Mixed systems (or, how a simple question turns into a long answer)

[Q] Might you be aware of a list of proprietary MOTOTRBO features that will not function on a “mixed” system? In other words, what features would be lost if non-Motorola equipment was introduced into a DMR system? For example, I recall the use of “compressed UDP header” requires an all-Motorola environment.

[A] I'm not aware of any list like this, but this question could be posed to any DMR equipment vendor and their answer will be more or less the same as mine. Also, the answer is not quite clear cut - in reality, some features will work; some features might work and some features won't work, depending on the conditions.

The DMR Association oversees interoperability testing between vendors. The IOP test result and certificate provides an assurance to buyers, that the listed equipment will be able to work with each other but there are some caveats:

• For DMR Tier 2, only the following features/functions are tested and only 1-4 are mandatory. This means that a vendor can elect not to test 5-8 and still achieve interoperability.

1. Talkgroup Call
2. Individual Call (OACSU and PATCS)
3. All Call
4. Radio Check
5. Call Alert
6. Radio Disable/Enable
7. Emergency Alarm
8. Emergency Call

• The above tests are generally performed between a radio from vendor X and repeater from vendor Y and not between radios. Although recently the tests for DMR Tier 2 have included both repeaters and radios from both vendors.
• For DMR Tier 3, the situation is similar with 5-8 being optional tests:

1. Registration (Denied/Granted) and Deregistration
2. Hunting and site change
3. Single site talkgroup call (message and transmission trunking as well as call denied and granted)
4. Single site individual text message.
5. Single site individual call with OACSU and FOACSU (as well as call denied and granted)
6. Multisite talkgroup call (message and transmission trunking as well as call denied and granted)
7. Multisite individual call with OACSU and FOACSU (as well as call denied and granted)
8. Multisite individual text message.

I know that the test procedure has been updated but I haven't seen any data to confirm whether more tests have been added. I'm sure someone will correct me! (Please)

Remember that interoperability only covers the RF air interface. This means that a repeater from vendor X cannot be used in a system from vendor Y. It also does not necessarily mean that a radio from W will work with a radio from Z but if radios from W and Z were separately tested on system X, one can infer that they will support the features/functions listed in 1-4 above.

In some cases, the trouble with ETSI TS 102 361, is that some things are not very well defined in my opinion, and so it's up to each vendor to decide how to implement the described feature. In this case, although it may be present in vendor X's radio, that feature will not work with other vendor's radios.

MOTOTRBO Capacity Plus is based on DMR but is a proprietary implementation, so other vendor's radios will not be able to work on this. Other vendors have systems like Capacity Plus and the same would be true for them.

MOTOTRBO Capacity Max will support radios from other vendors, provided that radio has demonstrated DMR Tier 3 interoperability.

To make things easy to understand, I would categorise features and functionality as will work; might work and won't work. Blogger.com does not really handle tables very well so instead, I've created this list using Google Sheets.

Click this image to open the list.

While I've done my best to make this list as accurate as possible, I cannot guarantee that it is exhaustive or free from errors. If you need to officially confirm whether a specific feature will work in a specific configuration, please contact the manufacturer or their representative. If you think there is an error, please let me know. 

A reminder once more that this is a personal website. All posts on this blog are my own and do not necessarily represent the positions, strategies, or opinions of my employer, Motorola Solutions.