Blogger Tricks

12 May 2012

SMS & SMSC Overview

SMS Types:

• Mobile Originated SMS
• Mobile Terminated SMS
• Application Originated SMS
• Application terminated SMS

• SMS is a globally accepted wireless service that enables the transmission of alphanumeric messages between mobile subscribers and external systems such as e-mail, paging and voice mail systems.

• SMSC is a server which serves as a main controller for routing of Short messages and for storing and forwarding of SMS.



• Reasons why SMSC is required?
  •  Routing of SMS
  •  Temporary storage
  •  Retries
  •  Value added service on SMS
  •  Interconnect mechanisms for various services like Paging, VMS,E-mail, etc.
SMS Routing in GSM:


SMSC Implementation:

There are two ways to implement the SMSC server in GSM network.

1. SMSC server itself having Gateway functionality.
2. SMSC server only for storing and forwarding and MSC is having Gateway functionality.

(1).SMSC - 1



> In this set up the SMSC server is connected to MSC via ss7 signaling links and talks on MAP layer.

The SMSC server itself performs the SMS routing functionality and sends and receives MAP layer messages.



Advantage



Since the SMSC itself is doing the routing, it becomes very easy to troubleshoot various SMS routing related problems.

Disadvantage

High number of signaling links required to handle high SMS traffic. Hence it requires costly SS7 cards and stacks in the SMSC server itself.

(2).SMSC - 2

> In this set up the SMSC is connected with MSC on TCP/IP links.
>This set up with SMSC is only possible with Nokia MSC. It is not supported with other vendor’s MSC.

Advantage:

> Very less number of TCP/IP links can cater to very high SMS traffic.

Disadvantage:

The functionality of SMSC server is restricted to only store and forward. It is also very difficult to resolve routing related functionalities as MSC is doing the same.