DSD improvements I am working on
- Thread starter EricCottrell
- Start date
-
- Tags
- dsdplus
- Status
How are you trying to install the dependencies, I have a kali box (not sure the version) I don't remember having any issues getting dsd complied. I just used apt-get to insatll most of them.
Hello,
I am using Kubuntu 14.04 for development. The ALSA support solves some of the problems with earlier versions. I have not merged in the portaudio stuff yet, but that may solve the same problems.
The dependencies depend on what additional packages you have to compile. I do not have guile installed because I do have to build anything other than dsd.
I had a busy weekend. I was able to add error correction/detection for DMR Voice Headers and TLC. Thanks to some enhanced propagation, I was able to receive a Hytera Tier 3 (Trunked) system in CT. I added some decoding of Tier 3 csbk blocks. The changes are in the Feature/DMRECC branch.
73 Eric
I am using Kubuntu 14.04 for development. The ALSA support solves some of the problems with earlier versions. I have not merged in the portaudio stuff yet, but that may solve the same problems.
The dependencies depend on what additional packages you have to compile. I do not have guile installed because I do have to build anything other than dsd.
I had a busy weekend. I was able to add error correction/detection for DMR Voice Headers and TLC. Thanks to some enhanced propagation, I was able to receive a Hytera Tier 3 (Trunked) system in CT. I added some decoding of Tier 3 csbk blocks. The changes are in the Feature/DMRECC branch.
Code:
Sync: -DMR mod: GFSK inlvl: 19% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 20% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 20% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
CACH: Tier 3 (Trunked) Sys_Params LN:12 LS:0 Reg SlotCount: 075
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 20% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 19% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
CACH: Tier 3 (Trunked) Sys_Params LN:12 LS:0 Reg SlotCount: 076
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Hyteria (104) - C Bcast Large Net:12 Site:0 Par:3 Reg Unknwn: 4 Parm1:0x01A0 Parm2:0xCA0000
Sync: -DMR mod: GFSK inlvl: 19% slot0 [slot1] CC: 0 CSBK
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 20% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
CACH: Tier 3 (Trunked) Sys_Params LN:12 LS:0 Reg SlotCount: 077
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 20% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 20% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
CACH: Tier 3 (Trunked) Sys_Params LN:12 LS:0 Reg SlotCount: 078
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 19% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
Sync: -DMR mod: GFSK inlvl: 19% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Hyteria (104) - C Bcast Large Net:12 Site:0 Par:3 Reg Unknwn: 4 Parm1:0x01A0 Parm2:0xFC0000
Sync: -DMR mod: GFSK inlvl: 19% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
CACH: Tier 3 (Trunked) Sys_Params LN:12 LS:0 Reg SlotCount: 079
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 19% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
Sync: -DMR mod: GFSK inlvl: 19% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 19% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
CACH: Tier 3 (Trunked) Sys_Params LN:12 LS:0 Reg SlotCount: 080
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 20% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
Sync: -DMR mod: GFSK inlvl: 20% [slot0] slot1 CC: 0 CSBK lb:1 pf:0 Standard FID - Aloha Netwkd Large Net:12 Site:0 Par: 3 Reg MSId:0x000000
Sync: -DMR mod: GFSK inlvl: 19% slot0 [slot1] CC: 0 CSBK lb:1 pf:0 Hyteria (8) - csbk:101111 fid:00001000 payload:0x0005000000000000
CACH: Tier 3 (Trunked) Sys_Params LN:12 LS:0 Reg SlotCount: 08173 Eric
How do you recognize a Tier III system? Does the control channel have a different sound to it than Connect Plus? I don't think I've come across one in my travels yet....
Hello,
The frequency with the control channel does have a different cadence, but the SLCO and CSBKs are different. It was interesting picking up this system as Hyteria took the standard trunking and extended it with their own messages rather than replacing most of the SLCOs and CSBKs.
The system is likely one being built out by Marcus Communications in CT. The also have a statewide Passport/LTR system.
Digital Radio In Action - Hytera
73 Eric
The frequency with the control channel does have a different cadence, but the SLCO and CSBKs are different. It was interesting picking up this system as Hyteria took the standard trunking and extended it with their own messages rather than replacing most of the SLCOs and CSBKs.
The system is likely one being built out by Marcus Communications in CT. The also have a statewide Passport/LTR system.
