How bad are wireless speeds?

I just got a di-524 dlink router, certainly not the cream of the crop but if
it says 54mbs on the box I expect it to work that way. Anyways everything is
setup in my room I have good connectivety, strong 54mbs connection to the
wireless router. I have WEP enabled on the router too, but I run some file
transfer tests.

On wired-wired my speeds where 80mbits solid,
On wireless-wired speeds dropped to 11mbits (this would be 802.11b speeds
right?) even though my connection was at 54mbs. I understand WEP can reduce
speeds.. but this much?
On wireless-wireless it got even worse. 5mbits!!

"Suburban" <(E-Mail Removed)> wrote:
>I just got a di-524 dlink router, certainly not the cream of the crop but if
>it says 54mbs on the box I expect it to work that way.

That's comparing apples to oranges.

Before deciding what to expect you should go to the effort of
learning exactly what is running at 54 Mbps, and how that
affects your use. When you make "measurements", you need to
determine what you are measuring, so that you don't measure
apples and compare to oranges...

All of this information is available on the web... but you
will have to make an effort to find it. Use google, and read.
About all I can do is point you at some basics...

>Anyways everything is
>setup in my room I have good connectivety, strong 54mbs connection to the
>wireless router.

What is a "strong 54mbs connection"?

>I have WEP enabled on the router too, but I run some file
>transfer tests.

So, you measured through put!

>On wired-wired my speeds where 80mbits solid,

You accept that on a 100 Mbps ethernet! Why??? ;-)

>On wireless-wired speeds dropped to 11mbits (this would be 802.11b speeds
>right?) even though my connection was at 54mbs.

Do you mean your throughput was 11 Mbps? (How many other
connections were currently transferring data at the time you
measured this? And just how did you determine it was 11 Mbps?)

>I understand WEP can reduce
>speeds.. but this much?

Nope, it don't.

>On wireless-wireless it got even worse. 5mbits!!

Notice the nice round comparison? Twice as many connections
transferring data, exactly half the throughput? Works pretty
close to that every time.

Wireless 802.11g provides 54 Mbps total but spreads it over
however many connections there are. It is also simplex, so it
goes at 54 Mbps in one direction first, and then at 54 Mbps in
the other direction. The overhead is large, and the result is
that throughput just about half the single direction data rate.
You won't see better than about 23-26 Mbps over a 54Mbps wireless
link. If you have two connections, that will be divided between
them, and you will see about 12 Mbps.

I can't tell what is causing your initial drop to 10-11 Mbps,
but it could be a number of things. It can't be that it is
operating as 802.11b, because you necessarily have at least a
24Mbps connection.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) (E-Mail Removed)

>>Anyways everything is
>>setup in my room I have good connectivety, strong 54mbs connection to the
>>wireless router.
>
> What is a "strong 54mbs connection"?
>
The "strong" refers to the signal strength

>>I have WEP enabled on the router too, but I run some file
>>transfer tests.
>
> So, you measured through put!
>
yes.. I thought that was what I was implying

>>On wired-wired my speeds where 80mbits solid,
>
> You accept that on a 100 Mbps ethernet! Why??? ;-)
>
various reasons. I'm aware I'm not going to get the maximum speed out of the
network but when it's less than half the established speed the question
needs to be asked. If I was only getting 20mbits/sec on file transfers on a
wired connection I would try to find out why too.

>>On wireless-wired speeds dropped to 11mbits (this would be 802.11b speeds
>>right?) even though my connection was at 54mbs.
>
> Do you mean your throughput was 11 Mbps? (How many other
> connections were currently transferring data at the time you
> measured this? And just how did you determine it was 11 Mbps?)
>
Yes of course. The wireless network properties says it established a 54mbps,
but my file transfers (throughput) only achieve 11mbps. How did I determine
it? I transferred a file from one of my computers to another over the
wireless. The server is on a wired link and the client is on wireless. I
regularly transfer files through ftp from one computer to another.

