Short Message Service Center Computer Science Essay

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.


Nowadays, SMS which defined as short messaging services is a communication technology that widely used. SMS plays an important role in many people daily lives, especially the younger generations. The users of SMS is growing rapidly from day to day, there are almost 3.5 trillion of SMS messages are exchanged in 2008 as indicated by Portio Research(2008).

SMS is available for most mobile phone and it does not require to download any software for used it. A single SMS can support up to 160 characters and those characters can be in words or numbers or an alphanumeric combination.

SMS is a universal data service and is supported on GSM, TDMA, and CDMA networks. An SMS message can originate from an external system such as e-mail or mobile device and is routed through the network, via the short messaging service center (SMSC), to its destination.SMS is able to deliver messages in any time, regardless of whether phone calls is in progress.

SMS is store and forward service which means the message will pass through the SMS Center before it is delivery to the recipient and it has one or more messaging centers to manage and handle the SMS for each mobile network. Therefore SMS is reliable in delivery of the message. Even though the recipient is temporary unavailable for receiving the message due to the signal issue or the recipient mobile devices is off.

A SMS is able to send to many people at a time, and it has the features of confirmation of message delivery, which is means by the sender will received a notification message when the message is successfully delivery to the recipient.

2.0 Network Elements and Architecture

Short Messaging Entities (SME)

SME is an entity that may receive or send short messages. The SME may be located in a mobile station, fixed network or another service center.

Short Message Service Center (SMSC)

Short message service center (SMSC) is responsible for handling the SMS operation such as relaying and store-and forwarding of a short message between an SME and mobile station. Every SMS message that sent out from a mobile phone will reach the SMS center first before forward to the destination. The main responsibility of SMSC is to route the SMS messages and regulate the process. The SMSC will store the SMS message if the recipient is unavailable such as the mobile phone of recipient is switched off or out of signal, while the recipient is available, the SMSC will forward the SMS message to the recipient.

SMS-Gateway/Interworking Mobile Switching Center (GMSC/ IWMSC)

The SMS gateway MSC (SMS-GMSC) is an MSC capable of receiving a short message

from an SMSC, interrogating a home location register (HLR) for routing information, and

delivering the short message to the "visited" MSC of the recipient mobile station.

The SMS interworking MSC (SMS-IWMSC) is an MSC capable of receiving a short

message from the mobile network and submitting it to the appropriate SMSC. The SMSGMSC/SMS-IWMSC are typically integrated with the SMSC.

Home Location Register (HLR)

HLR is a database that used for management and serve as permanent storage to store the subscriptions and service profiles. Upon interrogation by the SMSC, the HLR provides the routing information for the indicated subscriber. The HLR also informs the SMSC, which has previously initiated unsuccessful short message delivery attempts to a specific mobile station, that the mobile station is now recognized by the mobile network to be accessible.

Visitor Location Register (VLR)

VLR is a database that contains temporary information about subscribers that needed by the MSC in order to service visiting subscribers.

Mobile Switching Center (MSC)

MSC performs the switching functions of the system and controls calls to and from other telephone and data systems.

Base Station System (BSS)

All radio-related functions are performed in the base station system (BSS). The BSS

consists of base station controllers (BSCs) and the base transceiver stations (BTSs), and

its primary responsibility is to transmit voice and data traffic between the mobile stations.

Mobile Station (MS)

The mobile station (MS) is the wireless terminal capable of receiving and originating short messages as well as voice calls. The wireless network signaling infrastructure is based on Signaling System No 7 (SS7). SMS makes use of the mobile application part (MAP) which defines the methods and mechanisms of communication in wireless networks, and uses the services of the SS7 transaction capabilities application part (TCAP). An SMS service layer makes use of the MAP signaling capabilities and enables the transfer of short messages between the peer entities.