Abstract: A video sequence is to be transmitted at a selectable quality from a server over a network. A network control protocol operates in response to a control parameter to allocate to the server a share of available transmission capacity in proportion to the value of the control parameter. First, one determines a plurality of transmission rate values that are needed over successive time periods of the sequence for successful transmission of the sequence at a reference quality; then the control parameter is set, proportional to the transmission rate value and communicated to the control protocol at corresponding time instants. The sequences can then be transmitted, encoded at a quality from time to time selected in dependence upon the actual transmission capacity made available by the network to the server.

Abstract: Path characterization information is provided to a data sender relating to a network characteristic such as congestion experienced by data units traversing a path across a data network from the data sender towards one of a plurality of data receivers. The data units have associated therewith information indicative of the network characteristic. The path is traversed by the data units having at least a first path portion between the data sender and a proxy node along which data units may traverse conveying a measure indicative of the network characteristic that is representable by any of a first set of codepoints. The data receivers are operable to provide data acknowledgement units in respect of data units they receive via a second path portion in which information indicative of the network characteristic may only be representable using codepoints of a second set of codepoints having less codepoints than the first set.

Abstract: Methods, apparatus and other means for providing path characterisation information to a data sender relating to a network characteristic such as congestion experienced by data units traversing a path across a data network from the data sender towards one of a plurality of data receivers, the data units having associated therewith information indicative of the network characteristic, the path being traversed by the data units having at least a first path portion between said data sender and a proxy node along which data units may traverse conveying a measure indicative of the network characteristic that is representable by any of a first set of codepoints, the data receivers being operable to provide data acknowledgement units in respect of data units they receive via a second path portion in which information indicative of the network characteristic may only be representable using codepoints of a second set of codepoints having less codepoints than the first set of codepoints.

Abstract: A video signal is coded using predictive coding. The degree of quantization that is applied is varied as a function of measures of predictive power, the idea being that a picture that is useful as a predictor for other pictures is worth coding well. These measures are formed in a pre-analysis of the pictures to obtain, for each macroblock analysed, a measure that depends on its similarity to a region for which it is a potential predictor. Preferably these measures are cumulative.

Abstract: There is proposed a modification to the ECN protocol to remove the one-to-one relationship between the network signalling congestion and the sender response to that congestion. The result is to allow a receiver terminal to exhibit some control of bandwidth share relative to other receiver terminals. The idea is to calculate the average CE arrival frequency from received data packets and to set ECE flags at a rate determined as a function of the average CE arrival frequency. Preferably, the function is a multiplier applied to the average CE arrival frequency. The effect of averaging the CE arrival frequency as well as application of a multiplier is a decoupling of the ECE marked ACKs sent by a receiver to the sender, and control of the resulting transmission rate at the sender.

Abstract: The bitrate for any practical video streaming system will vary considerably as a function of the difficulty of encoding the sequence in question. This variation is even more apparent when comparing different video clips of different genres for example where sports clips might require a higher average bitrate and fluctuate more due to the high activity of typical scenes, whereas a news report clip might require a much lower bitrate and be relatively static. As such, to deliver video streams at a constant quality to users sharing a contended network, a constant bandwidth method is not efficient to use across all the streams. The bandwidth allocated to each stream must be allowed to dynamically vary in time in accordance with the precise demands of the video being streamed at that time and also be within any network bandwidth constraints. The present invention defines such a method.

Abstract: A video sequence is to be transmitted at a selectable quality from a server over a network. A network control protocol operates in response to a control parameter to allocate to the server a share of available transmission capacity in proportion to the value of the control parameter. First, one determines a plurality of transmission rate values that are needed over successive time periods of the sequence for successful transmission of the sequence at a reference quality; then the control parameter is set, proportional to the transmission rate value and communicated to the control protocol at corresponding time instants. The sequences can then be transmitted, encoded at a quality from time to time selected in dependence upon the actual transmission capacity made available by the network to the server.

