1. Gemini is a trademark of Radio Systems Information Ltd, www.rsi-uk.com
TETRA drive-test tool
Gemini is a trademark of Radio Systems Information Ltd,

2. Key Features
Independent and objective TETRA network performance measurement tool
Measurement of speech quality to ITU-T Rec. P.862
Use for network acceptance & ongoing performance
Compatible with TETRA radio terminals
Motorola MTM800E
Sepura handportable & vehicle
Cleartone
Survey using up to 4 radios simultaneously
Scalable design: from walk-testing to multiple vehicles
Powerful built-in analysis functions

4. How does Gemini™ 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

5. Master in
Survey Vehicle
Slave in
Office
TETRA
Gemini Schematic
GPS

6. Analysing Results Results displayed as icons on maps
Speech quality measured as Mean Opinion Score
original quality
standard TETRA quality
poor TETRA quality
very poor TETRA quality
Following examples show different types of analysis on maps

7. Colour indicates audio quality

8. Colour indicates Base Station

9. Colour indicates Signal Strength

10. Poor Coverage Area
Lots of handovers, No Service and Call Drops
Good Coverage Area
All calls completed OK

12. 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

17. Gemini™ Antenna Combiner
Connect up to 4 TETRA radios to a single antenna in a survey vehicle
Meets all ETSI interference requirements

18. Gemini™ Applications Network acceptance Investigating problems
Benchmarking network performance
Annual performance checks
Objective measurements for contractual negotiations