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:[email protected]] On Behalf Of Tomcsányi, Domonkos Sent: Thursday, February 13, 2020 10:07 AM To: Sandi Suhendro <[email protected]> Cc: openbsc <[email protected]> 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 <[email protected] <mailto:[email protected]> > 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 <[email protected] <mailto:[email protected]> > 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 <[email protected] <mailto:[email protected]> > 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 <[email protected] <mailto:[email protected]> > 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
