Internet Access Blocked By Lexus

atce4 · June 28, 2008

Whenever I visit a friends house both our laptops have problems connecting to his wireless router. We tried to eliminating things such as my mobile phone, my laptop, etc, but to no avail. Yesterday when I visited him the same problem occurred and it happened just as I arrived. I'm not his most popular visitor at the moment for obvious reasons so we decided to try and track down the source of the problem. He said that the only other common factor he could come up with is my car which I park on his driveway. I thought 'no way', how can my car cause this? So to humour him I said OK I'll move the car off the drive. Would you believe it ...the connection comes back straight away. So I move the car back onto the drive and still all is ok. That is until I lock the car and then the connection drops out. Unlock the car and all is well again....

Anyone any ideas what might be causing this? I can only think of the ultrasonic movement detector but surely that would be confined to the vehicle interior. Never have any wireless problems myself at home and the car is kept locked on my driveway

It all seems a bit wierd to me....

Geoffers · June 28, 2008

Its not the movement sensors - ultrasonic wouldn't interfere but they aren't ultrasonic anyway - they are microwave. The emitter side is a lot less than 2.4Ghz from memory so not even the same frequency. Besides, they are so low power even outside they would be absorbed very quickly so in the car they are going nowhere.

The control unit could theoretically interfere but its passive in the IS200 until it gets a signal from the remote. Only then does it negotiate. (Assuming you have the oem security system still)

Interesting one this one. Radio is a very difficult field to determine where the issues are.

It may not be the car electronics. Try it with the Battery off. (Don't forget it will reset your radio stations, ecu, etc.)

Where is the router physically? Could be the carrier bouncing and the error rate is just to high.

Have you tried different channels? Your car could also be acting to direct a neighbours signal. Not enough to negotiate so you may not see it, but enough to interfere. Again the car could be reflecting from a portable phone base station, etc.

If your neighbour has a wireless network, it wouldn't be surprising that they are already using channel 1 and channel 11. Unfortunately, you can't completely avoid interference just by using other channels. Wireless protocols 802.11b and 11g only have 3 non-overlapping

channels. (1,6 and 11) Therefore when 4 or more channels are used in the same area, the level of interference can increase notably.

Try physically moving the router if possible. Try the Battery off the car (to see if you are emitting something). Try switching off other electronic equipment.

If you could see how the electromagnetic fields change with their environment you'd be very surprised it works at all sometimes!

Yaumeister · June 28, 2008

This is oddly not the first time I heard of this, I think Lazyboy reported the same problem a while back.

You two should compare wireless router brand and maybe frequency channel, might be able to find a common cause.

Dego · June 28, 2008

My Belkin wireless router has a safe mode for operation in areas of high RF traffic and pre-existing wireless networks, it is maybe worth looking to see if your router has a similar capability.

atce4 · June 28, 2008

Thanks for all your very helpful comments and suggestions.

My friend has no problems with his wireless connection at all when I'm not there despite there being a number of other users nearby. He also parks his Focus in the same spot and again no problems. I think that I can probably eliminate reflections from various sources as this problem only happens when my car is locked, not when it is left unlocked. Also I'm not sure what disconnecting the Battery would actually prove since I know all is ok when the car is unlocked?

I also forgot to mention in my original post that moving the laptops to the rear of the house normally restores the connection to the router so it seems that the interference may only be affecting the laptops; not sure moving the router would help but it's probably worth a try. Also I will try different channels too.

Again, thanks for the help... will try and keep you posted :)

Geoffers · June 28, 2008

Also I'm not sure what disconnecting the battery would actually prove since I know all is ok when the car is unlocked?

You are right - nothing. I missed that bit when I first read it. Although locking the car will change the groundplane properties. Its not going to prove anything because you have multiple things creating the same outcome.

I also forgot to mention in my original post that moving the laptops to the rear of the house normally restores the connection to the router so it seems that the interference may only be affecting the laptops; not sure moving the router would help but it's probably worth a try. Also I will try different channels too.
Again, thanks for the help... will try and keep you posted :)

Where is the router? Could it just be a narrow band of interference and the laptops are in between it?

Best thing is to wrap the house in tin foil. It will keep it cool in the summer too. :D

atce4 · June 28, 2008

This is oddly not the first time I heard of this, I think Lazyboy reported the same problem a while back.
You two should compare wireless router brand and maybe frequency channel, might be able to find a common cause.

Thanks Yaumeister, I found Lazyboys post but unfortunately no further information there. I have linked to this thread as it might help him too

I have done a bit more searching and found this interesting clip on YouTube... http://uk.youtube.com/watch?v=A0oF0eq6mPI

The last 15 seconds or so are rather revealing and may well have got to the bottom of this riddle or at least a logical explanation :)

MacRS200 · June 29, 2008

I have done a bit more searching and found this interesting clip on YouTube... http://uk.youtube.com/watch?v=A0oF0eq6mPI
The last 15 seconds or so are rather revealing and may well have got to the bottom of this riddle or at least a logical explanation :)

Very interesting and a bit wierd, what's transmitting in the car?

atce4 · June 29, 2008

As the problem only seems to occur when the car is locked I think it is probably either the alarm control unit or the microwave movement sensors inside the car that are causing the interference.

Looks like wifi channel 9 is the one that gets most affected so changing to another one might help