Menu
▾
▴
openbts-discuss
|
From: Gerhard <ope...@gk...> - 2015-09-10 12:02:35
|
Hello, I'm struggling to get OpenBTS 5.0 with an USRP B200 to work. After I have build, installed and run OpenBTS, all I get is the network showing up on my Android device. When I try to connect to it, it fails (even with open registration enabled). There are no hints in the logfiles. The "tmsis"-table stays empty. I found mails of people with the same issues.[1] However thy got it working by increasing the performance of the virtual machine. This did not work for me. Another mail said that the internal clock of the B200 is way to bad for using it with OpenBTS.[2] Is that so? How can I find out, if the clock is causing the issues? The OpenBTS book and several other sources state to set "rxgain" to 0-10 for USRP devices. However, Matt Ettus said (regarding the gain of a B200) via the USRP-users mailing list: "0dB of gain is unusably low. You should be using at least 40dB unless there is a very strong signal." What value should I use? My setup is * Ubuntu 12.04.05 LTS Server (32 bit) * OpenBTS 5.0 ($ ./switchto.sh 5.0) * USRP B200 (no external clock) * UHD 003.009.000 * No Antennas attached (Phone is next to the USRP) Did I miss something obvious? I played with settings like "Band", "C0", "power", "rxgain" even "RSSITarget", but no luck. I tried my setup with and without antennas. Still no luck. Any help is welcome Cheers! Gerhard [1] http://sourceforge.net/p/openbts/mailman/message/34400070/ [2] http://sourceforge.net/p/openbts/mailman/message/32682034/ |
|
From: Tom T. <tom...@et...> - 2015-09-10 23:02:05
|
On Thu, Sep 10, 2015 at 8:02 PM, Gerhard <ope...@gk...> wrote: > I'm struggling to get OpenBTS 5.0 with an USRP B200 to work. After I > have build, installed and run OpenBTS, all I get is the network showing > up on my Android device. When I try to connect to it, it fails (even > with open registration enabled). There are no hints in the logfiles. The > "tmsis"-table stays empty. Likely case is RACH bursts being missed. Can you give OsmoTRX a try as a replacement for OpenBTS transceiver? Note the section on compatibility with OpenBTS. http://openbsc.osmocom.org/trac/wiki/OsmoTRX > Another mail said that the internal clock of the B200 is way to bad for > using it with OpenBTS.[2] Is that so? How can I find out, if the clock > is causing the issues? Typically, but not always, If the handset is able to detect the network, then clocking is sufficient for test calls other basic services. > The OpenBTS book and several other sources state to set "rxgain" to 0-10 > for USRP devices. However, Matt Ettus said (regarding the gain of a > B200) via the USRP-users mailing list: "0dB of gain is unusably low. You > should be using at least 40dB unless there is a very strong signal." > What value should I use? The point of confusion is that gain ranges vary across different USRP devices. For example, gain range on the RFIC based B200 is roughly 0-75 dB while the range on X300 with UBX daughterboard is 0-30 dB. The OpenBTS book assumes a range closer to the latter, which ends up in the low to middle part of the range. 40 dB on RFIC is close to mid-level, which is a reasonable starting point. With GSM handsets we are dealing high transmit power levels, so lowering the Rx gain at close range makes sense. Setting gain down to 0 dB is excessive and typically reserved for directly coupled use cases (i.e. not OTA). > My setup is > * Ubuntu 12.04.05 LTS Server (32 bit) > * OpenBTS 5.0 ($ ./switchto.sh 5.0) > * USRP B200 (no external clock) > * UHD 003.009.000 > * No Antennas attached (Phone is next to the USRP) Nothing abnormal. Attaching antenna(s) with lowered gain settings is recommended over raw SMA connectors for consistency. Also check logging for anything unusual; INFO logging level is fine. -TT |
|
From: Alexander C. <ale...@gm...> - 2015-09-11 00:23:46
|
