Abstract: A road toll system comprises a vehicle-mounted unit comprising a satellite navigation system implementing a position tracking function; transmitting means for transmitting position or route information to a remote server; and a unique identification device for attaching to the vehicle, and associated with the satellite navigation receiver. The road toll system function is enabled only when the identification device is present. The identification device comprises an electronic device which is adapted to alter by detachment or attempted detachment such as to prevent the road toll system function being enabled. This system increases the security of this type of system and makes fraudulent use of the system increasingly difficult.

Abstract: A road toll system comprises a vehicle-mounted unit having a satellite navigation receiver. A first data processing means determines a route taken based on satellite navigation data provided from the receiver, and the satellite navigation data is associated with a variable identity. A road toll level is derived. A second data processing means receives the road toll level provided by the first data processing means, and the satellite navigation obtains the determined road toll level from the second data processing means using the variable identity. This provides a thin client scenario (the receiver does not implement the map calculations), but with data security corresponding to a thick client solution. Thus, the map matching and trip cost computation steps are delegated by the on-board unit to an external unit, but this delegation is performed anonymously, so that no data sent for external processing compromises the privacy of the data.

Abstract: A road toll system comprises a vehicle-mounted unit having a satellite navigation receiver. A first data processing means determines a route taken based on satellite navigation data provided from the receiver, and the satellite navigation data is associated with a variable identity. A road toll level is derived. A second data processing means receives the road toll level provided by the first data processing means, and the satellite navigation obtains the determined road toll level from the second data processing means using the variable identity. This provides a thin client scenario (the receiver does not implement the map calculations), but with data security corresponding to a thick client solution. Thus, the map matching and trip cost computation steps are delegated by the on-board unit to an external unit, but this delegation is performed anonymously, so that no data sent for external processing compromises the privacy of the data.

Abstract: A road toll system comprises a vehicle-mounted unit having a satellite navigation receiver. A first data processing means determines a route taken 5 based on satellite navigation data provided from the receiver, and the satellite navigation data is associated with a variable identity. A road toll level is derived. A second data processing means receives the road toll level provided by the first data processing means, and the satellite navigation obtains the determined road toll level from the second data processing means using the 10 variable identity. This provides a thin client scenario (the receiver does not implement the map calculations), but with data security corresponding to a thick client solution. Thus, the map matching and trip cost computation steps are delegated by the on-board unit to an external unit, but this delegation is performed anonymously, so that no data sent for external processing 15 compromises the privacy of the data.

Abstract: A road toll system comprises a vehicle-mounted unit comprising a satellite navigation system implementing a position tracking function; transmitting means for transmitting position or route information to a remote server; and a unique identification device for attaching to the vehicle, and associated with the satellite navigation receiver. The road toll system function is enabled only when the identification device is present. The identification device comprises an electronic device which is adapted to alter by detachment or attempted detachment such as to prevent the road toll system function being enabled. This system increases the security of this type of system and makes fraudulent use of the system increasingly difficult.

Abstract: A road toll system comprises a vehicle-mounted unit comprising a satellite navigation system implementing a position tracking function; transmitting means for transmitting position or route information to a remote server; and a unique identification device for attaching to the vehicle, and associated with the satellite navigation receiver. The road toll system function is enabled only when the identification device is present. The identification device comprises an electronic device which is adapted to alter by detachment or attempted detachment such as to prevent the road toll system function being enabled. This system increases the security of this type of system and makes fraudulent use of the system increasingly difficult.

Abstract: An electronic apparatus comprises a main apparatus portion, a unique identification device for attachment in close proximity to the main apparatus portion and an interrogation system provided as part of the main apparatus portion for wirelessly interrogating the identification device such that the main apparatus portion function is enabled only when in close proximity to the identification device. The identification device is adapted to be made disfunctional by detachment or attempted detachment. In this arrangement, the main apparatus portion is the normal electronic apparatus to be protected from theft. It is provided with an interrogation system so that it can be made to cease functioning if not in close proximity to the identification device.

Abstract: A system implements a location based service, and comprises a satellite navigation receiver implementing a position tracking function for providing the location of a user of the service. An analogue RF receiver receives satellite signals and performs at least a frequency downconversion. Correlation and decoding functions are applied to the downconverted signals for deriving location information from detected specific satellite signals. The system further comprises a server for receiving samples of the downconverted signals, and for verifying the samples are consistent with the expected satellite signals at that time and location. The invention provides a counter measure for detecting the counterfeiting of, or tampering with, the satellite signals at the receiver. A check can be made that the received satellite signals correspond to those which are expected at that location and time.

