... 2479MHz 2,Transfer rate:250 wireless voice doorbell with clear voice for hot sell 1V21,2.4G ISM Public ... 20dBm(100mw)4,AFH Adaptive Frequency Hopping technology, with wireless LAN and Bluetooth devices share 2.4G band ... then the CALL button, enter the main CALL with the red lightB:No response signal 4 seconds means ... can hang up on the call of the process. E:The indoor monitor is busy, then drops twice, ...