Digital Matter Cellular products (G52S, G60, G100, Dart, Remora, Oyster, Flexi1) allow the modem to automatically select the network to register on.

The Automatic Network Selection Mode Procedure works in this way:

The Mobile Station (MS) selects and attempts registration on other Public Land Mobile Networks (PLMNs), if available and allowable, in all of its bands of operation in the following order:

  1. Home Public Land Mobile Network (HPLMN) (if not previously selected);
  2. Each PLMN in the "PLMN Selector" data field in the SIM (in priority order);
  3. Other PLMNs with received signal level above -85 dBm in random order;
  4. All other PLMNs in order of decreasing signal strength.

If successful registration is achieved, the MS indicates the selected PLMN. If registration cannot be achieved because no PLMNs are available and allowable, the MS indicates "no service" to the user, waits until a new PLMN is available and allowable and then repeats the procedure. If there were one or more PLMNs which were available and allowable, but a Location Register (LR) failure made registration on those PLMNs unsuccessful or an entry in a forbidden Location Area Identity (LAI) list prevented a registration attempt, the MS selects the first such PLMN again and enters a limited service state.

(Credit to Telit for providing this information)