17 May
2012
17 May
'12
12:32 p.m.
Hi Alexander,
yes I'm aware that a BTS would need to be transmitting all time, which
is not best starting point for being power-efficient. However good to
get confirmation that multi-ARFCN can be avoided. I mailed to BB list
as I see this part as most probable technical show stopper for this
initiative. The chip designs seem to be targeted for mobile broandband
applications with all that unnecessary functionality at a silicon
screaming for more power. Also proprietary L1 can be a major problem
when cost of BTS module needs to be kept minimal (modules getting
lost, damaged, stolen, or vandalized) and also this stuff would need
to be affordably available for the developers. Actually, SMS-only
supporting base-stations could be a first viable application for an
open L1 implementation?
We're though about balloon raising the antenna up and also flying
drones with BTS as payload. Flying or floating might work well on
still weather, but probably not at all under heavy winds. Not sure
whether this would acceptable shortcoming for the imaginary
"customer". Balloon-approach might just have worked better in case
Haiti, I see the point.
Thanks for hinting the OpenBTS mailing list, I'll drop a line there too.
Best Wishes,
Kalle Pietilä
On Thu, May 17, 2012 at 10:17 AM, Alexander Chemeris
<alexander.chemeris(a)gmail.com> wrote:
Hi Kalle,
BTS has to transmit constantly on it's main ARFCN, no matter do you
make calls or just send SMS. So while you operate a single ARFCN you
can't save power by employing only SMS. On the other hand, for SMS a
single ARFCN would be enough to provide a good capacity, while support
for calls would require a multi-ARFCN config which would be quite
power hungry.
Have you thought about using a balloon for carrying a BTS instead of
dropping to a ground? This would give you much better coverage easily
then on-the-ground installation.
PS I think this would get more responses from the OpenBTS mailing
list, then from OsmocomBB mailing list, as this is definitely a
network-side question.
On Wed, May 16, 2012 at 10:28 PM, Kalle Pietila <kalle.pietila(a)gmail.com> wrote:
Dear baseband enthusiasts,
on SMOS project we had this crazy idea for catastrophe communications
in which cellular base stations would be miniaturized enough to be
airdropped into disaster zones. We felt that this might
be possible if all functionality except SMS was stripped from the base
stations (hence SMOS, SMS Our Souls). Most ideally such technology
would come in near cellphone size (excluding batteries), something
like osmocom's earlier "Phone acting as BTS" hackwork.
We did not have the guts nor skills to start doing this by ourselves,
so we just published our findings and studies under Creative Commons
BY license. As we wish to keep this idea open to everyone, our
web-documentation would benefit on this regard from some more in-depth
HW-related analysis and suggestions (our team fell short on this
area). Once it's all published, it cannot be patented. I personally
see some humanitarian & karma-improving angle in doing it this way.
Helping human kinds in disaster should not be bound by patent laws.
So I'm asking for constructive criticism and also offering possibility
to write some informal blogs about your views on
www.zygomatica.com/smos (with our team's editorial support) . At the
same time it should be noted that such technically oriented blog
writings at my friends' site zygomatica.com would likely reach 50
readers at most. To put it more nicely, reaching the widest possible
audience is not our focus here anyways.
My technical vision is presented at
http://www.zygomatica.com/wp-content/uploads/2012/04/SMOS6-Technical-goals-…
.. and the full list of formal documents at end of
http://www.zygomatica.com/smos/ . The other provided background
material might be even more valuable to those that start considering
this idea more seriously.
So, For instance, can stripping down the functionality just to
supporting SMS delivery bring down the power consumption in any
significant manner?
Thanks and regards,
Kalle Pietilä
P.S. Mailed to this list as suggested by Harald.
--
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru