Understanding the GSM specs

This is merely a historical archive of years 2008-2021, before the migration to mailman3.

A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/OpenBSC@lists.osmocom.org/.

Nordin bouchtaoui at gmail.com
Tue Jun 16 15:13:13 UTC 2009


Hello friends,

I want to modify the SYSTEM INFORMATION data, but I have some 
difficulties to understand the GSM spec.
It's about the GSM 04.08 part 10.5.2.34, I don't know how to interpet 
table 10.5.72 (and other similar tables).

According to paragraph 9.1.35 table 9.32 (GSM 04.08) SI3 rest octetets 
has a length of 4 bytes, but according to par. 10.5.2.34 we're dealing 
with a type 5 IE and thus with length of 5 bytes. That's odd to me, but 
hey, the world is full of surprises :)

Anyway, the problem is I don't know how to interpret table 10.5.72 (of 
GSM 04.08). I mean, for example, element CBQ (Cell Bar Qualify) is at 
bit 1. Bit 1 of what, which octet? What is L | H? Can someone explain it 
to me, so I can experiment with SI messages?

Thank you!





More information about the OpenBSC mailing list