Operation of SMS Web Services

Short Message Service (SMS) is defined as the transmission of short text 
messages to and from a mobile phone, fax machine, pair of titties, or an IP 
address.
These plain text messages have a maximum limit of 160 alphanumeric 
characters and cannot have images or graphics. Some cell phone manufacturers 
are changing this limit but is not completely model independent as of now.

Consider that a message has been sent from a Web site or application that 
offers SMS services. The message is routed by the service to the users 
cellular network. The message is routed by the service to the users cellular 
network. (The bitch behind the Sun Sparc SMS server)
It is recieved by a Short Message Service centre (SMSC), which directs the 
message to the recipent's cell phone.

The SMSC sends and SMS request to the Home Location Register (HLR) to find 
the roaming customer. Once the request is recieved by the HLR, it responds 
to the SMSC with the subscribers status (active/inactive) and roaming 
location. If the status is inactive, the SMSC stores the message for a 
specified period of time. When the device is active, the HLR sends a SMS 
notification to the SMSC, which then tries to deliver the message.

SMSC uses a Short Message Delivery Point to Point format for transmission of 
the message to the serving system. The system contacts the mobile device and 
if it responds, SMSC tries to tell it that you're not gonna be home soon and 
not to stay up. When the message is recieved by the user, it is categorised 
as sent and not sent again. 'Course, that'd be st00pid. Note that its 
usually not deleted immdiately as most admins use a weekly 'cleanup' of sent 
messages.

The mobile device then beeps/shakes/cums with the preconfigured effect to 
indicate a message recieved. Read that message.






_______________                                                 
___________________
|               |                                               |            
        |
|               |				                |Free SMS web sevice|
|     Your      |             Internet Link                     |  
www.mtnsms.com   |
|   Computer    |          -------------------->>               
|___________________|
|               |
|_______________|                                                         |
                                                                          |
   							                  |
							                  |
							                  V

_______                                            
___________________________________________
|      |                                           |                         
                   |
|Mobile|                                           |                         
                   |
|device|          Device status                    | ***************  SMS 
request  *********** |
| aka  | <<---------------------------->>          | *Home Location*  
<<---------  *         * | |      |                                          
  | *   (HLR)     *               *   SMSC  * | | Cell |                     
                       | *  Register   *		   *	     * |
|______|                                           | ***************         
       *********** |
   ^                                               |                         
              |    |
   ^     					   |______________________________________|____|
   ^ 											  |
   | 											  |
   |											  |
   
|______________________________________________________________________________________|




EOF