Gerhard, As an additional tip - OsmoTRX has an improved signal clipping detection which can help you understand when you're saturating receiver with a strong signal from your phone. Not for the faint of heart - you can enable DEBUG logging level and see if a transceiver decodes any bursts at all. It may generate A LOT of output, so be prepared. By default it logs to syslog which can quickly grow to Gbs in size. There a patch in fairwaves/master branch not yet merger to master which disables syslog output - you can use it. Also note, that sometimes osmo-trx detects bursts when there is none, which is ok and is not a bug. On Thu, Sep 10, 2015 at 6:33 PM, Tom Tsou <tom...@et...> wrote: > On Thu, Sep 10, 2015 at 8:02 PM, Gerhard <ope...@gk...> wrote: >> I'm struggling to get OpenBTS 5.0 with an USRP B200 to work. After I >> have build, installed and run OpenBTS, all I get is the network showing >> up on my Android device. When I try to connect to it, it fails (even >> with open registration enabled). There are no hints in the logfiles. The >> "tmsis"-table stays empty. > > Likely case is RACH bursts being missed. > > Can you give OsmoTRX a try as a replacement for OpenBTS transceiver? > Note the section on compatibility with OpenBTS. > > http://openbsc.osmocom.org/trac/wiki/OsmoTRX > >> Another mail said that the internal clock of the B200 is way to bad for >> using it with OpenBTS.[2] Is that so? How can I find out, if the clock >> is causing the issues? > > Typically, but not always, If the handset is able to detect the > network, then clocking is sufficient for test calls other basic > services. > >> The OpenBTS book and several other sources state to set "rxgain" to 0-10 >> for USRP devices. However, Matt Ettus said (regarding the gain of a >> B200) via the USRP-users mailing list: "0dB of gain is unusably low. You >> should be using at least 40dB unless there is a very strong signal." >> What value should I use? > > The point of confusion is that gain ranges vary across different USRP > devices. For example, gain range on the RFIC based B200 is roughly > 0-75 dB while the range on X300 with UBX daughterboard is 0-30 dB. The > OpenBTS book assumes a range closer to the latter, which ends up in > the low to middle part of the range. > > 40 dB on RFIC is close to mid-level, which is a reasonable starting > point. With GSM handsets we are dealing high transmit power levels, so > lowering the Rx gain at close range makes sense. Setting gain down to > 0 dB is excessive and typically reserved for directly coupled use > cases (i.e. not OTA). > >> My setup is >> * Ubuntu 12.04.05 LTS Server (32 bit) >> * OpenBTS 5.0 ($ ./switchto.sh 5.0) >> * USRP B200 (no external clock) >> * UHD 003.009.000 >> * No Antennas attached (Phone is next to the USRP) > > Nothing abnormal. Attaching antenna(s) with lowered gain settings is > recommended over raw SMA connectors for consistency. Also check > logging for anything unusual; INFO logging level is fine. > > -TT > > ------------------------------------------------------------------------------ > Monitor Your Dynamic Infrastructure at Any Scale With Datadog! > Get real-time metrics from all of your servers, apps and tools > in one place. > SourceForge users - Click here to start your Free Trial of Datadog now! > http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140 > _______________________________________________ > Openbts-discuss mailing list > Ope...@li... > https://lists.sourceforge.net/lists/listinfo/openbts-discuss -- Regards, Alexander Chemeris. CEO, Fairwaves, Inc. https://fairwaves.co Subscribe to Fairwaves news: http://eepurl.com/baL_pf |
|
From: Gerhard <ope...@gk...> - 2015-09-23 15:25:19
|
Hi Tom, Hi all, sorry for not answering earlier. I've just got some spare time and was able to test your suggestions. It worked! By using the OsmoTRX instead of the OpenBTS transceiver my phone was able to register on the network! Thanks for this suggestion" Now there is a follow-up question in my mind: Why did it work? Is OsmoTRX more sensible when it comes to detecting and handling RACH bursts? Furthermore, I would really like to use the "original" transceiver, because my goal was to do some GPRS. Citing from the OsmoTRX page [1]: "OsmoTRX is fully compatible with OpenBTS for voice and SMS services. Due to differences in handing of GPRS, OsmoTRX does not support GPRS when used with OpenBTS, however, GPRS with the Osmocom stack is supported." Any hints on what I can do to get my setup to work with the OpenBTS transceiver? Or is the only solution the hard way (enable DEBUG logging)? ;) As always: any help is welcome. Cheers Gerhard [1] http://openbsc.osmocom.org/trac/wiki/OsmoTRX#OsmoTRXwithOpenBTS On Sep 11, 2015 at 00:33 AM Tom Tsou wrote: > On Thu, Sep 10, 2015 at 8:02 PM, Gerhard <ope...