Cellbroadcast Decoding Problem

Today was the second cellbroadcast test in Germany / Bavaria. I still have decoding issues with the messages. See Screenshot.

SM-G960F
e_starlte-user 10 QQ3A.200805.001 eng.root.20230204.011449 dev-keys,stable-release

Any hints?

What kind of app is this? Plain universal SMS receiver or a special app for emergency?

Apps & Notifications (Apps & Benachrichtigungen) → Emergency Messages (Notfallbenachrichtigungen).

That’s an integrated function in Android. So it’s not the normal SMS app and not a 3rd party app.

Hmm, only my /e/ devices (1.8.1 q & r, mata & T2e emerald respectively) have entries in the Emergency alert history but they are all clear and readable.
When tapped on they show the original alert dialogs (severe winter storm in Southern California? Global warming? More like next ice age. :grin: )

Unfamiliar with the decoding issues. Today is the first time I ever checked that area. My devices are either good to go or display nothing.

EDIT: Just noticed there’s a thread about this or similar subject here…

When I remember back to my beginnings with SMS and the day when I received my first messages using a self-written application on a PC it looked exactly like this, especially because I did all the decoding myself without any library or so.

SMS messages may have three different coding systems:

  • 7bit GSM character set (based on ASCII but changed at some positions to include ä ö ü Ä Ö Ü ß and some others)
  • 8bit, especially taken for small pieces of data but normally not used for readable text
  • 16bit UCS2 (a subset of Unicode, UTF-16)

If a receiver can’t read a received message the reason can be on both the sender’s side and the receiver’s side. They must agree to use the same coding system but indeed this is just an assumption. It’s possible that the receiver assumes an encoding the sender hasn’t used (for instance UCS2 is rather unusual in Europe, more used in Asia). Correct decoding may also depend on language settings on the receiver (see National Shift Tables). And I would also not wonder if the sender has a bug in encoding. This is possible when you always use the same few devices for testing and they are of course all good.

3 Likes

Received a test alert 10 days ago (I’m in France, north-west coast), decoding was OK.
Xiaomi Mi MIX 3 running /e/ 1.8.1 on Android 11.


I think the app is this one (I may be wrong):

Did now activate also the test warnings. Never got anything until now here in Switzerland.