1. Prepared for Montgomery County ARES
June 26, 2018
Jack Gerbs, WB8SCT

2. Presenter Brief Bio: Been a ham for a long time
Been playing with DMR for a long time
Not an expert on DMR, but I do have some experience
Contact Info:
Jack Gerbs, WB8SCT (good on QRZ) -

3. Disclaimer
In the interest keeping this technology presentation at a level most Ham’s can understand, I have taken liberties with some definitions and explanations.
Not all the images and information presented is my original content. Some (most) of the content has been ripped off from the Internet and I have not given proper credit to those who deserve it.

4. Goals for the Presentation
Review digital modes being used on VHF and UHF
Compare DMR vs. System Fusion
Review how the world-wide DMR network is built
Provide a starting point to programing a DMR radio

5. Question?
How many believe that digital modes can communicate over a greater a distance than traditional analog?
True or False?

6. Digital Modes vs. Analog
The question was a very bad question!
On VHF and UHF for voice traffic, analog has a greater coverage area (R2D2 or full drop)
For text data, digital modes, with extensive error correction coverage area can greatly be increased.

7. DMR – How did we get here? FCC Mandate
By January 1, 2013, all public safety and industrial land mobile radio systems must operate within 12.5 KHz, or equivalent-efficiency.
Equiviant-efficency is further defined as:
One voice path in a 12.5 KHz channel
Two voice paths in a 25 KHz channel
Data Operations on channels greater 12.5 KHz must employ data rates greater than 4.8 kbps per 6.25 KHz channel,
FCC’s Ultimate rebanding goal is 6.25 KHz

8. Digital Modes
NXDN Developed by ICOM & Kenwood (FDMA, 6.25 or 12.5 KHz)
P25 Tier 2 and above (TDMA)
DMR Tier 1 – FDMA 12.5 Khz (Motorola)
DMR Tier 2 - TDMA, 12.5 KHz (Motorola)
DSTAR (JARL) 6.25 KHz AMBE+
Fusion (FDMA 12.5 KHz AMBE+2) (Vertex Standrad/Motorla)

9. TDMA vs FDMA TDMA – Time Division Multiple Access
There are two time slots and and each time slot can handle a conversations (two simultaneous conversations on one frequency).
FDMA – Frequency Division Multiple Access
The user takes the whole frequency and there are two carriers in the channel. Typically one carrier is used for voice and the other for data.

10. Analog vs TDMA vs FDMA

11. TDMA Timing (Radio)

12. TDMA Timing and Payload Frame (Radio)

13. TDMA Timing and Payload Frame (Repeater)
CACH – Common Announcement Channel

14. Which is Better, DMR (TDMA) or Fusion (FDMA),
My thesis:
DMR is a better technology for typical Amateur Radio application, unless you have a need for low latency data.

15. DMR Beats Fusion - Thesis Support
TDMA – Offer two simultaneous conversations on one frequency
Radio is only transmitting in one time slot
35% to 40% battery efficiency
The second slot can be used for data, but because it uses only one TS, there is high latency
World and wide area network fully developed
FDMA – Takes full 12.5 KHz for a user (full channel)
No appreciable battery efficiency
Because data is transmitted on the second carrier, it offers low latency
No world or wide area networks current exist (WIRES)

16. The DMR Network The key components to the DMR Network are:
The Internet
Access Bridges:
c-Bridge/TL-NET
Brandmeister
The keepers of the databases (Database Keepers)

17. The Database Keepers
Database Keepers at the high level are DMR-MARC, Brandmeister, DMR Plus and it is growing.
At a lower level anyone who owns or operates a c-Bridge/TL-NET, can custom program talkgroups and provide inter/intra-repeater connectivity.

18. Bridged Network Example

19. Programming a DMR Radio
Based on TYT MD-380

20. DMR Terminology Key Terms: User ID Talk Groups (Digital Contacts)
Digital RX Groups
Zones
Color Codes
Admit Criteria
Time Slot

21. DMR User ID
Each radio needs to be programmed with a semi-unique DMR User ID. DMR-MARC is the keeper of DMR IDs.
Use this link to request a DMR User ID:

22. DMR Talk Groups (TYT – Digital Contacts)
Talk group examples: 9, 2, 3139, 3169
Digital contacts can be setup as a Group Call or a Private Call
Group Call Talk Groups (TG) are a way for groups of users to share a time slot (one-to-many) without distracting and disrupting other users of the time slot

23. DMR Talk Groups (TYT – Digital Contacts)
Private Call digital contacts are primarily used to map individual DMR user IDs to some alpha text that can be displayed on the radio. Map a DMR ID to a call sign and name.
Other uses for Private Call are:
Sending text messages
Steering the repeater to a TG under DMR Plus

24. Digital Receive Groups
A receive group defines what TG your radio will hear (listen to) for the selected channel on your radio
You can program multiple TGs into a digital receive group
This ability makes your radio highly customizable, but has become a complicated concept for many newbies.
Example, On channel 5, named Ohio State, you can listen to Ohio State, Local 9 and Local 2.

