| 摘要 |
The system uses an additional memory to retain the current connection information to avoid the need for re-initialisation. The mobile telephone includes a receiver receiving radio frequencies transmitted by different telecommunications systems, of which one is authorised. A circuit then searches amongst the available frequencies in order to locate one frequency, called the synchronisation frequency, and synchronises itself with this frequency. A security system is provided to retain in memory the frequency of the current cell on to which the mobile telephone is synchronised. When an error is detected, resulting in the loss of communication and need to re-initialise communication, the mobile telephone is able to synchronise itself directly on to the memorised frequency without effecting the conventional measurements of signal power. |
