SDR# TETRA Demodulator Trunk Tracking Demonstration

ScanHen

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Mar 18, 2018
Messages
41
I was asked to report this error

81966
 

Attachments

  • TETRA_error_MM-3-4_2020-03-20_13-17-53.7312_burst.txt
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hamradionl

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Mar 23, 2014
Messages
730
TETRA_error_LLC_2019-12-13_12-45-59.4712_burst.txt

CurrTimeSlot, 2
MAC_PDU_Type, 0
Fill_bit, 1
Position_of_grant, 1
Encryption_mode, 0
Random_access_flag, 0
Length_indication, 27
Address_type, 3
USSI, 11512921
Capacity_Allocation, 1
Granting_delay, 10
MacPduRealSize, 123
PduStartOffset, 0
LLC_Pdu_Type, 13
LLC_Pdu_SubType, 2
Flow_control, 0
Advanced_link_number, 3
Link_feedback_information_flag, 1
CRC_check: 15322

BURST[124]: 0011000011011011101011111010110001011001010001101001101100110010000001110111001111010010001001100111110000011000111110010111
 

thewraith2008

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Joined
Nov 22, 2016
Messages
1,867
TETRA_error_LLC_2019-12-13_12-45-59.4712_burst.txt

CurrTimeSlot, 2
MAC_PDU_Type, 0
Fill_bit, 1
Position_of_grant, 1
Encryption_mode, 0
Random_access_flag, 0
Length_indication, 27
Address_type, 3
USSI, 11512921
Capacity_Allocation, 1
Granting_delay, 10
MacPduRealSize, 123
PduStartOffset, 0
LLC_Pdu_Type, 13
LLC_Pdu_SubType, 2
Flow_control, 0
Advanced_link_number, 3
Link_feedback_information_flag, 1
CRC_check: 15322

BURST[124]: 0011000011011011101011111010110001011001010001101001101100110010000001110111001111010010001001100111110000011000111110010111
Your posting something you have already sent to me and has been dealt with.

I might add that you sent it 3 months after it occurred and failed to send the screenshot which also shows additional information to debug the error.



Latest version (v1.7.0.0) can be found here: Release post
 

RevWil

Newbie
Joined
Mar 21, 2020
Messages
2
Hey,

first of all, thanks for keeping the project alive.
I have a question for the wishlist:

Would it be possible in the future to create a function where you can use a custom sound for every new MS registration that is happening?
I'm talking about the actual "MS Registration" tab.

82012

I'm not into coding at all so I'm asking with a lot of reservation.

Thank you and greetings
 

syscodec

Member
Joined
Feb 20, 2019
Messages
22
I found the follow quote in the standards in relation to the encryption of the SSI (element of the Layer 2 MAC) for encrypted PDUs.
The following would seem to indicate that the SSI is always encrypted for encrypted PDUs.






Latest version (v1.7.0.0) can be found here: Release post

I have noticed (encrypted network) that SSIs (encrypted) remain same for a long time (many months MS has same encrypted SSI) before they are changed .... Also it could be possible (it is possible here where I live) to call to SSI from GSM network (it requires prefix + SSI) and if someone answers then the SSI probably is not encrypted
 

thewraith2008

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Nov 22, 2016
Messages
1,867
I have noticed (encrypted network) that SSIs (encrypted) remain same for a long time (many months MS has same encrypted SSI) before they are changed .... Also it could be possible (it is possible here where I live) to call to SSI from GSM network (it requires prefix + SSI) and if someone answers then the SSI probably is not encrypted
Yes calls to phones can occur via the E.164 Gateway. I've seen these on occasions.
These are private calls but you will only hear one side of call.
When used, the ISSI is 16777184. The other number should also be shown.

@ScanHen
Not sure why that error occurs.
I can see where it fails and there seems to be a issue with the length and elements repeating which they shouldn't be.
May something with it been a reconstructed PDU.

If you see that error again please send the error again so I can compare to what you already sent.



Latest version (v1.7.0.0) can be found here: Release post
 

Ubbe

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Sep 8, 2006
Messages
9,668
Location
Stockholm, Sweden
Everything that can communicate in tetra systems has an issi. So each telephone patch will have it's own issi. Each console has it's own unique issi. Each server that can send or receive SDS messages has it's own issi.

/Ubbe
 

hamradionl

Member
Joined
Mar 23, 2014
Messages
730
Is this possible ?
1 unit connect both to tetra and gsm the other units call in to this tetra-gsm is possible use the tetra-gsm as gateway from GSM to Tetra?
 

Ubbe

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Sep 8, 2006
Messages
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Location
Stockholm, Sweden
Tetra usually use a PBX inteface, that is like a phone exchange with trunked lines to the telephone company. It has one common phone number that people call from gsm or landline and that also will be displayed when tetra users call out using the phone interface but it will act as 16-32-64 normal phone lines that can have that many simultanious ongoing phone calls. It doesn't matter if calls go to/from gsm or landlines.

Usually when people call to the tetra system they get a connect tone and then dial the issi number. Some PBX setup have the phone company set up a whole number serie 555-5xxx-xxxx that the x's are the issi or perhaps just the last 5 digits in the issi.

If gsm/landline would like to speak to a talk group it is usually done by having a mobile tetra radio connected by a EM interface to the system that then use a voice activated transmit function and that tetra radio have an issi and are set to one specific TG.

/Ubbe
 

Marco192

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Joined
Aug 9, 2014
Messages
93
Under MS Registrations on a encrypted network I sometimes see lines like this:

MS request for registration/authentication ACCEPTED for SSI: xxxxxx GSSI:xxxxx - Roaming location updating
BS result to MS authentication: Authentication successful or no authentication currently in progress SSI: xxxxxx - Authentication successful or no authentication currently in progress
MS request for registration/authentication ACCEPTED for SSI: xxxxxx GSSI:xxxxx - Attachment for next ITSI attach required - ITSI attach


Are those stations and groups that are being used unencrypted on a encrypted network or is the TTT showing some ISSI and GSSI info encrypted stations?
 

Ubbe

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Sep 8, 2006
Messages
9,668
Location
Stockholm, Sweden
All radioterminals in a tetra system are registred in a database. The text only show that the ISSI is valid and it is accepted to be used with that TG according to the database. It has nothing to do with encryption. The database can validate an ISSI to be used with certain TG's and to use specific sites.

/Ubbe
 

Marco192

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Aug 9, 2014
Messages
93
All radioterminals in a tetra system are registred in a database. The text only show that the ISSI is valid and it is accepted to be used with that TG according to the database. It has nothing to do with encryption. The database can validate an ISSI to be used with certain TG's and to use specific sites.

/Ubbe

I understand the part about registration and authentication of terminals, but my understanding was that all the traffic/network info was encrypted so that you can not see any ISSI and GSSI numbers.
 

Erik40

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Joined
Dec 4, 2015
Messages
60
I have a valid ISSI and valid GSSI, if I want to log in, the radio says, registration error, often a verification error, how is that possible?
 
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