I have a simple question for the REAL DMR guru.
1) Does DMR Simplex work on TS1, TS2 or does not matter
2) Does DMR Simplex use the full 12.5KHz
I have conducted the following tests
I have a TYT MD398 which is Tier 1 only at 12.5Khz and talks quite nicely to my Anytone D878 on CC1 TG99.
I have a pi-star hotspot configured for TS1 but both radio and hotpot are configured for simplex operation.
Both the MD398 and the Anytone work just fine through the hotspot to the TGIF Server which shows them on TS2.
From the MMDVMHost log with the DMRGateway Rule TGRewrite0=2,16000001,1,1,999999
This should convert 16030232 on TS2 to 30232 on TS1
The MMDVM Board converts it back to TS2 or the radio on TS2 take over.
M: 2023-10-17 12:37:49.271 DMR Slot 2, received RF voice header from VE3RD to TG 16030232
M: 2023-10-17 12:37:50.399 DMR Slot 2, received RF end of voice transmission from VE3RD to TG 16030232,
The TGIF Server which shows it on TS2.
The radio is now set to TS1 and the log shows the following
M: 2023-10-17 13:18:27.044 DMR Slot 2, received RF voice header from VE3RD to TG 14030202
M: 2023-10-17 13:18:27.813 DMR Slot 2, received RF end of voice transmission from VE3RD to TG 14030202, 0.7 seconds, BER: 0.1%, RSSI: -47/-47/-
When I change the anytone radio to repeater mode, the radio no longer functions properly
My conclusion is that DMR Simplex does not use a 6.25KHz time slot but uses the full 12.5KHz and will receive any transmission on either TS1 or TS2
also does this mean a pi-star hotspot in simplex mode is also using 12.5KHz?
Can anyone shed some official light on this, Is there any documentation that can confirm or deny my conclusions.
Phil VE3RD
DMR Simplex 12.5KHz???
Re: DMR Simplex 12.5KHz???
Single freq (simplex) hotspots run DMO there are no TS allocations with DMO. Its simply, what you set in ur radio gets passed to the server.
A dual freq (duplex) hotspot carries its ts allocations to the server, so the server can route the two traffic 'streams' idependently on the 2 TS.
Sent via smoke signals using my SM-G935F
A dual freq (duplex) hotspot carries its ts allocations to the server, so the server can route the two traffic 'streams' idependently on the 2 TS.
Sent via smoke signals using my SM-G935F
Andrew M1DNS.
Pi-star Admin Team.
Pi-star Admin Team.
Re: DMR Simplex 12.5KHz???
Programmed two Anytone D878's as follows, all on the same simplex frequency
1 TS1 Simplex Mode
2 TS2 Simplex Mode
3 TS1 Repeater Mode
4 TS2 Repeater Mode
makes no difference which mode I transmit on the other radio will respond regardless of which mode I select on it
Also the MD398 (TS1) opens both D878's regardless of which mode is selected.
I am now wondering if the fact that the TX and RX frequencies are the same has anything to do with it.
BM does not show a TS when I go through a pi-star Hotspot. The field is blank
1 TS1 Simplex Mode
2 TS2 Simplex Mode
3 TS1 Repeater Mode
4 TS2 Repeater Mode
makes no difference which mode I transmit on the other radio will respond regardless of which mode I select on it
Also the MD398 (TS1) opens both D878's regardless of which mode is selected.
I am now wondering if the fact that the TX and RX frequencies are the same has anything to do with it.
BM does not show a TS when I go through a pi-star Hotspot. The field is blank
Re: DMR Simplex 12.5KHz???
If you have a simplex hotspot you are running DMO.
Only with a duplex hotspot (which mimics a rptr) or when making use of an actual DMR rptr will you be able to make use of the two TS independently.
Doesnt make any difference the mode in ur radio, if ur running it into a simplex hotspot.
Sent via smoke signals using my SM-G935F
Only with a duplex hotspot (which mimics a rptr) or when making use of an actual DMR rptr will you be able to make use of the two TS independently.
Doesnt make any difference the mode in ur radio, if ur running it into a simplex hotspot.
