17 June 2018

STANAG-4285 128 bit 1536F protocol (UK MoD?)

I followed these STANAG-4285 transmissions on 14548.2/usb throughout the morning and the first part of the afternoon. Unlike similar S-4285 broadcasts, there is not a continuous broadcast and the messages are transmitted to the need and always using the 1200bps Long interleaver sub-mode.
After convolutional decoding and de-interleaving, the data link protocol exhibits a 128-bit structure but actually it's the 1536-bit TDM protocol (thanks to KarapuZ). TDoA multilateration using 4 KiwiSDRs as sensors points to Cyprus Island as Tx site: maybe UK MoD from Akrotiri?

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