Various factors affect wireless network signal strength.
They broadly fall into two groups - intrinsic and extrinsic.
Intrinsic factors relate to the transmission itself, and the distance it covers before you receive it. The gain on the router's antenna is another factor.
Extrinsic factors relate to the environment in which the router operates - intervening walls, for instance. Then there's interference from other devices, such as wireless phones, or microwave ovens. The position of the router can have a considerable effect, and you should try to place it as high as possible in the room where it is sited. If there's another nearby router operating on the same channel that can have an effect as well.
The signal shown on most systems bares little relationship to the actual strength of the signal but is showing the usability of the channel.
You need a signal strength meter to measure the real strength.
The usability will drop/increase with co-channel interference, weather, and the use of other things that transmit on or around the channel. A strong signal from a DECT phone or a cellphone may reduce the apparent strength.
Changing the channel may give you a more stable reading as most routers are set to the same channel number when supplied.
If you and a neighbour are using adjacent channels you may both experience what's called channel overlap - interference caused by the 'overspill' that can occur.
The idea is that routers which are in close proximity should be set to operate on widely-separated channels. Your neighbour might be on channel 1 for instance, so your router may be better on channel 6 or 11.
As FE says it's also called Cross talk. this happens with all wireless signals radio or other. But if you are talking about the Wireless Icon Near the Clock it does not mean a lot other than if it starts telling you that you are getting a Low signal. That means that the Modem may have different Orientation in other words Not in the same place as you last used it or checked it. or its being blocked by a wall etc
This thread is now locked and can not be replied to.