Sent via smoke signals using my SM-G935F
Andrew M1DNS.
Pi-star Admin Team.
Pi-star Admin Team.
Re: DMR Simplex 12.5KHz???
FWIW:
(Anytone muddies all this in the CPS: it gives you the option of selecting 12.5 or 25 for a channel, but in reality, only 12.5 works for digital mode, while 25 only works in analog mode. Earlier versions of the CPS didn't have the 25mhz grayed out for digital, hence the confusion. The CPS's for TYT's aren't any clearer on this situation either.)
The shifts of course determine the bits. The bits are grouped into slots: 108 bit chunks (for DMR anyway), and further sequenced, in time - slotted - in an interleaved fashion - hence the term "time slot". DMR, according to specs, uses two equal sized slots, for voice only, while D-Star uses two unequal slots, one for data and one for voice.
There is nothing I've seen anywhere that suggests that the two time slots are joined in any way, into a "generic slot" (for DMR).
Programatically, joining of the slots would be messy. Joining of the two slots in D-Star is meaningless, anyway.
Simplex, in simple terms, basically means you can not transmit and receive at the same time, while duplex can (and hence the two frequencies, otherwise you'd have a feedback situation, duh).
But simplex implies that only one time slot can be handled at a time, whereas duplex can receive on one time slot while transmitting on the other slot. This is, duplex can take advantage of the two frequencies for receiving/transmitting. Again, duh.
Theoretically, simplex can handle either time slot but for simplicity in the software and firmware, restricts its operations to just one time slot, traditionally TS2. Which means the other time slot runs "empty".
[edit: someone else put all this more succinctly then I could: don't confuse FREQUENCY (the transport mechanism) with TIME (the delivery mechanism , i.e. TDMA).]
Everything I see, on all my hotspots, show either TS1 or TS2. Admitted, I don't look at the BM displays often, but as I recall, because of the filtering set up for hoseline, the time slot may simply be omitted (not displayed) but doesn't mean the traffic is "slotless".
You will see some interesting effects, get interesting results when you select a talkgroup to be static on both time slots!
First, you may or may not see traffic come back at you on both time slots - it seems to be hit or miss. (Don't know why this is, but maybe others can shed some light on this phenom).
When you do see traffic on both slots AND you happen to be the one transmitting on one of those slots, either directly on the same hotspot or a different hotspot running in parallel, you may hear an "echo" of yourself at the end of your QSO, as, with a varying lag, the last second or two comes back at you on the other slot.
Several years ago, when I first set up a duplex hotspot, I used to see a lot of "double-slotting" (as I call it) on the dashboard; now not so much, as (I think) it appears changes on the server side have cut down on this. But the odd QSO or two still leak through from time to time.
You also have to consider the talk group involved here too: is it, per chance, a talkgroup that is "reflected" into other networks? Are those networks all playing by the same rules concerning time slots, transposing slots, cross modeing, etc.?
Something to consider when you're doing these tests. And interpreting the results.
For clarity here: the 6.25/12.5 KHz refers to the channel separation: DMR used 4FSK (four state frequency shifting) with each state shifted/separated by 12.5 (+1944, +648, -648, -1944 Hz around the carrier freq); same as Fusion and P25 (D-STAR uses 6.25). It has nothing to do directly with "slots".My conclusion is that DMR Simplex does not use a 6.25KHz time slot but uses the full 12.5KHz and will receive any transmission on either TS1 or TS2
also does this mean a pi-star hotspot in simplex mode is also using 12.5KHz?
(Anytone muddies all this in the CPS: it gives you the option of selecting 12.5 or 25 for a channel, but in reality, only 12.5 works for digital mode, while 25 only works in analog mode. Earlier versions of the CPS didn't have the 25mhz grayed out for digital, hence the confusion. The CPS's for TYT's aren't any clearer on this situation either.)
The shifts of course determine the bits. The bits are grouped into slots: 108 bit chunks (for DMR anyway), and further sequenced, in time - slotted - in an interleaved fashion - hence the term "time slot". DMR, according to specs, uses two equal sized slots, for voice only, while D-Star uses two unequal slots, one for data and one for voice.
