Verify a strong wireless signal is being received by your device.
INSTRUCTIONS & INFO
Ensure the antenna is in an upright position.
Check the color of the signal strength LED; if it is green the AT&T Wireless Home Phone is receiving a strong signal.
A yellow signal strength LED indicates moderate signal strength, which may be adequate; however moving the WHP Base Unit to an alternate location with better reception (usually near a window or exterior wall) is recommended.