29 May 2015

CIS-60 HDR modem 35.5 Bd, π/8-DPSK8


CIS-60 is one of the Russian OFDM HDR (High Data Rate) Modem modes,  it uses 60 data carriers and 1 pilot carrier located 3300 Hz from dial frequency, as usual in CIS HDR modem series. According to my logs, CIS-60 comes in two waveforms (I have logged both the twos):
- Baudrate 30, modulation QPSK
- Baudrate 35.5, modulation π/8-DPSK8
in both the cases the carriers are 44.5 Hz spaced and the signals spreads a 2800 Hz bandwidth. Sometimes you could hear operators chatting (in voice) followed by a waveform switch, i.e. from DPSK-4 to DPSK-8: I do not know if it's for tests purposes or for some other reason. The original signal has been resampled to 8888.8 Hz.





radioscanner.ru reports CIS-60 DPSK-8 waveform here:
http://signals.radioscanner.ru/base/signal231/ 

Logs

29/05/15 14850.0 --- Unid North Korean Diplo, PRK 1435 LSB FSK 1200/1200 ARQ (aka DPRK-ARQ)
28/05/15 07616.7 --- Unid Egyptian Diplo 2016 USB PacTOR-II 100/200
28/05/15 14635.0 --- Unid 1144 USB unid 5-symbol MFSK 34+34 system, 47 baud
18/05/15 14557.1 --- Russian Mil 1220 USB CIS-60, OFDM HDR modem Br 35.5 Sh 44.5 DPSK-8
27/05/15 10370.0 SPI324 Polish Mil, POL 1406 USB MIL 188-141A clg LCR154


26 May 2015

ALE Logs

27/05/15 12192.0 VQ7 Polish Mil, POL 0646 USB MIL 188-141A clg VQ6
27/05/15 12192.0 VQ1 Polish Mil, POL 0642 USB MIL 188-141A clg VQ7
27/05/15 12192.0 VQ1 Polish Mil, POL 0641 USB MIL 188-141A clg VQ8 handshake + voice
27/05/15 12192.0 VQ1 Polish Mil, POL 0638 USB MIL 188-141A clg VQ3
27/05/15 12192.0 VQ3 Polish Mil, POL 0636 USB MIL 188-141A clg VQ1
27/05/15 12192.0 VQ1 Polish Mil, POL 0635 USB MIL 188-141A clg VQ4
26/05/15 08190.0 RHP Saudi Air Force, ARS 2056 USB MIL 188-141A clg AAP
26/05/15 14550.0 J62 Royal Moroccan Army, MRC 1437 USB MIL 188-141A sndg
26/05/15 14550.0 R31 Royal Moroccan Army, MRC 1430 USB MIL 188-141A sndg
26/05/15 14550.0 P52 Royal Moroccan Army, MRC 1421 USB MIL 188-141A sndg
26/05/15 14550.0 P53 Royal Moroccan Army, MRC 1419 USB MIL 188-141A sndg


wikipedia: Royal_Moroccan_Army

25 May 2015

HFDVL modem: OFDM 73-tone (13 pilot tones) QPSK

(I-56578, ANgazu)


Total carriers: 73
Pilot carriers: 13
Data symbols per OFDM symbol: 60
Native sample rate (sps): 9600
FFT length (samples): 256
Modulation: QPSK
Bit rate (bps): 3600
Bandwidth (Hz): 2737.5
Samples per OFDM symbol: 320

OFDM parameters, body segment



The most interesting feature is the way the 13 pilot tones are formed, and why - at a first look - we found only 1 pilot tone (the higher one).

We found that all the even tones have QPSK modulation (at least into the seen signals) :


 and the top tone (the 73th) is clearly a pilot one:

  
We found that in the odd tones there is a new element in absolute constellation that generates a PSK8 pattern in diff constellation. We guess this element is a scattered pilot and, for some reason we do not know, it shifts diff constellation of 45 degrees, giving the false PSK8:


Skipping symbols, we could see the 'no modulated pilot' feature for these tones. Then, according to our analysis, the 13 pilots coule be formed in the following way:

- 1 fixed pilot tone (73th);
- 12 scattered pilots which are chosen in turn from 3 different sets (each set contains 12 odd tones);
(...and we are quite positive that we have exactly identified all the tones of each set).

