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Feature #3561
closedDocument multi-arfcn support in OsmoTRX user manual
Start date:
09/17/2018
Due date:
% Done:
100%
Spec Reference:
Description
<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.
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