18 Mar
2012
18 Mar
'12
7:25 p.m.
Hi Alexander,
Thank you for your reply.
Actually, you just point the right question.
Andrey, would you have an approximate idea about how long it would need you
to design the preselector ?
Best regards.
Jean-Samuel.
:-)
On Sun, Mar 18, 2012 at 6:11 PM, Alexander Chemeris <
alexander.chemeris(a)gmail.com> wrote:
Jean-Samuel, thank you for the detailed answer.
I agree that 2 weeks of delay is ok, but 2 months is definitely not.
We should optimize our processes as much as we can.
Regarding the need for the preselector, I have no other option as to
trust you and Andrey that we need it even for the mid-range BTS.
Could we start updating UmTRX and manufacturing the next prototype
batch while still discussing the mezzanine board? This would allow us
to get to the result faster.
2012/3/18 Jean-Samuel Najnudel - BJT PARTNERS SARL <jsn(a)bjtpartners.com>om>:
--
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru
Hi Alexander,
I fully agree with your vision. Especially that "the best is an enemy to
a
good". Moreover, it is also very important
for me to deploy the UmTRX in
Mayotte ASAP as my local partners would pressure me quite a lot in the
near
future.
However, I really belive this preselector is not just for scoring the
best
performances as possible as an RF geek, cool and
fun challenge. We really
need a preselector, not only to pass the GSM specs. I do not care that
much
about the GSM specs, especially the hard to pass
macro BTS specs.
However,
as I mentioned you in Berlin in last december, I
really think sampling
the
whole 1.5 MHz band would be a real problem. The
preselector is good to
pass
the spec but it is also the only reasonable
solution to lower the
sampling
band down to about 200 KHz. Actually, I would
really need this. Even for
my
experiment network in Mayotte, this would not be
realistic to deploy the
network and provide reliable services without this preselector.
I really think this preselector is mandatory, in practice, even if we do
not
care about the GSM specs. Without this, I would
not even be able to
deploy
the UmTRX in Mayotte.
I agree with you when you mention some markets would still not need this
preselector.
First market is lab equipments. However, I am not sure volumes would be
that
high, especially as even a basic low cost SSRP is
good enough for many
lab
use cases.
Second market is the femtocell market. However, for this market, the
UmTRX
would anyway be too expensive for most business
cases. Except ip.access
who
can sell much more than everybody else because of
their first mover
advantage, most of the femtocell vendors target list prices around 300
Euros
(eg: HSL) and even lower (most 3G femto vendors).
Considering this
competition, I believe it would be really difficult to succeed in the
femtocell market with the current UmTRX design. We would need something
even
more low cost orienteed and probably also more
embedded.
The market I relly believe in is the mid-range mid-capacity BTS market.
There are many high performance macro BTS vendors. There are many simple,
cheap and reliable femtocell vendors. There are not much mid-range BTS
vendors. If we want something than can cover a few kilometers range,
that is
energy efficient and which use IP standards, you
only have something
like 3
vendors: Vanu, VNL and IP.access. These guys are
really expensive.
Offering
a better value product would not be that
difficult, at least compared to
the
other markets.
Moreover, this mid-range mid-capacity BTS market is potentially huge.
This
is the most suitable system we would need to
cover most of the next 2.5
billion guys who do not have a reliable and affordable phone service
(sometimes just no service at all).
Again, I agree with you, Time To Market is very important. However, I do
not
think a few weeks delay would make you miss the
opportunity.
Also, the customers on this market (mainly rural and local carriers)
would
have very similar needs as mine. Most of them
would probably need to get
a
narrow sampling band (< 1.5 MHz) to avoid
problems with interferences
(1st
TRX to the other, other existing carrier...)
causing, among other issues,
ADC saturation. As me, these customers would need the preselector.
The preselector would anyway need a VCO/PLL, a mixer and an IF SAW
filter,
even if we do not expect to pass the GSM spec.
