Gemini

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Gemini

• TETRA drive-test tool

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

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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

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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

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Colour indicates audio quality
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Colour indicates Base Station
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Colour indicates Signal Strength
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Poor Coverage Area Lots of handovers, No Service
and Call Drops
Good Coverage Area All calls completed OK
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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

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Gemini Antenna Combiner

• Connect up to 4 TETRA radios to a single antenna
  in a survey vehicle
• Meets all ETSI interference requirements

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Gemini Applications

• Network acceptance
• Investigating problems
• Benchmarking network performance
• Annual performance checks
• Objective measurements for contractual
  negotiations