6231 net (6231.0 KHz)
I recently spotted the frequency 6231.0 KHz on USB where stations connect following the same procedure as of AB-net and use STANAG-5066 HMTP protocol which is transported by a STANAG-4285 modem configured for 1200 bps and short interleaver (Figs. 1,2). As in the 5054-net, the message transfer is not preceded by ALE or selcall phase and this supports the idea of scheduled tansmissions.
The post related to AB-net and 5054-net (HRV MORH-u) can be read here
|Fig.1 - the HF waveform (Stanag-4285)|
|Fig.2 - 1776 bit period (Stanag-5066)|
While the transmissions in the AB-net are scheduled on tuesday and thursady from 0830 UTC (0730, daylight savings time), transmissions on this frequency start at 0800 UTC on monday and wednesday (most likely 0700, daylight savings time). These are the heard callsigns, listed in the call-order:
GHU3 (net-control station)
Stations are contacted a first time by GHU3 for a radio-check then, in case of messages, the stations shall be contacted a second time and in the same order. Unless the initial 188-141 2G-ALE phase, the message transfer follows the schema seen here, used in the AB-net.
The HMTP headers in Fig. 4 prove that this net belongs to the HRV MORH-u network as the previous AB-net and 5054-net: same OS (Linux Open-SUSE), same STANAG-5066 application ("CroS 5066", developed by CROZ) and same attachment filename.
|Fig.5 - D_PDU headers|
Below the updated S-5066 Addresses Table and the Network Map.
AB-net 5838.0 KHz (...)
ALE S-5066 Add. E-mail Add.
ABC7 006.008.001.039 email@example.com (ncs)
ABD1 006.008.004.166 firstname.lastname@example.org
ABG6 006.008.004.165 email@example.com
ABF2 006.008.006.226 firstname.lastname@example.org
ABS5 006.008.008.215 email@example.com
ABK4 006.008.002.144 firstname.lastname@example.org
ABH3 006.008.002.055 ?
5054/6231-net 5054.0 KHz, 6231.0 KHz
CALL S-5066 Add. E-mail Add.
ZIO4 006.008.003.032 email@example.com
NIK2 006.008.003.036 firstname.lastname@example.org
ULI6 006.008.003.037 email@example.com
CIK5 006.008.003.039 firstname.lastname@example.org
Anyway, these are tactical callsigns and rotate likely on a monthly base: e.g. in January 16 2017 the station email@example.com has been heard with callsign CHP3 (was CIK5) and obviously with same S-50966 Address (006.008.003.039).
 further recordings are needed