MIMO needs that router & card have it to work?.

If I buy a MIMO pcmcia card and my router don't have MIMO . Do I notice a
improvement over normal wirelles card or not?

Thanks
Xavi

Hi Xavi,

I don't think you will get a great improvement in your wireless LAN.

Naim
www.networkingland.com/mimomain.htm


xavi wrote:
> If I buy a MIMO pcmcia card and my router don't have MIMO . Do I notice a
> improvement over normal wirelles card or not?
>
> Thanks
> Xavi

[POSTED TO alt.internet.wireless - REPLY ON USENET PLEASE]

In <e4c8hn$1t9$(E-Mail Removed)> on Tue, 16 May 2006 12:11:55 +0200, "xavi"
<(E-Mail Removed)> wrote:

>If I buy a MIMO pcmcia card and my router don't have MIMO . Do I notice a
>improvement over normal wirelles card or not?

No.

--
Best regards, SEE THE FAQ FOR ALT.INTERNET.WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/FAQ_for_alt.internet.wireless>

"xavi" <(E-Mail Removed)> hath wroth:

>If I buy a MIMO pcmcia card and my router don't have MIMO . Do I notice a
>improvement over normal wirelles card or not?

Probably no improvement. In theory, a MIMO PCMCIA card has the same
multiple signal handling benifits of a MIMO wireless access point.
Internally, the PCMCIA MIMO design is almost identical to that of the
MIMO access point.

In reality, the lack of sufficient antenna seperation makes a MIMO
PCMCIA card a marginal proposition. If the antennas resembled those
on the MIMO access point, there would certainly be a benifit, but not
with the typical tiny and squashed together antennas found on PCMCIA
cards. However, if you're working in a highly reflective environment,
the MIMO PCMCIA card will probably offer some improvement in
reflection immunity.

To illustrate the problem, the Linksys WMP54GX PCI card has 3 external
antenna connections, and a truely bizarre looking antenna farm. The
antenna is not pictured on the Linksys site, but if you search Froogle
for WMP54GX, you'll see some photos. That's what your PCMCIA card
antenna farm will need to look like in order to derive some benifits
from MIMO technology.



--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

> In reality, the lack of sufficient antenna seperation makes a MIMO
> PCMCIA card a marginal proposition. If the antennas resembled those
> on the MIMO access point, there would certainly be a benifit, but not
> with the typical tiny and squashed together antennas found on PCMCIA
> cards. However, if you're working in a highly reflective environment,
> the MIMO PCMCIA card will probably offer some improvement in
> reflection immunity.

I don't know if my enviroment is reflective or not.

I have a 54 Mbps usb stick and always connect at this velocity but quicly it
go only at 20Mb, and after a while only at 11Mbs.

If I buy a normal pcmcia card could go at 54Mbps or better should buy a
MIMO.

Another option could be buy two cheaps 100 MBps (pcmcia & pci card) from the
same brand and when I need to conect laptop-desktop it would runs faster
without pass through router.

Or also is impossible go at 100Mbps even with two card of same brand?.

Thanks again
Xavi

> In reality, the lack of sufficient antenna seperation makes a MIMO
> PCMCIA card a marginal proposition. If the antennas resembled those
> on the MIMO access point, there would certainly be a benifit, but not
> with the typical tiny and squashed together antennas found on PCMCIA
> cards. However, if you're working in a highly reflective environment,
> the MIMO PCMCIA card will probably offer some improvement in
> reflection immunity.

I don't know if my enviroment is reflective or not.

Now I have a 54 Mbps usb stick and always connect at this velocity but
quicly it
go only at 20Mb, and after a while only at 11Mbs.

If I buy a normal pcmcia card could go at 54Mbps or better should buy a
MIMO or a pcmcia with a external antenna?.

Another option could be buy two cheaps 100 MBps (pcmcia & pci card) from the
same brand and when I need to conect laptop-desktop it would runs faster
without pass through router.

Or also is impossible go at 100Mbps even with two card of same brand?.

Thanks again
Xavi

"xavi" <(E-Mail Removed)> hath wroth:

>> In reality, the lack of sufficient antenna seperation makes a MIMO
>> PCMCIA card a marginal proposition. If the antennas resembled those
>> on the MIMO access point, there would certainly be a benifit, but not
>> with the typical tiny and squashed together antennas found on PCMCIA
>> cards. However, if you're working in a highly reflective environment,
>> the MIMO PCMCIA card will probably offer some improvement in
>> reflection immunity.

