Linux diskless os using rf?

I'm having problems with nfs using udp to load an os from a hp unix server to mobile Linux Redhat device using rf (802.11b). I have all the network configurations in the etc hosts file, because it works about 25% of the time, the other 75% of the times, I make conncetion to the server and do not load all the information correctly, and the application fails to start on the mobile device. I thought maybe using TCP instead of UDP would resolve the issue, but I'm not entirely sure whats causing the issue, or how to force the nfs settings to TCP vs UDP.

Can anyone point me in the right direction on this?