It was developed to facilitate a more efficient way for operators to interconnect networks, and played a large part in the transition to third-generation systems.
In 2000 the GSMA (GSM Association) developed the idea of GRX to handle all roaming between public land mobile networks (PLMNs).
[1] Usually, GRX is based on a private or public IP backbone and uses GPRS Tunnelling Protocol on the session layer (OSI Layer Five) between the visited PLMN (Public Land Mobile Network) and the home PLMN.
The GRX operator can therefore act as a hub, allowing a GPRS subscriber to interconnect with many roaming partners without the need for dedicated links.
For operators this is advantageous in that it allows quicker implementation of roaming partners, faster time to market for new operators and lower capital expenditure seeing as it is a scalable solution depending on bandwidth and quality of service requirements.