British Telecommunications Public Limited Company

The Technology Partnership, Plc.

Psytechnics Limited

British Telecommunications Corporation

Lucida Medical Ltd.

Antony William Rix

Michael Peter Hollier

Philip Gray

Richard J B Reynolds

David Smith

Paul Alexander Barrett

Mathew Richard Palmer

Richard Jb Reynolds

David Russell Anderson

Matthew C B Lumb

Philip J Sheppard

Richard John Buchan Reynolds

Gray Philip

Eleanor J Beamond

Phil Gray

Tom Goldstein

Philip Michaelson-Yeates

Richard E Pittaway

Martin Orrell

Ian George

Phillip Gray

Philip Julian Sheppard

Richard John Reynolds

According to the invention there is provided a method of estimating an amount of at least one biomarker for a subject, based on an image of the subject imaged by a medical imaging method, the method comprising: processing the image to identify at least one tissue type within a region of interest of the image and determining an amount of each identified tissue type; associating each identified tissue type with a measure of biomarker production; calculating a total amount of biomarker production for the identified tissue types.

Method for biomarker estimation

A system for controlling an electricity supply to a load comprises at least one battery for storing energy. The system also comprises a controller for determining when to switch between a first mode wherein electricity is supplied to the load from a mains electricity circuit; and a discharging mode wherein electricity is supplied from the battery to the load via the mains electricity circuit. The determining is based on information associated with the electricity supply.

System and method for controlling an electricity supply

A wireless receiver, in the form of a mobile telephone, includes a DAB receiver and a GSM/GPRS transceiver which enables bi-directional point-to-point data communications via a service provider. The DAB receiver is arranged to receive media data from an over-the-air broadcast channel, the media data primarily representing television and radio streams. In order that the streams can be decoded and decrypted by media playing software on the wireless receiver, a provisioning operation is employed to provide NSC header files and DRM licenses to users in response to them making content requests. The header files and licenses are sent over a separate data channel and in advance of the broadcast content.

Decoding media content at a wireless receiver

The degree of degradation imposed on signals transmitted over a communications link from a transmitter to a receiver is tested. A predetermined test signal is transmitted using spare capacity detected by a voice activity detector when no speech is to be transmitted over the communications link. The test signal received by the receiver is compared with the reference signal, and a measure of the degradation of signals caused by the communications link is generated therefrom.

Test signalling

The perceptual quality of voice signals used for Voice over IP (VoIP) systems is assessed. The content of the voice data packets may be altered in order to increase the perceived quality of the VoIP system.

Method to reduce the distortion in a voice transmission over data networks

A method and apparatus for assessing the perceptual quality of stereo speech signals transmitted via a telecommunications network and recorded acoustically from an acoustic terminal device in which a mono reference signal comprising a single channel is aligned with a degraded stereo signal comprising a left and a right channel; a delay between each channel of said degraded signal and said reference signal is estimated; a noise masking indicator in dependence upon said estimated delays is generated; the level of the stereo signals is adjusted in dependence upon said noise masking indicator; a set of perceptually relevant parameters for each of said reference and degraded signals are generated; the perceptually relevant parameters of the reference signal with the perceptually relevant parameters of the degraded signal to generate a disturbance profile are compared; and a speech quality prediction is generated in dependence upon said disturbance profile.

Speech quality assessment with noise masking

This invention relates to measurement of error characteristics of a communication channel. The invention is of particular use for measuring perceived transmission performance of the communication channel. The invention provides a method and apparatus for measuring the transmission error characteristics of a channel employing frame based transmission in which a frame classification indicator is generated for an expected frame, according to data received via said channel, and in which the following steps are repeatedly performed: generating frame classification data relating to the expected frame; updating a statistical representation of the transmission error characteristics according to said frame classification. The invention also provides a method and apparatus for measuring perceived transmission performance of a communications channel in which the perceived transmission performance is generated according to measured transmission error characteristics.