There is nothing I've seen anywhere that suggests that the two time slots are joined in any way, into a "generic slot" (for DMR).
Programatically, joining of the slots would be messy. Joining of the two slots in D-Star is meaningless, anyway.
Simplex, in simple terms, basically means you can not transmit and receive at the same time, while duplex can (and hence the two frequencies, otherwise you'd have a feedback situation, duh).
But simplex implies that only one time slot can be handled at a time, whereas duplex can receive on one time slot while transmitting on the other slot. This is, duplex can take advantage of the two frequencies for receiving/transmitting. Again, duh.
Theoretically, simplex can handle either time slot but for simplicity in the software and firmware, restricts its operations to just one time slot, traditionally TS2. Which means the other time slot runs "empty".
[edit: someone else put all this more succinctly then I could: don't confuse FREQUENCY (the transport mechanism) with TIME (the delivery mechanism , i.e. TDMA).]
Where are you seeing this "blank"? Hoseline? Sysop repeater info section?BM does not show a TS when I go through a pi-star Hotspot. The field is blank
Everything I see, on all my hotspots, show either TS1 or TS2. Admitted, I don't look at the BM displays often, but as I recall, because of the filtering set up for hoseline, the time slot may simply be omitted (not displayed) but doesn't mean the traffic is "slotless".
Question: how do have the API set up for these tests? Have you assigned the talkgroup(s) involved here as "static"? Have you, per chance, set the same talkgroup static in both time slots?Programmed two Anytone D878's as follows, all on the same simplex frequency
1 TS1 Simplex Mode
2 TS2 Simplex Mode
3 TS1 Repeater Mode
4 TS2 Repeater Mode
makes no difference which mode I transmit on the other radio will respond regardless of which mode I select on it
Also the MD398 (TS1) opens both D878's regardless of which mode is selected.
I am now wondering if the fact that the TX and RX frequencies are the same has anything to do with it.
You will see some interesting effects, get interesting results when you select a talkgroup to be static on both time slots!
First, you may or may not see traffic come back at you on both time slots - it seems to be hit or miss. (Don't know why this is, but maybe others can shed some light on this phenom).
When you do see traffic on both slots AND you happen to be the one transmitting on one of those slots, either directly on the same hotspot or a different hotspot running in parallel, you may hear an "echo" of yourself at the end of your QSO, as, with a varying lag, the last second or two comes back at you on the other slot.
Several years ago, when I first set up a duplex hotspot, I used to see a lot of "double-slotting" (as I call it) on the dashboard; now not so much, as (I think) it appears changes on the server side have cut down on this. But the odd QSO or two still leak through from time to time.
You also have to consider the talk group involved here too: is it, per chance, a talkgroup that is "reflected" into other networks? Are those networks all playing by the same rules concerning time slots, transposing slots, cross modeing, etc.?
Something to consider when you're doing these tests. And interpreting the results.
Re: DMR Simplex 12.5KHz???
This is why the Tier 1 MD398 cannot be used on a Repeater - Data is transmitted on both time slots at the same time.
And this is why single frequency mode only uses TS2 and TS1 stays idle
All the documentation I see in ETSI indicates TS2 for all single frequency simplex operations
And this is why single frequency mode only uses TS2 and TS1 stays idle
All the documentation I see in ETSI indicates TS2 for all single frequency simplex operations
Re: DMR Simplex 12.5KHz???
Interesting tibit from the Shark Openspot 3 manual
– You can set the TDMA channel for data in DMO mode. DMO mode is enabled if the modem’s RX and TX frequencies match, or the modem is in DMR Hotspot mode. In this case, only one TDMA channel will be used for communication. Note that on BrandMeister, DMO mode links the two timeslots together, so this setting is irrelevant.
– You can set the TDMA channel for data in DMO mode. DMO mode is enabled if the modem’s RX and TX frequencies match, or the modem is in DMR Hotspot mode. In this case, only one TDMA channel will be used for communication. Note that on BrandMeister, DMO mode links the two timeslots together, so this setting is irrelevant.