Hi, I don’t have info on any studies of the type that you asked about, but I can give you some general information.
1. The PDAs won’t have the same receiver sensitivity as the laptops. Consequently, a signal that is strong enough for the laptop may not be strong enough for the PDA to maintain a reliable connection, even when they are both on the same desk.
2. PDAs are more susceptible to interference than laptops. This is simply a matter of physics. The smaller receivers have minimal filtering capabilities. So, if you have 2.4 GHz cordless phones, 2.4 GHz wireless mice, etc., the possibility of interference on the PDAs is greater.
3. For troubleshooting purposes, test the PDAs in other wireless networks and compare the results. If they are stable on other networks, it will be an indication of a local, correctable problem.
Hope this gives you a starting place. –Bob Young