Abstract: A mobile radio network comprises a plurality of communication points, each of which are capable of communicating with any other communication point. Each communication point has a proximity sensor, a transmitter/receiver (14), which is able to send signals to and receive signals from the other communication points. Elements for controlling the transmitter/receiver and elements for storing data to identify the communication points is also described.

Abstract: A power management system for electrical and electronic apparatus has a number of components which may be switched to a low power state. A power controller (20) is coupled to each component in the apparatus and a plurality of power modules (22, 24, 26) are each associated with a component. Each power module is coupled to the power controller for each component its associated component makes use of. It sends signals to that power controller indicating whether or not its associated component wishes to make use of the component coupled to that power controller. The power controller switches its component to a low or high power state in dependence on the received signals.

Abstract: A method is provided of extracting desired signals st from contaminated signals yt measured via respective communication channels. The system comprising the desired signals st and the channels is modelled as a state space model. In the model, the desired signals have time-varying characteristics which vary more quickly than second time-varying characteristics of the channels.

Abstract: A power management system for electrical and electronic apparatus has a number of components which may be switched to a low power state. A power controller (20) is coupled to each component in the apparatus and a plurality of power modules (22, 24, 26) are each associated with a component. Each power module is coupled to the power controller for each component its associated component makes use of. It sends signals to that power controller indicating whether or not its associated component wishes to make use of the component coupled to that power controller. The power controller switches its component to a low or high power state in dependance on the received signals.

Abstract: A power management system for electrical and electronic apparatus has a number of components which may be switched to a low power state. A power controller (20) is coupled to each component in the apparatus and a plurality of power modules (22, 24, 26) are each associated with a component. Each power module is coupled to the power controller for each component its associated component makes use of. It sends signals to that power controller indicating whether or not its associated component wishes to make use of the component coupled to that power controller. The power controller switches its component to a low or high power state in dependence on the received signals.

Abstract: A location system for objects having location devices (16) as a means for repeatedly interrogating the location devices on each object to provide position signals. A means (18) to detect the position signals are provided. The position of each object and the area associated with each object are determined from the position signals and stored. The system is then able to determine the relative locations of the thus determined objects and associated areas.

Abstract: A mobile radio network comprises a plurality of communication points, each of which are capable of communicating with any other communication point. Each communication point has a proximity sensor, a transmitter/receiver (14), which is able to send signals to and receive signals from the other communication points. Elements for controlling the transmitter/receiver and for storing data to identify the communication points.

Abstract: A system which enables the position of each plurality of mobile labelled objects in a specified environment to be determined from the transit times to fixed receivers of ultrasound energy transmitted by object mounted transponders which are triggered by radio energy, wherein the specified environment is divided into cells each have a radio transmitter transmitting the radio triggered signals, these radio transmissions being multiplexed in accordance with identifying characteristics of the respective cells, no two cells with the same identifying characteristics overlapping one another.

Abstract: A system for determining the position of each of a plurality of objects in a specified environment by determining the transit times of slowly propagating measurement energy transmitted from a measurement energy transmitter on each object to a plurality of fixed measurement energy receivers in the specified environment, the transmission of the measurement energy being triggered by a burst of high speed propagating trigger energy into the specified environment from a trigger energy transmitter, the measurement energy transmitter on each object being triggered by an object-mounted trigger energy receiver, each burst of trigger energy being encoded so as to trigger one only of the measurement energy transmitters, wherein a coordinating control system determines the order in which the measurement energy transmitters are triggered, in response to updatable information relating to service demands of the trigger energy transmitter and/or objects.

Abstract: A system which enables the position of each of a plurality of movable labelled objects to be determined in an environment having two or more isolated zones, wherein the objects carry transponders which, in response to encoded radio signals, transmit ultrasonic signals of which the transit times to a plurality of fixed receivers are determined, the transponders in the different zones being triggered in a common timeslot but in staggered relationship for one zone as compared to another, and an algorithm is applied to verify the consistency of the transit times having regard to the possible movements of objects from one zone to another.

Abstract: A system for determining the position of a labelled object within an environment containing a plurality of detectors sensitive to energy of a first type and located at known positions therearound, wherein the object has a transmitter for transmitting energy of the first type, and each object is labelled by means of a receiver forming part of a communication link with a remote controlling transmitter for triggering the object-mounted transmitter. The transit time between the transmitter and each detector is used to determine the straight line distances between the object and the receivers, to enable the position of the object relative to the receivers to be determined. The arrival and departure of an object into and from the environment is determined by a second communication link from a second transmitter on each object, to a remote receiver. The two communication links may be combined in a bi-directional radio communication system.

Abstract: A method for encoding digital information to be transmitted from a first device to a second device, wherein the digital information is mapped according to a map of n rows and m columns which define a plurality of cells (n×m) and wherein each of said cells has a pixel value. The method is useful for compressing bitmapped images to be rendered by the simplest of graphics engines. Thus the method is particularly suited to the transmission of images to a relatively slow client on which the images are to be rendered in real time and on which any complex decompression would be too costly for such rendering. Raw compression ratios are comparable to those obtained with standard run-length encoding, but the number of drawing primitive calls required to render the compressed images directly is substantially less.

Abstract: An ultrasonic location system for indoor environments, enabling the determination with high accuracy of the positions and orientations of objects to be tracked, wherein transmitting units (20, 22, 24) on the objects to be tracked transmit encoded ultrasonic pulses which are detected by receiver units (12 to 18) located by known positions around a room, and the receiver units are adapted to detect times-of-flight of the ultrasonic pulses in conjunction with decoding of the pulses to identify which time-of-flight applies to each transmitting unit.