The Wavetek 4201S  is used for testing all GSM bands (GSM 900/1800/1900, including E-GSM and GSM-R. The Wavetek 4201S can be used via the RS-232-C interface, allowing remote operation. Using the SCPI instruction set or the LabWindows driver allows individual test procedures to be used. In addition to the already complete testing capabilities of the 4201S, the 4202S adds Data and SMS testing.