wireless connection speed

[DanPopescu]

I have a laptop and a desktop linked through a router - DLINK DI 624
The router has a peed of about 100 mbps speed
Why at status of wireless connection on laptop I have a speed of around 20 mbps. Takes me a lot of time to copy a file from desktop to laptop. Anyone has an ideea how to improve the speed? I have allready installed the latest firmware for the router. I haven't seen any improvment.
Thank you

 

[shannanl]

If I am not mistaken your speed decreases with the distance to your router. How far away are you? What kind of walls, etc. do you have between you and the router?

Shannan

 

[DanPopescu]

just 1 concrete wall distance about 7 meters

 

[TheLad]

Is your laptop card compatible with 802.11g because if not I would assume that you won't get maximum speed out of the wireless connection as a result because the connection will be using 802.11b instead of the newer and faster version.

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[eyec]

wireless is NOT as fast as wired. period.

 

[SunnyByfleet]

Basically the 108 mbps speed quoted is a theoretical speed. The actual speed attainable will be much lower, as you have found out.

First of all, the laptop and desktop wireless NICs will both have to be 802.11g compatible, otherwise everything runs at a theoretical 11mbps.

Next, to hit a theoretical 108mbps they will have to be DLink and designed specifically for the WAP, otherwise they will operate at the bogstandard theoretical 54mbps.

Now, what is the difference between theoretical speeds and actual speeds?

Take a peek at this data sheet, taken from the DLink site:

ftp://ftp10.dlink.com/pdfs/products/DI-624/DI-624_ds.pdf

Notice the graph on the right? It has actual and theoretical values. The actual values are in red, and much smaller than the theoretical values quoted.

Looking at the graph, your quoted 20mbps is about right for bog standard 802.11g

As the other poster hinted, if you want to copy loads of files, use a wired connection. The wireless figures quoted by the whole of the wireless industry are a bit of a con.

 

[cdogg]

Right, the actual values do not include overhead that is required by the wireless technology. Some of it gets eaten up by packet header information (security, directional, etc). Another chunk is reserved for the spread spectrum of the 2.4GHz.

Although D-link advertises up to 108mbps, the Wireless-G technology is limited to 54mbps. What they are saying is that there are using high compression schemes on data being transferred, which in essence makes it smaller and more can fit onto each packet that is transferred. It gives the illusion that you're actually connected at a faster speed.

The problem with this approach is that it's not constant. If you read the fine print under that chart SunnyByfleet posted, you'll see that not all data is compressable. It's more marketing than anything, if you ask me. Also, a standard 100mbps ethernet connection at full duplex is going to be significantly faster anyway...

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[Jasen]

It's not compression they use to accomplish this, it's spectrum hogging. Instead of using only a single channel for the connection, they use mulitple channels, thereby increasing the available bandwidth for use between the devices. Larger spectrum bandwidth means more data can be crammed into the signal.
My Gigabyte does the same thing. When I put it into "super-G" mode, it sets itself to channel 6, but if you watch with a spectrum analyzer you can see that there's now RF traffic on the entire 2.4Gz range. It takes up channels 1 through 11 with it's chatter. This is completely outside of 802.11 standards, but they do it. Any nearby neighbors with wifi will receive interference, and give you interference, no matter what channel they use.

 

[cdogg]

Jasen,

Perhaps there is some of that going on, but did you read the fine print under the chart in the link above? Here's what it says:

"[blue]...utilizing Packet Bursting, FastFrames, Turbo Mode and Compression techniques. Data already compressed may not benefit from the D-Link 108G compression technique.[/blue]"

So maybe there is more going on than just compression, but they sure went out of their way to say that you might not see any benefit if data is already compressed. That is what led me to believe that this is the most important part of their technology for speed above 802.11 standards.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884