Multimode Digital Voice Communication

MULTIMODE DIGITAL VOICE COMMUNICATION

WITH DMR FOCUS

JANUARY 19, 2018

TOBIE BOUTOT

WHO AM I

• VE9XAB – Tobie Boutot

• Started as Power Electronic Engineer at UNB

• Designed and Built high power converter for renewable energy conversion

• Research Engineer – Dissociation of methane into its element using plasma

• High Power Microwave - plasma in chemical process

• Integration of an autopilot in fixed-wing drone

• Research Engineer at U de Moncton

WHY DIGITAL???????

• Bandwidth

• FCC is moving other services to narrow band

• DV modes use no more than 12.5 KHz, some 6.25

• Clear Quiet Audio

• Digital audio does not include hiss or noise, even as signals weaken.

• Digital just drops out entirely when signal too weak

• Digital Extras

• Radio can display Callsigns, Text Messages, more

POPULAR DIGITAL MODES IN AMATEUR RADIO

• D-Star – Digital Smart Technologies for Amateur Radio (FDMA)

• Wires-X/System Fusion - Wide-coverage Internet Repeater Enhancement System

(FDMA)

• NXDN (IDAS/NEXEDGE) – Icom/Kenwood Collaboration (FDMA)

• DMR – Digital Mobile Radio (TDMA 2-TS)

• P25 (Phase 1) – Project 25 or APCO P25 (Phase 1 FDMA, Phase 2 TDMA 2-TS)

• TETRA - Terrestrial Trunked Radio, formerly known as Trans-European Trunked Radio

(TDMA 4-TS) No known U.S./Canada amateur deployments

HOW POPULAR ARE THEY

• DMR- 1165 repeaters >10000 registered users

• D-Star- 1143 repeaters

• Wire-X/Fusion- 314 repeaters

• P25 248 repeaters

• NXDN- 93 repeaters

DIGITAL VS ANALOG

DMR AND DIGITAL VOICE (DV)

• FDMA (Frequency Division Multiple Access)

• D-Star

• P25 Phase 1

• NXDN

• TDMA (Time Division Multiple Access)

• DMR Tier 2

• P25 Phase 2

• DMR Tier 3 – Trunk system, 2-slot TDMA, multi-channels

DMR – DIGITAL MOBILE RADIO

DMR is divided into three “Tiers”

• Tier I (single channel)

• Tier II (2-slot TDMA– the standard for Amateur Radio)

• Tier III (trunking protocol)

DMR – HALF THE CHANNEL BANDWIDTH

Traditional Analog

25 kHz

Channel Bandwidth

1 Channel

1 Repeater

DMR

12.5 kHz

Channel Bandwidth

2 Channels

1 Repeater

fc fcfc + 12.5 fc - 12.5 fc – 6.25 fc + 6.25

2 CHANNELS – ONE FREQUENCY

Each TDMA Channel is 60ms long, containing 2 x 30ms time slots

DMR TERMINOLOGY

• Talk Groups - Think of a Talk Group as a repeater or as a group of repeaters that are activated when you

key them up.

• Channels - A Channel is a specific Talk Group on a specific repeater.

• Zones - A Zone is a grouping of individual channels

• Color Codes - DMR repeaters use Color Codes (CC) much like analog repeaters use CTCSS or DCS

• Code Plugs - A code plug is simply a radio’s configuration file

• TS – Time Slots – DMR has 2 time slot – 2 independent DV channel

• Roaming

• C-bridge - The C-Bridge in essence is part database manager, part master control hub; and part gateway. It

is responsible for the assignment of what talk groups are available to a particular network; as well as the

repeaters attached to that network. Think of it almost like a router for DMR talkgroups.

• Admit Criteria - The Admit Criteria determines when your radio is allowed to transmit

SOME DMR PORTABLE RADIOS

SOME DMR MOBILE RADIOS

I HAVE A DMR RADIO – WHAT’S NEXT

• You NEED to get an ID before you transmit

• https://www.radioid.net/#!

• Lots of info on:

• http://www.dmr-marc.net/

DMR-MARC REPEATER MAP - WORLDWIDE

DMR REPEATER - FREDERICTON

Callsign: VE9FTN

Frequency: 147.165

Offset: + 0.6 KHz

Color Code: 1

DMR REPEATER – SAINT-JOHN

Callsign: VE9SJN

Frequency: 145.490

Offset: - 0.6 KHz

Color Code: 1

DMR REPEATER – GRAND FALLS

Callsign: VE9ARZ

Frequency: 145.290

Offset: -0.6 KHz

Color Code: 12

DMR REPEATER – SPRINGHILL, NS

Callsign: VE1XPR

Frequency: 145.290

Offset: -0.6 KHz

Color Code: 1

DMR REPEATER – MONCTON

• Callsign: VE9DMR

• Frequency: 146.925

• Offset: +0.6 KHz

• Color Code: 1

TALK GROUPS ON OUR SYSTEM

SO… WHAT IS MULTIMODE DIGITAL VOICE?????

• Hardware & Software that support more than

• one DV mode

• So one repeater can support DMR QSOs,

• D-Star QSOs, Fusion QSOs, P25 etc.

• One mode at a time – other mode radios will

• not hear, but will see a busy repeater

• Or a Homebrew Hotspot can do the same

WHY MULTIMODE?

• With limited coordinations on VHF and even UHF, one repeater can support

several modes

• MultiMode Hotspots at home or travelling give us more flexibility, now and in

the future

• Two kinds of MultiMode users:

• Those preferring a single mode, using proven H/W & S/W, with flexibility to try a new

mode

• Those who like several modes, have several radios, and use all of them

• Some users even have several Hotspots, one for each mode

POPULAR MULTIMODE PRODUCT

• MMDVM – Jim KI6ZUM just gave you details. Open Source and Creative Commons.

Various board versions available; most popular are the ZUM board and ZUMspot.

Sold by Bruce Given VE2GZI: mmdvm.blogspot.com

• DVMEGA Dutch hotspot RF boards, works with G4KLX software, so similar

experience to MMDVM products

• BlueDV Software supports AMBE3000 devices like the Northwest Digital Radio’s

ThumbDV

• DV4mini German designers, created DSP modem DVRPTR. USB stick is low power

hotspot that supports multiple modes

• SharkRF openSPOT Stand-alone device, separate computer like Pi not needed. Local

transcoding DMR-Fusion.

QUESTIONS ?