separating MIMO antennas

I have a PC that acts as a wired router/gateway, and I want to add
this wireless PCI card http://www.modecom.eu/product.php?id=428

My only worry is my router is in the basement, and I'm not so sure if
the signal is going to make it through two ceilings...

I was wandering what would happen if I placed each antenna on
different floor? Will a MIMO card still work?

On Sep 4, 10:00*am, TomaszK <tomasz...@gmail.com> wrote:

> I was wandering what would happen if I placed each antenna on
> different floor? Will a MIMO card still work?

No, don't do that. There is a report on a study by Cisco that Jeff
can link for you, but basically, it confuses the system if the
antennas are different, directional or too far apart and can make
things whacky. These antennas are meant to be in the same place both
transmitting/recieving to the same clients - only seperated a bit.

Apart from that, it's not too clear what your setup is. Is it your pc
acting as router or do you have another router in the basement?

Instead of running an antenna cable upstairs, run an ethernet cable
from your existing router to upstairs and use an additional access
point or router (operating as access point) where ever coverage is
too weak.

In fact, if you don't need wifi in the basement, just operate the AP/
Router upstairs and it may cover the upper two floors.

There may be some advantage to using a pc as router, and a wireless
pci card for an AP, but in most cases, I think it's limiting, more
trouble and complicates things without saving any money. Generally
best to get an inexpensive wireless router.

Also, consider if you really need the speed of N because you are
planning to stream video around your house ? If not, then G is
less expensive and very good choice.

Cheers,
Steve

On Sep 5, 11:57*am, Jeff Liebermann <je...@cruzio.com> wrote:

>
> Holdit. *You're mixing up MIMO and diversity reception. *The article I
> was referring to:
> <http://www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note091...>
> is only about diversity reception, not MIMO. *
>
> If you remove all but one of the typically 3 antennas from a MIMO
> router, you get essentially 802.11g speeds. *If the error rate is
> insufficient to maintaint MIMO speeds, the router will revert to
> 802.11g. *I presume (not sure) that the multiple antennas revert back
> to a diversity receive mechanism when not running MIMO speeds.
> Therefore, diversity reception issues might still apply and become a
> problem.


OK. My bad. Thinking I understood! So, it's not the same at all as
diversity, though it might be ultimately have similar problems when
the antennas are seperated from each other?

How's this ?

" You can't seperate the multiple antennas in a multiple antenna radio
(be it diversity or MIMO) and expect it to work like two or more
radios in different places, sending and receiving appropriately to
each client connecting seperately to each antenna. Instead, it will
likely confuse the radio causing it to drop back to G (if N) and
possible attempts to transmit on one antenna in response to reception
on another - generally screwing the link up when multiple users
connect to different antennas with different coverage."

Please correct me Jeff (no doubt you will!) I'm just trying to
extract some direct advice out of the confusion.

Related question? If I understand correctly, the only way to run
multiple antennas with different coverage (on the same radio) is to
use an RF splitter (expensive, with some losses) on a single antenna
jack, so as to transmit and receive on all antennas simultaneously?

Steve