>>I understand WEP can reduce
>>speeds.. but this much?
>
> Nope, it don't.
>
>>On wireless-wireless it got even worse. 5mbits!!
>
> Notice the nice round comparison? Twice as many connections
> transferring data, exactly half the throughput? Works pretty
> close to that every time.
>
right but it's only confirming to me my thoughput is still 11mbps when my
connection to the router says 54mbps

> Wireless 802.11g provides 54 Mbps total but spreads it over
> however many connections there are. It is also simplex, so it
> goes at 54 Mbps in one direction first, and then at 54 Mbps in
> the other direction. The overhead is large, and the result is
> that throughput just about half the single direction data rate.
> You won't see better than about 23-26 Mbps over a 54Mbps wireless
> link. If you have two connections, that will be divided between
> them, and you will see about 12 Mbps.
>
> I can't tell what is causing your initial drop to 10-11 Mbps,
> but it could be a number of things. It can't be that it is
> operating as 802.11b, because you necessarily have at least a
> 24Mbps connection.
>
fair enough, I was just wondering if it was WEP, but maybe I probably need
to get an even faster wireless router

On Sat, 16 Jul 2005 17:31:52 -0400, "Suburban" <(E-Mail Removed)> wrote:

>I just got a di-524 dlink router, certainly not the cream of the crop but if
>it says 54mbs on the box I expect it to work that way. Anyways everything is
>setup in my room I have good connectivety, strong 54mbs connection to the
>wireless router. I have WEP enabled on the router too, but I run some file
>transfer tests.
>
>On wired-wired my speeds where 80mbits solid,
>On wireless-wired speeds dropped to 11mbits (this would be 802.11b speeds
>right?) even though my connection was at 54mbs. I understand WEP can reduce
>speeds.. but this much?
>On wireless-wireless it got even worse. 5mbits!!
>
It would help if you told us what kind of client device you are using.

I am going to guess and say a USB dongle of some sort?

I ask because USB 1.1 is rated at 12mbps. So if you had some sort of wifi device
plugged into a USB 1.1 port, you couldn't expect any more speed than 12mbps at
most.

On Sat, 16 Jul 2005 17:31:52 -0400, "Suburban" <(E-Mail Removed)>
wrote:

>I just got a di-524 dlink router, certainly not the cream of the crop but if
>it says 54mbs on the box I expect it to work that way. Anyways everything is
>setup in my room I have good connectivety, strong 54mbs connection to the
>wireless router. I have WEP enabled on the router too, but I run some file
>transfer tests.

What are you using for client radios?
How far away from the DI-524 in feet?

>On wired-wired my speeds where 80mbits solid,

How are you measuring this? I suggest you try IPerf:
http://www.noc.ucf.edu/Tools/Iperf/default.htm

>On wireless-wired speeds dropped to 11mbits (this would be 802.11b speeds
>right?) even though my connection was at 54mbs. I understand WEP can reduce
>speeds.. but this much?
>On wireless-wireless it got even worse. 5mbits!!

First a bit of explanation. Under ideal conditions, you'll get and
maintain a 54Mbit/sec association up to about 8ft from the access
point. Put a few reflectors and add some interference from other
radios in the room, and the speed will drop rapidly. I scribbled a
long and detailed explanation on speed adjustments effects yesterday.
The discussion is on diversity reception, but the explanation involves
speed reduction to deal with error rate reduction:
| http://groups-beta.google.com/group/...068f44529dbe2e

The following was stolen from:
| http://www.intel.com/business/bss/in...nt/hotspot.pdf
I don't consider the numbers very accurate and are very optimistic.
If you want speed, you loose range. Period. Incidentally, the above
article is excellent reading on how Wi-Fi really works.

Rate Approximate Max Indoor Range
1 Mbps 350 ft.
2 Mbps 250 ft.
5.5 Mbps 180 ft.
6 Mbps 300 ft.
9 Mbps 250 ft.
11 Mbps 150 ft.
12 Mbps 200 ft.
18 Mbps 170 ft.
24 Mbps 140 ft.
36 Mbps 100 ft.
48 Mbps 95 ft.
54 Mbps 90 ft.

Also, 54MBits/sec is NOT the transfer speed you'll see with a
benchmark program. It's the wireless connection or association speed.
Transfer speed is roughly 33 to 50% of the connection speed. The best
you can do with a TCP file transfer benchmark under Windoze at
54Mbits/sec is about 24Mbits/sec.

This is stolen from an Atheros PDF at:
http://www.atheros.com/pt/athe ros_range_whitepaper.pdf
with some additions and corrections by me.

