I have a company pager and a personal cell phone.
I usually leave my cell phone off. My wife calls me on the pager and I turn on the cell phone and return her call.
BTW, the company doesn't have my cell number.
As long as the battery is in the cell phone as you go from one cell to the next the cellphone tells the cell that you are in the cell not exactly where within the cell but still that you are in a specific cell.