Digital Radio In Action - Hytera
73 Eric
Thanks Eric.... Keep up the great work!!
Hello,
I need to bring in the PortAudio changes from upstream and see if my audio changes are needed.
There were a couple of interesting developments over last weekend and I recently got a few new toys.
Over the past couple of months I started using DMR on the local DMR-MARC (Ham) repeaters. My radio collection is growing with a Hytera VHF Mobile, a Motorola XPR 4550 UHF mobile, and a Motorola XPR 6550 UHF portable. The XPR 6550 is a nice radio.
I tried out some of the features on the Motorola radios simplex while looking at dsd. Many of them use CSBKs with a Motorola FID. DSD's decoding of simplex DMR does not work very well, as it expects repeater output. The remote monitoring is interesting as it causes the called radio to transmit audio for about 15 to 20 seconds. So I have a couple of radios to try things out on. I would buy a DMR repeater as well, but rather save the 2,300 dollars for other things.
I did some experiments over the weekend and figured out a way for DSD to decode both DMR slots while decoding voice. It can be done without the massive restructuring I thought was needed, but I am still not totally happy with the current code. The disadvantage is the data streams go by quickly on the screen during voice calls instead of slowing down.
Since there is now a possibility of decoding voice in both slots, I went for it. I changed the audio output to stereo and had slot 0 output on the left and slot 1 on the right. The majority of the work was modifying the state data to handle two slots and handling the merging of two interleaved audio stream into one. Slot 0 voice is more complex as output has to be delayed to either merge it with slot 1 voice, or output it when slot 1 is data. It basically works, but it is not completely done yet. So nothing has been pushed to the repository.
I am thinking of putting in single key keyboard commands so the user can select the voice slot to decode. More work to do.
73 Eric
I need to bring in the PortAudio changes from upstream and see if my audio changes are needed.
There were a couple of interesting developments over last weekend and I recently got a few new toys.
Over the past couple of months I started using DMR on the local DMR-MARC (Ham) repeaters. My radio collection is growing with a Hytera VHF Mobile, a Motorola XPR 4550 UHF mobile, and a Motorola XPR 6550 UHF portable. The XPR 6550 is a nice radio.
I tried out some of the features on the Motorola radios simplex while looking at dsd. Many of them use CSBKs with a Motorola FID. DSD's decoding of simplex DMR does not work very well, as it expects repeater output. The remote monitoring is interesting as it causes the called radio to transmit audio for about 15 to 20 seconds. So I have a couple of radios to try things out on. I would buy a DMR repeater as well, but rather save the 2,300 dollars for other things.
I did some experiments over the weekend and figured out a way for DSD to decode both DMR slots while decoding voice. It can be done without the massive restructuring I thought was needed, but I am still not totally happy with the current code. The disadvantage is the data streams go by quickly on the screen during voice calls instead of slowing down.
Since there is now a possibility of decoding voice in both slots, I went for it. I changed the audio output to stereo and had slot 0 output on the left and slot 1 on the right. The majority of the work was modifying the state data to handle two slots and handling the merging of two interleaved audio stream into one. Slot 0 voice is more complex as output has to be delayed to either merge it with slot 1 voice, or output it when slot 1 is data. It basically works, but it is not completely done yet. So nothing has been pushed to the repository.
I am thinking of putting in single key keyboard commands so the user can select the voice slot to decode. More work to do.
73 Eric
Boatanchor
Member
- Joined
- Jul 17, 2011
- Messages
- 991
Alien language 
Nice work Eric.
Since most of what you guys are talking about may as well be written in Swahili (Linux speak), is there any chance that some, or all of these developments will make it into a Windows compiled version at some stage?
I guess the other obvious question (I apologize if this has been raised elsewhere), is whether DSD will ever be capable of P25 Phase 11 support?
I run both DSD and DSD+ and whilst I appreciate the additional tuning functions and slightly better decoding of DSD+, I still prefer the P25 audio quality of the original DSD. I find the original DSD has more realistic sounding audio dynamic range and tonal qualities than DSD+, which sounds too compressed to my ear.
For example, DSD+ often enhances unwanted background/ambient noise and brings it up to almost the same level as the voice (poor dynamic range). DSD on the other hand seems to produce a more realistic reproduction, with the voice being a lot louder than any background/ambient noise.
The difference is really quite stark.
DSD audio actually sounds more akin to my real P25 radios than DSD+ does.
