8 Apr
2009
8 Apr
'09
7:05 p.m.
Hello Marcel,
On Wed, 08 Apr 2009 18:19:20 +0200, "Marcel Klein" <marcel(a)koeln.ccc.de>
wrote:
Okay now I have access to some more cell phones. But still the same
issue even with a Nokia 3330 and Nokia 6210.
Sony Ericson k800i (no branding) - doesn't find the network most of the
time or rather takes very long (when I'm lucky). Only one network in
list when it manages to find my network. (Just happened once that
everything was correct).
Nokia 3330 and 6210 - Finds the network quick or just needs to be
rebooted. Only one network in list.
Siemens S45 - Network not found (yet)
I already tried several networks that really exist but without success.
ARFCN is free and stable - I checked this with a radio.
I am rather sure this is an issue with the BS-11 clock. It requires a
very accurate and stable clock for GSM (in my tests with just one
phone a BTS clock detuned by about 1 ppm causes the phone to no longer
see both test network and official network). There are most certainly
differences between the phones too in regards to how much inaccuracy
they tolerate.
You can make a test to see if it is a problem with the clock: take a SIM
card from a phone which is registered (location updated has been done)
to the BS-11 network and put it in a phone which did not find the
BS-11 network. Now the phone should be able to see the BS-11 network
when powered on because it immediately listens on the ARFCN of the
BS-11 and does not register (and synchronize its clock) to an
official network first. However it most certainly will no longer
find the official networks.
Best regards,
Dieter
--
Dieter Spaar, Germany spaar(a)mirider.augusta.de
8 Apr
8 Apr
5:14 p.m.
New subject: BS-11 runs, but no Network on my Mobile
Dieter Spaar wrote:
I am rather sure this is an issue with the BS-11
clock. It requires a
very accurate and stable clock for GSM (in my tests with just one
phone a BTS clock detuned by about 1 ppm causes the phone to no longer
see both test network and official network). There are most certainly
differences between the phones too in regards to how much inaccuracy
they tolerate.
You can make a test to see if it is a problem with the clock: take a SIM
card from a phone which is registered (location updated has been done)
to the BS-11 network and put it in a phone which did not find the
BS-11 network. Now the phone should be able to see the BS-11 network
when powered on because it immediately listens on the ARFCN of the
BS-11 and does not register (and synchronize its clock) to an
official network first. However it most certainly will no longer
find the official networks.
Yep you are right. Tried that just now.
Hm wouldn't it be possible to sync our clock with the official networks
(without an extra ISDN-line)? Somebody told me that there are several
ways to sync the clock. Here we discussed the ISDN way, but somebody
told me that it should also be possible to set the clock over GPS and/or
other networks in our area.
kenny_
5:18 p.m.
New subject: BS-11 runs, but no Network on my Mobile
Marcel Klein wrote:
Hm wouldn't it be possible to sync our clock with
the official networks
(without an extra ISDN-line)? Somebody told me that there are several
ways to sync the clock. Here we discussed the ISDN way, but somebody
told me that it should also be possible to set the clock over GPS and/or
other networks in our area.
Or can't we just use ntpd? :D
(I'm already running my e1 card in slave mode...)
kenny_
5974
days inactive
5974
days old
2 comments
2 participants
participants (2)
-
Dieter Spaar -
Marcel Klein