I thought the 2.4 SMs were in fact V/H because the slant patch
wouldn’t fit in the case? Am I remembering this wrong? There
was a whole thread about it.
*From:*Af [mailto:[email protected]] *On Behalf Of *Kurt
Fankhauser
*Sent:* Tuesday, November 22, 2016 8:06 PM
*To:* [email protected] <mailto:[email protected]>
*Subject:* Re: [AFMUG] Dual-slant 900mhz omni (for PMP450)
ordering group
When did 450 start working with mixing Slant and Linear? Whats
your definition of working? Last time I tried running a 2.4ghz
450 AP with a V/H Omni and the slant SM's they all would operate
in Mimo-A mode (instead of Mimo-B) which basically resulted in
throughput being cut in half. Or are you saying that it works
because the product does run in Mimo-A mode when it cant
distinguish the chains? I guess for me I would want to run in
Mimo-B mode to get maximum throughput.
On Tue, Nov 22, 2016 at 7:41 PM, Ken Hohhof <[email protected]
<mailto:[email protected]>> wrote:
I would be very surprised if you couldn’t use the dual slant
yagi at the SM and a V/H sector or (shudder) omni at the AP.
You could open a ticket with Support or post on the Cambium
community. But if 2.4 and 3.65 can do it, why would 900 lack
this capability? Why would a Dalmatian not have spots?
*From:*Af [mailto:[email protected]
<mailto:[email protected]>] *On Behalf Of *George Skorup
*Sent:* Tuesday, November 22, 2016 5:19 PM
*To:* [email protected] <mailto:[email protected]>
*Subject:* Re: [AFMUG] Dual-slant 900mhz omni (for PMP450)
ordering group
It's not as simple as taking the slant adapter off of the
Cambium yagi. The adapter is threaded. You'll need slightly
longer bolts and nuts to convert it to H/V.
Ideally, I'd like to leave them as slant and get away with a
H/V omni during site conversions. Then there's no going back
to the customers after swapping to Cambium OEM slant sectors.
What we could do right now if we really wanted to, is use an
Antel h-pol and a separate v-pol omni like L-com/Hyperlink or
something like that. I know Ben Royer has done that. I think
it was an MTI diving board though, and whatever v-pol omni.
On 11/22/2016 4:56 PM, Mathew Howard wrote:
I'm pretty sure the 900mhz 450i can do the phase thing...
the 3.65ghz PMP450 definitely can (the high gain
integrated thing is H/V, but all the other 3.65ghz is
slant, so it does work), so it'd seem pretty odd if these
couldn't. I did do some testing with mixing H/V and slant
antennas, and it seemed to work fine, but I didn't really
do enough testing to know for sure. It looks like you can
change the Cambium yagis to H/V pretty easily (theres a
metal piece the holds the mount to the antenna at a 45
degree angle, that looks to be removable... haven't
actually tried it though).
Tower loading is definitely a problem with these
things... so far all of our deployments have only been
one or two sectors, because we usually don't need nlos
coverage in all directions anyway, but I certainly
wouldn't want four of them on most of our towers. Itelite
makes a little (closer to the size of a normal 2.4ghz
sector) 11dbi dual polarity H/V sector that could
somewhat help with that, if they work half way
decently... they're not exactly anywhere near the same
quality as the Cambium sectors, and I'm assuming they
don't have good enough F/B ratio to do frequency re-use,
but they are nice and small and I'm hoping they'll be
usable for some stuff. We have one of them up, but I
haven't had time to do anything with it yet, so I don't
know how well it's going to work.
On Tue, Nov 22, 2016 at 1:45 PM, George Skorup
<[email protected] <mailto:[email protected]>> wrote:
The scenario I have at many 900 sites is >15-20
customers using 4x90 ABAB on FSK. There is no other
option. 900 is the only thing that works. And I'm
already using 16MHz. The top of the band is hosed
with paging. I might be able to sneak a 5MHz channel
in somewhere, but it will depend on the site.
The next problem is tower loading. I already have
four sectors. Adding another four of the Cambium OEM
is unpossible. So if I can have an omni to get the
site converted to 450i, take the FSK sectors down and
put 450i sectors in their place and then take the
omni down.
That Alpha is hugemongous, but is dual slant. The KP
will be H/V. So how would the SM handle being in a
mixed H/V and slant environment? Can the 900 450i do
the phase thing?
The final problem which could make this a big waste
of money is the smart grid rollout that we will see
in the next year or two. If I get FSK speeds out of
the 450i after they turn it up, that's pretty much
suicide.
I would club baby seals for some TVWS gear that works.
On 11/22/2016 9:12 AM, Kurt Fankhauser wrote:
You are wasting you time with omni's on 900mhz.
So your sacrificing a lot of gain to get 360
degree coverage which in turn will result in
higher overall noise floor and lower signal when
this 450 product really starts to shine you need
25db+ SNR at the client side to get the higher
modulation connections. So even if you got the
Omni you'd going to be lucky to get 8-10db SNR to
the client which means your only going to be
running at 2x speed and getting 10mbps download
which will probably be intermittent. I had a lot
of omnis on FSK 900 and I can tell you that after
having used the cambium slant sector on 450 I am
a firm believer in sectors only for 900 from here
on out. I have connections that are 3-4 miles out
running 10mhz channels and getting 40mbps
down/10mbps up. You will never get that with an
Omni unless you have LOS and if you have LOS then
why aren't you using another frequency band?
On Tue, Nov 22, 2016 at 2:03 AM, Colin Stanners
<[email protected]
<mailto:[email protected]>> wrote:
I've been looking for dual-slant 900mhz omni
options that would allow lower-cost PMP450
900mhz deployment on middle-of-the-woods
towers where there are only a small number of
customers (and low noise). I know that "omnis
suck compared to sectors", but having nothing
at all sucks more. Due to the difficulty of
designing dual-slant antennas and the small
market, options are very few.
Commscope has the CH360QS, only 5dbi gain at
~900mhz... and it's a cellular base station
omni with all the fancy doodads: 1800-2200Mhz
band that WISPs can't use, internal GPS
antenna, internal diplexer, remote-controlled
signal tilt on the upper band, etc. At $3500
per antenna I hope that it makes your
breakfast too.
Alpha has the best design that I found at
present, the AW3464. ~7dbi gain
http://alphaantennas.com/products/small-cells/aw3464/
<http://alphaantennas.com/products/small-cells/aw3464/>
. It's ~$1200 USD which is still inexpensive
compared to any other NLOS options.
But currently those antennas cannot be bought
- I spoke with Crossover Distribution and
Alpha, they haven't received enough POs to
make a production run, need 50 orders at a
bare minimum. So if anyone else is really
interested in one or more of these antennas,
ready to buy for sure if they are available,
e-mail me "If available, I will buy x number
of the Alpha AW3464 at $1200/USD each from
Crossover." and I'll make a list, once it
hits 50+ antennas I'll speak with Crossover
and see if it can happen.