Abstract: There is proposed a modification to the ECN protocol to remove the one-to-one relationship between the network signalling congestion and the sender response to that congestion. The result is to allow a receiver terminal to exhibit some control of bandwidth share relative to other receiver terminals. The idea is to calculate the average CE arrival frequency from received data packets and to set ECE flags at a rate determined as a function of the average CE arrival frequency. Preferably, the function is a multiplier applied to the average CE arrival frequency. The effect of averaging the CE arrival frequency as well as application of a multiplier is a decoupling of the ECE marked ACKs sent by a receiver to the sender, and control of the resulting transmission rate at the sender.

Abstract: A video signal is coded using predictive coding. The degree of quantisation that is applied is varied as a function of measures of predictive power, the idea being that a picture that is useful as a predictor for other pictures is worth coding well. These measures are formed in a pre-analysis of the pictures to obtain, for each macroblock analysed, a measure that depends on its similarity to a region for which it is a potential predictor. Preferably these measures are cumulative.

Abstract: The bitrate for any practical video streaming system will vary considerably as a function of the difficulty of encoding the sequence in question. This variation is even more apparent when comparing different video clips of different genres for example where sports clips might require a higher average bitrate and fluctuate more due to the high activity of typical scenes, whereas a news report clip might require a much lower bitrate and be relatively static. As such, to deliver video streams at a constant quality to users sharing a contended network, a constant bandwidth method is not efficient to use across all the streams. The bandwidth allocated to each stream must be allowed to dynamically vary in time in accordance with the precise demands of the video being streamed at that time and also be within any network bandwidth constraints. The present invention defines such a method.

Abstract: A computer natural language translation system inputs source language text and outputs target language text. The target language text is generated from the source language text using stored translation data generated from examples of source and corresponding target language texts. The stored translation data includes a plurality of translation components, each having surface data representative of the order of occurrence of language units in the component; dependency data related to the semantic relationship between language units in the component; and link data linking dependency data of language components of the source language with corresponding dependency data of language components of the target language. The surface data of the source language is used in analyzing the source language text, and the surface date of the target language is used in generating the target language text.

Abstract: A computer language translation development system, for developing data for use in translation, comprising: means for utilising corresponding source and target example texts to generate translation units each comprising, in the source and/or target language, a first language item and a second language item of the same language, and means for subsequently generating restrictions on candidate second language items which can be combined with each said first language item. A computer language translation development system, for developing data for use in translation, comprising: means for generating original translation units each comprising, in the source and/or target language, a first language item, and property data which restricts with which second language items that first language item can occur; and means for generating additional synthetic translation units comprising new combinations of the first language items and property data of said original translation units.

Abstract: Training apparatus for training a user to engage in transactions (e.g. a foreign language conversation) with another person whom the apparatus is arranged to simulate, the apparatus comprising: an input for receiving input dialogue from a user; a lexical store containing data relating to individual words of said input dialogue; a rule store containing rules specifying grammatically allowable relationships between words of said input dialogue; a transaction store containing data relating to allowable transactions between said user and said person; a processor arranged to process the input dialogue to recognise the occurrence therein of words contained in said lexical store in the relationships specified by the rules contained in said rule store in accordance with the data specified in the transaction store, and to generate output dialogue indicating when correct input dialogue has been recognised; and an output device for making the output dialogue available to the user.

Abstract: A computer language translation development system, for developing data for use in translation, comprising: means for utilising corresponding source and target example texts to generate translation units each comprising, in the source and/or target language, a first language item and a second language item of the same language, and means for subsequently generating restrictions on candidate second language items which can be combined with each said first language item. A computer language translation development system, for developing data for use in translation, comprising: means for generating original translation units each comprising, in the source and/or target language, a first language item, and property data which restricts with which second language items that first language item can occur; and means for generating additional synthetic translation units comprising new combinations of the first language items and property data of said original translation units.

Abstract: Apparatus for use within a system for translating a document from a source language to at least one target language, comprising means for parsing said document using grammar rules specific to said source language, to derive a source language semantic structure; means for processing said source language semantic structure, to detect the presence therein of semantic elements which are specific to said source language, and to replace said semantic elements with replacement elements which are generic to a plurality of possible said target languages, to generate a generic semantic representation of said document.