Cellular Network Infrastructure » Radio Access Network » OsmoTRX

<Ppp__> LLL, according to dev_param_map in osmo-trx UHDDevice.cpp, B200 only supports 1 TRx, B210 supports 2
<Ppp__> but we have a B200 in RnD osmo-gsm-tester setup
<Ppp__> same in prod
<Ppp__> I'm not sure if sysmocell5K supports more than 1 TRX, I'll try
<LLL> Ppp__: ah yes, B200 vs B210.  We do have B210 at sysmocom, too
<LLL> Ppp__: you can also have two ARFCN next to each other on one RF port, thoug
<LLL> +h
<TTT> LLL: well yeah, b200 and b210 diff is just mimo.
<TTT> Unless somehow that code relies on the FPGA to do combining ?  because both b210 channel must be tuned to the same RF center frequency.
<LLL> Ppp__: "multi_arfcn" is the feature that allows you to run two ARFCN in a single wideband radio
<LLL> Ppp__: in this case, according to MCBTS_SPACING, the ARFCNs must be 800kHz, i.e. 4 apart.  So something like "1, 5, 9" should work as they're each separated by 4
<Ppp__> LLL, I'm currently using 868 and 870
<Ppp__> does it need to be 4, or at max 4?
<LLL> Ppp__: see also commitlog message 76764278169d252980853251daeb9f1ba0c246e1
<LLL> Ppp__:  I think it needs to be exactly 800khz spacing
<Ppp__> ok I'll try
<LLL> Ppp__: as you can see in getLogicalChan(), the number of channels (ARFCNs) can either be 1, 2 or 3.
<LLL> Ppp__: tuneTx/tuneRx will fail if the frequency difference is not exactly 800kHz
<LLL> http://lists.osmocom.org/pipermail/openbsc/2016-June/009409.html
<Ppp__> ok now it accepted setting up the device
<LLL> Ppp__: also see thread http://lists.osmocom.org/pipermail/openbsc/2016-August/009571.html and responses
<LLL> Ppp__: AFAIR we do have a ticket for an OsmoTRX user manual. Seems like you start to qualify as author :P
<Ppp__> yes I already read that one, thanks. I'm reading the first one now :)
<Ppp__> LLL, there is a user manual already
<Ppp__> but of course I couldn't write information I didn't know haha
<LLL> Ppp__: yes, I know, but not with those details AFAIK
<LLL> Ppp__: http://lists.osmocom.org/pipermail/openbsc/2016-August/009572.html
<LLL> Ppp__: http://lists.osmocom.org/pipermail/openbsc/2016-August/009599.html

Let's add this kind of knowledge into OsmoTRX user manual.