Time Slot’s and Color Codes…what the hell..?

A timeslot is relatively easy to explain. It divides the digital transmission on the frequency in two channels, named TS1 and TS2. Analog communication can only do one communication on a channel at a time. In DMR two conversations can happen at the same time as the digital packets need less “space” (see graphic below). Depending on the setup of your repeater you will have i.e. static TG’s in TS1 and dynamic TG’s in TS2. Which are static and which are dynamic depends on the sysop and recommendation of i.e. the Brandmeister community. If you want to use a specific TG, simply select the TS2, the TG you want and press PTT for a short time. Depending on the time-out value the repeater sysop has set, you are now in this TG dynamically and without any activity of you (i.e. a QSO), this dynamic TG will be removed after 6-10 mins.

Same with color code. The color code you have set for a digital repeater in the Channels List of your codeplug must correspond with the color code this repeater uses. Most repeaters use color code (CC) 1.You will find the CC’s typically in the repeater lists in the internet for your region, state or country. Here is a worldwide repeater list as an example I have created, which covers all Brandmeister repeaters worldwide which I could find. Due to inconsistencies in the database I dumped the records which made no sense, therefor I am pretty sure it is not complete, but it is a start for you. Keep in mind that if a repeater works on multiple frequencies, it can not have the same name for both frequencies, you have to modify such an entry in your codeplug channel list or in the channels.csv file if you are importing from there.

In the above graphic the 12.5 kHz Bandwidth of a channel is subdivided into 2 TS’s. DMR Radio one and three use TS1 and DMR Radio two and four are using TS2 simultaneous on one channel frequency without disturbing each other.

DMRplus, Brandmeister, etc., which network to use ?

I personally prefer Brandmeister (BM), others DMRplus (D+), DMR-MARC etc.. Actually you can use all, if you have many different local DMR networks, just in one radio. The only thing you should take care of is to name channels and talkgroups in a way that you can distinguish which repeater does what (BM, D+, DMR-MARC etc.). If I would use more than one network, my repeaters would be named i.e. “D+ DB0PBS” or “BM DO0ERK” and so on.

The same should be done for Talkgroups (TG’s). Brandmeister’s world Talkgroup is TG91, DMRplus uses TG1 for woldwide. Therefor I would name the TG’s “D+ world” (=1) and “BM world” (=91) in the Talkgroup list accordingly, like in this example: TalkGroups marked for Brandmeister (BM). The only thing I have to do now to switch between the networks, is to use the right repeater with the right Talkgroup.

Of course there are are Multi-Net Bridges (Interfaces between different networks like DMRplus, Brandmeister and technologies like C4FM, DStar etc.) available in each of the networks. I never used them or played around with them, therefor pls. do your own research in the internet. This presentation gives you a bit more information.