Why not trying to select
good
performance components to try (not guarantee but
just try) to pass this
spec. This would not need much more research and development efforts and
total BOM will not be that much more expensive. Moreover, we can really
expect some of your customers would not agree to deploy a system that
does
not pass the GSM spec. A mid-range BTS would need
a Tx power around 5 to
10
Watts. Above 2 Watts, the hardware is considered
as a macro BTS.
Considering
this, I really think we should try (not take one
year delay for this but
just try) to pass the GSM macro BTS spec.
Honestly, I may be wrong but I do not believe Andrey will take that much
time to design the preselector. For the BOM extra cost, we talk about 60
USD
per UmTRX board. I agree with you, this is not
nothing but this really
worth
the money. I actually believe value would be
really good with this. Even
with my very tight budget, this would not be able problem for me to pay
this. The extra cost would be much lower than all the worries and time
spent
on frequency planning, interferences and blockers
problem solving on the
field.
Anyway, I also really think, even with the high performance preselector,
the
UmTRX system is still really cost effective
compared to the competitors.
I
really feel confident about this.
Best regards.
Jean-Samuel.
:-)
On Sun, Mar 18, 2012 at 8:45 AM, Alexander Chemeris
<alexander.chemeris(a)gmail.com> wrote:
>
> Andrey and all,
>
> 18.03.2012 2:31 пользователь "Andrey Sviyazov"
<andreysviyaz(a)gmail.com>
> написал:
> >> Regarding the GSM spec, I believe these blocker tests are hard to
pass
> >> and not that useful in most
practical situations. However, I do not
care
> >> that much about passing this spec
for my network deployment in
Mayotte but I
> >> really believe passing the spec will
be very important for you if
you wish
> >> to sell your hardware solution to
some major operators. Moreover, as
we
> >> would anyway need a superheterodyne
selective filtering to get a
reasonably
> >> narrow Rx sampling band (< 1.5
MHz LMS band), it does not cost that
much
> >> more to try to pass the GSM spec.
> >
> > You right, it is important for us and may be it is really important
for
> > systems with high channel dencity.
>
> I completely support everything which could make our product better
> without increasing its cost. But we also must ensure to release UmTRX in
> time. What we all should keep on mind is that "the best is an enemy to a
> good". We should focus on those 10% of simple tweaks which bring us 90%
of
> improvement. Otherwise we'll be swamped
with the other 90% of tweaks and
> will miss the market opportunity. I can't stress it more - we MUST
release
> UmTRX ASAP. Even if it doesn't meet
macro-BTS requirements. We'll be
able to
> fix this in the next version if ever needed -
we can't know the real
demand
> until we release the first version.
>
> I would be glad of what I've just said is obvious and already lives in
> your heart. Otherwise it's extremely important you understand this
deeply,
> not formally. Please let me know if you
don't, I'll explain in more
details.
>
> > Furthermore, it is very easy to lose the reputation of the product,
but
> > it is very difficult then to fix it
back.
>
> This is true. And the best way to keep the reputation is to
realistically
> understand UmTRX capabilities and avoid
overmarketing. In other words,
with
> just reasonable product quality, our
reputation depends solely on the
right
> marketing. E.g. we might explicitly warn
customers that it's not
suitable
> for macro-BTS installations and they could do
so on their own risk only.
>
> > I think, low cost doesn't sign low quality, so we must to have good
> > hardware on market for good sales and promote OpenHW :)
>
> This is very true. Just keep in mind that "good hardware" means
"minimally
> viable hardware at low price" and
doesn't mean "super high quality mumbo
> jumbo with many zeros in the price". Our customers value simplicity and
low
cost over
complexity and golden plates.
That said, I can't help with decisions on the RF side and here I rely on
you, guys. That's why it is so important for you to understand all these
"abstract" marketing ideas.
Sent from my Android device.
--
Regards,
Alexander Chemeris
CEO, Fairwaves LLC
http://fairwaves.ru