14 Feb
2020
14 Feb
'20
9:01 a.m.
Another thing, usually even a bad clock is OK, when the phone can’t see any commercial
network. Quite often they sync their clock on some commercial carrier on power-up and then
can’t see any networks with bigger frequency offset. My solution is placing the phone in a
metal cookie box that shields it from receiving any commercial network, but the SDR right
next to it has enough power to get through. Then the phone starts a more exhaustive search
with sweeping its TCXO over a bigger range. Once the phone has registered I take it out,
and it keeps the connection without issues until phone or BS are restarted, then the same
issue applies.
Ralph.
From: OpenBSC [mailto:openbsc-bounces@lists.osmocom.org] On Behalf Of Tomcsányi, Domonkos
Sent: Thursday, February 13, 2020 10:07 AM
To: Sandi Suhendro <djks74(a)gmail.com>
Cc: openbsc <openbsc(a)lists.osmocom.org>
Subject: Re: Commercial MSs do not see the network
Hi Sandi and Joachim,
@Sandi: no worries about spelling :).
@both: thanks for the idea, it is what I was thinking about initially as well.
I will check if I can get a good 10 MHz reference from some device. I was just informed
however that Exynos devices do not need to be examined during my tests, so I’ll probably
put this on hold for now. The lab at our HQ also has a UmTRX if I recall correctly, so
worst case I could always ask them to do the tests. I just wanted to make sure it is the
HW setup, not the config causing the trouble :). Now I’m confident that it is the lack of
the clock source.
Thank you all for chiming in.
Cheers,
Domi
2020. febr. 13. dátummal, 2:11 időpontban Sandi Suhendro <djks74(a)gmail.com
<mailto:djks74@gmail.com> > írta:
Hi Domi,
Sorry for wrong spell. Wkwkk...
Have you try with GPSDO?
Some phone cannot sync or weak with the wave. Worth to try :)
regards,
Sandi / DUO
On Thu, Feb 13, 2020, 02:16 Tomcsányi, Domonkos <domi(a)tomcsanyi.net
<mailto:domi@tomcsanyi.net> > wrote:
Hello Sandi and Neels,
@Neels: :-) \o thanks.
@Sandi:
Thank you for the idea. I have changed the attenuation to oml, and I could observe the
following:
All Qcomm based devices now see the network and with a bit of luck they could register:
Xiaomi Mi5, Samsung A90 5G, iPhone X.
However any Exynos based device (S6, S7, S8) simply refuses to even detect the network.
Any time I put in a sysmocom SIM in a Qcomm based device it happily goes on the new
network. On the other hand if the same SIM card is plugged into an Exynos device it shows
No service and even with manual search it cannot detect the network.
I assume with other radio hardware (e.g. umTRX) there are no issues with Exynos devices,
so it is most probably the USRP not being good enough I think.
However if anybody has any other ideas I’d still be happy to get any feedback and try
things out :).
Cheers,
Domi
2020. febr. 12. dátummal, 14:20 időpontban Sandi Suhendro <djks74(a)gmail.com
<mailto:djks74@gmail.com> > írta:
Dear Tomi,
have you try to set attenuation set to OML and osmo-trx?
osmotrx rx-gain 30
osmotrx tx-attenuation oml
Im not sure but I saw your attenuation is set. :-)
I think I face the problem before but using Motorola C115/117 cannot connect, but it was
resolved now long time ago with newer osmo-bts.
regards,
Sandi
On Wed, Feb 12, 2020 at 7:10 PM Neels Hofmeyr <nhofmeyr(a)sysmocom.de
<mailto:nhofmeyr@sysmocom.de> > wrote:
On Wed, Feb 12, 2020 at 09:42:42AM +0100, Tomcsányi, Domonkos wrote:
p.s. It is simply awesome to experience the power of
opensource when dealing with 2G. Every step of the way above I was using software created
and shared by you guys. It is a great feeling, had to share it :-).
Thanks Domi!!
I hope someone has answers your questions, I don't but wanted to wave back
anyway \o_
~N
--
Best Regards,
Sandi