1. Digital Mobile Radio A. K. A
Digital Mobile Radio A.K.A. (Mototrbo) a registered trademark of Motorola Corporation
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2. What is DMR Commonly known as Digital Mobile Radio
A standard for digital voice communications
Published by ETSI in 2005
Goal is: low cost, low complexity; and interoperability between manufacturers
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3. The DMR Standard
Two-Slot TDMA DMR Tier II/Tier III occupies a 12.5 kHz bandwidth with two channels sharing using Time-Division Multiple Access (TDMA)
Digital Modulation 4FSK
Vocoder agreed upon is AMBE +2 amongst vendors
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4. The Benefits of DMR
Allows 2 simultaneous voice conversations using a single repeater like having 2 repeaters in 1 box
Improved audio performance over analog
More efficient use of radio spectrum vs. analog
+12 DMR radio manufactures = lower radio prices
Capable to being linked to over 800 other DMR repeaters worldwide
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5. Range Improvement of DMR vs Analogue
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6. How this all works getting stated
Radio
Subscriber ID that uniquely identifies you as being allowed on the greater DMR network
A understanding of the repeaters, their talkgroup lineup the talk group ID and timeslots each talk group occupies as well as the repeaters color code. (a color code is to DMR what CTCSS PL is to analog)
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7. What is a Talk Group
It is a chat room within the repeater system that allows users connected with the same talk group to communicate.
Can be networked
Can be non networked.
Typically we see repeaters hosting a total of 16 talk groups
They can be either active always or PTT
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8. PTT vs. Active Always
PTT – for example if you want to engage the feed for a particular talk group you simply key the repeater wait a second, then the repeater lis linked to the said talk group for a specified period in time then goes back to default.
Active Always – The repeater has that particular talk group on all the time on a particular time slot. No user intervention required.
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9. Why do we use PTT
We only have two time slots. If every talk group was active on and you were communicating with someone on TS 1 and another TS 1 talk group keyed up you QSO would be ended for you.
To not tie up the resources of the entire networked repeater system. Moving from a wide area talk group to a PTT is suggested for QSO lasting longer then 5 min.
You start out on California when you key up you key up all 56 repeaters within the state. You are in LA talking to a station in Visalia the reasonable choice would be to move to a PTT talk group for example Cal 1. What happens is on each of the respective repeaters only that time slot and talk group is utilized so efficiency is greatly improved and it opens up the Timeslot on the remaining 54 repeaters to do what they want.
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10. Fresno (Bear Mountain) 442.2875 + 5.0Mhz Color Code 3
CenCal DMR Repeaters
Fresno (Bear Mountain) Mhz Color Code 3
Visalia VHF (Park Ridge) Mhz Color Code 2
Visalia UHF (Park Ridge) Mhz Color Code 2
Clovis (Meadow Lakes) Mhz Color Code 1
Visalia Low Level (KVIS) Mhz Color Code 1
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11. Talk Groups
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12. CenCal DMR Talkgroup lineup
Time Slot #
Local 2 1
CenCal 1 - PTT
221
CenCal 2 - PTT
222
CenCal
236225
NorCal PTT
5150
SoCal - PTT
76225
CAL 1 - PTT
2251
CAL 2 - PTT
2252
California
3107
North America - PTT 3
World Wide - PTT
TAC PTT
310
Southwest
3176
Audio Test - PTT
9999
Parrot - PTT
9998
Comm 1
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13. Programming How do you get 16 talk groups into one single channel?
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14. Programming
You Don’t!!!!!
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15. Programming
We program a bit differently then Ham’s are used to thinking.
We make use of Zones (this can be the name of the repeater) the zone is a bank of channels
We make use of Channels (these are included in the zone list.
Each talk group is a individual Channel inside the zone with its own set of variables. On the same repeater what remains the same are: Tx Frequency, RX Frequency and Color Code
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16. Programming What changes is:
The contact name, and the time slot the contact name is.
What is the contact name?
It is your talk group assigned to that channel
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17. Where do I go to get code-plug Primers to get me going
Under programming
Select sample code plugs
They have several available from: Motorola, Hytera, and Connect Systems.
Make sure to put your subscriber ID in its called Radio ID in most of the programs.
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18. Where is DMR Today? Less Resistance to Digital Coverage c-Bridge
CSI Radios
Fastest growing digital mode in North America
Chart courtesy of VA3XPR
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19. Where is DMR in California today?
56networked repeaters
190% growth rate year over year!
15% of U.S. DMR repeaters are here in
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20. California DMR Statistics!
672 unique IDs issued to California DMR users as of
10% of all global DMR users are right here!
Why are our numbers so high?
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21. It’s the Coverage!
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22. It’s the Coverage!
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23. It’s the Coverage!
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24. What’s in store?
Will continue to support and build out network.
Will place greater emphasis on interconnections and standardization
Aligning Talk Groups
Time Slots, Always on, PTT
Ensure Roaming is supported
Starts with talk groups, enabled, settings
Continue to be a repository for information
Web, RF Coverage Maps, Yahoo! Group, Flickr
Drive standards on radio and repeater programming
Sharing of info, Codeplugs
Continue to make it an easy mode for people to join and enjoy!
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25. The END To download this presentation please got to:
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