Hi,

When I make a cellphone call from say Louisiana to California, how is the call transmitted: I am interested in knowing the exact details. How many base stations may be involved and when? When are wireless and wired mediums used? Is the method of transmission similar to that of a landline telephone?

Suppose the person in California is visiting Colarado and has roaming option, how is the call transmitted to him/here in Colarado instead of California? i.e how is the location information obtained and call diverted to Colarado instead of California? I am interested in knowing the technical details as accurately as possible.

Thanks...

Cell phones constantly send data to the towers, indicating that they are online and ready for a call. The tower receives the signal and sends the data to the switching office for that carrier. When you move from city to city, the switching office keeps up with your location. When you roam onto another carrier, the same happens. When someone calls your #, the switching office knows where your phone is, since your location is constantly updated.