Abstract: An interpolation filter for processing a sequence of input samples provided at an input rate controlled by an input clock, so as to generate interpolants at an output rate controlled by an output clock, which is substantially independent of the input clock. The filter includes a plurality of stages arranged in a succession in which each of the stages, except for a first stage in the succession, is coupled respectively to a preceding one of the stages.

Abstract: Disclosed is a method for providing first and second interleaved bit streams to a modulator in order to transmit the first and second interleaved bit streams through at least two antennas in a mobile communication system. An encoder encodes a transmission data stream into a first bit stream with first priority and a second bit stream with second priority being lower than the first priority. An interleaver interleaves the first and second bit streams into the first and second interleaved bit streams. The modulator modulates the first and second interleaved bit streams.

Abstract: A method and system for transferring a transport stream, such as from a satellite receiver to a networked computer system, are provided. The transport stream is parsed to derive multiple elementary streams including associated program identifiers, which are used to determine corresponding transfer locations in a host memory. Direct memory access transfers of the multiple elementary streams are then performed to the corresponding transfer locations in the host memory.

Abstract: A method and apparatus are provided for flexible time-division multiplexing, and demultiplexing, of serial line data, from 1-n client lines, based on the SONET standard (e.g. OC-48 or OC-192) whereby a predetermined and reconfigurable number of STS-1s are allocated to each client. A multiplexer includes 1 to n mappers for mapping the data of 1 to n clients, according to a predetermined bandwidth allocation, to an N×STS-1 SONET payload, each mapper using y STS-1s where y is 0 to N, the y STS-1s being selected on a sequential or non-sequential concatenation basis from the N STS-1s. Each mapper maps the data of one client and each allocated STS-1 is allocated to one client and the total number of STS-1s allocated to the clients is less than or equal to N. An aggregator aggregates the mapped data into a composite STS payload comprising N STS-1s. A bandwidth allocation receiver receives the bandwidth allocation.

Abstract: Channel quality estimating section 104 estimates the channel quality from the reception signal quality and outputs the result to transmission method determining section 105 and control signal dividing section 108. Transmission method determining section 105 determines a transmission method of a signal transmitted to communication partner from channel conditions and outputs the result to switch 106, switch 107 and control signal dividing section 108. Control signal dividing section 108 divides the transmission method information into high-speed control signal which is transmitted periodically and low-speed control signal which is transmitted on demand rather than periodically. Moreover, control signal dividing section 108 determines the combinations of low-speed control signal and high-speed control signal outputted from a tendency of communication quality, and outputs the result to modulator 114.

Abstract: Variable bit rate information is transmitted across a transmission link (20) at a constant bit rate by multiplexing individual variable bit rate elementary data streams (161 and 162) into a composite data stream (18) having a constant bit rate. A receiving device (22) receives the constant bit rate stream but delays processing thereof by an interval typically a fraction of the transmission interval. Following the delay interval, the receiving device processes the data at a rate that is independent of, but typically not greater than, the constant bit rate.

Abstract: An add/drop cross connection apparatus of an SDH system, comprises an aggregate unit matching device for providing matching with the aggregate units, a higher order path connection circuit for subjecting received higher order path data to cross connection by space switching, a lower order path connection circuit for subjecting received lower order path data to cross connection by space switching, and a selector for selectively delivering the data supplied from the aggregate units, higher order tributary device, and lower order tributary device, wherein the selector delivers the data to the higher order path connection circuit or lower order path connection circuit according as the data is the higher or lower order path data.

Abstract: An apparatus that includes a node having a scheduling cycle. The scheduling cycle is partitioned into amounts of data such that one of the partitioned amounts of data serviced per scheduling cycle corresponds to a data rate that corresponds to a highest speed grade managed by the node.

Abstract: An outer encoder and an inner encoder encode subsets of information to be transmitted, to improve protection by adding redundancy. The redundancy permits decoding of the information from less than a complete encoded block of information. The use of a combiner at an outer decoder enables better outer decoding of symbols.

