Wireless LAN connection lost

Hello!

We have this problem for quite a long time now: fork lifter using a wireless terminal pc are losing their connection to the wireless lan when driving through our company. What I figured out so far is that "roaming" isn´t working perfectly. If I run a ping for a few minutes, SAP GUI loses the connection as soon as two pings are missing. When the overall network connection is back after these two missing pings everything is working again, with the exception of SAP GUI. Windows is working, network is working, Ping is working, only SAP GUI has lost the entire session. Why is SAP GUI so ****?

Thanks for any help!