We are building a Location based service using SMS.

I wanted to know that if such a service is deployed by any service provider.

our service is receiving some kind of requests through SMS, and in addition to the SMS text can the network provide some information to the application that handles requests about the location from which the SMS was sent.

like can it tell us that from which city was the SMS sent or may be in which the cell the phone is currently. do network service providers provide such information.

we basically want to provide location based services to those customers who do not have a smartphone with GPS capability. what kind of protocol would we be required to use to get the information about the origin of the sms.