Gemini™

TETRA drive-test tool

Gemini is a trademark of Radio Systems Information Ltd, www.rsi-uk.com

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

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

Master inSurvey Vehicle

Slave inOffice

TETRA

Gemini Schematic

GPS

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

• Connect up to 4 TETRA radios to a single antenna in a survey vehicle

• Meets all ETSI interference requirements

Gemini™ Antenna Combiner

Gemini™ Applications

• Network acceptance

• Investigating problems

• Benchmarking network performance

• Annual performance checks

• Objective measurements for contractual negotiations