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DMR

What is a DMR ID?

This is a unique identifier assigned to you and your callsign. It is programmed into your radio and transmitted to the network whenever the radio transmits. This ID identifies you on the network.

The DMR ID can be obtained from RadioID.net.

What is a Color Code?

In a MOTOTRBO radio or repeater, there is a color code field which allows the selection of one of 15 color codes. A radio which has been programmed with color code 1 will not be able to transmit on a repeater configured with color code 2 and so forth. A radio can be configured with multiple color codes - one for each channel. A repeater can only be configured with one color code.

Color code is useful because it can prevent radios from one site or system mistakenly roaming to another site or system which uses the same frequencies. Although there is activity from the neighboring system, the radio will ignore all transmissions from the other system because it has a different color code.

This is also useful for telecommunication regulators who have to allocate the same frequency to two DMR licensees in the same region. The regulator simply has to specify a color code in the license conditions - much like PL/DPL was used in analogue as a guard tone.

There is a limitation of course, if two geographically adjacent radio systems use the same frequencies, yet use a different color code, there will be audio quality issues in the area where radio users are able to receive signals from both systems at roughly the same signal strength.

MOTOTRBO radios can also be configured to be “polite” to other systems using the same frequency. In the CPS, it is possible to set the TX Admit Criteria to be Color Code Free. This will only permit the radio to transmit if there is no signal, or if the signal present on the receive frequency has the same color code.

What is a Talkgroup?

What is a C-Bridge?

The C-Bridge is the secret to IPSC (Internet Protocol Site Connect) which involves the linking of multiple repeaters to a single network, or to multiple networks. The C-Bridge is also the source of audio feeds of the various audio streams that make DMR what it is. The C-Bridge in essence is part database manager, part master control hub and part gateway. It is responsible for the assignment of what talk groups are available to a particular network; as well as the repeaters attached to that network.

What is a Code Plug?

DMR Radios are configured using “Code Plugs”, which define the repeaters, talk groups, and other settings used by the radio to communicate. Every manufacturer uses their own format, which may or may not be compatible with similar models. Though this model of programming allows a large amount of customization for a given radio, it is also very time intensive – and unlike analog and some digital modes, you must program a DMR radio with a code plug before it will work.

Who is DMR-MARC?

MARC stands for Motorola Amateur Radio Club Worldwide Network. It is one of the original DMR network coordinators and is still to this day extremely popular and reliable.

Who is BrandMeister

The Brandmeister Network was born from several worldwide hams and software engineers who joined together to create a digital repeater network consisting of master servers and peer repeaters all over the world.

DMR APIs on RepeaterBook

Repeaterbook.com utilizes two APIs to supplement repeater data.

radioid.net

In order to use DMR through Internet Protocol Site Connect (IPSC) servers, each DMR appliance (radio, repeater, hot spot, etc.) needs to have a DMR ID. For the amateur radio service, these can be obtained through Radioin.net. Radioid.net maintains a complete database of all assigned DMR IDs and who, or what, the ID was assigned to. Repeaterbook.com queries the database in two ways.

  1. Repeaterbook queries the repeater call sign and frequency to obtain the DMR ID.
  2. Repeaterbook queries the DMR ID to obtain the color code and IPSC information.

Radioid.net rules require a registrant to use their own call sign and not the repeaters call sign. In some circumstances, a repeater may have a club call sign, or other call sign, that is not the same call sign as the individual requesting the DMR ID. When this occurs, Repeaterbook may not successfully retrieve the repeater's DMR ID from the API. In this case, no information is retrieved. Repeaterbook admins should not assume that the repeater record is invalid if the DMR ID cannot be obtained via the frequency and call sign of the repeater. There are other search parameters, such as frequency and location, that can be utilized to try to find the DMR ID. If the DMR ID is manually entered into a repeater record, that ID is used to obtain the information from the API since the ID is a unique value in the record.

The API is queried by Repeaterbook whenever a repeater is edited or moderated at the admin level. It is also automatically queried when a new DMR repeater is added to the database. The listed color code, DMR ID, and ISPC Network is gathered and recorded to the repeater's record in the database and displayed on the repeater's details page and elsewhere.

If there is incorrect data on Repeaterbook which would include the DMR ID or color code, this data can be changed and overridden by a Repeaterbook admin. However, the IPSC is queried directly from radioed.net and written directly to the database. Repeaterbook would encourage repeater managers to update the data on Radioid.net so that Repeaterbook can obtain the correct information.

BrandMeister.info

BrandMeister also hosts the Halligan API. This API utilizes the DMR ID of repeaters connected to the BrandMeister IPSC to display the current static talkgroup settings for the repeater. This data is not recorded into the database but is queried in real-time on the repeater's details page.

Repeater managers can change the display of the static talkgroups by updating their settings on Brandmeister.network. Repeater owners can also request an admin to update the Repeaterbook list of talkgroup info. Repeater managers may also request to be made a Repeater Record Custodian and manage talkgroups on their own (self service).

Other Resources

dmr.txt · Last modified: 2019/12/09 13:58 by kd6kpc