Chapter 7, Problem P16P

Program Plan Intro

MSC:

• MSC stands for Mobile Switching Center that will connects calls by switching the digital voice data packets from one network to another network.
• It will also give the data that is required to support mobile service benefactors.

HLR in GSM network:

• The HLR stands for Home Location Register; it is the reference database for benefactor parameters.
• The Home Location Register is an integral component of Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA) and Global System for Mobile Communications (GSM) network.
• It maintain the benefactor information like user name, address, account status, phone number etc.
• If the mobile user is currently roaming in another network, the HLR contains enough data to obtain an address in the visited network to which a call to the mobile user should be routed.

VLR in GSM network:

• The VLR stands for Visitor Location Register; it has a copy of the data which is stored at the HLR.
• The database of VLR contains some duplicate data and also more precise data related to the benefactor remaining contained by the VLR coverage.
• The VLR entries come and go as mobile users enter and leave the network.
• It is normally co-located with the MSC that coordinates the setup of a call from and to the visited network.