Key issues to consider when switching to digital

January 2012

Going digital – 12.5 kHz DMR or 6.25 kHz FDMA?

• Two of the most important reasons that LMR users go digital are to add voice capacity and to more easily add data applications

• This presentation sets out the important issues for the user to think about

Adding capacity – 12.5 kHz DMR or 6.25 kHz FDMA?

Adding data applications nearly always means that more capacity is needed to ensure:• Existing voice quality of service is to be maintained and • The new application is to work well

There are real differences between DMR and 6.25 kHz FDMA when it comes to increasing capacity in terms of:• Spectrum efficiency is existing licenses• Infrastructure requirements

Digital migration in existing 12.5 kHz licences - DMR

Analogue to digital migration with DMR

Existing analogue talk paths in a 12.5 kHz license

New digital talk paths in your 12.5 kHz license

Double capacity in current license?

Digital migration in existing 12.5 kHz licences - FDMA

Analogue to digital migration with 6.25 kHz FDMA

Existing analogue 12.5 kHz license

New digital talk pathsIn 12.5 kHz license

Double capacity in currentlicense?

Spectrum efficiency - DMR and 6.25 kHz FDMA

Existing analogue 12.5 kHz licence

New digital channels

6.25 kHz spectrum efficient?

New channels fit legacy devices?

No risk of new interference issues?

DMR Migration 6.25 kHz FDMA Migration

Spectrum use - DMR vs 6.25 kHz Migration

• Because DMR uses the same 12.5 kHz channels as analogue co-existence between analogue and digital is simple• Ease of migration• Ease of long co-existence between analogue and digital

Going digital DMR and 6.25 kHz FDMA licence summary

Going digital with DMR means:

• Doubling capacity in existing licenses

• Keeping existing spectrum

• No new frequency co-ordination requirements

• Being able to continue to use legacy analogue radios in your spectrum

• No new risk of interference as the channel characteristics stay the

same and proven 12.5 kHz signals are maintained

Use of infrastructure: DMR compared to 6.25 kHz FDMA

Migrating from one

channel DMR to two

channel DMR:

No extra

complexity

No extra

cost

Power

efficient

No extra

space

No new

site issues

No extra

maintenance

One channel DMR

Two channels DMR

Use of infrastructure: DMR compared to 6.25 kHz FDMA

Migrating from one channel

FDMA to two channel FDMA:

Extra complexity

Extra cost

Greater power use

More space

Potential site issues

Extra maintenance

One channel 6.25 kHz FDMA

Two channels 6.25 kHz FDMA

DMR advanced features – not possible with FDMA

• Advanced control features through reverse channel signalling

• System flexibility through simultaneous voice and data calls, two way calls, double data rates enabled by two slot TDMA

Power efficiency of DMR compared to 6.25 kHz FDMA

• Two slot TDMA structure means transmitter

is used 50% less than with FDMA • This means DMR radios are more power efficient than

FDMA and give greater battery life/unit of battery capacity• Significant with data applications

Adoption of DMR technology today

• There is a strong supplier base of DMR• Over 1,000,000 DMR 2-way radios are in operational use• DMR manufacturers support a robust and established vendor

interoperability testing programme

Summary

When you switch to digital:

• Understand the real differences in the technology that is on offer

• Understand the license implications

• Understand the infrastructure requirements today and tomorrow

• Understand the strength of the DMR supplier base

• Make the smart choice