Lucent Technologies Inc.

At&t Bell Laboratories

Agora Laboratories Inc.

George John Kustka

Subrahmanyam Dravida

Peter David Magill

Bharat Tarachand Doshi

Kotikalapudi Sriram

Curtis A Siller

John N Mailhot

Kim N Matthews

Alireza F Faryar

Rajiv Laroia

Arun N Netravali

Scott C Knauer

Eric D Petajan

Alireza Farid Faryar

Jin-Der Wang

Nuri Ruhi Dagdeviren

Peter H Westerink

Nelson Botsford, Iii

Charles A Webb, Iii

Andres C Gonzalez

A method, system and apparatus for adapting the multimedia content for presentation by an application that uses, processes or otherwise services the multimedia content ('multimedia application') is provided. The method includes receiving the multimedia content formatted in accordance with at least one of a plurality of multimedia protocols; using a function abstracted from the plurality of multimedia protocols to adapt the multimedia content in accordance with one or more capabilities of the multimedia application; and sending the multimedia content so adapted to the multimedia application for presentation.

Universal multimedia engine and method for producing the same

An Asymmetric Digital Subscriber Loop (ADSL) Discrete Multi-Tone system has disjoint and adjacent upstream and downstream channels. During the training phase of an ADSL connection, an ADSL DMT transmitter first determines a round trip propagation delay by transmitting a ranging signal to a far-end ADSL endpoint. During the subsequent communications phase, the ADSL transmitter synchronizes transmission of DMT symbols to a reference clock. In addition, the cyclic extensions of each DMT symbol are increased as a function of the propagation delay.

Reduction of interference in discrete multi-tone (DMT) based communications systems

The specification relates to a method and apparatus supporting multiple access, bi-directional data and multimedia transfer described over a hybrid fiber/coax (HFC) network, though applicable to transmissions over other media as well. The protocol associated with the present invention supports downstream broadcast transmission from headend to cable modem, and also provides for allocation of bandwidth for cable modems to transmit back to the headend. The protocol supports different access modes such as STM, ATM, and VL; within each subframe of a subframe/frame/masterframe structure. The protocol is utilized over a system which provides for forward error correction (FEC) and scrambling/descrambling, while eliminating the deleterious effects on the error correcting capability of the FEC due to the bit error spreading associated with a scrambling/descrambling function. The protocol adapts to changing demands for a mix of circuit and packet mode applications and allocates upstream and downstream bandwidth in response to the a variety of bursty and isochronous traffic sources.

Method and apparatus for digital transmission incorporating scrambling and forward error correction while preventing bit error spreading associated with descrambling

The specification relates to a broadband multiple access protocol for bi-directional hybrid fiber/coax (HFC) networks. The protocol supports downstream broadcast transmission from headend to cable modem, and also provides for allocation of bandwidth for cable modems to transmit back to the headend. Although the present invention is described in relation to an HFC network, it is also equally applicable to a wireless communications environment. The protocol supports different access modes such as synchronous transfer mode, asynchronous transfer mode, and variable length data. The protocol adapts to changing demands for a mix of circuit and packet mode applications and allocates upstream and downstream bandwidth in response to the a variety of bursty and isochronous traffic sources. In order to satisfy the quality of service requirements of varied applications, while maintaining high bandwidth efficiency, the protocol utilizes a frame structure with frame partitioning into regions; one region dedicated to STM payload and asynchronous, second region dedicated to ATM and VL payloads, messaging and control.

Method and apparatus enabling synchronous transfer mode, variable length

The specification relates to a broadband multiple access protocol for bi-directional hybrid fiber/coax (HFC) networks. The protocol supports downstream broadcast transmission from headend to cable modem, and also provides for allocation of bandwidth for cable modems to transmit back to the headend. Although the present invention is described in relation to an HFC network, it is also equally applicable to a cellular wireless communications environment. The protocol supports different access modes such as STM, ATM, and VL; within each subframe of a subframe/frame/masterframe structure. The protocol adapts to changing demands for a mix of circuit and packet mode applications and allocates upstream and downstream bandwidth in response to the a variety of bursty and isochronous traffic sources. In order to satisfy the quality of service requirements of varied applications, while maintaining high bandwidth efficiency, the protocol utilizes a subframe structure with subframe partitioning into regions; one region dedicated to STM payload transmission, a second region dedicated to ATM cell transmission, and a third region dedicated to VL payload transmissions.