Anyway, keep up the good work
Rick
Nice work Eric.
Since most of what you guys are talking about may as well be written in Swahili (Linux speak), is there any chance that some, or all of these developments will make it into a Windows compiled version at some stage?
I guess the other obvious question (I apologize if this has been raised elsewhere), is whether DSD will ever be capable of P25 Phase 11 support?
I run both DSD and DSD+ and whilst I appreciate the additional tuning functions and slightly better decoding of DSD+, I still prefer the P25 audio quality of the original DSD. I find the original DSD has more realistic sounding audio dynamic range and tonal qualities than DSD+, which sounds too compressed to my ear.
For example, DSD+ often enhances unwanted background/ambient noise and brings it up to almost the same level as the voice (poor dynamic range). DSD on the other hand seems to produce a more realistic reproduction, with the voice being a lot louder than any background/ambient noise.
The difference is really quite stark.
DSD audio actually sounds more akin to my real P25 radios than DSD+ does.
Anyway, keep up the good work
Rick
Boatanchor-
Adding P25Ph2 is a matter of writing a protocol parser/decoder, much like what Eric is working on for DMR. (in fact very similar because of the 2-slot behavior he is working on). The half-rate codec is already included in mbelib.
The protocol is documented in "TIA-102.BBAB - Project 25 Phase 2 Two-Slot Time Division Multiple Access Physical Layer Protocol Description" and/or "TIA-102.BBAC - Project 25 Phase 2 Two Slot TDMA Media Access Control Layer Description". I don' t have those documents handy, but I'm sure some other folks on the forum do.
Adding P25Ph2 is a matter of writing a protocol parser/decoder, much like what Eric is working on for DMR. (in fact very similar because of the 2-slot behavior he is working on). The half-rate codec is already included in mbelib.
The protocol is documented in "TIA-102.BBAB - Project 25 Phase 2 Two-Slot Time Division Multiple Access Physical Layer Protocol Description" and/or "TIA-102.BBAC - Project 25 Phase 2 Two Slot TDMA Media Access Control Layer Description". I don' t have those documents handy, but I'm sure some other folks on the forum do.
misunderstanding
adding the fact that i'm french and no fluent with english !!
I have some questions
what Git contains the last modifications files ? is it :
git clone https://github.com/LinuxSheeple-E/dsd
or
https://github.com/szechyjs/dsd
what is the other branch
https://github.com/LinuxSheeple-E/dsd/tree/Feature/DMRECC
last question
I have an copilation error in Cmajke in master DSD :with :
cmake ../
-- Found LibSndFile: /usr/lib/i386-linux-gnu/libsndfile.so
CMake Error at cmake/FindLibMbe.cmake:18 (MESSAGE):
Could not find mbe
Call Stack (most recent call first):
CMakeLists.txt:10 (find_package)
mbe is mbelib ?
thanks for answers
adding the fact that i'm french and no fluent with english !!
I have some questions
what Git contains the last modifications files ? is it :
git clone https://github.com/LinuxSheeple-E/dsd
or
https://github.com/szechyjs/dsd
what is the other branch
https://github.com/LinuxSheeple-E/dsd/tree/Feature/DMRECC
last question
I have an copilation error in Cmajke in master DSD :with :
cmake ../
-- Found LibSndFile: /usr/lib/i386-linux-gnu/libsndfile.so
CMake Error at cmake/FindLibMbe.cmake:18 (MESSAGE):
Could not find mbe
Call Stack (most recent call first):
CMakeLists.txt:10 (find_package)
mbe is mbelib ?
thanks for answers
It depends on what modifications you are looking for. Eric's modifications are mostly in the DMRECC branch, while https://github.com/szechyjs/dsd has portaudio. Github can produce a nice graph to help you see what is in which branch:
https://github.com/szechyjs/dsd/network
As for the error, yes, mbe means mbelib; it can't find that- you need to install it before doing the build on DSD.
https://github.com/szechyjs/dsd/network
As for the error, yes, mbe means mbelib; it can't find that- you need to install it before doing the build on DSD.
nearly a the end but ..
