PDA ADHOC ETHERNET WIRELESS DROPS OUT

[sfrosty]

I'm utilizing an AD-HOC computer to computer wireless Ethernet connection between my laptop and my PDA to transfer data between my laptop and PDA.

The LabVIEW application on the PDA runs great once I have a good wireless Ethernet radio connection! However, I am having continuous trouble with the wireless Ethernet radio connection. It can take minutes to finally establish connection at times, sometimes it won't connect for hours, sometimes it will connect immediately. The signal strength meter on the PDA will go from good to best to good to dropping out entirely. Some days it works great, connects quickly, and stays connected. Some days it hardly connects at all. It all appears only to happen in my work environment, which includes being in a building and also outside on a test track. I tried the system at home over a recent 4 day holiday. The system connected immediately, and stayed connected every time for the entire four days. I would shutdown and re-connect from time to time. Every time the response was excellent.

I'm thinking that I may be having some type of radio interference problem at work. I've tried 9 different broadcast frequencies to no avail. Is there a way of increasing the signal strength of the radio frequency being transmitted from the PDA? Something I'm missing?

The Dell Axim 51V PDA is running windows mobile with the latest bios upgrade. The latest bios version hasn't offered any soultion.   I also have the same issues with a  Dell Axim 3.1 PDA running pocket PC 2003.

[Conseils]

You don't say which WIFI you are using but the following is applicable to 54g and the older standard.

This is the nature of WIFI but you can improve matters.... If someone has one of those television transmitters that uses WIFI 2.4Ghz you are probably shot although I can report that the XBOX 360 controllers seem to exist very happily....

Set the data rate as low as possible to support the application and also set the Fragment Threshold and RTS thresholds lower (750 from 2500).

You may also find it helpfull to turn of auto channel hopping and fix the channel as well as turning off features such as pre-amble length detection and if there is a roaming decision parameter adjust it for distance rather than throughput. Turn it off if you can.

I also found that fixing IP addresses routes etc. seems to help as well and it seems more tolerant of drop outs as a result.

This is generally in the configuration parameters for the hardware.

This will need to be done at both ends.... I suspect however that an access point would be better as the antenna location will or should be optimised That's one reason why people use them. In an industrial context the best I have seen to date is the CISCO stuff but it costs....

Message Edité par Conseils le 05-13-2006 10:06 PM