R&S®CMD55 Digital Radiocommunication Tester
Setting the standards for compact digital mobile radio testers
The major test functions are:
- Mobile synchronization
- Location update
- Incoming call setup
- Outgoing call setup
- Mobile power level control
- Handover (channel change, timeslot change)
- Peak power measurement
- High dynamic range burst analyzer (option CMD-B4 and CMD-B42)
- Spectrum due to Switching measurement (option CMD-B4 and CMD–B43)
- Spectrum due to Modulation measurement (option CMD-B4 and CMD–B43
- Timing Advance measurement
- SACCH measurement (eg RxLev, RxQual, power level)
- Echo test
- Call clearing by mobile
- Call clearing by CMD
- DC current/voltage measurements
- Phase and frequency error measurement (option CMD-B4)
- Measurement of power ramping as a function of time (option CMD-B4)
- Bit-error rate (BER) and Fast BER measurement (option CMD-B4)
Operation of the CMDis extremely user-friendly and requires no detailed GSM/PCN knowledge. The high-contrast, backlit LCD provided with softkeys on both sides allows convenient callup of test routines under menu control. Various network-specific parameters are preset and permit direct testing without any operator control. In addition, it is of course possible to modify all parameters individually in the configuration menus.
The autotest function enables complete measurement routines to be started at a keystroke without any further intervention by the operator being required. The test results in tabular form are displayed on the screen.
The CMD is remote-controlled via the RS-232 or IEEE/IEC-bus interface using SCPI-compatible commands. In the remote-control mode the CMD is designed for fast speed to yield high throughputs in production.
The echo test allows very rapid go/nogo analysis covering all essential parts of the mobile. Words spoken into the microphone of the mobile are sent to the CMD, stored in buffer memory and sent back to the phone. In this way it is possible to check the whole signal path from the microphone via the RF transmitter section, RF receiver section, modulator, demodulator, signaling section, speech coder/decoder, analog audio components through to the loudspeaker.
In addition to the normal RF input/output, the CMD has a high-sensitivity input and a high-level output which enable tests on modules or on handhelds with built-in antenna by using couplers like the CMD-Z10.
Fault localization in mobile telephones requires various measurement functions that can also be used without signaling so that defective units can be tested down to modular level. The basic model of CMD already provides some of these functions, eg signal generation with or without modulation or power measurements, other functions being available as optional extensions.