Non-overlapping Modulation Max Max Max
Channels ------- | Link TCP UDP
| | | | |
802.11b 3 CCK 11 5.9 7.1
802.11g (with
802.11b) 3 OFDM/CCK 54 14.4 19.5
802.11g only 3 OFDM 54 24.4 30.5
802.11g turbo 1 OFDM 108 42.9 54.8
802.11a 13 OFDM 54 24.4 30.5
802.11a turbo 6 OFDM 108 42.9 54.8

Note that if you have 802.11b compatibilty mode enabled, you get to
slow down even more. The receiver has to listen for 802.11b stations
and simply stops everything while this is done. If it finds an
802.11b signal, it deals with it before returning to 802.11g file
transfers. If you even have an 802.11b device anywhere in range, your
802.11g file transfer performance will suffer.

Finally, all the above is between a wired LAN computah, plugged into
the wireless router, to a wireless computah. If you go wireless to
wireless, divide your thruput by at least two. That's because the
access point is simplex and can only transmit or receive one at a
time. The access point is doing a store and forward on each packet
between wireless clients.

I don't wanna speculate on the validity of your benchmark test without
first having a clue as to your setup and testing methodology.


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

Johann Beretta <(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> On Sat, 16 Jul 2005 17:31:52 -0400, "Suburban" <(E-Mail Removed)>
> wrote:
>
>>I just got a di-524 dlink router, certainly not the cream of the crop
>>but if it says 54mbs on the box I expect it to work that way. Anyways
>>everything is setup in my room I have good connectivety, strong 54mbs
>>connection to the wireless router. I have WEP enabled on the router
>>too, but I run some file transfer tests.
>>
>>On wired-wired my speeds where 80mbits solid,
>>On wireless-wired speeds dropped to 11mbits (this would be 802.11b
>>speeds right?) even though my connection was at 54mbs. I understand
>>WEP can reduce speeds.. but this much?
>>On wireless-wireless it got even worse. 5mbits!!
>>
> It would help if you told us what kind of client device you are using.
>
> I am going to guess and say a USB dongle of some sort?
>
> I ask because USB 1.1 is rated at 12mbps. So if you had some sort of
> wifi device plugged into a USB 1.1 port, you couldn't expect any more
> speed than 12mbps at most.
>
>

AND, any other USB devices plugged in will also affect the speed of a
wireless USB since most PC's I've seen use one single interupt for all of
the on-board USB devices. CPU time is then needed to process those other
devices as well.

On Fri, 22 Jul 2005 23:48:00 -0500, DanS
<(E-Mail Removed)> wrote:

>AND, any other USB devices plugged in will also affect the speed of a
>wireless USB since most PC's I've seen use one single interupt for all of
>the on-board USB devices. CPU time is then needed to process those other
>devices as well.

Most all in one motherboard combine the IRQ lines from video,
ethernet, USB, firewire, and the kitchen sink, into one IRQ line.
They can do this because NONE of these devices use the IRQ line for
anything more than indicating an error condition or exception. The
bad old daze of serial I/O and hard disk programmed I/O, where the IRQ
line was thrashed for every character or block, are long gone. Same
with the parallel port that can easily run without ever thrashing it's
IRQ line. I've tested about 12 simultaneous USB devices on a single
USB 2.0 hub without the slighted indication of any IRQ related
performance hits. There was a problem when I attached a DVD burner
and three wireless devices. However, it was the DVD burner that took
the performance hit, not the wireless devices.

Incidentally, the maximum number of devices that can be attached are
127 USB devices.

Have you actually tried plugging in a mess of USB devices and seen any
deterioration in wireless performance? I haven't.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
# (E-Mail Removed)
# (E-Mail Removed) AE6KS

"DanS" <(E-Mail Removed)> wrote in message
news:Xns969C8A825F1Fidispcom@216.196.97.142...
> Johann Beretta <(E-Mail Removed)> wrote in
> news:(E-Mail Removed):
>
> > On Sat, 16 Jul 2005 17:31:52 -0400, "Suburban" <(E-Mail Removed)>
> > wrote:
> >

> >>On wired-wired my speeds where 80mbits solid,
> >>On wireless-wired speeds dropped to 11mbits (this would be 802.11b
> >>speeds right?) even though my connection was at 54mbs. I understand
> >>WEP can reduce speeds.. but this much?
> >>On wireless-wireless it got even worse. 5mbits!!

There is a difference between clock rate and data rate. In a shared Ethernet
system wireless or a HUB wired system you get around 30% throughout compared
to clock speed.
So 30% of 54M is around 15M.

When you go from client to client via wireless this will be halved since the
first client sends the data to the Access point and then the access point
sends the data to the second client.

Tony