What is SMS? - Short Message Service (SMS) is the ability to send and receive short alphanumeric messages to and from mobile telephones. SMS can also be used as a transport for binary payloads and to implement the WAP stack on top of the SMSC bear. SMS was created as part of the GSM Phase 1 standard.

Why use SMS? - SMS allows users to directly transmit messages to each other without the use of an operator (it is, however, necessary to have the underlying operator controlled wireless service). The first user can send a message to a mobile unit, via a direct connect computer. The SMS protocol of messaging is also "smarter" then standard paging. SMS is a store and forward method therefore, if the end user is not available, the mobile unit is powered off, or the unit is outside a service area, when the unit comes back on line the message will appear. A SMS message can also be sent "certified," where it will notify the message originator of the end user's receipt of the message.

How would you send an SMS Message over the Internet? - The front-end would simply be a section for the message (limit) and a destination address (mobile number). Then, based on your architecture, a lower layer would have to create the correct message based on the request or the message is generate server side. In the case of an end-user sending a message to a mobile unit, it would be a SMS-DELIVER message. Then entire message would then be "encapsulated" in a TCP/IP message and send to the appropriate Short Message Service Centre (SMSC). The MSC would then remove the TCP/IP layer from the message and process the message as if it were generated locally by an operator.