>I don't know if my enviroment is reflective or not.

Lots of metal in the building, such as file cabinets, metal furniture,
and metal doors, are reflective. Lots of wood and plaster in the
building are absorptive.

>I have a 54 Mbps usb stick and always connect at this velocity but quicly it
>go only at 20Mb, and after a while only at 11Mbs.

You may have an interference problem. Wi-Fi will start at the fastest
speed and slow down until the bit error rate improves to the point
where communications is reliable. If your system slows down that
much, it might be picking up garbage from somewhere. It doesn't need
to be another wi-fi system. I can be a 2.4GHz cordless phone,
microwave oven, or wireless video camera.

The speed is also reduced with longer ranges. Using the built in
antennas, you will not get 54Mbits/sec connection speeds beyond about
4 meters range. At that point, it drops to 36Mbits/sec or lower. If
you have reflections and interference problems, it will drop even
more.

At what range are you testing the USB stick?
How many walls are you going through?
Is there aluminum foil backed insulation in the walls?

>If I buy a normal pcmcia card could go at 54Mbps or better should buy a
>MIMO.

Niether will give you 54Mbits/sec if you have interference problems.
However, MIMO will work somewhat better going through walls (multiple
paths). However, that's for a MIMO access point, not for a MIMO
PCMCIA card. The MIMO PCMCIA card cannot work as well as a MIMO
access point because of the inability to properly position and
seperate the antennas.

>Another option could be buy two cheaps 100 MBps (pcmcia & pci card) from the
>same brand and when I need to conect laptop-desktop it would runs faster
>without pass through router.

I don't understand what you're suggesting. If you mean using a CAT5
ethernet wire instead of wireless, I strongly suggest you consider
this possibility. Wired networking is always more reliable and faster
than wireless.

>Or also is impossible go at 100Mbps even with two card of same brand?.

I don't understand this either. Two wireless card will NOT go
anywhere near the 108Mbits/sec claimed on the data sheet. You might
get a 108Mbit/sec connection at very short range (perhaps 2 meters),
but the thruput will be no more than perhaps 60Mbits/sec. This is
under absolutely ideal conditions, with no interference or
reflections. It's not going to happen. Put any distance beween the
client and access point and the conenction speed goes down to 802.11g
speeds rapidly.

A 100baseTX-FDX wired ethernet connection will yield about 80Mbits/sec
thruput.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

> Two wireless card will NOT go
> anywhere near the 108Mbits/sec claimed on the data sheet.

This is what I want to know.

You might
> get a 108Mbit/sec connection at very short range (perhaps 2 meters),
> but the thruput will be no more than perhaps 60Mbits/sec. This is
> under absolutely ideal conditions, with no interference or
> reflections. It's not going to happen. Put any distance beween the
> client and access point and the conenction speed goes down to 802.11g
> speeds rapidly.

OK. I use the laptop on the second and third floor and the desktop on the
first where is the router. Wide walls and wireless phone close. But I'm
thinking that the pc is to close to the router and create inteferencies.

And the 108 MBps will be if someday I need to copy a lot of bytes, I suposse
that I'll have to put two pcs very close, but It would save me to write a
dvd or to conect wired.

Thank for your answers I'm new on this and you show me a lot.

Xavi

"xavi" <(E-Mail Removed)> hath wroth:

>> Two wireless card will NOT go
>> anywhere near the 108Mbits/sec claimed on the data sheet.
>
>This is what I want to know.

I think this will help:

http://www.tomsnetworking.com/2006/0...king_ntk_2006/
It's 14 pages long but worth reading.

The three rules of Wireless Networking
1) It never goes as fast as they say it does
2) It never goes as far as they say it does
3) It never sets up as easily as they say it does

>OK. I use the laptop on the second and third floor and the desktop on the
>first where is the router. Wide walls and wireless phone close. But I'm
>thinking that the pc is to close to the router and create inteferencies.

The PC *MIGHT* create interference but I've never seen any PC or
laptop do that. Spread spectrum is very resistant to interference
from such signals as a PC might generate. Proximity to a monitor
causes problems due to radiation from the flyback transformer. In
general, interference sources must be either spread spectrum (2.4GHz
cordless phones) or high power (microwave oven). I consider it very
fortunate that you have any form of connection through 3 floors and 2
floors. One access point per floor will help considerably as 2.4GHz
does not like going through walls and floors.