Thanks for answer
After successfull mbelib compilation , there are still errors with make in dsd like :
git clone https://github.com/LinuxSheeple-E/dsd
cd dsd
git checkout Feature/DMRECC
cd dsd
mkdir build
cd build
cmake ..
make -------> errors
/usr/local/include/itpp/base/itassert.h:34:28: fatal error: itpp/itexports.h: Aucun fichier ou dossier de ce type
/usr/local/include/itpp/itbase.h:128:36: fatal error: itpp/base/base_exports.h: Aucun fichier ou dossier de ce type
/usr/local/include/itpp/itcomm.h:75:39: fatal error: itpp/comm/multilateration.h: Aucun fichier ou dossier de ce type
/usr/local/lib/libitpp.so: undefined reference to `itpp::g711_details::MuLaw_Properties::expansion_table'
/usr/local/lib/libitpp.so: undefined reference to `itpp::g711_details::G711_Base_Properties::compression_table'
/usr/local/lib/libitpp.so: undefined reference to `itpp::g711_details::ALaw_Properties::expansion_table'
all like itpp was baddly installed (itpp is 4.3.1)
any ideas ?
Thanks for answer
After successfull mbelib compilation , there are still errors with make in dsd like :
git clone https://github.com/LinuxSheeple-E/dsd
cd dsd
git checkout Feature/DMRECC
cd dsd
mkdir build
cd build
cmake ..
make -------> errors
/usr/local/include/itpp/base/itassert.h:34:28: fatal error: itpp/itexports.h: Aucun fichier ou dossier de ce type
/usr/local/include/itpp/itbase.h:128:36: fatal error: itpp/base/base_exports.h: Aucun fichier ou dossier de ce type
/usr/local/include/itpp/itcomm.h:75:39: fatal error: itpp/comm/multilateration.h: Aucun fichier ou dossier de ce type
/usr/local/lib/libitpp.so: undefined reference to `itpp::g711_details::MuLaw_Properties::expansion_table'
/usr/local/lib/libitpp.so: undefined reference to `itpp::g711_details::G711_Base_Properties::compression_table'
/usr/local/lib/libitpp.so: undefined reference to `itpp::g711_details::ALaw_Properties::expansion_table'
all like itpp was baddly installed (itpp is 4.3.1)
any ideas ?
very very close
Previous message solved with 4 time compilation of itt ++
Now dsd error is :
couldn't open /dev/audio
alsamixer is displaying : sound card : Pulseaudio
Git used :
Git clone https://github.com/LinuxSheeple-E/dsd
cd dsd
git checkout Feature/DMRECC
what is the way to activate /dev/audio ?
linux : kali 1.0.7 under wmware workstation and sound card is virtual audio cable
thanks
Previous message solved with 4 time compilation of itt ++
Now dsd error is :
couldn't open /dev/audio
alsamixer is displaying : sound card : Pulseaudio
Git used :
Git clone https://github.com/LinuxSheeple-E/dsd
cd dsd
git checkout Feature/DMRECC
what is the way to activate /dev/audio ?
linux : kali 1.0.7 under wmware workstation and sound card is virtual audio cable
thanks
Hello all,
I've spent some time looking into the not-so-excellent performance of C4FM signal demodulation (specifically P25) on the DSD library. The latest Gaussian fit makes an improvement but even on ideal reception conditions the BER doesn't go lower than 0.5%. Why it's not zero has been nagging me for quite some time. This is what I've learned so far:
By far, the best approach for the signal equalization (what you do to the signal after FM demodulation and before attempting to digitize it) is the "integrate and dump filter." This is the recommended approach on the P25 TIA document and has also been mentioned in this forum. The current cosine filter doesn't do much on P25 signals.
The integrate and dump filter requires a very precise timing of the symbol sampling. The TIA document mentions a "stochastic gradient clock recovery" but doesn't elaborate in its details.
The current implementation of DSD does a clock recovery (see method "getSymbol") on P25 signals essentially by looking at the zero crossings. Zero-crossings are assumed that should happen in the middle of the symbol and thus the timing can be adjusted forward or backwards. This implementation does a decent job and it is extremely simple and fast. However I believe its limitations are the root of the high BER even on ideal conditions. Besides, DSD doesn't implement a proper integrate and dump filter.
Using kind of a brute-force approach to calculate the ideal timing for each sample and applying an integrate and dump filter I was able to reduce the BER to 0% on the afore mentioned ideal conditions. This improvement confirms the idea that a better clock recovery is crucial to the quality of the demodulation for P25.
