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

Reply to
xavi
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Hi Xavi,

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

Naim

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xavi wrote:

Reply to
Panda

No.

Reply to
John Navas

"xavi" hath wroth:

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.

Reply to
Jeff Liebermann

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

Reply to
xavi

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

Reply to
xavi

"xavi" hath wroth:

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.

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?

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.

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.

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.

Reply to
Jeff Liebermann

This is what I want to know.

You might

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

Reply to
xavi

"xavi" hath wroth:

I think this will help:

formatting link
'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

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.

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.

Good luck.

Reply to
Jeff Liebermann

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

Reply to
xavi

"xavi" hath wroth:

Connect to each other as in Ad-Hoc mode? Or individually connect to the router? Please supply an equipment list (maker and model) of everything involved. Also the computer operating systems. I can't troubleshoot without numbers.

That's not enough signal.

You cannot mix Infrastructure (access point) wireless communications with Ad-Hoc (peer to peer) wireless communications. The client radios must be configured for one or the other. You can switch back and forth between ad-hoc and infrastructure modes, but not run them at the same time.

The wireless access point acts somewhat as a repeater between two wireless clients. This makes it easier to communicate through an access point than going directly between clients. Going throught the wireless router is probably best.

Reply to
Jeff Liebermann

Yes. Ad-hoc is what I want. Cause router is only 54Mbps and pcmcia and my future pci card are 108MBps.

supply an equipment list (maker and model) of

Pcmcia SMC 108Mbps (SMCWCBT-G EU), router comtrend 536+, wlan usb 2.0 (ct-wn4320z). Adsl2+ 20Mbs.

Pc XP3000+ and laptop thinkpad 600e. S.O Windows 98SE.

In w98 I have problems when security is active, If I not encript I can connect always and surf internet but If I activate WPA/PSK the utility say all it's OK but can navigate.

Sometimes I've solve it turning off the encryption on the router and when pc begins to surf then I activate the WPA on router and card and the pc remains connected .

But its no good cause I have to connect first wired to disconect the encripton and what I want is to remove all the wired connections of my house.

Thanks Xavi

Reply to
xavi

"xavi" hath wroth:

Bad decision. You will only get 108Mbits/sec connection under perfect and ideal conditions. That means about 2 meters maximum range and no interference from any other source of 2.4GHz RF. I've found that I have to force the clients to use 108Mbits/sec only speed in order to maintain a 108Mbit/sec connection, or the slightest noise pickup will reduce the speed down to 54Mbits/sec or lower. It will not recover for many minutes. Some client drivers do not allow you to force

108Mbits/sec. Going through multiple walls and floors will never work at 108Mbits/sec.

Also, even if you do get a 108Mbit/sec connection, you will only get perhaps 60Mbits/sec UDP thruput. Less for TCP.

Use an access point.

20Mbits/sec ADSL2+? I'm jealous. I only have 1.5Mbits/sec. I can see why you want speed. In order to get the full 20Mbits/sec download speed with wireless, you will need to maintain a 54Mbits/sec connection. That is going to be difficult and limited to a range of about 3-5 meters.

Thank you. The IBM 600e is relatively slow with a PII-366 processor. I have several. You will probably never get 60 Mbits/sec thruput with this machine because the i/o and hard disk system cannot keep up. You can prove it to yourself by plugging in an 10/100 baseT PCMCIA ethernet card, and try benchmarking file transfers to the XP3000+ machine. I use IPerf 1.70:

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Something is wrong. Windoze does not correctly report whether you have successfully negotiated a WEP/WPA key. It just sits there forever saying "obtaining IP address". However, the problem is obvious. Many vendors didn't bother implimenting WPA-PSK encryption in Ad-Hoc mode. The IEEE 802.11b/g specifications did not require support for anything faster than 11Mbits/sec or more secure than WEP in Ad-Hoc mode. To do WPA-PSK, one needs an 802.1x authentication server. In WPA-PSK, that's supplied by the access point itself. In Ad-Hoc, there's no access point to provide authentication, so WPA-PSK fails. WEP might work, but that's almost a waste of time as the security is terrible.

Yes. WPA-PSK is usually supported only with an access point in the system (infrastructure mode).

Leave the wires. They're faster and far more reliable than wireless. Wireless should be used only when wires are impractical or impossible.

Reply to
Jeff Liebermann

I only get 1,5 MB/s.... and on downloads from very good sources.

I've changed the HD with a samsung 60GB ata100 5400rpmn.

No, he get the IP, DNS and mask correctly and say all is OK, simply can't connect to the net, until I remove the encriptyon. :(

I have the same problem with the usb and the pcmcia on both pcs, only on XP with the zero windows acces seems that encription works but sometimes fails too. :(

Maybe is a conflict with the wired card and his configuration, because windows say that two connections have the same.

I've always talking about router to card connection, ad-hoc is impossible for me by now.

But wires are so ugly... :P

Thanks Xavi

Reply to
xavi

Finally I've found the problem, It was "sygate personal firewall", when I activate the WPA it create a strange conflict with the firewall. (?)

I found it reinstalling windows, and all was OK until install Sygate firewall (then begins the problems) and solved when uninstalling.

I had sygate personal firewall on both computers and on all my windows :P

Thanks Xavi

Reply to
xavi

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