Dell TrueMobile 1180 User Manual page 34

The quality of the connection (signal strength) is indicated graphically by the color of the vertical bars in the TrueMobile
1180 Wireless Utility icon and is indicated verbally by the description (in this case, Excellent).
Three vertical green bars indicate that the signal strength is very good or excellent.
Two vertical green bars indicate that the signal is good.
Two vertical yellow bars indicate that the signal strength is marginal.
Suggested action: Move closer to the access point.