CalypsoBTS and modern OsmoBSC

Vadim Yanitskiy axilirator at gmail.com
Tue May 9 17:44:40 UTC 2017


Hi,

> I found that the manual from the main site is outdated.

Yeah, still couldn't find some time to update the wiki.

> If I understood it correct, I have to setup calypso bts
> as bts of type nanoBTS, correct?

Why do you think so? No, CalypsoBTS has nothing related
toip.access nanoBTS. From the other side, we don't have
a dedicated type for OsmoBTS, so you can use 'sysmoBTS'.

> I can sync with commercial cell, I can run OsmoBSC and
> OsmoBTS but I still cannot find my network from my personal
> phone in searching mode.

Please watch a great Sylvain's talk, where he explained
almost everything you need to know:

"Further hacks on the Calypso platform"
https://media.ccc.de/v/29c3-5226-en-further_hacks_calypso_h264

In short: BTS should transmit a continuous beacon on C0 to be
detected. Normal MS can't do that. CalypsoBTS was hacked to
perform the following timeslot layout: Tt_R_ttt, where
'T' means TX on Downlink, 'R' means RX on Uplink, and 't' means
channel filling - dummy bursts. Phone cannot RX and TX at the
same time, so one phone serves only one TS. With two phones
you have the following layout: TT_RRttt, so you have two
timeslots served.

This is why you will have some detection troubles even with
working BSS setup :/

> In logs of osmo-bts I can see:
>
> <0000> rsl.c:246 Tx RSL RF RESource INDication
> <000b> trx_if.c:397 transceiver (phy0.0) rejected TRX command with
> response: 'RSP SETTSC -1'
> <0000> rsl.c:2353 (bts=0,trx=0,ts=0,ss=0) Rx RSL BCCH_INFO

Just delete the 'settsc' line from your config, because CalypsoBTS
transceiver only supports 'setbsic'.

Have a fun!


With best regards,
Vadim Yanitskiy.
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