Hi Harald,
On Fri, Jun 17, 2016 at 6:13 PM, Harald Welte <laforge(a)gnumonks.org> wrote:
On Thu, Jun 16, 2016 at 10:10:50AM -0700, Tom Tsou
wrote:
There are still, however, benefits (i.e. cost and
higher capacity
support) to the multi-carrier approach on a single physical RF channel
that make it worthwhile to support in mainline.
I strongly agree. Multi-TRX is a feature for a single BTS with multiple
transceivers (and one of them, per sectors). Having those on separate
physical radio ports means you need to use external (expensive/lossy)
combiners to combine those signals before amplification and feeding the
transmit antenna.
I completely agree that multi-arfcn support should be in the master.
That said, I don't agree that it's always superior to existing
approach we have with UmTRX/UmSITE where we use separate radio paths
for different TRX. We couldn't achieve power efficiency and
flexibility if we were using multi-arfcn approach. Not to mention that
single ARFCN per TRX allows us to use simpler receivers.
You also don't need a combiner if you want to route two TRX to a
single antenna - X-Pol antennas are very popular and easy to get. And
for more powerful BTS's (like 10W per channel) you can get real
benefit from diversity receive, which again requires separate radio
paths for both channels.
--
Regards,
Alexander Chemeris.
CEO, Fairwaves, Inc.
https://fairwaves.co