From 72e569f784c78d8a1c28fdc090cf815843279016 Mon Sep 17 00:00:00 2001 From: Pau Espin Pedrol Date: Wed, 19 Sep 2018 17:43:09 +0200 Subject: osmotrx: configuration: Add section to document multi-arfcn feature Change-Id: Id04c7f7c36d8a8be8145ef8009ece26ef1a7cdff --- OsmoTRX/chapters/configuration.adoc | 49 +++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/OsmoTRX/chapters/configuration.adoc b/OsmoTRX/chapters/configuration.adoc index cdde366..87d7903 100644 --- a/OsmoTRX/chapters/configuration.adoc +++ b/OsmoTRX/chapters/configuration.adoc @@ -34,3 +34,52 @@ trx <7> Configure the first channel. As no other channels are specified, `osmo-trx` assumes it is using only one channel. <8> Configure the device to use `BAND1` Tx antenna path from all the available ones (device specific). <9> Configure the device to use `LNAW` Rx antenna path from all the available ones (device specific). + +[[multiarfcn_mode]] +=== Multi-ARFCN mode + +The Multi-ARFCN feature allows to have a multi-carrier approach multiplexed on a +single physical RF channel, which can introduce several benefits, such as lower +cost and higher capacity support. + +Multi-ARFCN support is available since osmo-trx release `0.2.0`, and it was +added specifically in commit `76764278169d252980853251daeb9f1ba0c246e1`. + +This feature is useful for instance if you want to run more than 1 TRX with an +Ettus B200 device, or 3 TRX with an Ettus B210 device, since they support only 1 +and 2 physical RF channels respectively. No device from other providers or even +other devices than B200 and B210 from Ettus are known to support this feature. + +With multi-ARFCN enabled, ARFCN spacing is fixed at 800 kHz or 4 GSM channels. +So if TRX-0 is set to ARFCN 51, TRX-1 _must_ be set to 55, and so on. Up to +three ARFCN's is supported for multi-TRX. + +From BTS and BSC point of view, supporting multiple TRX through multi-ARFCN +feature in OsmoTRX doesn't make any difference from a regular multi-TRX setup, +leaving apart of course the mentioned ARFCN limitations explained above and as a +consequence physical installation and operational differences. + +.Example: osmo-bts-trx.cfg using 2 TRX against an osmo-trx driven device +---- +phy 0 + osmotrx ip local 127.0.0.1 + osmotrx ip remote 127.0.0.1 + instance 0 + instance 1 +bts 0 + ... + band GSM-1800 + trx 0 + phy 0 instance 0 + trx 1 + phy 0 instance 1 +---- + +.Example: osmo-trx.cfg using Multi-ARFCN mode to run 2 TRX +---- +trx + ... + multi-arfcn enable + chan 0 + chan 1 +---- -- cgit v1.2.3