Dmr Tier 2 Repeater

1. Dmr Tier 2 Repeater Frequency
2. Dmr Tier 2 Repeater Kit

Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.If you violate these guidelines your post will be deleted without notice and an infraction will be issued.

We are not against discussion of this issue. You just need to do it in the right place. For example:https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html. I am trying to understand the DMR Tier-II in more detail.

My current understanding is that DMR Tier-II is basically a 'repeater based' Digital Mobile Radio (Tier-I being simplex). If my understanding is correct DMR Tier-II also allows a multi-site operation mode. That is multiple repeaters at various locations in a region, but all connected through an IP (Internet) back bone.In DMR Tier-II multi-site mode of operations:-1. How are the frequencies assigned?

I am trying to understand the DMR Tier-II in more detail. My current understanding is that DMR Tier-II is basically a 'repeater based' Digital Mobile Radio (Tier-I being simplex). If my understanding is correct DMR Tier-II also allows a multi-site operation mode. DMR Tier II is based on the following ETSI standards. ETSI TS 102 361-1 Air interface ETSI TS 102 361-2 Voice and generic services and facilities ETSI TS 102 361-3 Data protocol DMR Tier III. DMR Tier III covers trunking operation in frequency bands 66-960MHz. The Tier III standard specifies two slot TDMA in 12.5kHz channels. Kenwood DMR hand portable radios and repeaters meet with ETSI TS 102 361 Tier 2: Conventional DMR. Kenwood's DMR range is designed to meet the requirements of users who operate small-scale communication systems and/or who require an ETSI compliant solution.

Will each of the repeater in each site have a different frequency?2. How will a station (especially mobile station) know which repeater (within the multi-site repeater system) is the best to use at any given time?If there any internet references explaining the DMR Tier-II multi-site installations & workings please do give me a link of the same.Thanks in advance. The same way you would with an analogue linked system. You can tag the frequencies with a call sign, frequency, Mountain name, club name or what ever you want that will give you an indication of where the repeater is, and if you are with in its foot print.Motorola allows a function called ‘roaming’ where repeaters beacon at set intervals, this allows the subscriber(mobile or portable) to determine which repeater has the strongest signal. Majority of ham based DMR will not do this though.Sent from my iPhone using Tapatalk. More or less correctFrequencies are assigned by repeater coordination bodies.

Dmr Tier 2 Repeater Frequency

If geographically separated they can be the same, if not separated far enough, they would need to be different.The same way you would with an analogue linked system. You can tag the frequencies with a call sign, frequency, Mountain name, club name or what ever you want that will give you an indication of where the repeater is, and if you are with in its foot print.Motorola allows a function called ‘roaming’ where repeaters beacon at set intervals, this allows the subscriber(mobile or portable) to determine which repeater has the strongest signal.

Majority of ham based DMR will not do this though.Sent from my iPhone using Tapatalk. More or less correctFrequencies are assigned by repeater coordination bodies. If geographically separated they can be the same, if not separated far enough, they would need to be different.The same way you would with an analogue linked system. You can tag the frequencies with a call sign, frequency, Mountain name, club name or what ever you want that will give you an indication of where the repeater is, and if you are with in its foot print.Motorola allows a function called ‘roaming’ where repeaters beacon at set intervals, this allows the subscriber(mobile or portable) to determine which repeater has the strongest signal. Majority of ham based DMR will not do this though.Sent from my iPhone using Tapatalk. Sure we have it but you have to listen to the analogue repeater I'd every ten minutes.Repeater coordination requires that in most instances the repeater pair your using is at least 100 miles from another user of that pair and the chances of interfering with each others operation is minimal.

Thanks for the detailed responses. Is there a hard & fast rule that a frequency can have only 2 Talk Groups (Time Slot 1 & Time Slot 2) associated to it? Or can I have multiple talk groups added to the Time slots.

And the Time slots would get assigned to the Talk groups in a round-robin fashion?Eg:-Time slot 1: TG1, TG3, TG5Time slot 2: TG2, TG4, TG6And the transmissions (from the repeater on a single frequency) would be like.Time slot1.TG1Time slot2.TG2Time slot1.TG3Time slot2.TG4Time slot1.TG5Time slot2.TG6Time slot1.TG1.Time slot2.TG6PS: In many tutorial videos I saw multiple talk groups getting associated with a channel (which I understand to be a repeater frequency). So taking this scenario further:-Step 1: A user keys up and tells the repeater (A) the talkgroup and the slot. The repeater listens for the Tx from the user (on the Time slot).Step 2: The repeater (A) then re-broadcasts the message to the talk group which was the intended receipient.

The repeater (A) also sends out the message on the IP (internet) network to other repeaters.Step 3: Other repeaters (B) gets the message and see if it is for a TalkGroup which they have promised to Rx/Tx. If yes, they too broadcast this message on the TalkGroup and on the slot which they have configured for that talk group. Radios listening to the TalkGroup (and on the chosen time slot) on other repeater (B) would also hear the message.Since all this happen within micro seconds, none of the users actually see any delay. Is my understanding correct? So taking this scenario further:-Step 1: A user keys up and tells the repeater (A) the talkgroup and the slot.