The pilot tones configuration changes at every OFDM symbol: we do not know the reason (perhaps to contrast propagation conditions?) and the algorithm that determines the initial configuration; possibly the BPSK preamble has these data inside, but it's just a guess. Anyway, as said above, it looks like that all the odd tones are pilots-candidate (we could say “virtual pilots”) and only 12 of them are used - in turn - to form the real pilots, while the remaining 24 + the 36 even tones are used to transport user data (60 tones).
Here is an example of a possible pilot tones scheme that assumes the configuration A as the initial configuration:

configuration A (73th tone + 12 tones of the set-A)
configuration B (73th tone + 12 tones of the set-B)
configuration C (73th tone + 12 tones of the set-C)
...and so on, restarting from configuration A 

The trailing segment of the signal just exhibits all the odd (pilots candidate) tones, some using BPSK modulation.


Two words about the speed. Official documentation say:

Total carriers 73, Pilot carriers 13, Data symbols per OFDM symbol 60, Bit rate (bps) 3600 (assuming Bit rate to be the “system” speed “on the air”). Since the 30 baud PSK-4 modulation, the system grants 30 * 2 * 60 = 3600 bps data rate.

The HFDVL modem (waveform is developed by the groups "CeTIC" from the Universidad de Las Palmas de Gran Canaria and "GAPS" from Universidad Politécnia de Madrid, other than Aeropuertos Españoles y Navegación Aérea) has been heard mostly on USB 14350.0 and 14828.5 transmitting from Spain: we think that they are conducting tests that involve transmitters in two diferent sites which exchanges data. In one of our 14828.8 KHz recordings is quite clearly visible the different quality of the signals:

Emailing the HFDVL modem manufacturer, we got a confirm about what we were thinking: "[...]Yes, there are two modems transmitting and at this moment there are not other frequencies involved in the test."

24 May 2015

Logs: 20-24 May

24/05/15 14508.0 5601 Unid ALE 1543 USB MIL 188-141A CLG 20001 followed by CODAN selcall (same IDs)
24/05/15 14828.5 ---  (prob from Spain) 1515 USB HFDVL modem, OFDM 73-tone (13 pilot tones), QPSK 30 baud (in tests)
24/05/15 16222.0 ---  Egyptian Diplo 0905 USB Codan 16-tone
23/05/15 12581.5 XSV  Tianjin Radio, CHN 2045 CW/SITOR-MARKER
21/05/15 12734.0 ---  Russian Mil 1400 USB CIS OFDM 48-tone ALE, 4 x PSK-2 50 Baud [1]
20/05/15 14600.0 ---  Russian Mil 1320 USB AT-3004D 12-tone PSK-2 120 Bd

[1] https://www.dropbox.com/s/el0e10lm0m98sit/websdr_recording_2015-05-21T12_06_47Z_12734.0kHz.wav?dl=0

21 May 2015

AT-3004D (CIS-12): MPSK 12-tones PSK-2, PSK-4 120 Baud


CIS-12 is a Soviet military pseudo OFDM 12-tones + 1 pilot tone modem allowing scrambled voice or data-communication at 120 Baud rate, modulation PSK-2 or PSK-4. CIS-12 is also known as MS5 or FIRE while the modem name is AT-3004D (or its newer counterpart  AT-3104).  
http://signals.radioscanner.ru/base/signal37/


"An interesting feature of these signals is that the sub-carriers are not orthogonal, since the manipulation speed is 120 Hz and channel spacing is 200: it means that each channel is formed separately, not as in OFDM using IFFT all at once, although the OFDM technology is used. CIS-12 modems may appear in three different variants, according to the n-ary PSK modulation: 2-PSK, 4-PSK offset (doesn't turn on 180^) and 4-PSK.Channels 1-10 are for user-data while 11 and 12 for the inspection. Accordingly, the aggregate information rate is 1200 and 2400 (PSK-2 and PSK-4)."

PSK-2 waveform:
 

PSK-4  waveform:
KarapuZ sent me a sample of this mode along with his comment:
"this mode modem is less resistant to interference, it is mainly used to transmit a surface wave, or at a distance of not more than one hop. A chance to hear him in Italy is very small".


 

19 May 2015

today log

18450.0 --- North Korean Diplo, PRK 1455 USB DPRK-ARQ 1200Bd/1200
13945.0 --- Tunisian Police, TUN 1255 USB PACTOR-II ARQ 100Bd/200 DQPSK encrypted
12129.5 --- Unid (prob Russian Mil) 0640 FSK 100Bd/2000





RUS-ARQ 100Bd/2000


FSK  ARQ system 100 Baud and 2000 Hz shift heard this morning (19 May) on 12129.5 cf starting from 0640, s/off at 0650. It sounds like an ARQ system, possibly from Russian Governative (then the nickname RUS-ARQ). As far as I know, the signal is sent by an outstation to its main 'home' station, that in its turn operates in CIS 3x100 (VFT 3 x FSK-2 channels) on three correspondents. All these stations (main and oustations) operate in synchronous mode, usually not far apart in frequency.

