SMS – Short Messaging Service is quite a buzz word in the developing community nowadays. When it comes to .NET environment, developers are really into it finding a solution for sending and receiving SMS from their web applications. Most of the web sites have a SMS feature that enables them to send a simple text to mobile numbers for instant correspondence. For its speed, accuracy and productivity, SMS is one of the most successful services among the various wireless services.
SMS is capable of delivering numerous data services to wireless devices, including voice-mail alerts, fax services, ring tones, games etc. A SMS may also be a TMS (Text-Messaging service). A wireless text message is a short string of up to 256 characters that can be sent to a mobile device.
Though the text messaging service was initially used with the PAGERS that support alpha-numeric numbers, it has found a place in the mobile phones also.
Many mobile wireless carriers have made it extremely difficult for developers to get into knowledge source of SMS and its features. They use different modes of handling SMS messages for many reasons. One of the reason is that the cost involved for the very message itself. Some carriers develop API for SMS that can send or receive SMS using the TCP/IP.Some others use protocols like Simple Network Paging Protocol (SNPP), the Wireless Communication Transport Protocol (WCTP), and the Short Message Peer to Peer (SMPP). Some carriers now expose a Simple Mail Transport Protocol (SMTP), an e-mail interface to send short text messages. In this case, the e-mail address will be the device's phone number or pager identification number, along with the wireless carrier's special domain. For example, a phone with Reliance service will have an e-mail address of 3135551212@mobile.Reliance.net.
Requirements for SMS integration with any application
The prerequisite for using the SMS capabilities is the
SMS gateway. You can have access to the SMS with mobile network(service providers), via a web interface or an API. They would supply you with a set of APIs that work with their SMS servers. Again, this involves a cost for sending messages and providing services.
Alternatively, there are a few mobile phone web sites that allow you to send/receive an SMS using their web site. You can develop a web page in ASP.NET that can be posted to that site for providing SMS services to your users. In India,
www.mantraway.com, www.mysmsaddress.com, are few websites that offer the SMS and related services for corporate and high volume SMSC links using SMPP
(Short Message Peer to Peer) communication protocol.
A SMSC (Short Message Service Center) regulates the message transfer to and from the mobile phones in GSM-networks. This includes not only short text messages but also fax, voice- or e-mails. It delivers the messages, temporarily stores them in case the respective recipient is currently not available and takes care of charging. There is at least one SMSC per network.
The third option is considering a subscription to a SMS webservice using which you can send or receive SMS in your application. Go to
www.webservicex.com, you can find a number of webservices that deals with SMS services. One of the most widely used service is available in
SMS services can be provided with the use of GPRS (General Packet Radio Service) that offers Internet email services. This would be the simplest form of providing SMS services in your applications.
GPRS facilitates continuous wireless connection to data networks and access to your favorite information and entertainment services. It allows mobile phones to be used for sending and receiving data over an Internet Protocol (IP)-based network. Besides SMS, other service protocols like WAP, MMS, SMS, Java and the PC dial-up (for example, Internet and e-mail) are also supported by GPRS.
Unlike SMS gateway services, Internet email services stores the messages using mailbox services. The emails are actually stored and the user gets a notification on their mobile phone and can then retrieve the full email by dialing in to collect it, forward it, and so on. Gateway services offers a wireless email platform wherein it simply translates the message from SMTP(the Internet email protocol) into SMS and sends to the SMS Center.
Most of the times, on receiving a new email, Internet email users do not get notifications on their mobile phones. They need to dial in periodically to check their mailbox. However, we can link the Internet email system with an alert mechanism such as SMS or GPRS, and users can be notified when a new email is received.
SMS services in .NET applications
The Mobile Internet Toolkit (MMIT) from Microsoft also called as ASP.NET mobile controls is an extension to the .NET Framework and ASP.NET that allows developers to write mobile Web applications targeting multiple devices such as cell phones and PDAs. The MMIT frees the developer to concentrate on the application logic and leave the UI rendering to the runtime. To install MMIT, you need to have the Microsoft .NET Framework version 1.0 or later. Because MMIT is an extension of ASP.NET you must also have IIS running.
Mobile applications are of two types: Web-based and device based.
Web based mobile applications run on the server, typically the Web server, and is accessed by mobile devices through the Internet and SMS services are provided by Internet Email messages.
Device specific mobile applications are standalone applications running on the devices itself, with or without Internet access. For this type of application, Microsoft provides a scaled-down version of the .NET Framework—the .NET Compact Framework (.NET CF).
This article dealt with basic understanding of SMS service and using them in mobile web applications.