Change the General Packet Radio Service settings on an Android mobile phone by going to the settings menu, selecting the Networks option, choosing the Mobile Networks menu, and pressing the Network Mode. You can then set your phone to operate only on GSM networks, or to automatically switch between GSM and CDMA networks.
GPRS is a technology that works with GSM mobile telephone networks to let mobile phone users send and receive data by browsing the Internet, in addition to using voice service. GSM mobile networks are second- generation mobile phone technology that use circuit-switched technology, which operates by dedicating an open switch to a single user. GSM was designed for voice service. GPRS, which is a packet-switched technology, is faster than circuit-switched technology and allows the network to remain on all the time. Those characteristics facilitate faster data transfer rates for users.
The GPRS setting on an iPhone can be changed by going to the Settings menu, opening the Cellular menu, selecting the Cellular Data option, and changing the network. One reason to change or turn off the GPRS option on a mobile phone is to avoid being charged for using networks outside of the user's home service area.