DIGITAL MOBILE RADIO

THE VERY BASICS

DIGITAL MOBILE RADIO

THE VERY BASICS

John ‘Miklor’ K3NXU 2018 .

The DMR Difference

• History

• Audio Quality

• Spectrum Efficiency

• The Local and Worldwide Network

• Repeater vs. Hotspot

• Code Plugs

• DMR today in our area

Brief History

• DMR developed in Europe by ETSI European Telecomm Standards Inst

Adopted as Commercial Standard 20 years ago

• Commercial Business Equipment Proprietary Equipment and Software

High Cost

Not ham radio friendly

• Ham Radio Equipment (2 years ago) Field Programmable

Ham Friendly

Ham Friendly • TYT MD-380 Motorola xpr7550

Single Band Single Band

< $100 vs $500-$700

Anytone D868 Ailunce HD1 TID TD-9800 Dual Band Dual Band Single Band

Features & Audio

Audio Quality Digital vs Analog

TDMA

Spectrum Efficiency

Analog FM = 25 kHz DMR (TDMA) = 12.5 kHz

Tier I European License Free Band (not ham)

Tier II TDMA Commercial & Ham Standard

Spectrum Efficiency – 30ms Time Slots

Time Slots

Much like a Duplex House

Two totally separate

families in one structure. Time Slot 1 Time Slot 2

Each house has its own

set of rooms (Talk Groups)

Talk Groups

Talk Groups

TG Time Slot

• Local 2 Local Cluster of Repeaters 2

• Local 9 Main Repeater Only 9

• TAC 310, 311 Secondary Chat Groups 310, 311

• Nationwide National Calling Channel 3100

• PA TAC Local Cluster of Repeaters 31421

• PA State PA Statewide 3142

• MD State MD Statewide 3124

• NE Reg’l Northeast Regional 3172

• Mid Atlantic Mid Atlantic Region 3173

Over 1100 Talk Group Possibilities ^

Talk Groups

TG Time Slot

• Local 2 Local Cluster of Repeaters 2 2

• Local 9 Main Repeater Only 9 2

• TAC 310, 311 Secondary Chat Groups 310, 311 2

• Nationwide National Calling Channel 3100 1

• PA TAC Local Cluster of Repeaters 31421 1

• PA State PA Statewide 3142 1

• MD State MD Statewide 3124 1

• NE Reg’l Northeast Regional 3172 1

• Mid Atlantic Mid Atlantic Region 3173 1

FT / PTT

Talk Groups

TG Time Slot

• Local 2 Local Cluster of Repeaters 2 2 FT

• Local 9 Main Repeater Only 9 2 FT

• TAC 310, 311 Secondary Chat Groups 310, 311 2 PTT

• Nationwide National Calling Channel 3100 1 PTT

• PA TAC Local Cluster of Repeaters 31421 1 PTT

• PA State PA Statewide 3142 1 FT

• MD State MD Statewide 3124 1 FT

• NE Reg’l Northeast Regional 3172 1 FT

• Mid Atlantic Mid Atlantic Region 3173 1 FT

Sample Repeater

Configuration

Local 2

Local 2

Local / Worldwide Network

• 449.725 MHz (Shrewsbury)

• 447.275 MHz (Keystone)

• DMR Repeater

• Stand Alone System

• Can be IP Networked

with c-Bridge

Local Network

National / World Wide Networks

DMR Marc/Brandmeister

Networks

Repeaters Direct Connect

TG Compatibility

Networks

Local 2 (Rpt)

Local 9 (Rpt)

PA TAC < > PA TAC

310, 311, 312 < > 310, 311, 312

313 > 319 x 313 > 319

State Groups < > State Groups

Regional Groups x n/a

Nationwide 3100 < > Nationwide 3100

Repeat vs Hotspot

Repeater vs. Hotspot

• Repeater’s provide both Local and WW area coverage

• Hotspot

Replaces a Repeater

Very short range

Brandmeister

But Why ?

