What's the range of a wireless network?

wireless network design for two type
1- directional or Omni .so the range of wireless network depend on your design .
Omni depend on the frequence you use and the environment you have .Directional depend on the clearance between the antennas it may be one of three
1- LOS
2- nLOS3 NLOS after that you can get the max distance depend on the power of you device transmitter .

depend on your equipments some for meters and some for kilometers

this is a really wide area, because there are many elements govern the range for a wireless system, for example antenna type, antenna gain, frequancy of operation , tx power, antenna tilt, antenna Azimouth, ..etc.

I think its better if we ask this question for specific protocol or wireless application.

another example what is the average range of a GSM site ?

Thre's no range for wirless network just give the mone and iwill cover all earth with wirless

A wireless repeater is a stand-alone unit positioned within range of a wireless router or access point.
Repeaters (sometimes called "range expanders") serve as a two-way relay station for Wi-Fi signals.
Clients too far away from the original router or AP can instead associate with the same local wireless network through the repeater

From my side i will never count on the range of the wireless, i always count on the place and it's infrastructure, and with a good site survey you can determine the range of the wireless and the device that you want to select.
Regards

I guess one missing factor here which is the receiving device, so you need to understand the wireless client as the smartphone antenna and power is not equal to laptop wireless card, and the same for the other handheld devices, so even if your wireless access point is strong, don't forget the client range.

AROUND15 KM CIRCLE DIAMETER

Wireless communication depend on your equipments and line of site

Most802.11b/g have a range of around150-160 feet to300 -350 feet .
That range you will get when its a open area.
You can extend the range of the same device by connecting a directional antenna like8 dbi -10 dbi .
when u connect the same device with example10dbi directional antenna it will reach upto5-10 KM (Kilo - Meter).
So i wireless network it's all depend about the device selection and how you configure the devices..