The recordered signal can be downloaded from here:
https://www.dropbox.com/s/wmkqgaw5s5ew7f2/19-May-2015-064925%2012.127500%20MHz.wav?dl=0



18 May 2015

Logs: 09-17 May

17/05/15 06247.0 --- Unid 2025 USB TADIL-A/LINK-11 CLEW
17/05/15 14451.0 CM2OR2 Algerian AF, ALG 0837 USB MIL 188-141A clg BSF
17/05/15 14380.0 105001 Unid 0806 USB MIL 188-141A clg 106001
16/05/15 15563.2 --- Russian diplo/intel FSK 200Bd/1000 Link ID 32821 Msg Number 052 : Msg Type 07145 
16/05/15 23141.2 --- Unid 0725 (cf) HFDVL modem Br 30 Sh 37.5, possibly tests 

15/05/15 12580.5 OSY Sail Mail node Brugge, BEL 0605 USB Pactor-III "D8600 de OSY" 
15/05/15 14380.0 3232 Unid 0625 USB MIL 188-141A clg 129 (15May15) (AAI)
15/05/15 15871.5 --- Unid 0642 USB Thales Systeme 3000 OQPSK/MFSK-8 ALE (every ~10 mins) 

15/05/15 14108.9 HB9AK Winlink Gateway Berne, SWI 1317 USB Pactor-III wkg HB9AIU [1]
13/05/15 12603.5 SVO Olympia radio, GRC 0620 USB Sitor-B/100/170 news in greek 
13/05/15 19522.0 --- Unid Egyptian MFA 0700 USB Sitor-A clg OOVQ Beijing Embassy then into Sitor-B 
13/05/15 04618.0 BP24 Bundespolizei boot Bad Bramstedt, D 2048 clg BPLEZS
12/05/15 14320.0 --- Unid 0640 LSB DPRK-ARQ FSK 1200Bd/1200 

12/05/15 17000.0 --- Unid 0650 USB Thales Systeme 3000 robust-data
12/05/15 13989.0 --- Unid prob Russian Mil 0715 FSK 500Bd/1000 
11/05/15 10370.0 SPT42 Polish Mil, POL 1145 USB MIL 188-141A clg SNB813 +voice + TWS
09/05/15 10110.0 EK9 Greek Military GRC 0612 USB MIL 188-141A clg GEF 


[1] 

http://www.winlink.org/ 
http://www.swiss-artg.ch/index.php?id=63

15 May 2015

SITOR FEC (SITOR-B)


The SITOR-FEC mode is used in broadcast applications where a return channel is not required or unavailable. Two sub-modes are in use: General broadcasting to a number of stations and selective addressing of only one station. SITOR-FEC transmissions are used in maritime radio communication to distribute traffic lists, news, safety and weather information (Navtex and DSC-GMDSS). Amateurs also use the FEC mode for calls to all (CQ calls). The selective FEC is used when the receiving station must operate under "radio silence" conditions and hence cannot transmit.


In most cases SITOR-FEC transmissions uses a rate of 100 Baud using the standard shift of 170 Hz. SITOR recasts ITA2 into a 7 bit code called CCIR 476. Each 7-bit character in CCIR 476 has 4 marks (ones) and 3 spaces (zeros). Each character is transmitted twice with an interval of 35 bits. In the case of error-free reception of both characters, the character is displayed on the screen. No character is displayed if both characters are received in error.

11 May 2015

short log, HFDVL and UK WinDRM modems

08345.0 ---: Unid 0634 USB STANAG-4197 (08May15) (AAI)
13560.0 ---: British Mil/Gov, G 1310 USB winDRM modified, OFDM 51-tone Br 37.5 Sh 46.8 (06May15) (AAI) [1] 

14828.6 ---: Unid 1850 USB HFDVL modem OFDM 73-tone Br 30 Sh 37.5 PSK-4 [2]
(04May15) (AAI)14836.0 ---: Russian Mil 1135 USB CIS-12/AT-3004D MPSK-12 Br 120 PSK-2 (08May15) (AAI)
18713.0 ---: Russian Diplo 1220 USB Serdolik MFSK-34 Br 40, Sh 40 (08May15) (AAI)


Two interesting waveforms here: 