Why use a Hotspot ?

• No nearby repeaters

• Heavy traveling

• Long Conversations

So, where’s the activity?

1500 Talk Groups – Your Choice

Activity Levels TG Activity

• Local 2 Local Cluster of Repeaters 2 Low FT

• Local 9 Main Repeater Only 9 Low FT

• SPA Local Keystone & Shrewsbury only 31425 Low FT

• PA TAC Local Cluster of Repeaters 31421 Low PTT

• PA State PA Statewide 3142 Med FT

• MD State MD Statewide 3124 Med FT

• NE Reg’l Northeast Regional 3172 Med FT

• TAC 311,312 Chat Groups 311, 312 Med PTT

• TAC 310 Main Secondary Chat Group 310 High PTT

• Nationwide National Calling Channel 3100 High PTT

Op Notes

Operating Notes • 3 second pause before PTT

Network Latency

Courtesy Pause

• 1 second pause after PTT Channel Busy Radio needs to sync to DMR signal

• Time Slot in use Green Light Time Slot busy tone Someone on same TS but different TG

• Talk Group in use You may not immediately hear an active Talk Group

Operating Notes • Avoid Calling CQ

This is not HF. There is no DX, WAS, etc.

• Announce your talk group

Scanning or radio without a display

• Avoid long QSOs on wide area talk groups

Please move to a TAC channel

• Time Slots

Each Time Slot will only support one QSO at a time.

regardless of the number of talk groups available.

Dash Boards

Dashboards

• Netwatch

Watch the DMR Network activity Real Time

• Hoseline Listen to Brandmeister Talk Groups Real Time

Netwatch

Hoseline

Dashboard Links

• Netwatch http://cbridge.wr3irs.com:2135/MinimalNetwatch

Allows you to view DMR network activity Real Time

• Hoseline http://hose.brandmeister.network/group/91/

Listen to Brandmeister network talk groups Real Time

• Miklor.com K3NXU.com (DMR Section)

www.miklor.com/DMR/ www.K3NXU.com

Reference • http://www.Miklor.com/DMR/

Code Plug

• FM Frequency / CTCSS

• DMR Frequency / Color Code

Three Main Divisions

(1) Contact List (Talk Groups)

(2) Create the Channel Information

(3) Group the Channels into Zones

Code Plug

Step 1 - The Contact List aka Talk Groups

This is where the Talk Groups are stored.

- Talk Group Name

- Talk Group Number

- Group or Private (Select Group)

Code Plug

Step 1 - The Contact List aka Talk Groups

Code Plug

Step 2 - The Channel Information

Mode Digital

Frequency Rx and Tx

Color Code 1

Channel Spacing 12.5 kHz

Time Slot Whatever was specified for the repeater

Tx Contact Talk Group from Contact List

Rx Contact “None” will default to the Tx Contact

Power High or Low

Tx Criteria “Always”, Color Code, Channel Free

Scan List Optional

Code Plug

Step 2 - The Channel Information

Code Plug

Step 3 - The Zone This is where you assign your favorite channels to a cluster or channel bank.

They can be grouped by:

- Repeater

- Location

- Activity

- Analog Repeaters

- Simplex

- etc. You can mix and match. The choice is yours.

Code Plug

Step 3 - The Zone

Code Plug

Step 4 - Scan Groups

This is where you create a group of receive channels that

you would like to Scan.

Assign the Scan Group to a specific channel.

Code Plug

Step 4 - Scan Groups

MD / PA

Code Plug

Step 4 – Scan Groups

MD, PA Cluster

May 2016

44000 Registered DMR IDs

333 in PA

May 2018

96000 Registered DMR IDs

1400 in PA 600 in MD 100 in DE

Oct 2018

112,000 Registered DMR IDs

DMR in the USA

DMR in the Mid-Atlantic

MD, PA Clusters (Local 2)

V = VHF U = UHF

* = Limited Coverage ** = Coming Soon

MD, PA Clusters