If there is satellites and providing each smartphone signal for GPS why they dont use direct calling service? Why we need to install signal towers in every 1 kilometer of city/town?
GPS satellites provide a relatively 'weak' 'low bandwidth' 'unidirectional' signal.
This is sufficient for positioning purposes, but not for (data intensive, bidirectional) voice or data services.
It is, of course, possible to provide data/voice via satellite (see cruise ships), but the antenna/power requirements/price simply don't fit consumer phones.
Longer distance => more power, less bandwidth, more expensive => "signal towers in every 1 kilometer" are more efficient than satellites
Then I found my answer these signal towers are only satellites those are getting our location like how far you are from tower and in which direction and these signal towers are benchmarks of any area I have attached image to clear my picture how I see things. (Ignore its funny look becoz I created in MS Paint)
You found an answer - unfortunately it is a wrong one.
GPS is independent of cell towers. GPS has been in place and working long before cell towers were able to provide adequate positioning services for end users.
These days mobile phones will draw on all available data (cell tower id, visible WLAN, GPS, ...; search for "Assisted GPS" or "Augmented GPS") to get your location. This will enhance accuracy and speed of detecting your location, but it they remain different systems/methods.
A signal tower doesn't really care, how far away you are. Your cell phone will determine which available signal tower provides the best service and use it (that's how an IMSI-Catcher works - be more "attractive" and guys will pick you over others ;-) ) - this is not about position (GPS) but signal strength/quality.
iC