25. Color Codes
DMR repeaters use Color Codes (CC) much like repeaters user CTSS or DCS
CC must be programmed to match the repeater CC, the default is CC1.
The only real purpose to use different CC is when multiple repeaters are operating on the same frequency have overlapping coverage areas.

26. Admit Criteria
Admit Criteria determines when your radio is allowed to transmit
Should typically be set to “Color Code Free” for DMR repeater use
For digital simplex and analog repeater use it should be set to “Always”

27. Time Slot In DMR there are two time slots (TS), TS1 and TS2
Each channel is required to be on a time slot
There use to be a basic standard for what TG are carried on which TS, but that is now in a great deal of flux (there are no rules anymore).

28. Time Slot
DMR-MARC Repeater Web Site

29. Zones Zones are a grouping of channels.
Radios have a limited amount of zones, and a limited amount of channels can be programmed into a zone

30. DMR Radio Limitations All radios have limitations:
Maximum Channels, 16 or 32 or 99 or 1,000+
Maximum amount of zone
Channels per zone
Maximum amount of talkgroups (Digital Contacts)
Maximum amount of receive groups

31. 9 - Easy Steps to Program Your Radio (TYT MD-380)
Install programming software
Backup your Radio
Get your DMR User ID and program it into the radio
Define what Talk Groups (TGs) are to be programmed, Group Call and Private Call
Group Call are the actual TGs, example Local 2, Local 9, Ohio State.
Private Call are the user DMR ID mapped to alpha text
Create your Digital Receive Groups. These are selected from your Group Call TGs
Create Channels
Place channels into xones
Program the radio
Save configuration

32. 1. Backup up Your Radio This should be standard operating procedure!
Before making any changes to a radio, back it up
This includes brand new radios, so you can always get back to the original factory setting

33. Primary Programming Interface
Two things to know:
You click on the plus sign + or the minus sign – to expand or compress each section.
To program each section, right mouse click on the item and select the drop down or the item you wish to add, change or delete.

34. DMR ID and General Information
Select this section to enter you DMR ID and general information. If you are unsure what to enter, leave it at default.

35. Enter Your DMR ID
Other optional information can be entered, such as call sign. Typically leave anything you are not sure about alone, this is why we make a backup!

36. Button Options
There are several user definable button on each radio.

37. Button Options
There are several user definable button on each radio. I find it handy to have High/Low power, Repeater/Talkaround (put repeater on simplex) and Nuisance Delete (temporary locks out noisy signals when scanning on analog)

38. Talk Groups (Digital Contacts
Enter you talk group and private call IDs here.

39. Define Your TGs Contact Name is any name you want to give to the TG
If it is a TG, select Group Call, if it is an ID mapping to user, select Private Call
You are going to have to search for this info. The DMR-MARC repeater map and user database

40. Digital RX Groups
A receive group defines what TG your radio will hear (listen to) for the selected channel on your radio
You can listen to multiple TGs on a single channel

41. Digital Receive Groups
Example 1: Ohio State with only one contact member.

42. Digital Receive Groups
Example 2: Group List Name TS-2. I use TS-2 to stand for Time slot 2. For this group, I have included most of the TGs that operate on time slot 2.

43. Creating a Channel
There are quite a few details to programming the channel information.
The TYT-MD380 supports both digitial and analog channels. For analog channels you have the option of wide or narrow band. For amateur radio use wide band, 25KHz.

44. Creating a Channel
Channels are programmed under the Cannels Information section. Here is an example of the channel list.

45. Creating an Analog Channel
Simplex Channel. Note the key components that need to be entered.

46. Creating a Digital Channel
Example of a digital channel for Ohio State. This channel will only receive the Ohio State talk group. Note the Group List setting.

47. Creating a Digital Channel
Same as previous slide, but the Group List is now TS2-LC-OH. We created this Group List to include many of the TGs associated with Time Slot 2

48. Review of the TS2-LC-OH Group
We previously crated this which is capable to receiving these 3 TGs

49. Creating a Zone (Easy)
Zone are a grouping of channels. Radios typically have a 16 channel zone, based on the 16 position channel switch.
Radios with optical encoders, up/down buttons or trackballs, can have several hundred channels in a zone. The TYT-2017 has 64 channels per zone. The TYT MD-380 has 16 channels per zone

50. Analog Zone Example
Zone are a grouping of channels. Radios typically have a 16 channel zone, based on the 16 position channel switch.
Radios with optical encoders, up/down buttons or trackballs, can have several hundred channels in a zone. The TYT-2017 has 64 channels per zone. The TYT MD-380 has 16 channels per zone

51. Digital Zone Example

52. Only Two Things Left To Do
Final Steps
Always save the configuration you just crated before uploading it to the radio
After saving the configuration upload it to your radio

53. questions?