Signal strength is a measurement that expresses the quality or value of a particular signal at a certain distance from its source. This is often used in telecommunications with regard to radio or wireless network signals, either through a wide area network or a local one. It typically indicates numeric measurements regarding how powerful the signal is at a certain location, and the way in which these signals are measured can vary. Signal strength can also be discussed in terms of either a strong or weak signal in a particular area.
The term “signal strength” can be used to refer to many different types of signals, although it usually indicates the magnitude of some form of energy used to send information. Radio broadcasts, for example, can be received at different locations in a certain radius away from the source of the broadcast signal. The maximum range at which the broadcast can be received and listened to by someone with a radio receiver is based on signal strength. Locations closer to the origin of a signal typically receive it more strongly, while more distant locations may only receive a weak signal.
Professionals in telecommunications and scientists researching energy and different forms of signals often measure and evaluate signal strength using numerical values. These quantitative measurements indicate the strength of a signal using different scales, though a higher value typically indicates a stronger signal. Wireless network signals and powerful radio station broadcasts both can be similarly measured in terms of decibels (dB) or in milliwatts (mW).
These types of values are not typically meaningful for most customers or users of a network, however, and so signal strength is frequently communicated in general terms regarding qualitative values. This means that words like “strong” and “weak” are frequently used to describe the strength of a signal. Signal strength is often expressed in terms of “bars” for wireless phone signals. This is based on the visual interface on many phones that indicates the strength of a signal using a number of bars on the screen.
There are a number of different factors that can affect signal strength, including distance from a signal’s source and environmental obstructions. Someone may be able to receive a wireless phone signal from just outside his or her home, but entering the house or going downstairs into a basement may disrupt that signal. Energy waves used in telecommunications can typically be interfered with by other emissions or signals, which means that there can be other complications for a signal in some areas. Construction equipment or various electronic devices can all interfere with a signal and reduce its strength.