The repeater listens for the Tx from the user (on the Time slot).Step 2: The repeater (A) then re-broadcasts the message to the talk group which was the intended receipient. The repeater (A) also sends out the message on the IP (internet) network to other repeaters.Step 3: Other repeaters (B) gets the message and see if it is for a TalkGroup which they have promised to Rx/Tx. If yes, they too broadcast this message on the TalkGroup and on the slot which they have configured for that talk group. Radios listening to the TalkGroup (and on the chosen time slot) on other repeater (B) would also hear the message.Since all this happen within micro seconds, none of the users actually see any delay.

Is my understanding correct? Only one TG can be active at a time on any time slot, even if multiple 'static' talkgroups are programmed for that time slot.

If the repeater is transmitting something from TG2 on TS2. And something from TG1 arrives at the repeater. It simply is not transmitted if both TG's are assigned to TS2.

When a repeater is transmitting or receiving on a timeslot it does so for only one talkgroup at a time. This is why network admins and repeater operators request that statewide talkgroups be used as 'calling channels' and QSOs be moved off to 'TAC' or local TGs. If a statewide TG is set as static on a repeater's timeslot, every transmission ties up that timeslot from being used by others for calling. If every repeater in the state has the statewide TG set as static, then a user key-up on that TG keys up every repeater in the state.

This is also why 'static' talkgroups must be chosen. That clarifies it. So when repeaters are linked up, it is never in a one-way scheme and every repeater exchanges its traffic both ways to the repeaters connected to it. Which also kind of ensures that only one person can talk to one talk group at a time. From what I understand a 'busy channel lock out' feature exists in DMR Tier II systems as well.And the scenario which mentioned also makes repeater interlinking a good system to pass messages all across a state (or a big geographic area). Some thing like a 'trunk channel' which can be used for emergency purposes.

Thank you, and this was one big question which I had in my mind. So as per my understanding:-1. Repeater A has got two TGs on TS2; TG1 (which is also configured on Repeater B) and TG2 (which is also configured on Repeater C).2.

There is traffic on TG1 (as some one using Repeater B started talking). Repeater A, TS2 would now start Tx-ing this message.3. Within nano-seconds there is traffic on TG2 (as some one starts using Repeater C).

But Repeater A would NOT Tx this message, as it is already busy with Tx from TG1. So listeners of TG2 on Repeater A, will miss this message.4. Repeater D also is a subscriber to TG2 on TS2.

But repeater D would Tx this message, as it does not have any other traffic on any other talk groups. Listeners on Repeater D would be able to receive the message. So it means that if the requirement is that multiple talk groups need to remain in constant contact, and the geographical area is wide so that multi-site repeaters are required, then Tier III (trunking) is the only way out. But if the requirement is more simpler; just two groups (TG1 and TG2), but it has to reach a wider area then Tier-II multi site option would also work out.

The two groups would be configured in the same time slots on each repeater in multi-site configuration, and they all would be connected over IP. The moment there is Tx on one Talk Group all repeaters in multi-site would simultaneously Tx it (in the same Time slots). Thank you, and this was one big question which I had in my mind. So as per my understanding:-1. Repeater A has got two TGs on TS2; TG1 (which is also configured on Repeater B) and TG2 (which is also configured on Repeater C).2.

There is traffic on TG1 (as some one using Repeater B started talking). Repeater A, TS2 would now start Tx-ing this message.3. Within nano-seconds there is traffic on TG2 (as some one starts using Repeater C). But Repeater A would NOT Tx this message, as it is already busy with Tx from TG1. So listeners of TG2 on Repeater A, will miss this message.4. Repeater D also is a subscriber to TG2 on TS2.

Dmr Tier 2 Repeater Kit

But repeater D would Tx this message, as it does not have any other traffic on any other talk groups. Listeners on Repeater D would be able to receive the message. So it means that if the requirement is that multiple talk groups need to remain in constant contact, and the geographical area is wide so that multi-site repeaters are required, then Tier III (trunking) is the only way out. But if the requirement is more simpler; just two groups (TG1 and TG2), but it has to reach a wider area then Tier-II multi site option would also work out. The two groups would be configured in the same time slots on each repeater in multi-site configuration, and they all would be connected over IP. The moment there is Tx on one Talk Group all repeaters in multi-site would simultaneously Tx it (in the same Time slots).

Ailunce HD1 Dual Band DMR Digital DCDM TDMA Waterproof Two Way RadioDescription:HD1 dual band digital radio uses Digital Mobile Radio (DMR) Tier 2 Standard protocol. It is compatible with the popular MOTO TRBO series Tier I and II using standard encryption, as well as other makes and models of DMR supported radios. It is also compatible with any existing analog two-way radio operating on the supported UHF and VHF frequencies for easy migration to digital technology.