interface.