Method and apparatus for transmission error characterization

The present invention relates to a method and apparatus for determining channel degradation information in which a known data sequence is compared to a transmitted version of the known data sequence to provide such information. To assess performance of a public land mobile network, it is convenient if assessment apparatus is located in the network rather than in a mobile station. The invention provides a technique for efficiently sending data characterizing channel degradation caused by the network to mobile station communication channel from the mobile station back to the network, where the channel degradation information is reconstructed.

Method and apparatus for measurement of channel transmission accuracy

The present invention provides a test method which can determine whether a user terminal is capable of supporting a real time connection, such as a computer telephony link, with a network terminal while simultaneously supporting a connection with a WWW server.

Method to assess the quality of a voice communication over packet networks

The perceptibility of degradations caused to signals transmitted over a transmission medium is measured by generating one or more predetermined transmission degradation conditions (e) and subjecting a test signal (S) to the transmission degradation conditions (e) in a network simulation device. The degree M(e) to which the or each transmission degradation condition (e) is perceptible to the human perceptual system is measured and a data set is generated and stored for converting one or more transmission degradation conditions (e) to respective values of perceptibility M(e). The data set may be a look-up table or an empirically determined formula. The data set may then be used on live traffic (S'), by identifying objectively measured transmission degradation conditions (e) in the received signal (S&#x2032;) and retrieving from the data set in the data storage means (7) a value of perceptibility (M) associated with the transmission degradation conditions (e) so identified. In this way a measure of the subjective significance of degradation in the signal (S&#x2032;) can be derived from objective measures of degradation.

Apparatus for assessing the performance of telecommunications systems by comparison of a reference signal with the same signal as degraded by the system under test tends to give unreliable results when used to test connectionless packet-switching equipment. This is because variable delay in delivery of the individual packets can result in the test signal and reference signal becoming unsynchronised. This may lead to the apparatus recording a poorer performance than a human tester would have recorded. To overcome this problem, the invention separates the test signal into a series of individual sections, which are synchgronised and analysed separately, and a quality value, aggregated over all the sections, is derived.

Measurement of signal quality

A test stimulus includes two signals R , S. Signal S is transmitted to a customer equipment interface and over a system under test to a complementary remote apparatus. The test apparatus has two inputs processed by a number of functional elements. The first input is the reference signal R . The other input is a corresponding test signal R&prime; generated at remote test apparatus as a test signal R, identical with reference signal R , and transmitted over the system under test via the customer interface. These two versions of the same test signal are compared. Firstly, the signals R , R&prime; are processed by a psycho-acoustic model, the output of which is transmitted to a perceptual layer, and then to a conversion unit which also receives a further input from a non-optimum loudness rating unit. The output from the conversion unit is transmitted to a signal quality determination unit, which also receives an input from the customer equipment interface. The non-optimum loudness rating unit processes inputs from the customer equipment interface and signal generator. During an iterative process, the signal generator receives feedback control from the signal quality determination unit. The remote test apparatus similarly receives a modified version of signal S (viz S&prime;) from the network and compares it with a locally-generated reference version S . In an alternative arrangement the same test apparatus is connected to both test points of the network and processes both signals S and R, either serially or in parallel.

A communications system is tested to simulate a realistic conversation. A first measurement device make a call, through the system it is testing, to a second measurement device and the two devices converse using predetermined speech generated dynamically by each device in response to the signals received from the other, to simulate aspects of conversation over non-perfect communications system link. The progress of the conversation will therefore take different courses according to the quality of the link. For example, if an expected signal is detected by one device, it transmits an appropriate predetermined response to the other device. However, if the expected signal is corrupted, or not received at all, different predetermined responses (or no response at all) are transmitted to the other device. This in turn may cause the other device to repeat the original signal. Because all the responses, including those to poor quality signals, are predetermined, each device can readily determine the quality of the signals received, because each signal received by one device form the other must be one of a limited number of possible responses to the last transmission made by the one device to the other. The devices perform measurements on the sounds they receive from each other, and monitor the progress of the conversation to compute parameters describing aspects of the received signal quality.

Growing community of inventors

Cambridge, United Kingdom

Antony William Rix