Now, I don't think that the brute-force approach is the right one for a practical system and I'm not sure I should continue on that line. I have no clue what a "stochastic gradient clock recovery" algorithm looks like and I'm no expert in those matters, but if there's anyone able to came up with some hints I might be able to dedicate some more time to this.
Kind regards,
I've spent some time looking into the not-so-excellent performance of C4FM signal demodulation (specifically P25) on the DSD library. The latest Gaussian fit makes an improvement but even on ideal reception conditions the BER doesn't go lower than 0.5%. Why it's not zero has been nagging me for quite some time. This is what I've learned so far:
By far, the best approach for the signal equalization (what you do to the signal after FM demodulation and before attempting to digitize it) is the "integrate and dump filter." This is the recommended approach on the P25 TIA document and has also been mentioned in this forum. The current cosine filter doesn't do much on P25 signals.
The integrate and dump filter requires a very precise timing of the symbol sampling. The TIA document mentions a "stochastic gradient clock recovery" but doesn't elaborate in its details.
The current implementation of DSD does a clock recovery (see method "getSymbol") on P25 signals essentially by looking at the zero crossings. Zero-crossings are assumed that should happen in the middle of the symbol and thus the timing can be adjusted forward or backwards. This implementation does a decent job and it is extremely simple and fast. However I believe its limitations are the root of the high BER even on ideal conditions. Besides, DSD doesn't implement a proper integrate and dump filter.
Using kind of a brute-force approach to calculate the ideal timing for each sample and applying an integrate and dump filter I was able to reduce the BER to 0% on the afore mentioned ideal conditions. This improvement confirms the idea that a better clock recovery is crucial to the quality of the demodulation for P25.
Now, I don't think that the brute-force approach is the right one for a practical system and I'm not sure I should continue on that line. I have no clue what a "stochastic gradient clock recovery" algorithm looks like and I'm no expert in those matters, but if there's anyone able to came up with some hints I might be able to dedicate some more time to this.
Kind regards,
D
DaveNF2G
Guest
From Wikipedia at Stochastic gradient descent - Wikipedia, the free encyclopedia
In stochastic (or "on-line") gradient descent, the true gradient of Q(w) is approximated by a gradient at a single example:
w := w - alpha * nabla * Q sub i * (w)
Couldn't get the Greek symbols to reproduce here.
In stochastic (or "on-line") gradient descent, the true gradient of Q(w) is approximated by a gradient at a single example:
w := w - alpha * nabla * Q sub i * (w)
Couldn't get the Greek symbols to reproduce here.
Hello,
/dev/audio is the OSS device. If you are getting that without specifying input or output, then the ALSA support is not compiled in. CMake checks if the ALSA development files are available and will only compile ALSA support when it detects the files.
On Ubuntu you need to install libasound2 and libasound2-dev for ALSA support.
73 Eric
Hello,
I have been experimenting to see if I could get itpp to decode the punctured convolutional codes used in NXDN.
The results are very promising. I compared the hex values with the NXDN specifications and the information makes sense. I need to create the crc routines next and see if the infomation is valid.
This is only the beginning, so it will be awhile before this feature is available.
73 Eric
I have been experimenting to see if I could get itpp to decode the punctured convolutional codes used in NXDN.
