Disruptive Technologies, Education and Some Social Issues » how sms works http://www.kenneyjacob.com Disruptive Technologies, Modern Education, Shrouded Social Issues and Dirty media propaganda Fri, 25 Nov 2011 10:52:17 +0000 en hourly 1 http://wordpress.org/?v=3.2.1 How SMS Works http://www.kenneyjacob.com/2007/06/19/how-sms-works/ http://www.kenneyjacob.com/2007/06/19/how-sms-works/#comments Tue, 19 Jun 2007 16:02:40 +0000 Kenney Jacob http://www.kenneyjacob.com/2007/06/19/how-sms-works/ SMSC in a GSM network.

Finally the picture is mine. Took me 30 mins.

BTS – Base Transceiver Station (Antenna)

BSC – Base Station Controller

MSC – Mobile Switching center

HLR- Home Location Register

VLR – Visitor Location Register

SMSC – Short Message Service Center

When a user sends an SMS, the request is placed via the MSC. The MSC forwards the SMS to the SMSC where it gets stored. The SMSC queries the HLR to find out where the destination mobile is and forwards the message to the destination MSC if the destination mobile is available. If the mobile is not available the message gets stored in the current SMSC itself. In most installations If a mobile is not available for SMS delivery the SMSC will not retry. Instead the destination MSC will inform the SMSC when the mobile comes back in range.

SMS handling is a store and forward operation unlike USSD.

SMS has got a validity period, for which it will wait for the destination mobile to the available. After that time the SMSC will delete the message.  The validity period can be set by the user. Normal validity is 1 day.Similar Posts:

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