When the mobile has a public GSM network SIM card, network transition is available, enabling the mobile phone to transition between the public and private GSM networks.
Enabling mobile phones to transition between networks
For Windows 5/6 and Symbian handsets, the entire transition operation is transparent to the mobile phone user. A Netswitch mobile client application is downloaded to the mobile and handles the transition, seamlessly, between the carrier mobile network of choice and the private mobile network. The application is delivered to the phone using an SMS message containing the download link. Once the application is installed, it will automatically start. For users with older model phones, manual transition using key strokes is available.