Abstract: A method is proposed for switching a radiocommunications terminal from a first radiocommunications network, with which the terminal is synchronized and registered, to a second radiocommunications network. The terminal has first and second connection profiles associated respectively with the first and second radiocommunications networks. According to the method, the terminal performs the following steps: for the second connection profile, a preliminary and at least partial synchronization of the terminal with the second radiocommunications network; and upon a switching request: a complete synchronization, based on said preliminary and at least partial synchronization, of the terminal with the second radiocommunications network; and registration of the terminal with the second radiocommunications network.

Abstract: A method and apparatus are provided for synchronizing a terminal with a frequency from an ordered initial sequence of frequencies of a radio-communications network. An available power spectrum associates to each frequency of the initial sequence a power value representing the power with which the frequency is received by the terminal. At least one first range of consecutive frequencies is determined within the initial sequence, having a power variation below a first predetermined threshold. The terminal attempts at least one first synchronization with a frequency of the first range. If each first synchronization fails, the terminal obtains a modified sequence by modifying the position of the frequency or frequencies of the at least one first range of the initial sequence or by eliminating the at least one first range. The terminal then attempts a second synchronization with at least one of the frequencies of the modified sequence.

Abstract: A method is proposed for switching a radiocommunications terminal from a first radiocommunications network, with which the terminal is synchronized and registered, to a second radiocommunications network. The terminal has first and second connection profiles associated respectively with the first and second radiocommunications networks. According to the method, the terminal performs the following steps: for the second connection profile, a preliminary and at least partial synchronization of the terminal with the second radiocommunications network; and upon a switching request: a complete synchronization, based on said preliminary and at least partial synchronization, of the terminal with the second radiocommunications network; and registration of the terminal with the second radiocommunications network.

Abstract: A method is provided for detecting scrambling of a radiocommunication network. The method is applied by a radiocommunication circuit capable of being connected to the network by being synchronized on a radiocommunication channel. The method includes a final detection phase, having the following steps: detection of verification of the following final condition: there are N radiocommunication channels on which the radiocommunication circuit cannot be synchronized despite detection of a power level normally sufficient for being synchronized, where N>2; and if the final condition is verified, generation of a final scrambling signal with a probability of scrambling equal to 100%. The method also includes at least one intermediate detection phase, having the following steps: detection of verification of at least one intermediate condition; and if the at least one intermediate condition is verified, generation of an intermediate scrambling signal with a probability of scrambling of less than 100%.

Abstract: A method is provided for locating a radiocommunication device in a radiocommunication network comprising a plurality of distinct geographical cells. The device comprises a radiocommunication module allowing reception of radiocommunication carriers. Each carrier is associated with a cell of the network and is defined by a frequency and a cell identifier. The module performs the following steps: obtaining initialization information comprising a predetermined list of N1 reference carriers; selecting N carrier(s) from among the N1 reference carriers; for each carrier selected, determining the cell identifier, termed the current cell identifier, associated with the selected carrier, on the basis of system information messages conveyed by the carrier; and obtaining an item of information regarding the location of the radiocommunication device, on the basis of the current cell identifier or identifiers.

Abstract: A method is provided for detecting scrambling of a radiocommunication network. The method is applied by a radiocommunication circuit capable of being connected to the network by being synchronized on a radiocommunication channel. The method includes a final detection phase, having the following steps: detection of verification of the following final condition: there are N radiocommunication channels on which the radiocommunication circuit cannot be synchronized despite detection of a power level normally sufficient for being synchronized, where N>2; and if the final condition is verified, generation of a final scrambling signal with a probability of scrambling equal to 100%. The method also includes at least one intermediate detection phase, having the following steps: detection of verification of at least one intermediate condition; and if the at least one intermediate condition is verified, generation of an intermediate scrambling signal with a probability of scrambling of less than 100%.

Abstract: A method is provided for locating a radiocommunication device in a radiocommunication network comprising a plurality of distinct geographical cells. The device comprises a radiocommunication module allowing reception of radiocommunication carriers. Each carrier is associated with a cell of the network and is defined by a frequency and a cell identifier. The module performs the following steps: obtaining initialization information comprising a predetermined list of N1 reference carriers; selecting N carrier(s) from among the N1 reference carriers; for each carrier selected, determining the cell identifier, termed the current cell identifier, associated with the selected carrier, on the basis of system information messages conveyed by the carrier; and obtaining an item of information regarding the location of the radiocommunication device, on the basis of the current cell identifier or identifiers.

Abstract: A method and apparatus are provided for synchronizing a terminal with a frequency from an ordered initial sequence of frequencies of a radio-communications network. An available power spectrum associates to each frequency of the initial sequence a power value representing the power with which the frequency is received by the terminal. At least one first range of consecutive frequencies is determined within the initial sequence, having a power variation below a first predetermined threshold. The terminal attempts at least one first synchronization with a frequency of the first range. If each first synchronization fails, the terminal obtains a modified sequence by modifying the position of the frequency or frequencies of the at least one first range of the initial sequence or by eliminating the at least one first range. The terminal then attempts a second synchronization with at least one of the frequencies of the modified sequence.