Abstract: A low-speed subscriber extension type system interfaces with a switch link through a system backboard, receives a cell transmitted from the switch link, then multiplexes/demultiplexes the received cell through a UTOPIA interface after a switch link and ATM layer processing. A low-speed subscriber physical layer board transmits data, which is physical layer-processed in the low-speed subscriber board, to a low-speed subscriber, and serializes a cell transmitted from the low-speed subscriber board into a clock and data before transmission. Each low-speed extension board exchanges a cell with the low-speed multiplexing/demultiplexing board through a low-speed bus, performs physical layer processing on the cell of the corresponding board, and transmits a received cell to the corresponding subscriber through the low-speed extension physical layer board.

Abstract: The preferred embodiment of the present invention provides an improved receiver that can receive and process many different data types in addition to decoding MPEG-2 transport streams. The preferred embodiment minimizes hardware complexity by using the same loaders for both MPEG-2 and alternative stream data. The preferred embodiment utilizes a bypassable synchronizer and a bypassable packet parser to allow alternative data streams to be sent to system memory for decoding by a the host processor. When receiving MPEG-2 transport streams, the bypassable synchronizer and bypassable packet parser are used to synchronize and filter the MPEG-2 transport stream. The parsed MPEG-2 streams are then loaded into a packet buffer and passed to the video and audio decoders. When non-MPEG-2 stream data is provided, the bypassable synchronizer and bypassable packet parser instead forward the data to the packet buffer without performing synchronization or filtering.

Abstract: A dummy bit elimination device in a coding apparatus for use in a submarine cable system. The dummy bit elimination device has a converter for eliminating only dummy bits from FEC (Forward Error Correction) code. The coding apparatus has an optical-to-electrical signal transducer, a demultiplexer, a coder for generating an FEC code, a multiplexer for multiplexing inputs, and an electrical-to-optical signal transducer. The dummy bit elimination device is inserted between the coder and the multiplexer so that the outputs of the coder are fed to the converter and an outputs of the converter are fed to the multiplexer.

Abstract: A multimedia information system comprises first and second communication terminal apparatuses for exchanging information data using a common first communication protocol or first and second communication protocols which are different from each other, a first communication network for transmitting information data in accordance with a third communication protocol different from the first and second communication protocols, and first and second communication interface apparatuses for respectively connecting the first and second communication terminal apparatuses to the first communication network, the first communication interface apparatus comprises first conversion means for converting information data in accordance with the first and third communication protocols between the first communication terminal apparatus and the first communication network, and the second communication interface apparatus comprises second conversion means for converting information data in accordance with the second and third commun

Abstract: A communications network comprising a wireless local area network includes a plurality of access points connected to a host computer and each other, and a plurality of mobile units with each mobile unit being arranged for association with at least one access point. The mobile units are arranged to periodically scan for and identify the most eligible access point for association at the highest data rate on the basis of a performance criteria at the current data rate.

Abstract: A method and apparatus are disclosed for determining the data rate of a received signal in a communication system utilizing code division multiple access (CDMA) techniques. The well-known Viterbi decoding-based rate detection approach is combined with the conventional repetition pattern-based rate detection approach. The hybrid approach possesses the advantages of both prior approaches, without their disadvantages. The computationally efficient repetition pattern-based data rate detection approach, while not as reliable as the Viterbi decoder-based data rate detection approach, provides reliable data rate detection most of the time. The repetition-pattern data rate detection approach is used as long as a predefined reliability metric is satisfied, and only uses the more computationally intensive Viterbi decoder-based data rate detection approach when detection reliability may be compromised.

Abstract: A protocol independent multiplexer is described that allows for multiple different protocols that operate at different bit rates to be combined and output in a format that may have yet another bit rate. The multiplexer includes a series of inputting devices that are each coupled to a respective buffering device, a mapping device coupled to each of the buffering devices, and an outputting device coupled to the mapping device. Each of the inputting devices receive an input optical signal and forwards recovered data information to the corresponding buffering device. The buffering devices store the data information and output to the mapping device, the outputting being controlled by the mapping device to ensure that the buffering devices remain approximately half full. The mapping device formats the data information into individual data units and outputs the data units to the outputting device which subsequently multiplexes the data units.

Abstract: The present invention is directed to a method and system for unloading one or more T1 payloads from a target ATM cell where a target ATM cell has traveled over an ATM network that is emulating a T1 link. A plurality of ATM cells are stored in a cell buffer at a first rate. A buffer controller selects the target ATM cell from the bottom of the cell buffer. The buffer controller sends the T1 payloads carried in the target ATM cell to an elastic store buffer. The elastic buffer sends a plurality of timeslots in each T1 payload to a switch matrix at a second rate.

