GPRS

From Mobileradicals

What is GPRS ?

The General Packet Radio Service is an essential part of the migration of existing GSM services to 3G and provides not only the provision of packet data into the network, it allows the user to have a constant connection to the internet, and it provides the evolutionary path for GSM to 3G.

In circuit switched systems users have to connect to the data service and are charged for as long as they stay connected, regardless of whether they fully utilise the link or not. This leads to a situation where users must go through the long connection and verification procedure every time they wish to access data. In packet data systems where capacity is allocated as and when it is required, consumers are only charged by the amount of data they transmit and receive. This means the system can allow users to remain logged into the network as long as their phone is switched on.

GPRS adds two new hardware elements to the existing GSM system to support packet data, these being the Serving GPRS Support Node (SGSN), which controls the routing of packet data within the mobile network, and the Gateway GPRS Support Node (GGSN) which connects the mobile network to the general internet infrastructure. Packet data is therefore added within the same GSM structure and is separated from voice traffic at the Base station controller which has a new hardware element, the packet data control unit, to achieve this purpose. All other changes are achieved through software so that GPRS was a very cost effective upgrade as no physical changes were required at the base-stations which would have been a very labour intensive.