[1] UK Mil/Gov modified WinDRM
[2] HFDVL modem OFDM 73-tone Br 30 Sh 37.5 PSK-4


UK modified WinDRM


British Military/Government OFDM 51-tone modem, a odified WinDRM waveform with no evidence of the three Pilot Tones which are one of the WinDRM features. Parameters are Br 37.5, Sh 46.8, modulation is QAM and QPSK each two (Pic. 1). 
It is an "ON/OFF" system with 53.33 mSec periods (ACF of 106.66 mSec as shown in Pic. 2), in this sample no info is sent apparently during the ON (data) periods. It's clearly visible that the "ON" segments are sent using all the 51 channels and are interspersed alternatively by the subsets of odd and even channels (Pic. 3)


Pic.1 modulation

Pic. 2 ACF value
Pic.3 symbol by symbol view

5 May 2015

Logs: 23 Apr - 04 May

05879.0 RK3: Polish Military, POL 2033 MIL 188-141A clg PY30 (25Apr15) (AAI)
07608.0 ---: Russian Mil 1950 12-tones PSK-2 120 bps (28Apr15) (AAI)
08190.0    ---: GdF,I 1940 USB proprietary PSK 2400Bd bursts (28Apr15) (AAI)
09025.0 GQBL USAF KC-10A 86-0038 1256 MIL 188-141A clg WC1 (30Apr15) (AAI)
09088.0 CM2OR2: Algerian AF Oran, ALG 0730 MIL 188-141A clg ZEN (22Apr15) (AAI)
10175.0 334123 Turkish Civil Defense, TUR 1927 MIL 188-141A clg 339013 (03May15) (AAI)
10175.0 335013 Turkish Civil Defense, TUR 1927 MIL 188-141A clg 343013 (03May15) (AAI)
10175.0 303013 Turkish Civil Defense, TUR 1931 MIL 188-141A clg @?@ [/>A2008 356013 ](03May15) (AAI)
10254.0 --- Unid 0720 Thales Systeme 3000 serial burst 2000 Bd OQPSK (02May15) (AAI) [1]
10588.0 FC4FEM1: FEMA Region 4, Thomasville, GA 0618 MIL 188-141A sndg (27Apr15) (AAI)
10888.0 ---: Russian Mil, 0630 CIS-12, MPSK 12-tone PSK-2 120Bd/200 (23Apr15) (AAI)
11030.0 ---: [not copied] 0635 MIL 188-141A clg HE3 (22Apr15) (AAI)
11059.0 TU4: Polish Mil, POL 0641 MIL 188-141A clg IN6 (22Apr15) (AAI)
12666.5 FUG: French Navy, F 1300 STANAG-4285 600L "FH DE FUG QSL P R 241028Z AVR 15 TIME 1252Z K DFF" (24Apr15) (AAI)
13596.6 --- Unid 1150 ARQ-E 184.6/850 idling (04May15) (AAI)
13870.0 CENTR3: MFA Bucuresti, ROU 0549 MIL 188-141A clg LAS (24Apr15) (AAI)
14060.0 K35: Israeli AF aircraft, ISR 0640 MIL 188-141A sndg (24Apr15) (AAI)
14060.0 AA1 Israeli Air Force, ISR 0704 MIL 188-141A clg W37 (01May15) (AAI)
14060.0 AAA Israeli Air Force, ISR 0707 MIL 188-141A clg W01 (01May15) (AAI)
14397.5 ---: unid 1440 Hagelin HC-256 voice scrambler, short QSO (23Apr15) (AAI) [2]

14430.0 CM6: Prob AFHQ 6th Mil Region Algerian AF, ALG 0721 MIL 188-141A clg HE5 (29Apr15) (AAI)
14538.0 PL2: Polish Mil, POL 0650 MIL 188-141A clg TIS KO1 (23Apr15) (AAI)
14538.0 K01: Polish Mil, POL 0651 MIL 188-141A clg TWAS ME3 (23Apr15) (AAI)
15043.0 JNR: US Airforce Puerto Rico, PTR 0613 MIL 188-141A sndg (29Apr15) (AAI)
15043.0 HAW: US Airforce Ascension Is, ASC 0618 MIL 188-141A sndg (29Apr15) (AAI)
16175.0 ---: Russian Mil, RUS 0610 VFT 3 FSK-2 x 100 Baud (24Apr15) (AAI)
16285.0 STAT5: Tunesian MOI, TUN 0649 MIL 188-141A clg STAT154 (27Apr15) (AAI)
18459.0 132 Chinese Air Defense, CHN 0709 MIL 188-141A clg 131 (30Apr15) (AAI)
18755.5 --- Unid 1130 Thales Skymaster robust-data MFSK-8 125 Bd (03May15) (AAI) [3]


