Thinkpads Forum

Hi all: I have a new T61 with the atheros card, and a T43 with the intel wireless. I was expecting the T61 to get better reception (seeing as it has the better card *and* the plastic lcd cover). Unfortunately, the T43 appears significantly better-- networks that have only 3 bars on the T61 have 4 bars on the T43. However, the T61 does pick up some networks that the T43 does not (these typically show up in the T61's wireless network list as having no bars). Has anyone else attempted to test T61 wireless performance against T4x? I'd be interested in getting some more data (although the decreased wireless performance does not bother me *too* much.) Stay well and thanks in advance!

I don't think one can use "bars" from the wireless client as a precise way to measure strength. (four bars in one program could be the same or less than 2 bars in another). I think at a minimum you would need to compare transmission power or some other numeric value in (dBm) between the cards/drivers/clients in order to draw a better view of what might be happening.

If anything, since your atheros is pulling in more networks that the intel could be capable of seeing, then that alone might infer that the atheros has better range.

It has been my experience that much of the advantages of the atheros cards had over the intel cards was eroded when intel released the version 9.x drivers in summer 2006. We now use the intels exclusively at work in our Dell Latitudes. Both Atheros and Intel made some good wifi cards/drivers these days indeed.

Thanks for your reply! Can anyone here suggest a program that I can use to accurately measure wireless reception? And can anyone else chime in on their T4x versus T61 wireless reception experiences? I'd like to try to test Lenovo's claim that the plastic lid on the T61 is better for wireless reception than the magnesium lids on the T4x series. Many thanks again, friends.

Bottom line is a file transfer of some sort. Just run one of those "How fast is my Internet" tests online over and over at farther and farther distances until you notice a significant drop in speed.

The much loved/hated Access Connections measure signal strength in percent. Might that be one way to compare apples to apples?

newt43 wrote:Thanks for your reply! Can anyone here suggest a program that I can use to accurately measure wireless reception? And can anyone else chime in on their T4x versus T61 wireless reception experiences? I'd like to try to test Lenovo's claim that the plastic lid on the T61 is better for wireless reception than the magnesium lids on the T4x series. Many thanks again, friends.

I am running Tomato firmware in my Buffalo Wireless Router. The Tomato firmware lets you look at all the wireless devices connecting to your router and shows their signal strength in dBm. I just set up a T42 for my daughter to take back to Paraguay with her, and while doing so, noticed that my T61 had a far higher signal strength when placed side-by-side. Tomato shows RSSI in dBm. I believe my T61 was typically in the mid to high -30s (~-35-37dBm), while the T42 was running in the -70s to -80s a lot of the time. However, there seemed to be a problem with this T42's wireless antenna, card or software. I took it apart to make sure the antenna was properly connected, which it was, so I did not really figure out why the signal was so low. I also tested a T30 with an 802.11b card, and the T61 had a considerably better signal than the T30 did as well.

google netstumbler...download and install on both machines...it will give you ssid, signal strength, snr...plus lots of other info on networks it can see

CYoung234 wrote:....I just set up a T42 for my daughter to take back to Paraguay with her, and while doing so, noticed that my T61 had a far higher signal strength when placed side-by-side.

That was a good informative, detailed, post...thanks.

But bear in mind that the wavelength of Wifi is measured in -inches-.

And in a multi-path situation (actually very very common in most indoor spaces) two seperate bounce path signals can cancel at the receiving end, if one of the paths is longer by half a wavelength, so that one signal arrives 180-deg out of phase with the other.

What I'm trying to say is that, at these frequencies, moving a device by just -inches- can change the received signal-strength drastically.

So....a "side by side" is in reality the exact opposite...it sounds like 'identical' but in this case is 'the two positions aren't at all equal/identical/equivalent".

The only way to do a true 'side by side' is to put the 2nd test computer in the exact same position as the 1st, then run the tests.

You'll notice the same effect on cellphones, where if you slowly move the phone while watching the sig-meter, you'll see it go from 25% to 75% just by moving the phone 9 inches. Move it 9 inches further, and the sig drops down to 25% again.

The phone antenna is moving into a 'null' every half-wavelength...

PS: this is precisely what 'Diversity' antennas are about...and for.

They are spaced an integral multiple of half-wavelengths apart. Thus, when one ant. is in a 'null', the other has a high probability of being at a peak.

The radio (wifi card) is constantly measuring sig-levels on both ports (ants), and switches when the difference rises above a chosen threshold.

newt43 wrote:Thanks for your reply! Can anyone here suggest a program that I can use to accurately measure wireless reception?

If running xp google for netstumbler. If vista look for vistumbler.