Abstract: First and second devices having clocks which may have different clock rates. Obtaining a measure of the distance of propagation of a signal passing between the devices involves transmitting a first signal 12 from the first device to the second device. After a turnaround time TAT, a second signal 14 is transmitted from the second device to the first device. Any error in the clocks may lead to an error in the measurement of the turnaround time TAT. One device contains circuitry to calculate the ratio of the clock rates of the first and second devices, either by adjusting frequency divider ratios until there is LO frequency match, or by determining the offset frequency of an envelope of a mixed signal. The ratio of the clock rates is used to compensate the turnaround time TAT, to mitigate error. The accurate distance measurement can be used to determine if a relay attack has taken place in a vehicle security system.

Abstract: A time-of-flight ranging system, such as a keyless access Control system, comprises a first part and a second part, e.g., a portable device such as a key fob. Both parts have a transceiver for effecting communication with each other. At least the first part includes a device, e.g., a processor, for determining the distance between the two parts based on time-off-light. To save power, when the two parts are a relatively great distance apart, a time-of-flight measuring device computes the time based on a relatively coarse algorithm, and when the parts are relatively close, the computation is carried-out using a more precise algorithm. The clock frequency may be reduced when the two parts are a relatively great distance apart, and increased when they are closer. Further the transmitter power may be reduced when the two parts are relatively close together and increased when they are a relatively great distance apart.

Abstract: A network for locating a wireless tag comprises a plurality of wireless nodes. The nodes are not connected together by a wired network. Each node is included in a floor tile for installation inside a building and configured to be wirelessly connectable to at least one other node. When the floor tiles are installed, the plurality of nodes form a mesh or grid and provide overlapping wireless coverage for locating the tag by reference to the mesh.

Abstract: Method for obtaining range and/or positional information of electronic devices typically rely on a device (A) re-questing that another device (B) supplies a reply message (22), which contains some timing information (T2, T3) on the signals received and sent. Problems that arise in such networks comprise: firstly, some devices (C) may be out of range of the device (A) that initiates the ranging measurements, and secondly, some devices (B, C) may not be allowed to communicate with each other and thus, the distance between these devices cannot be found. This invention discloses that in these cases, eavesdropping on messages (21, 22, 24) passing between other devices (A, B, C) in the system can result in that distances between additional devices are found. Furthermore, by using eavesdropping the number of transmissions, and therefore the potential for collisions, is reduced. Thus, the power consumption of the nodes in the network can be lowered.

Abstract: The invention provides a technique of correcting time data based on a clock signal affected by jitter. The error due to jitter in a time measurement of an event in the clock signal (17) is determined at the time of the event or as an average over a number of events. A measurement is made of a time dependent reference variable associated with a long-time constant device (19), such as a capacitor, which is relatively immune to localised jitter. The measurement may be a reading of the voltage across a charging capacitor. The measured value is compared to an expected value and the time error is based on the result. The expected value may be known from look-up tables (18) in the memory (6) of the device (1) comprising the capacitor (19) or calculated from known charging rates of the capacitor. The error due to jitter of a time measurement is approximately linearly proportional to the difference in voltage between the measured and the expected values of the capacitor.

Abstract: This invention provides compositions and methods for producing low cholesterol poultry eggs using hypocholesterolemic compounds, cholesterol lowering supplements, and feeds therefrom. Preferably, this invention provides microbial statins without methyl group in C6, as shown in formula V, in order to produce low cholesterol poultry eggs. The invention allows producing low cholesterol poultry eggs without concomitant reduction of egg production by providing microbial statins, compactin and pravastatin as well as their derivatives, as cholesterol lowering components. This invention also provides methods for producing low cholesterol poultry eggs without huge increase of production cost since the effective amount of cholesterol lowering composition containing microbial statin costs 1/120-¼ of that of synthetic statin.

Abstract: A time-of-flight ranging system, such as a keyless access control system, comprises a first part (10) and a second part (12), which may implemented as a portable device such as a key fob. Both parts have signal transmitting and receiving means (14, 22 and 26, 32) for effecting communication with each other. At least the first part comprises means for determining the distance between the first and second parts based on time-offlight. In order to save power, when that first and second parts are a relatively great distance apart, the time-of-flight measuring means computes the time based on a relatively coarse algorithm, and when the parts are relatively close, the computation is carried-out using a more precise algorithm.

Abstract: A method of determining the relative position of a secondary station (SS) in a radio system including at least one master station (MS) and a plurality of secondary stations (SS), comprises the master station establishing a master log of the time stamp of signals transmitted by active stations and their identities and active secondary stations (SS) establishing a log of the time stamp of signals transmitted by other stations and their respective measured received quality. One of the active secondary stations forwards its log to the master station and the master station correlates the time stamps in the received log with the time stamps in the master log in order to determine the identities of the transmitters and utilizes the measured signal quality indications in the received log to determine the relative position of the secondary station with respect to the locations of the transmitters identified.