Tait DMR Tier 2 FAQs – Part II

dmr-t2-faq-2Last week, in Part I of DMR Tier 2 FAQs, we covered the features of Tait’s DMR Tier 2 solution and compared it to our DMR Tier 3 offering. This week, we delve deeper into specifics like location services, console support, interoperability, and encryption.

Q. Why does Tait require a node to support multi-site DMR Tier 2 solutions?

To create a multi-site IP linked system, we use a Tier 2 Node. This centralized architecture is very useful for system connectivity/application, as with DMR Tier 3.

  • The node reduces the bandwidth required by the supporting multisite IP network. Otherwise, every individual DMR TB93 repeater/base station has direct IP connectivity for remote management (example of a single site remote upgrade).
  • The node makes a number of interfaces to the outside world, to support both third-party applications and an increasing range of Tait network management products.
  • The node allows future network features to be placed within it, reducing the need to reprogram all base stations.
  • The node is the source of information that is exposed as an API to support applications such as Location Services.

Q. Does it mean we need a dedicated IP connection between the node and the repeaters?

A dedicated IP backbone (microwave, MiMOMax or fiber) for multi-site is required, but please note that generic Internet connectivity is not recommended. See the Tier 2 architecture diagram example that follows.

DMR Tier 2 setup

Q. How much rack space does the TB9300 use?

The TB9300 uses 4U (6.97″ or 177mm) of 19″ rack space for one of the following configurations:

  • A 100W base station with a Power Management Unit (PMU).
  • A single 50W base station with a PMU.
  • Dual 50W base stations with a PMU.

Q. Has Tait carried out DMR interoperability testing with other Tier 2 vendors?

Tait has carried out TP9300 interoperability tests on both Selex and Hytera infrastructure, under the procedures laid down by the DMR Association (www.dmrassociation.org).

Q. What are the DMR colour codes?

Colour codes separate DMR systems which share a common radio frequency, Colour codes range from 1 to 15.

Q. Do the TM9300 mobile and TP9300 portable support CCDI to send and receive Status and Short Data Messages?

The terminals can send packet data messages over CCDI, supporting either unconfirmed or confirmed short data transmissions with outgoing data in the raw data format. Confirmed transmissions expect a response transmission in the short data, raw data format. Status messages can also be sent via CCDI in a similar manner.

Q. What consoles do Tait support through the Node?

Tait currently supports Omnitronics Reditalk and DX-Altus, and Logic Wireless Crosswire consoles, all of which use the DMRA-released AIS protocol. Additional consoles in the roadmap include Zetron and Avtec.

Other console vendors can certify their solutions using AIS, by joining the DMRA, and becoming a registered member of the Tait Partner Program.

Q. How does Tait support Location Services over DMR Tier 2?

The TP9300 portable (with internal GPS) and the TM9300 (with external GPS) can send location data in DMR Packet Data Protocol unconfirmed format using short data, raw data messages. This data is extracted from the network in CCDI format via a radio dispatch station. (The dispatch station can also poll radios in CCDI format.) Unsolicited location messages will also be presented in CCDI. The radio dispatch station must operate on the same talk-group as the radios providing locations.

If the network has a node, location information can be extracted by API and delivered over an IP connection. The current validated Location Services Application uses the Omnitronics RediTALK console, which uses location information stored in the Tier 2 node.

Q. What are the specifications of the portable and mobile GPS?

We are using the same TP9300 portable (with internal GPS) and TM9300 (with external GPS), running DMR Tier 2 firmware. Typical cold start time is two minutes or less with a hot start of less than one minute. The horizontal precision typically is less than 10 metres in a clear sky view location. (These availability figures are applicable where over 90% of the sky is visible with the GPS aerial three feet off the ground.)

Q. Does Tait support beacons so that terminals on a Tier 2 multisite system can find the best channel to listen or transmit on?

Yes. The TN9300-2 Node that controls the multisite network can control beacon signals from the base stations. Beacon timing is set up in the node. The beacons provide the terminals with a method of determining which radio channel to set up a call on, while they move around the coverage area.

Q. How many bits is our DES encryption?

We support 56-bit DES encryption on DMR Tier 2.

Q. Does Tait Support ARC4 encryption?

We support ARC4 on DMR Tier 2.

Q. Can the graphic LCD on the TP9300 and TM9300 be programmed in Portuguese and other languages?

Currently, the programming application supports only English and French.

Q. Do we have voice alerts/voice announcements?

Voice annunciations for channel changes and battery level are supported on TP/TM9300 with DMR Tier 2 firmware. In future we will introduce the ability to load locally-recorded voice files for channel names.

Q. Is Bluetooth supported on the TP9300 portables?

Bluetooth functionality for the TP9300 Tier 2 and Tier 3 is the same. It supports Bluetooth headsets with Bluetooth PTT as a radio function key and/or a wired PTT on the radio accessory connector. It does not support wireless Bluetooth PTTs, wireless speaker microphones or data applications. Bluetooth is not available in our TM9300 mobiles.

Q. Can DMR Tier 2 support Voice + Data?

Tait DMR Tier 2 supports voice and limited data capabilities such as GPS. In a DMR Tier 2 system, each RF channel (one reciter) offers two available time slots for voice and/or data. We currently have validated voice, and data (IP Data for OTAP) as a potential on the roadmap.

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Read more about Tait’s DMR Tier 2 and Tier 3 solutions.

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