GPRS Call Back Mobile GPRS Mobile enables the customer to save money on their long distance charges. Just simply dial the number on the handset just like any other cell phone. No access number is required! How it works: By using our special handset, once you have dialed your desired number, the phone will submit a very small GPRS packet* to our system to invite the recipient. Once the recipient is connected, you will receive an incoming call from the number you have dialed. This product is best for customers with free incoming call options or service providers with one-way billing. *GPRS connection from your service provider is required.