@gk...> wrote: >> I'm struggling to get OpenBTS 5.0 with an USRP B200 to work. After I >> have build, installed and run OpenBTS, all I get is the network showing >> up on my Android device. When I try to connect to it, it fails (even >> with open registration enabled). There are no hints in the logfiles. The >> "tmsis"-table stays empty. > > Likely case is RACH bursts being missed. > > Can you give OsmoTRX a try as a replacement for OpenBTS transceiver? > Note the section on compatibility with OpenBTS. > > http://openbsc.osmocom.org/trac/wiki/OsmoTRX > >> Another mail said that the internal clock of the B200 is way to bad for >> using it with OpenBTS.[2] Is that so? How can I find out, if the clock >> is causing the issues? > > Typically, but not always, If the handset is able to detect the > network, then clocking is sufficient for test calls other basic > services. > >> The OpenBTS book and several other sources state to set "rxgain" to 0-10 >> for USRP devices. However, Matt Ettus said (regarding the gain of a >> B200) via the USRP-users mailing list: "0dB of gain is unusably low. You >> should be using at least 40dB unless there is a very strong signal." >> What value should I use? > > The point of confusion is that gain ranges vary across different USRP > devices. For example, gain range on the RFIC based B200 is roughly > 0-75 dB while the range on X300 with UBX daughterboard is 0-30 dB. The > OpenBTS book assumes a range closer to the latter, which ends up in > the low to middle part of the range. > > 40 dB on RFIC is close to mid-level, which is a reasonable starting > point. With GSM handsets we are dealing high transmit power levels, so > lowering the Rx gain at close range makes sense. Setting gain down to > 0 dB is excessive and typically reserved for directly coupled use > cases (i.e. not OTA). > >> My setup is >> * Ubuntu 12.04.05 LTS Server (32 bit) >> * OpenBTS 5.0 ($ ./switchto.sh 5.0) >> * USRP B200 (no external clock) >> * UHD 003.009.000 >> * No Antennas attached (Phone is next to the USRP) > > Nothing abnormal. Attaching antenna(s) with lowered gain settings is > recommended over raw SMA connectors for consistency. Also check > logging for anything unusual; INFO logging level is fine. > > -TT > |
|
From: Pierre B. <agm...@ag...> - 2015-10-08 19:03:44
|
Hello Gerhard, Hello Tom. I encountered the very same problem today using B200 as well. As far as I remember, using OpenBTS receiver was fine earlier this year, so I downgraded UHD back to 003.007.002 and got it working fine. I can try other UHD releases asap if it can help to get that bug fixed. 2015-10-08 20:22 GMT+02:00 Pierre Baudry <ag...@ag...>: > Hello Gerhard, Hello Tom. > > I encountered the very same problem today using B200 as well. > As far as I remember, using OpenBTS receiver was fine earlier this year, > so I downgraded UHD back to 003.007.002 and got it working fine. > > I can try other UHD releases asap if it can help to get that bug fixed. > > 2015-09-23 17:25 GMT+02:00 Gerhard <ope...@gk...>: > >> Hi Tom, Hi all, >> >> sorry for not answering earlier. I've just got some spare time and was >> able to test your suggestions. >> >> It worked! By using the OsmoTRX instead of the OpenBTS transceiver my >> phone was able to register on the network! Thanks for this suggestion" >> Now there is a follow-up question in my mind: Why did it work? Is >> OsmoTRX more sensible when it comes to detecting and handling RACH bursts? >> >> Furthermore, I would really like to use the "original" transceiver, >> because my goal was to do some GPRS. Citing from the OsmoTRX page [1]: >> "OsmoTRX is fully compatible with OpenBTS for voice and SMS services. >> Due to differences in handing of GPRS, OsmoTRX does not support GPRS >> when used with OpenBTS, however, GPRS with the Osmocom stack is >> supported." >> >> Any hints on what I can do to get my setup to work with the OpenBTS >> transceiver? Or is the only solution the hard way (enable DEBUG logging)? >> ;) >> >> >> As always: any help is welcome. >> >> Cheers >> Gerhard >> >> >> [1] http://openbsc.osmocom.org/trac/wiki/OsmoTRX#OsmoTRXwithOpenBTS >> >> >> >> On Sep 11, 2015 at 00:33 AM Tom Tsou wrote: >> > On Thu, Sep 10, 2015 at 8:02 PM, Gerhard <ope...