Method and system for applying a multi-protocol label switching network in general packet radio service

A system for applying a multi-protocol label switching (MPLS) network in general packet radio service (GPRS), the MPLS network being established by multiple differentiated service (DS) domains, each DS domain constructed by multiple label switching routers (LSRs) and label edge routers (LERs), the system comprising:

• at least a LER for use as a service GPRS supporting node (SGSN) connected to a wireless network base station, the SGSN interfacing to the LSR of its DS domain via a Gn interface;
• and
• at least a LER for use as a gateway GPRS supporting node (GGSN) connected to a packet switching network, the GGSN interfacing to the LSR of its DS domain via the Gn interface,
• wherein the Gn interface at a signalling plane between two SGSNs, between two GGSNs, or between a SGSN and a GGSN has a protocol stack including a physical layer, a MPLS layer and a RSVP/GTP layer from bottom to top, so as to utilize IP addresses of all SGSNs and GGSNs to establish all one-to-one pre-created label switching paths (LSPs) in the MPLS network of a GPRS backbone network in an initial state;
• the Gn interface at a transmission plane for GGSN has a protocol stack including a physical layer, a MPLS layer, a GTP layer and an IP layer from bottom to top;
• the Gn interface at a transmission plane for SGSN has a protocol stack including a physical layer, a MPLS layer, a GTP layer and a relay layer from bottom to top, so as to transmit packets between SGSN and GGSN by pre-created LSP and LSP tunneling.