SMS stands for short message service. Simply put, it is a method of communication that sends text between cell phones, or from a PC or handheld to a cell phone. The "short" part refers to the maximum size of the text messages: 160 characters (letters, numbers or symbols in the Latin alphabet). For other alphabets, such as Chinese, the maximum SMS size is 70 characters. But how do SMS messages actually get to your phone?
If you have read How Cell Phones Work, you can actually see what is happening. Even if you are not talking on your cell phone, your phone is constantly sending and receiving information. It is talking to its cell phone tower over a pathway called a control channel. The reason for this chatter is so that the cell phone system knows which cell your phone is in, and so that your phone can change cells as you move around. Every so often, your phone and the tower will exchange a packet of data that lets both of them know that everything is OK.
Your phone also uses the control channel for call setup. When someone tries to call you, the tower sends your phone a message over the control channel that tells your phone to play its ring tone. The tower also gives your phone a pair of voice channel frequencies to use for the call. The control channel also provides the pathway for SMS messages. When a friend sends you an SMS message, the message flows through the SMSC, then to the tower, and the tower sends the message to your phone as a little packet of data on the control channel. In the same way, when you send a message, your phone sends it to the tower on the control channel and it goes from the tower to the SMSC and from there to its destination. The actual data format for the message includes things like the length of the message, a time stamp, the destination phone number, the format, etc. For a complete byte-by-byte breakdown of the message format, see this page.
History of smsSMS was created during the late 1980s to work with a digital technology called GSM (global system for mobile communications), which is the basis for most modern cell phones. The Norwegian engineers who invented it wanted a very simple messaging system that worked when users' mobile phones were turned off or out of signal range. Most sources agree that the first SMS message was sent in the UK in 1992.As SMS was born in Europe, it's not surprising that it took a little longer to make its way to the United States . Even today, texting enjoys much greater popularity in Europe , though its stateside use is on the rise. A July 2005 study found that 37 percent of U.S. mobile phone owners had sent or received at least one text message in the previous month
WHY SMS IS ONLY 160 CHARACTERS ?SMS was designed to deliver short bursts of data such as numerical pages. To avoid overloading the system with more than the standard forward-and-response operation, the inventors of SMS agreed on a 160-character maximum message size.But the 160-character limit is not absolute. Length limitations may vary depending on the network, phone model and wireless carrier. Some phones don't allow you to keep typing once the 160-character limit is reached. You must send your message before continuing. However, some services will automatically break any message you send into chunks of 160 characters or less. So, you can type and send a long message, but it will be delivered as several messages.
MMS stands for
MULTIMEDIA MESAGING SERVICE. It is the evolution of Short Message Service(SMS) (SMS is a text-only messaging technology for mobile networks). With MMS, a mobile device is no longer confined to text-only messages. It can send and receive multimedia messages such as graphics, video and audio clips, and so on. It has been designed to work with mobile packet data services such as GPRS and 1x. MMS-enabled mobile phones enable subscribers to compose and send messages with one or more multimedia parts. Multimedia parts may include text,image,audio and video. These content types should conform to the MMS Standards.
For example your phone can send an MPEG-4 video in AVI format, but the other party who is receiving the MMS may not be able to interpret it. To avoid this, all mobiles should follow the standards defined by OMA.
MMS was originally developed within the Third-Generation Partnership Program (3GPP), a standards organization focused on standards for the GPRS/GSM networks. Since then, MMS has been deployed world-wide and across both GSM/GPRS and CDMA networks. MMS has also been standardized within the Third-Generation Partnership Program 2 (3GPP2), a standards organization focused on specifications for the CDMA networks. . Mobile phones with built-in or attached cameras, or with built-in MP3 players are very likely to also have an MMS messaging client -- a software program that interacts with the mobile subscriber to compose, address, send, receive, and view MMS messages.
EMS, also referred to as
Enhanced Messaging Service. EMS is simply SMS with additional payload capabilities is a cross-industry collaboration between Ericsson, Motorola, Siemens and Alcatel, among others. EMS is a halfway house between SMS and MMS, providing some of the features of MMS. EMS is a technology that is designed to work with existing networks, but may ultimately be made obsolete by MMS.
EMS, an application-level extension to SMS for phones available on GSM, GPRS,TDMA and CDMA networks. An EMS enabled mobile phone can send and receive messages that have special text formatting ,animations, pictures, icons, sound effects and special ring tones.EMS messages that are sent to devices that do not support it will be displayed as SMS transmissions.