| 摘要 |
<p>In a typical radiotelephone system, such as GSM, each radiotelephone or cellular device requires a subscriber identification module (SIM) in order to communicate with a telecommunications network. Generally the SIMs are removable from a radiotelephone and may placed in another radiotelephone, which thereby connects to the network using information contained in the SIM. This, however, can prove extremely inconvenient for the user having two or more radiotelephones. One way around this problem is for the user to have just one SIM, and to physically transfer the SIM to whichever radiotelephone is currently in use. This, however, is cumbersome since first the power must be switched off, the SIM must be removed, the SIM inserted into the new device, the new device must be powered on, and finally the new device must go through the initialisation and network authorisation phases. During this time no calls can be made or received. This process is further hindered by the fact that in many radiotelephones the SIM is located behind the battery, so that the additional steps of removing and replacing the battery must be performed. Accordingly, one aim of the present invention is to overcome the above-mentioned problems.</p> |
