[osmocom-event-orga] good news everyone: BTS and bands

[Neels Hofmeyr]

So, today I rummaged throught the event pool boxes at sysmocom office.

Turns out:

a) I can find only two BTS in there. There are four amplifier+duplexer wooden
boards, but only two of them have a BTS on them. Does anyone know where the
other two went?

b) The good news is: both BTSes that I tested are quad band, i.e. they support
whichever band we want. Lynxis and I also each have one quad-band sysmoBTS. So
we have at least four BTS available now, I assume it will be six in the end.
(Details: a sysmoBTS is physically limited to specific bands. Which bands are
supported is indicated in the EEPROM, and if you configure osmo-bts.cfg with a
band that isn't supported, you get, during osmo-bts startup:
"DL1C <0006> l1_if.c:1453 BTS band GSM850 not supported by hw"
i.e. the two that worked at AfRA on sunday positively support the 850 band.)

c) To transceive with 2W, we need amps and duplexers.

The current four amps in the event pool are 1800; sysmocom has more than enough
lo-band amp boards that we could replace in these amps with "minimal mechanical
effort".

Sysmocom has three 850 duplexers available that we can transfer to the event
pool.


In summary:

If we get 850MHz spectrum:
We are limited by duplexers to three sysmoBTS 850MHz on 2W, and could setup
another one to three sysmoBTS 850MHz on 200mW.

If we get 1800MHz spectrum:
We can have four BTS on 2W like last year, and could setup two more on 200mW.
There are also two 1800 nanoBTS in the pool.

This is pretty good news, it means that whichever spectrum we get, we can do 2G
with at least three 2W cells. Now let's wait/hope for at least one license
confirmation, I think that is quite likely to happen.

Maybe we can even get both 850 and 1800, then we could do 2G on 1800 and 3G on
850. There are eight nano3G in the event pool, plus some more from me, lynxis,
maybe others.

~N