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Review of UMTS
work Architecture
The European/Japanese 3G standard is referred to as UMTS. UMTS is one of a number of standards ratified by the ITU-T under the umbrella of IMT-2000. It is currently the dominant standard, with the US CDMA2000 standard gaining ground, particularly with operators that have deployed cdmaOne as their 2G technology. At time of writing,Japan is the most advanced in terms of work deployment. The three incumbent operators there have implemented three different technologies: J-Phone is using UMTS,KDDI has a work, and the largest operator NTT o is using a system branded as FOMA (Freedom of Multimedia Access). FOMA is based on the original UMTS proposal, prior to its harmonization and standardization.
The UMTS standard is specified as a migration from the second generation GSM standard to UMTS via the General Packet Radio System (GPRS) and Enhanced Data for Global Evolution (EDGE), as shown in Figure. This is a sound rationale since as of April 2003, there were over 847 Million GSM subscribers worldwide1, accounting for
68% of the global cellular subscriber figures. The emphasis is on keeping as much of
the work as possible to operate with the new system.
We are now well on the road towards Third Generation (3G), where work will support all traffic types: voice, video and data, and we should see an eventual explosion in the services available on the mobile device. The driving technology for this is the IP protocol. Many cellular operators are now at a position referred to as , with the deployment of GPRS, which introduces an IP backbone into the mobile diagram below, Figure 2, shows an overview of the ponents in a work, and how it fits into the existing GSM infrastructure.
The interface between the SGSN and GGSN is known as the Gn interface and uses the GPRS tunneling protocol (GTP, discussed later). The primary reason for the introduction of this infrastructure is to offer connections to external works, such as the or