3 interesting waveforms here:


[1] Thales Systeme 3000 Serial Burst, PSK-4 with Skymaster ALE trailer
[2] Hagelin HC-256
[3] Thales Skymaster robust-data MFSK-8

Hagelin HC-256

14397.5 ---: unid 1440 Hagelin HC-256 voice scrambler, short QSO (23Apr15) 



The HagelinCryptos HC-265 is an analog dynamic synchronized voice scrambler.Preamble is transmitted on two FSK-2 channels, with periodic synchronization of every 400 milliseconds.

Thales Systeme 3000 robust MFSK-8


This is a Thales proprietary waveform is used in the TRC-3500/TRC-3600 and TRC-3700 series radios. The 'robust' mode uses the same tone library as 141A/B 2G ALE but callsigns are limited to a maximum length of 2 figures only. In addition to these ALE-functions facility, the transceivers can also use this waveform as a robust-data mode in order to transmit messages with 375 bps raw and 100 bps net datarate, although I have measured a bit rate of 125Bd.

I just heard this signal on 16256.5 KHz and 18755.5 USB, possibly from French Military.


Aurally and visually, it's looks like a standard MIL 188-141A signal and then it is easily mistaken for a normal ALE, but putting an ALE decoder on it the decoder itself just sits down without printing the expected commands and messages. As said, its parameters are the same of MIL 188-141A, i.e. 8 tones, 250 Hz spaced manipulated at 125 baud (see above for the datarate misure).



We will probably not find a fixed schedule, as these are tactical networks that come and go - often related to exercise traffic.

Thales Systeme-3000 Skymaster ALE

The signal reported here was heard on 2 May at 10.254.0 KHz on USB, around 0730z, and it is  Thales proprietary ALE protocol called Skymaster



The initial part of the signal - at first glance - uses PSK-4 (OQPSK) modulation at 2000 Baud speed and carrier frequency ~1600 Hz but it's likely an MSK modulation 2000Bd/1000: OQPSK and MSK are strictly connected and difficult to discriminate. The absolute phase variation diagram of this part it's a clue in favour of MSK.




The initial part is followed by short MFSK-8  125 Baud segment that is not compatible with MS 188-141 2G-ALE although the scope be the same.




The initial MSK part exhibits a 50ms ACF that corresponds to a 100-bit frame.


This proprietary waveform is used in their TRC-3500/TRC-3600 and TRC-3700 series radios.

 

RTTY ASCII



For ASCII mode standard baud rates from 110 to 300 Baud are available but non-standard baud rates may be selected. The ASCII code, which is internationally adapted as the CCITT ITA-5 alphabet, is used in all kinds of data transfer of information between computers or computer based equipment. Only the 7 bit values 0–127 are internationally defined and standardized. 


For asynchronous transmissions, the code consists of a start bit, 7 or 8 data bits, one parity bit (optional) and 1 or 2 stop bits. Frame lenght is 50 msec, then baudrate = (50/10)=5 and 1000/5 = 200.


Note the different structure of the frame in case of a RTTY Baudot (below):



1 May 2015

HF-FAX

HF-FAX are usually transmitted in single sideband according to the ATP (Automatic Picture Transmission) format, the signal shifts up or down a given amount to designate white or black pixels. A deviation less than that for a white or black pixel is taken to be a shade of grey. With correct tuning (1.9 kHz below the carrier frequency for USB, above for LSB), the signal shares some characteristics with SSTV, with black at 1500 Hz and peak white at 2300 Hz.


The start tone triggers the receiving system. It was originally meant to allow enough time for the drum of mechanical systems to get up to speed. It consists of rapid modulation of the video carrier, resulting in a characteristic rasp-like sound.
The start tone provides the Index Of Cooperation (IOC) which must be known to decode a radio fax transmission - this governs the image resolution, and derives from early radio fax machines which used drum readers, and is the product of the total line length and the number of lines per unit length (known sometimes as the factor of cooperation), divided by 'piGreco'. Usually the IOC is 576.


The phasing signal, consisting of a periodic pulse, synchronizes the receiver so that the image will be centered on the paper.



 Usually, 120 lines per minute (LPM) are sent (For monochrome fax, possible values are: 60, 90, 100, 120, 180, 240. For colour fax, LPM can be: 120, 240[1]). 



The stop tone at 450 Hz, optionally followed by black, marks the end of the transmission.