3G Mobile Network Architecture and Security Features

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Introduction

3G or 3rd generation is technology for mobile network is based on the IMT-2000 standards according to specification by International Telecommunication Union(ITU). It helps users in getting greater network capacity Through improved spectrum efficiency like video calls, broadband wireless data, music downloads, receiving streaming video from the Web, sending and receiving faxes, instantly downloading e-mail messages with attachments etc. 3G networks have potential transfer speeds of up to 3 Mbps (it takes around 15 seconds to download a 3-minute MP3 song). And if we compare the fastest 2G phone which can achieve up to 144Kbps(i.e. It takes around 8 minutes to download a 3-minute song) 3G speed much faster than it.
They are intended to provide a global mobility. In 1998 Third Generation Partnership Project (3GPP) was formed for the technical specification work.



. UMTS network elements and interfaces

The core network is divided logically into two domains circuit-switched (CS) and packet-switched (PS). The CS domains work is to handle circuit-switched connections, and the PS domains work is to handle the packet transfer. The core network of CS is built around Mobile Switching Centers (MSC) and the core network of PS around Serving GPRS Support Nodes (SGSN). The various registers of core network are common in both the domains. But Visitor Location Register (VLR) is typically employed by CS domain only. Note that not all the interfaces shown and named in figure A above and also the list of network elements in not comprehensive.


Visitor Location Register (VLR) – The visitor location register keeps the information about visitor in an area under particular MSC. One VLR can handles the visitor register of several MSC. It contain information of all the active subscribers in its area. It keep the record of all those subscribers also whose network is their home network. Thus the visitor location register name is little misleading as most of the user entries are from home network only. It has similar information as that of the home location register (HLR). But VLR keeps information which are keep on changing or temporarily in nature, whereas HCR is a permanent information storage. When a user make his subscription, his data in entered into his home HLR. Same is copied into VLR of that location. When user moves from location A to location B