3 Feb
2011
3 Feb
'11
3:45 p.m.
On Thu, 3 Feb 2011 14:54:14 +0100, Sylvain Munaut wrote:
But there is at least some kind of predictability. The assigned arfcn
and time slot is usually the same until a certain load it reached and
a second ts or even other arfcn/ts is used. The subchannel is hard to
predict as I've never seen a stable pattern, it looks quite random.
At least these are my observations with some live networks.
Regards,
Mad
We only send to GSMTAP recomposed L2 packets from
Normal Bursts.
We don't have debug support for other burst types like
dummy/sch/rach,
I'm not even sure the gsmtap has a "spec" for it, or that the
wireshark dissector has code to process it.
As gsmtap supports the payload type raw GSM Um burst and all possible
burst types like GSMTAP_BURST_ACCESS, ..._SCH and so on, it should be
possible to send these out to wireshark.
But I'm not sure whether the dissector already decodes them as it
doesn't
do it with normal bursts.
The second
question is about SI AGCH response, I didn´t find the
algorithm to know which SDCCH channel gives the BTS to the MS to
send/recv LAPDm bursts.
There is none specified ... the BTS is free to allocate whatever it
wants ... (well technically it's not the BTS itself, but other
component of the core network).