Abstract: A method and apparatus for a data transmission rate of multiples of 100 mega-bits per second (Mbps) in a terminal for a wireless metropolitan area network.

Abstract: A system and method of providing high-speed wireless local loop access using a wireless access multiplexer disposed in an access network coupled to a plurality of network termination (NT) nodes. The access multiplexer is coupled via an aggregate path to a Point of Presence (POP) switch on a common carrier running at a high aggregate bit rate. A Network Management System (NMS) is provided with a database for storing service subscription profiles for subscribers associated with corresponding NT nodes. The subscription profiles include information regarding subscribers' bandwidth requirements and other Quality of Service (QOS) parameters as per their subscriptions. Using the Label Distribution Protocol (LDP) messages and procedures, the access multiplexer establishes a plurality of wireless access channels to the corresponding network termination nodes based on the service subscription profiles stored in the NMS.

Abstract: An innovative channelizer design methodology is provided to adjust the narrowband channel frequency spacing and processing algorithm in order to develop a configurable multi-rate channelizer (20) for multiple applications with different input data rates and input channel group bandwidths. Given an input and output sampling rate and the input channel group bandwidth, the input channel spacing, the discrete Fourier transform (DFT) size, the valid output DFT bins, the dead zone implementation including the number of samples to blank for each chip, which exact samples to blank, the timing error immunity versus performance degradation balance may be derived to design hardware implementation of a configurable multi-rate channelizer for use in applications with different input data rates and input channel group bandwidths.

Abstract: The present invention is a novel and improved method and apparatus for transmitting data in a multiple carrier CDMA communication system. In the first implementation of the present invention, the data is encoded and the resulting encoded symbols are divided up and transmitted on different frequencies. The encoded symbols are provided to a symbol repetition means which keeps the symbol rate of data to be transmitted fixed. In a second embodiment, no symbol repetition is provided and variable length Walsh sequences are used to handle data rate variations.

Abstract: A new architecture capable of utilizing the existing twisted pair interface between customer premises equipment and an associated serving local switching office is used to provide a vast array of new services to customers. Using an intelligent services director (ISD) at the customer services equipment as an interface for the equipment to an existing twisted cable pair and a facilities management platform (FMP) at the serving local switching office as an interface to various networks and service opportunities, new services such as simultaneous, multiple calls (voice analog or digital), facsimile, Internet traffic and other data can be transmitted and received over the twisted cable pair by using digital subscriber loop transmission schemes. The new services include but are not limited to videophone, utility meter reading and monitoring, broadcasting and multicasting.

Abstract: In a control device for a storage device in which data streams are respectively divided into unit data, which are distributed to storage parts and are sequentially read therefrom for every unit data, there is provided a buffer memory which stores data to be written into the storage parts and data read from the storage parts. An input/output control part causes the unit data from the storage parts in an access cycle corresponding to a bit rate to be stored in the buffer memory and causes the unit data stored in the buffer memory at the bit rate to be written into the storage parts. An input/output interface part reads the unit data from the buffer memory at the bit rate and causes the data transferred at the bit rate to be stored in the buffer memory.

Abstract: An Ethernet mapping enables high speed Ethernet data streams having a data rate of 10 Gb/s to be transported across a synchronous packet switched network fabric having a standard SONET OC-192 line rate of 9.953280 Gbaud. The 10 Gb/s Ethernet data stream is compressed by removing interframe gaps between successive MAC frames to produce a compressed data stream, which is then mapped to a synchronous container. The synchronous container is then launched across the synchronous packet switched network fabric at a standard SONET OC-192 line rate of 9.953280 Gbaud. The synchronous container is preferably provided as a stripped STS-192c frame having only A1 and A2 octets of the Transport Overhead (TOH).

Abstract: A transport demultiplexor for demultiplexing an MPEG-2 compliant transport stream into a system data stream, a video data stream, and an audio data stream. The demultiplexor has frontend logic, a packet buffer, and data, video, and audio unloaders. The front end logic receives transport stream input packets, and delivers the transport stream packets to the packet buffer. The packet buffer, in turn, delivers system data to the system data unloader, video data to the video unloader, and audio data to the audio unloader.

