SMS GATEWAY

WHAT IS A SMS GATEWAY?
SMS Gateway is an interface between software applications mobile networks. An SMS Gateway allows interfacing software applications to send and/or receive SMS messages over mobile network.
Typically a SMS Gateway uses either one or more GSM modems or a direct network connection (HTTP(S), SMPP, CIMD etc) with the SMSC to send and receive messages to and from mobile networks. Software applications generally interface with the SMS Gateway either using ASCII text files, XML/SOAP or database tables. A good SMS gateway will

provide the developer with an ActiveX component or an API to interact with the gateway to read/write SMS messages, thus reducing the development time for implementing mobile messaging features in software applications
NEED OF SMS GATEWAY
One problem of SMS messaging is that SMSCs developed by different companies use their own communication protocol and most of these protocols are proprietary. For example, Nokia has an SMSC protocol called CIMD whereas another SMSC vendor, CMG, has an SMSC protocol called EMI. We cannot connect two SMSCs if they do not support a common SMSC protocol. To deal with this problem, an SMS gateway is placed between two SMSCs. This is illustrated in the following figure. The SMS gateway acts as a relay between the two SMSCs. It translates one SMSC protocol to another one. This way can be used by two different wireless carriers to interconnect their SMSCs for purposes such as enabling the exchange of inter-operator SMS messages. An SMS gateway acts as a relay between two sms centres.
SMS COMMUNICATION
HOW TO USE MICROSOFT HYPERTERMINAL TO SEND AT COMMANDS TO A MOBILE PHONE OR GSM/GPRS MODEM?
Microsoft HyperTerminal is a small program that comes with Microsoft Windows. We can use it to send AT commands to your mobile phone or GSM/GPRS modem. It can be found at Start -> Programs -> Accessories -> Communications -> HyperTerminal. If there is a problem of not finding it then it means we are using Windows 98, and then probably we have not installed it. We can go to Control Panel -> Add/Remove Programs -> Windows Setup tab -> Communications list box item -> Details button to install MS HyperTerminal.