From the home screen, select Apps (located in the lower-right).
From the APPS tab, select Settings.
From the SYSTEM section, select About phone.
View the following information:
The RSSI (Received Signal Strength Indication) should be greater than -58 dBm (e.g. -32 dBm). A value of -96 dBm indicates no signal. If the signal is between -82 dBm and -96 dBm, move the device to an alternate location (an outdoor location is preferable).