Abstract: A method and concomitant apparatus for incorporating one or more relatively low bitrate information streams (e.g., MPEG) into a relatively high bitrate information stream (e.g., SDTI) in a manner aligning low bitrate sub-stream splice entrance points and splice exit points within the frame boundaries of the high bitrate information stream. In this manner the splicing of the relatively high bitrate information stream at appropriate In Frames and Out Frames will provide relatively seamless splicing of information sub-streams.

Abstract: In a signal processing circuit capable of handling different signal rates, an STS-3 signal input as 78 M.times.2 parallel signals is converted by a serial-to-parallel converter into 19 M.times.8 parallel signals, thus making the number of signal lines equal to that of an STS-12 signal input as 78 M.times.8 parallel signals. Depending on whether the mode is STS-12 mode or STS-3 mode, a first selector selects the 78 M.times.8 parallel signals of STS-12 or the 19 M.times.8 parallel signals of STS-3, and supplies the selected signals to a signal processor. Depending on whether the mode is STS-12 mode or STS-3 mode, a second selector selects a 78-M clock or a 19-M clock and supplies the selected clock to the signal processor.

Abstract: A multicarrier transmission system (100) routes data symbols from a data source (142) to a multicarrier modulator (145). Each modulator (201, 202, 203) within the multicarrier modulator (145) is coupled to a corresponding gain adjuster (211, 212, 213) that distributes the available transmit power across various subcarriers. Power distribution, is determined in part, upon the noise sensitivity of the transmitted information. In accordance, data stream symbols of like sensitivity are grouped (520) and transmitted during defined time intervals. Each such group is assigned a unique transmission power level (530). At any given moment in time, all subcarrier transmission power levels will have an identical amplitude, thereby mitigating the impact of subchannel-to-subchannel interference.

Abstract: An apparatus and method using the forward error correction setting to enable simultaneous use of multiple modulation systems on terrestrial distribution networks including cable television systems is described. The system includes a transcoder having a demultiplexer for demultiplexing a forward-error-correction decoded signal into a main data stream with a bit rate suitable for 64-QAM cable transmission and an auxiliary data stream with a bit rate approximately half that of the main data stream. Two of such auxiliary data streams can be combined to generate an output data stream with a bit rate suitable for 64-QAM cable transmission. The system also includes a satellite transmitter which can adjust its convolution coding rate to either 1/2 or 3/4 for 64-QAM and 256-QAM cable channels respectively.

Abstract: A method and apparatus for digital signal transmission, in which data of plural media is transmitted and received over a communication transmission channel. A digital signal format for the transmitted digital signal has an ancillary data section ANC within which there are a plurality of channels for audio signals, each channel including a leading line number area LN, a type area TP, a byte count area BC, an error correction code ECC and a data area DT. The digital signal format also has a payload section PAD within which there are a plurality of channels for video signals, or the like. Each channel includes a type area TP, a byte count area BC, an error correction code ECC and a data area DT.

Abstract: A data multiplexing system which includes a plurality of data multiplexing buses through which a plurality of low-speed digital signals are collected into, and distributed from, a multiplexer/demultiplxer. In a data multiplexing mode, the low-speed digital signals entered from a plurality of low-speed transmission lines have their signal format converted by respectively corresponding low-speed interface circuits, and the resulting signals are multiplexed in time slots designated within a multiplexed signal of primary level on the up bus line of the corresponding data multiplexing bus. The high-speed multiplexer multiplexes the collected signals up to a predetermined signal level and sends the resulting secondary multiplexed signal to a high-speed interface module having a high-speed transmission line interface. The high-speed interface module converts the received secondary multiplexed signal and sends the resulting signal to the high-speed transmission line.

Abstract: A 1:N divider 40 divides an input high rate data signal into N (N being 2 or greater integer) division data signals. Data transmission rate converters 70.sub.1 -70.sub.N for converting the transmission rate of each of the N division data signals. The respective N division data signals are transmitted through N transmission lines 30.sub.1 -30.sub.n. A multiplier 50 multiplies the transmitted N division data signals into a single high rate data signal.