Method and apparatus enabling multiple access for multiple services and

Digital streams are converted into analog signals for recording by analog recorders, such as conventional video cassette recorders, onto analog storage media, such as conventional video cassette tapes. The recorded analog signals are then retrieved from the analog storage media using an analog player, such as a conventional video cassette player, and converted back into the original digital streams. The present invention allows conventional analog-based recording and playing equipment, like video cassette recorders/players, to be used for storing and retrieving digital data. In one embodiment, the digital streams correspond to digital audio/video data and the retrieved digital streams can be further processed to playback the audio/video streams using conventional television sets. In other embodiments, the digital streams correspond to other digital data streams that can be converted into analog signals for storage and retrieval using conventional video cassette recorders and conventional video cassette tapes.

Storage of digital data as analog signals

A temporally-pipelined predictive encoder/decoder circuit for encoding or decoding an input signal containing a sequence of data frames received at a particular frame rate and frame data rate into an output signal having an equal frame rate employs a plurality of N predictive encoders/decoders. An input buffer may be used to extract the information for each data frame in the input signal and supply such information to a corresponding one of the encoders/decoders at rate of 1/N of the particular frame data rate. Each encoder/decoder generates corresponding encoded/decoded information as it is received as well as provides digitized frame information to the encoder/decoder processing the next received image frame. The encoded/decoded information is provided to corresponding frame buffers which temporarily store such information. Each one of the frame buffers is connected to respective inputs of a multiplexer, wherein the encoded/decoded information is provided to a multiplexer output to form the encoded/decoded output signal. When information for the entire frame has been stored by a frame buffer, the stored data information is provided to the multiplexer output to provide the portion of the output signal corresponding to that frame.

Temporally-pipelined predictive encoder/decoder circuit and method

Apparatus for eliminating the truncation errors associated with a multiplicative leak factor employed in a predictive coding arrangement adds a temporally varying control signal that affects the leak factor multiplication output. Specifically, in one embodiment the leak factor multiplication output is modified by arbitrarily changing, or dithering, the level of the mean signal. In another embodiment, the leak factor multiplication output is modified by effectively dithering the leak factor itself. The latter is accomplished by adding the varying control signal prior to the truncated division which occurs in the leak factor multiplication process.

Truncation error correction for predictive coding/encoding

Encoded blocks of video information are selected for transmission at a plurality of channel rates based on the corresponding location of the portions of the video image represented by the encoded blocks. Each encoded block is designated an image type which determines its transmitted channel rate. The image types are associated with spatial positions of a video image such that encoded blocks within a first area of the video image are designated a first image type and encoded blocks within a second area of the image are designated a second image type. In general, data blocks representing the central portion of the video image are transmitted at a channel rate having less susceptibility to noise or other degradation, thereby ensuring that such portion can be received in fringe areas.

Method and apparatus for transmitting encoded blocks of video signals at

Blocks of HDTV picture information are selected for transmission at a plurality of channel rates of an HDTV transmitter. The size of each block of HDTV picture information is dependent on a target distortion parameter for the HDTV picture information. As a result of this selection, a portion of each block of HDTV picture information is transmitted at the lower channel rate, with the result that the HDTV transmitter range is maximized while maintaining a picture quality for the resulting HDTV video image.

Soft coding for HDTV

Apparatus for decoding a stream containing codes of a variable length code (VLC) takes advantage of the fact that a trie representation of the VLC can be pruned to leaves that each represent a complete binary trie. Combinational circuits or ROMs are then employed to decode the pruned trie, thereby substantially reducing the complexity of decoding a VLC. In one embodiment the decoding problem is partitioned into segments by considering a few bits at a time, starting with the most significant bits. Each segment either outputs a valid code or informs the next segment that the decoding process is incomplete and provides information to assist the next segment in its decoding effort. In applications where the VL code can be selected for greater efficiency of the decoder, the offered VL code can be restructured to minimize the number of k-nodes, to thereby minimize the pruned trie, and to concomitantly minimize the sizes of the ROMs in the decoder.

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Marlboro, NJ, United States of America

George John Kustka