GPRS Services

The bearer services of GPRS offer end-to-end packet switched data transfer. Of the two types of bearer services offered by GPRS only the point-to-point (PTP) service is available now and the point-to-multipoint (PTM) service will be made available in future releases of GPRS.

The PTP service offers transfer of data packets between two users. It is offered in both connectionless mode (PTP connectionless network service (PTP-CLNS), e.g., for IP) and connection-oriented mode (PTP connection-oriented network service (PTP-CONS), e.g., for X.25).

The PTM service offers transfer of data packets from one user to multiple users. There exist two kinds of PTM services:

• Using the multicast service PTM-M, data packets are broadcast in a certain geographical area. A group identifier indicates whether the packets are intended for all users or for a group of users.
• Using the group call service PTM-G, data packets are addressed to a group of users (PTM group) and are sent out in geographical areas where the group members are currently located.

It is also possible to send SMS over GPRS. In fact the 160 character limit in GPRS is not applicable in GPRS as in GSM. It is also planned to have other supplementary services like call forwarding unconditional (CFU), call forwarding on mobile subscriber not reachable (CFNRc), and closed user group (CUG).

Moreover, a GPRS service provider may provide a number of other non-standardized services built over IP like access to databases, messaging service, electronic monitoring and surveillance systems, whether forecast, traffic information broadcast etc.

GPRS also provides the facility to use both packet and circuit switched services simultaneously depending upon the class of the MS. Class A can use both services simultaneously, class B can register for both but use only one at a time whereas class C can at a time attach for only one type of service.