@gk...> wrote: >> >> I'm struggling to get OpenBTS 5.0 with an USRP B200 to work. After I >> >> have build, installed and run OpenBTS, all I get is the network showing >> >> up on my Android device. When I try to connect to it, it fails (even >> >> with open registration enabled). There are no hints in the logfiles. >> The >> >> "tmsis"-table stays empty. >> > >> > Likely case is RACH bursts being missed. >> > >> > Can you give OsmoTRX a try as a replacement for OpenBTS transceiver? >> > Note the section on compatibility with OpenBTS. >> > >> > http://openbsc.osmocom.org/trac/wiki/OsmoTRX >> > >> >> Another mail said that the internal clock of the B200 is way to bad for >> >> using it with OpenBTS.[2] Is that so? How can I find out, if the clock >> >> is causing the issues? >> > >> > Typically, but not always, If the handset is able to detect the >> > network, then clocking is sufficient for test calls other basic >> > services. >> > >> >> The OpenBTS book and several other sources state to set "rxgain" to >> 0-10 >> >> for USRP devices. However, Matt Ettus said (regarding the gain of a >> >> B200) via the USRP-users mailing list: "0dB of gain is unusably low. >> You >> >> should be using at least 40dB unless there is a very strong signal." >> >> What value should I use? >> > >> > The point of confusion is that gain ranges vary across different USRP >> > devices. For example, gain range on the RFIC based B200 is roughly >> > 0-75 dB while the range on X300 with UBX daughterboard is 0-30 dB. The >> > OpenBTS book assumes a range closer to the latter, which ends up in >> > the low to middle part of the range. >> > >> > 40 dB on RFIC is close to mid-level, which is a reasonable starting >> > point. With GSM handsets we are dealing high transmit power levels, so >> > lowering the Rx gain at close range makes sense. Setting gain down to >> > 0 dB is excessive and typically reserved for directly coupled use >> > cases (i.e. not OTA). >> > >> >> My setup is >> >> * Ubuntu 12.04.05 LTS Server (32 bit) >> >> * OpenBTS 5.0 ($ ./switchto.sh 5.0) >> >> * USRP B200 (no external clock) >> >> * UHD 003.009.000 >> >> * No Antennas attached (Phone is next to the USRP) >> > >> > Nothing abnormal. Attaching antenna(s) with lowered gain settings is >> > recommended over raw SMA connectors for consistency. Also check >> > logging for anything unusual; INFO logging level is fine. >> > >> > -TT >> > >> >> >> ------------------------------------------------------------------------------ >> Monitor Your Dynamic Infrastructure at Any Scale With Datadog! >> Get real-time metrics from all of your servers, apps and tools >> in one place. >> SourceForge users - Click here to start your Free Trial of Datadog now! >> http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140 >> _______________________________________________ >> Openbts-discuss mailing list >> Ope...@li... >> https://lists.sourceforge.net/lists/listinfo/openbts-discuss >> > > |
|
From: Gerhard <ope...@gk...> - 2015-10-19 12:37:04
|
Hi Pierre, Hi List, thanks for sharing this information. You are indeed right. With downgrading UHD to 003.007.003 I've got my setup to work (with using the OpenBTS transceiver). Cheers Gerhard Am 08.10.2015 um 21:03 schrieb Pierre Baudry: > Hello Gerhard, Hello Tom. > > I encountered the very same problem today using B200 as well. > As far as I remember, using OpenBTS receiver was fine earlier this year, > so I downgraded UHD back to 003.007.002 and got it working fine. > > I can try other UHD releases asap if it can help to get that bug fixed. > > 2015-10-08 20:22 GMT+02:00 Pierre Baudry <ag...@ag... > <mailto:ag...@ag...>>: > > Hello Gerhard, Hello Tom. > > I encountered the very same problem today using B200 as well. > As far as I remember, using OpenBTS receiver was fine earlier this > year, so I downgraded UHD back to 003.007.002 and got it working fine. > > I can try other UHD releases asap if it can help to get that bug fixed. > > 2015-09-23 17:25 GMT+02:00 Gerhard <ope...