GeminiTM
Drive-test tool for
digital radio networks
Gemini is trade mark of Radio Systems Information Ltd
Key Features• Measurement of speech quality to ITU-T Rec. P.862
• Compatible with TETRA radio terminals– Motorola MTM700– Sepura SRP2000– Cleartone
• Survey using up to 4 radios simultaneously
• Expandable design for large networks
• Very powerful built-in analysis functions
How does GeminiTM work?
• continuously makes calls between mobile and fixed parts of Gemini
• call failures logged
• call setup time logged
• speech samples sent on uplink & downlink to test speech quality
Analysing Results
• Results displayed as icons on maps
– original quality
– very poor TETRA quality
– poor TETRA quality
– standard TETRA quality
• Following examples show different types of analysis on maps
• Speech quality measured as Mean Opinion Score
Colour indicates audio quality
Colour indicates Base Station
Colour indicates Signal Strength
Poor Coverage Area
Lots of handovers, No Service and Call Drops
Good Coverage Area
All calls completed OK
Analysing Results
• Results displayed on Graphs - almost any parameter can be displayed against any other parameter
• Following examples show different types of analysis on graphs
GeminiTM Antenna
Combiner
• Connect up to 4 TETRA radios to a single antenna in a survey vehicle
• Meets all ETSI interference requirements
GeminiTM Applications
• Network acceptance
• Investigating problems
• Benchmarking network performance
• Annual performance checks
• Objective measurements for contractual negotiations