Checklist of possible interference sources:
Microwave oven
2.4Ghz video or security camera link (X10).
Municipal wireless networks.
Bluetooth devices (mouse, phone, PDA, headset, cell phone, etc)
Portable wireless TV camera used at sports events.
Frequency hopping cordless phones (Panasonic Gigarange)
802.11b/g wireless keyboards, PDA's, and cell phones.
2.4GHz game pads and controllers.
RF Excited Lighting (Fusion Lighting).
2.4GHz baby monitors.
2.4GHz ham radio operation.
WISP (wireless internet service providers) which may be using
non-802.11 type of modulation (i.e. WiMax).
Breezecom/Alvarion/Symbol/Raylink frequency hopping networks.
Western Multiplex or Proxim non-802.11 wireless links. (e.g Lynx).
HomeRF frequency hopping network.
Zigbee 802.15.4 sensor wireless network.
Microwave fruit drying oven, plastic mold preheater.
Unstable high power wi-fi power amplifier spraying garbage.

>And the 108 MBps will be if someday I need to copy a lot of bytes, I suposse
>that I'll have to put two pcs very close, but It would save me to write a
>dvd or to conect wired.

If you need to place the PC's close to obtain adequate speed for
copying large amounts of data, you can do better by connecting a
crossover ethernet cable between the PC's. Todays laptops are coming
with gigabit ethernet cards, which I've measured at about 300Mbits/sec
thruput without any tweaking or optimizing. I should go much faster
but was limited by the performance of the hard disks.

>Thank for your answers I'm new on this and you show me a lot.

Good luck.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Yesterday I bought a cheap SMC 108Mpbs pcmcia card and it improves a lot
over the usb stick.

But the pcmcia card and the usb stick can't connect among them even at a
very short distance.

The usb don't see the pcmcia signal and the pcmcia only see a very little
11% from the usb.

If I'll buy a pci wireless card can connect to pcmcia directly without pass
through router or not?

Thanks
Xavi

> >OK. I use the laptop on the second and third floor and the desktop on the
> >first where is the router. Wide walls and wireless phone close. But I'm
> >thinking that the pc is to close to the router and create inteferencies.
>
> The PC *MIGHT* create interference but I've never seen any PC or
> laptop do that. Spread spectrum is very resistant to interference
> from such signals as a PC might generate. Proximity to a monitor
> causes problems due to radiation from the flyback transformer. In
> general, interference sources must be either spread spectrum (2.4GHz
> cordless phones) or high power (microwave oven). I consider it very
> fortunate that you have any form of connection through 3 floors and 2
> floors. One access point per floor will help considerably as 2.4GHz
> does not like going through walls and floors.
>
> Checklist of possible interference sources:
> Microwave oven
> 2.4Ghz video or security camera link (X10).
> Municipal wireless networks.
> Bluetooth devices (mouse, phone, PDA, headset, cell phone, etc)
> Portable wireless TV camera used at sports events.
> Frequency hopping cordless phones (Panasonic Gigarange)
> 802.11b/g wireless keyboards, PDA's, and cell phones.
> 2.4GHz game pads and controllers.
> RF Excited Lighting (Fusion Lighting).
> 2.4GHz baby monitors.
> 2.4GHz ham radio operation.
> WISP (wireless internet service providers) which may be using
> non-802.11 type of modulation (i.e. WiMax).
> Breezecom/Alvarion/Symbol/Raylink frequency hopping networks.
> Western Multiplex or Proxim non-802.11 wireless links. (e.g Lynx).
> HomeRF frequency hopping network.
> Zigbee 802.15.4 sensor wireless network.
> Microwave fruit drying oven, plastic mold preheater.
> Unstable high power wi-fi power amplifier spraying garbage.
>
> >And the 108 MBps will be if someday I need to copy a lot of bytes, I
suposse
> >that I'll have to put two pcs very close, but It would save me to write a
> >dvd or to conect wired.
>
> If you need to place the PC's close to obtain adequate speed for
> copying large amounts of data, you can do better by connecting a
> crossover ethernet cable between the PC's. Todays laptops are coming
> with gigabit ethernet cards, which I've measured at about 300Mbits/sec
> thruput without any tweaking or optimizing. I should go much faster
> but was limited by the performance of the hard disks.
>
> >Thank for your answers I'm new on this and you show me a lot.
>
> Good luck.
>
> --
> Jeff Liebermann (E-Mail Removed)
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558