Universal Portable CTEL Interface (UPCI [UHI]) cellular phone subscriber to public telephone network - GF82.70-P-0004-04SX
Shown on model 221 up to 31.12.05
If the log-in procedure over the Base Transceiver Station (BTS), Base Station Controller (BSC) and the corresponding Mobile Service Switching Center (MSC) with verification of the access authorization by the Authentication Center (AC) has been completed, then the cellular phone subscriber can call the number of the party of his/her choice by dialing the corresponding number.
If the cellular phone subscriber is authorized, then the Mobile Service Switching Center (MSC) switches the call through to the public telephone network over the Public Switched Telephone Network (PSTN).