Abstract: The invention specifies various methods for the provision or calculation of a reference location for GPS-equipped mobile communications devices, specifically, GPS-equipped cellular phones. This is accomplished by providing certain GPS-related information over the cellular network, and by calculating reference locations based on various criteria, aided by actual position fixes provided by the built-in GPS receiver.

Abstract: In a mobile communication device, a method for compensating for a frequency adjustment in an oscillator shared between a communication circuit and a positioning signal receiver is provided. In one embodiment, the method begins to receive and store a positioning signal at a first time point. When, at a second time point, the operating frequency of the shared oscillator is adjusted, the frequency adjustment is recorded. After the positioning signal is completely received and stored, the processing of the positioning signal takes into consideration the frequency adjustment. In that embodiment, the processing hypothesizes a frequency shift in the received positioning signal. According to another aspect of the present invention, a method for determining the operating frequency of an oscillator detects a beginning time point of a reference signal received by the mobile communication device and enables a counter to count in step with a clock signal derived from the oscillator.

Abstract: In a mobile communication device, a method for compensating for a frequency adjustment in an oscillator shared between a communication circuit and a positioning signal receiver is provided. In one embodiment, the method begins to receive and store a positioning signal at a first time point. When, at a second time point, the operating frequency of the shared oscillator is adjusted, the frequency adjustment is recorded. After the positioning signal is completely received and stored, the processing of the positioning signal takes into consideration the frequency adjustment. In that embodiment, the processing hypothesizes a frequency shift in the received positioning signal. According to another aspect of the present invention, a method for determining the operating frequency of an oscillator detects a beginning time point of a reference signal received by the mobile communication device and enables a counter to count in step with a clock signal derived from the oscillator.

Abstract: In a mobile communication device, a method for compensating for a frequency adjustment in an oscillator shared between a communication circuit and a positioning signal receiver is provided. In one embodiment, the method begins to receive and store a positioning signal at a first time point. When, at a second time point, the operating frequency of the shared oscillator is adjusted, the frequency adjustment is recorded. After the positioning signal is completely received and stored, the processing of the positioning signal takes into consideration the frequency adjustment. In that embodiment, the processing hypothesizes a frequency shift in the received positioning signal. According to another aspect of the present invention, a method for determining the operating frequency of an oscillator detects a beginning time point of a reference signal received by the mobile communication device and enables a counter to count in step with a clock signal derived from the oscillator.

Abstract: In a satellite navigation system receiver co-located with a wireless communication system mobile terminal, periodic interference from the mobile terminal preventing bit-edge synchronization with one or more satellite signals is overcome by using Time Difference Of Arrival (TDOA) values associated with the satellite signals. Either a satellite signal free of periodic interference is chosen by inspection of the TDOA values, or the TDOA values are ranked and synchronization is attempted iteratively. Once a satellite signal is synchronized, the TDOA values are used to calculate synchronization for the remaining signals. The TDOA values may be transmitted to the mobile terminal by a satellite navigation signal information server connected to the wireless communication system, either individually or in broadcast mode to one or more cells. Alternatively, the mobile terminal may acquire the TDOA values from memory or from another data interface.

Abstract: A mobile terminal and system and method for determining the geographic location of the mobile terminal. A current cell identification number is determined for a cell in which the mobile terminal is located. The geographic location of the mobile terminal is determined based on data including at least one geographic position stored in a database and associated in the database with data representing the current cell identification number. The database may be updated with the geographic location and the current cell identification number.

Abstract: The invention specifies various methods for the provision or calculation of a reference location for GPS-equipped mobile communications devices, specifically, GPS-equipped cellular phones. This is accomplished by providing certain GPS-related information over the cellular network, and by calculating reference locations based on various criteria, aided by actual position fixes provided by the built-in GPS receiver.

Abstract: The invention discloses various methods whereby mobile communications devices, connected to a communications network can share data by acting as both clients and servers. Specifically contemplated is the sharing of GPS assistance data. Also disclosed is the formation and use of hierarchical groups of mobile communications devices for the purpose of information sharing.

Abstract: A mobile terminal and system and method for determining the geographic location of the mobile terminal. A current cell identification number is determined for a cell in which the mobile terminal is located. The geographic location of the mobile terminal is determined based on data including at least one geographic position stored in a database and associated in the database with data representing the current cell identification number. The database may be updated with the geographic location and the current cell identification number.