The Rohde & Schwarz CMD55 is a dual-band GSM digital radio communications test set engineered for transmitter and receiver characterization, signaling validation, and audio analysis across GSM900, GSM1800, and GSM1900 bands. Built for manufacturing, service, and development environments, it delivers fast IEEE-bus operation and user-friendly menu-driven test routines without requiring detailed GSM protocol knowledge. The instrument performs bit-error rate (BER) measurements, dynamic power ramp analysis per GSM Recommendations, spectrum analysis with 5-pole filtering, peak power measurement, SACCH parameter extraction (RxLev, RxQual, power level), phase and frequency error measurement, and DC current/voltage measurement. Signaling simulation includes base station emulation, mobile-to-base synchronization, location update verification, incoming and outgoing call setup, mobile power level control, handover testing (channel and time-slot changes), dual-band handover capability, and BCCH simulation with MCC, MNC, NCC, BA list, DTX, and DRX parameters. The compact, backlit LCD interface with softkeys supports remote control via RS-232-C or IEC/IEEE-bus using SCPI-compatible commands. Signal generation covers GFSK modulation with B × T = 0.5, constant envelope signals, unmodulated signals, and DECT bursts for module testing. Autotest and service mode functions enable rapid go/no-go assessment and precise fault location.
Technical Specifications
• Supported Bands: GSM900, GSM1800, GSM1900
• Modulation: GFSK with B × T = 0.5; constant envelope, unmodulated, and DECT burst signal generation
• Measurement Functions: BER, power ramp vs. time, spectrum analysis (5-pole filter), peak power, SACCH (RxLev, RxQual, power level), phase/frequency error, DC current/voltage, echo test
• Signaling Capabilities: Base station simulation, mobile synchronization, location update, call setup (incoming/outgoing), power level control, handover (channel, time-slot, dual-band), BCCH simulation with MCC/MNC/NCC/BA list/DTX/DRX
• Interface: RS-232-C or IEC/IEEE-bus with SCPI commands
• Display: High-contrast backlit LCD with softkeys
• Operation Modes: Menu-driven test callup, autotest, service mode
– Key Features
• Fast IEEE-bus operation for high-throughput production environments
• Quick go/no-go assessment capability
• User-friendly interface requiring no advanced GSM knowledge
• Dual-band handover testing
• Complete call lifecycle simulation and validation
– Typical Applications
• GSM mobile phone manufacturing test and burn-in
• Service center diagnostics and fault location
• Radio equipment development and validation
• Handover and mobility testing
– Compatibility & Integration
• Optional CMD-B4: Phase/frequency error, power ramp, BER measurement enhancement
• Optional CMD-B19: GSM1900 (DCS) band support
• Optional CMD-U11: High-speed processor with 8 MB RAM for advanced software
• Optional CMD-U18: RF generator output level modification
