Additional Features: Mobile-to-base station synchronization Location update Incoming call setup Outgoing call setup Mobile power level control Handover (channel change, timeslot change) Dual-band handover Peak power measurement SACCH measurement (eg RxLev, RxQual, power level) Echo test Call clearing by mobile Call clearing by network DC current/voltage measurement Phase and frequency error measurement Measurement of power ramp as a function of time Bit-error rate (BER) measurement The R&S CMD55 is capable of testing GSM1800 (formerly named PCN orDCS1800) and GSM1900 (formerly named PCS or DCS1900) mobile phones. This model combines small dimensions with high measurement accuracy and speed. The testers range of capabilities includes all signaling, generator and measurement functions required for verifying the correct operation of the DUT (Device Under Test). Thanks to its fast go/nogo tests and accurate analysis using optional extensions, the CMD55 is equally well suited for R&D, production and high-end service and production. Based on the wide-range know-how of Rohde & Schwarz in digital radiocommunication testing, which not least was obtained in developing type-approval test systems such as the GSM900 and GSM1800 system simulators, the CMD model is a  top-grade tester for present and future measurement applications.

Option	Description
B1	OCXO Reference Oscillator: frequency drift =1 × 10–7
B17	(/Q signals from the CMD modulator and burst trigger sign
B19	GSM1900 mobile station test (for CMD53/55 and CMD65 only)
B3	Multifrequency reference inp ut/output. For synchronizing DUT and measuring instrument with int ernal or external frequencies
B4	Fast Power Ramp, Phase/Frequency Error and BER Measurement: numeric/graphic display, various BER, RBER, FER test routines; required for fitting CMD-B41 and CMD-B42
B41	AF Measurement Unit with Frequency Counter: comprises AF generator, voltmeter, distortion meter and frequency counter, measurements up to 60 MHz
B42	High-Dynamic Burst Analysis: dynamic range >72 dB (CMD-B4 required)
B43	GSM900/1800/1900-Specific Measurement of spectra due to switching/modulation (CMD-B4 and CMD-B42 required)
B44	Multitone Generator and Analyzer for CMD5x and CMD6x: comprehensive audio tests up to 8460 Hz (CMD-B4 and CMD-B41 required)
B5
B51	Speech Codec
B6	TDMA Signals ans Adapter for CMD-B6x Options: required for fitting CMD-B61 and CMD-B62
B61	IEC/IEEE-Bus Interface: alternative for RS-232 interface (standard, CMD-B6 required)
B62	Memory Card Interface: archiving of results, etc. (CMD-B6 required)
B9
CMD-B1	OCXO reference oscillator
U18	Output leve at RF IN/Out: -15dbm
U20	A special RF converter for the CMD53/55
U5	SM time synchronization signal and demodulated I and Q s ignals