Abstract: A system implements a location based service, and comprises a satellite navigation receiver implementing a position tracking function for providing the location of a user of the service. An analogue rf receiver (12) receives satellite signals and performs at least a frequency downconversion. Correlation and decoding functions are applied to the downconverted signals for deriving location information from detected specific satellite signals. The system further comprises a server (30) for receiving samples of the downconverted signals, and for verifying the samples are consistent with the expected satellite signals at that time and location. The invention provides a counter measure for detecting the counterfeiting of, or tampering with, the satellite signals at the receiver. A check can be made that the received satellite signals correspond to those which are expected at that location and time.

Abstract: A road toll system comprises a vehicle-mounted unit having a satellite navigation receiver. A first data processing means determines a route taken 5 based on satellite navigation data provided from the receiver, and the satellite navigation data is associated with a variable identity. A road toll level is derived. A second data processing means receives the road toll level provided by the first data processing means, and the satellite navigation obtains the determined road toll level from the second data processing means using the 10 variable identity. This provides a thin client scenario (the receiver does not implement the map calculations), but with data security corresponding to a thick client solution. Thus, the map matching and trip cost computation steps are delegated by the on-board unit to an external unit, but this delegation is performed anonymously, so that no data sent for external processing 15 compromises the privacy of the data.

Abstract: An electronic apparatus comprises a main apparatus portion, a unique identification device for attachment in close proximity to the main apparatus portion and an interrogation system provided as part of the main apparatus portion for wirelessly interrogating the identification device such that the main apparatus portion function is enabled only when in close proximity to the identification device. The identification device is adapted to be made disfunctional by detachment or attempted detachment. In this arrangement, the main apparatus portion is the normal electronic apparatus to be protected from theft. It is provided with an interrogation system so that it can be made to cease functioning if not in close proximity to the identification device.

Abstract: A road toll system comprises a vehicle-mounted unit comprising a satellite navigation receiver implementing a position tracking function, a memory device storing toll payment information and means for determining the routes taken by the vehicle based on the position tracking information. A disabling system is provided for disabling the vehicle operation based on the toll payment information. This system uses a satellite navigation receiver to enable infrastructure-free road tolling to be implemented. The system includes a function disabling the vehicle if the road toll fees have not been paid. This saves effort in tracking down users that do not pay their tolls.

Abstract: A road toll system comprises a vehicle-mounted unit comprising a satellite navigation system implementing a position tracking function; transmitting means for transmitting position or route information to a remote server; and a unique identification device for attaching to the vehicle, and associated with the satellite navigation receiver. The road toll system function is enabled only when the identification device is present. The identification device comprises an electronic device which is adapted to alter by detachment or attempted detachment such as to prevent the road toll system function being enabled. This system increases the security of this type of system and makes fraudulent use of the system increasingly difficult.

Abstract: A first signal processor stage of an audio amplifier arrangement influences the signal strength of a received audio signal for at least part of the frequency range of the received audio signal. An output amplifier stage amplifies the audio signal influenced by the first signal processor stage. The audio amplifier arrangement further includes a transformer having a primary winding connectable to a mains voltage and having a secondary winding connected to an AC/DC converter whose outputs are connected to at least the output amplifier stage for feeding the output amplifier stage. A detection circuit generates a detection signal (Vms) which is related to the power load of the transformer. An analysis circuit detects in response to the detection signal whether the rise in temperature occurring in the transformer due to the power load has exceeded a specific norm.

Abstract: A system implements a location based service, and comprises a satellite navigation receiver implementing a position tracking function for providing the location of a user of the service. An analogue RF receiver receives satellite signals and performs at least a frequency downconversion. Correlation and decoding functions are applied to the downconverted signals for deriving location information from detected specific satellite signals. The system further comprises a server for receiving samples of the downconverted signals, and for verifying the samples are consistent with the expected satellite signals at that time and location. The invention provides a counter measure for detecting the counterfeiting of, or tampering with, the satellite signals at the receiver. A check can be made that the received satellite signals correspond to those which are expected at that location and time.