Setting test mode on the Gigaset handsets can be very useful. Detailed here is how to set a handset into test mode and what the numbers then mean. Once set go off on a walk round your site to find dead spots. Then change the base position to get the best coverage
The above screen Shows RX power at 100% , Frequency is 3 , TimeSlot is 02, Basestation code is 78 and finally Bit error rate is 100% (This means 100% Good not 100% error rate)
A short document on Setting test mode on Gigaset dect handsets for site surveys is available for download here. This shows you how to enable it and what each of the numbers mean.