Code:
Trunk-C Control Ch DATA 84184016 444914BB C0000000 00000001 3C840015 000015186
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 041B4016 41049040 16430A3D 4016450F 2500001F 00000F646
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Trunk-C Control Ch DATA 84184016 444914BB C0000000 00000001 3C840015 000015186
Trunk-C Control Ch DATA 04194016 44BBC000 00000000 00000000 0000000D 000007746
Code:
Trunk-D Composite Ch DATA 1047F9040 1B0000800106 0080010AD7A0
Trunk-D Composite Ch DATA 1047F9040 1900800108A8 00000000CBF0
Trunk-D Composite Ch DATA 030862420 0010240EBD08 62408001ED70
Trunk-D Composite Ch DATA 030862420 0010220EBD08 62408001FB00
Trunk-D Composite Ch DATA 030862420 0010240EBD08 62408001ED70
Trunk-D Composite Ch DATA 030862420 0010220EBD08 62408001FB00
Trunk-D Composite Ch DATA 1047F9040 0010240EBD08 62408001ED70
Trunk-D Composite Ch VOICE e: C22200230
Trunk-D Composite Ch VOICE e: 830862418
Trunk-D Composite Ch VOICE e: 420EBD328
Trunk-D Composite Ch VOICE e: 1047F9048
Trunk-D Composite Ch VOICE e: C41200638
Trunk-D Composite Ch VOICE e: 830862418
Trunk-D Composite Ch VOICE e: 440EBD6D8
Trunk-D Composite Ch VOICE e: 1047F9048
Trunk-D Composite Ch VOICE e: C22200238
Trunk-D Composite Ch VOICE e: 420EBD328
Trunk-D Composite Ch VOICE e: 1047F9048 ==
Trunk-D Composite Ch VOICE e: C41200638
Trunk-D Composite Ch VOICE e: 830862418
Trunk-D Composite Ch VOICE e: 030862428
Trunk-D Composite Ch VOICE e: C4120063F
Trunk-D Composite Ch VOICE e: 83086241F
Trunk-D Composite Ch VOICE e: 440EBD6DF T
Trunk-D Composite Ch VOICE e: C2220023F
Trunk-D Composite Ch VOICE e: 420EBD32F
Trunk-D Composite Ch VOICE e: 83086241F
Trunk-D Composite Ch VOICE e: 440EBD6DF EE
Trunk-D Composite Ch DATA 1047F904F 1900800108A8 00000000CBF0
Trunk-D Composite Ch DATA 1047F904F 1B0000800106 0080010AD7A0The results are very promising. I compared the hex values with the NXDN specifications and the information makes sense. I need to create the crc routines next and see if the infomation is valid.
This is only the beginning, so it will be awhile before this feature is available.
73 Eric
Hello,
I am mainly focusing on decoding Type-C and Type-D trunking since control channels are available 24/7. I was able to add enough decoding to decode the id, site number, and Type-D repeater number. I tuned around and linked together the multiple Type-C and Type-D channels I heard into systems. AAA in NH uses a Type-D system in Goffstown, NH, so it tends to be active after business hours.
The RAN is the site number mod 64 on Type-C systems, and a zero value does not match everything. Like other systems, the system id and site number are sent often, so the RAN value is not required for monitoring Type-C systems. Type-D does not use RAN.
Having the NXDN specification really helps, but one still has to wade through it. The common problem is the size and organization. You need to look in 4 or more different places for information on a frame. IDAS Type-D trunking is covered in two separate documents that copy like Conventional/Type-C documents with modifications. The contents of some messages are different on Type-D, but it does not appear to be too difficult to select the proper message format to use.
Type-D trunk systems are a digital form of enhanced analog LTR, so there is the concept of Free Repeaters, and Home Repeaters.
It appears Type-C uses a frequency mapping concept similar to P25 and other non-LTR systems. I have not found much about the mapping. The system ID uses a system category concept similar to DMR Tier-3. The category indicates where to split the id number into the system id and site id numbers. So the local category has a small number of sites and a large number of system ids while the global category has a large number of sites and a small number of system ids.
Both Type-C and Type-D have provisions for inter-system linking.
73 Eric
I am mainly focusing on decoding Type-C and Type-D trunking since control channels are available 24/7. I was able to add enough decoding to decode the id, site number, and Type-D repeater number. I tuned around and linked together the multiple Type-C and Type-D channels I heard into systems. AAA in NH uses a Type-D system in Goffstown, NH, so it tends to be active after business hours.
The RAN is the site number mod 64 on Type-C systems, and a zero value does not match everything. Like other systems, the system id and site number are sent often, so the RAN value is not required for monitoring Type-C systems. Type-D does not use RAN.
Having the NXDN specification really helps, but one still has to wade through it. The common problem is the size and organization. You need to look in 4 or more different places for information on a frame. IDAS Type-D trunking is covered in two separate documents that copy like Conventional/Type-C documents with modifications. The contents of some messages are different on Type-D, but it does not appear to be too difficult to select the proper message format to use.
Type-D trunk systems are a digital form of enhanced analog LTR, so there is the concept of Free Repeaters, and Home Repeaters.
It appears Type-C uses a frequency mapping concept similar to P25 and other non-LTR systems. I have not found much about the mapping. The system ID uses a system category concept similar to DMR Tier-3. The category indicates where to split the id number into the system id and site id numbers. So the local category has a small number of sites and a large number of system ids while the global category has a large number of sites and a small number of system ids.
Both Type-C and Type-D have provisions for inter-system linking.
73 Eric
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