@gk... > <mailto:ope...@gk...>>: > > Hi Tom, Hi all, > > sorry for not answering earlier. I've just got some spare time > and was > able to test your suggestions. > > It worked! By using the OsmoTRX instead of the OpenBTS > transceiver my > phone was able to register on the network! Thanks for this > suggestion" > Now there is a follow-up question in my mind: Why did it work? Is > OsmoTRX more sensible when it comes to detecting and handling > RACH bursts? > > Furthermore, I would really like to use the "original" transceiver, > because my goal was to do some GPRS. Citing from the OsmoTRX > page [1]: > "OsmoTRX is fully compatible with OpenBTS for voice and SMS > services. > Due to differences in handing of GPRS, OsmoTRX does not support GPRS > when used with OpenBTS, however, GPRS with the Osmocom stack is > supported." > > Any hints on what I can do to get my setup to work with the OpenBTS > transceiver? Or is the only solution the hard way (enable DEBUG > logging)? ;) > > > As always: any help is welcome. > > Cheers > Gerhard > > > [1] http://openbsc.osmocom.org/trac/wiki/OsmoTRX#OsmoTRXwithOpenBTS > > > > On Sep 11, 2015 at 00:33 AM Tom Tsou wrote: > > On Thu, Sep 10, 2015 at 8:02 PM, Gerhard <ope...@gk... > <mailto:ope...@gk...>> wrote: > >> I'm struggling to get OpenBTS 5.0 with an USRP B200 to work. > After I > >> have build, installed and run OpenBTS, all I get is the > network showing > >> up on my Android device. When I try to connect to it, it > fails (even > >> with open registration enabled). There are no hints in the > logfiles. The > >> "tmsis"-table stays empty. > > > > Likely case is RACH bursts being missed. > > > > Can you give OsmoTRX a try as a replacement for OpenBTS > transceiver? > > Note the section on compatibility with OpenBTS. > > > > http://openbsc.osmocom.org/trac/wiki/OsmoTRX > > > >> Another mail said that the internal clock of the B200 is way > to bad for > >> using it with OpenBTS.[2] Is that so? How can I find out, if > the clock > >> is causing the issues? > > > > Typically, but not always, If the handset is able to detect the > > network, then clocking is sufficient for test calls other basic > > services. > > > >> The OpenBTS book and several other sources state to set > "rxgain" to 0-10 > >> for USRP devices. However, Matt Ettus said (regarding the > gain of a > >> B200) via the USRP-users mailing list: "0dB of gain is > unusably low. You > >> should be using at least 40dB unless there is a very strong > signal." > >> What value should I use? > > > > The point of confusion is that gain ranges vary across > different USRP > > devices. For example, gain range on the RFIC based B200 is roughly > > 0-75 dB while the range on X300 with UBX daughterboard is 0-30 > dB. The > > OpenBTS book assumes a range closer to the latter, which ends > up in > > the low to middle part of the range. > > > > 40 dB on RFIC is close to mid-level, which is a reasonable > starting > > point. With GSM handsets we are dealing high transmit power > levels, so > > lowering the Rx gain at close range makes sense. Setting gain > down to > > 0 dB is excessive and typically reserved for directly coupled use > > cases (i.e. not OTA). > > > >> My setup is > >> * Ubuntu 12.04.05 LTS Server (32 bit) > >> * OpenBTS 5.0 ($ ./switchto.sh 5.0) > >> * USRP B200 (no external clock) > >> * UHD 003.009.000 > >> * No Antennas attached (Phone is next to the USRP) > > > > Nothing abnormal. Attaching antenna(s) with lowered gain > settings is > > recommended over raw SMA connectors for consistency. Also check > > logging for anything unusual; INFO logging level is fine. > > > > -TT > > > > ------------------------------------------------------------------------------ > Monitor Your Dynamic Infrastructure at Any Scale With Datadog! > Get real-time metrics from all of your servers, apps and tools > in one place. > SourceForge users - Click here to start your Free Trial of > Datadog now! > http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140 > _______________________________________________ > Openbts-discuss mailing list > Ope...@li... > <mailto:Ope...@li...> > https://lists.sourceforge.net/lists/listinfo/openbts-discuss > > > |
Thanks for helping keep SourceForge clean.
X