12.19
SMS stands for Short Message Service. It is a technology that enables the sending and receiving of messages between mobile phones. SMS first appeared in Europe in 1992. It was included in the GSM (Global System for Mobile Communications) standards right at the beginning. Later it was ported to wireless technologies like CDMA. The GSM and SMS standards were originally developed by ETSI. ETSI is the abbreviation for European Telecommunications Standards Institute.
As suggested by the name “Short Message Service”, the data that can be held by an SMS message is very limited. One SMS message can contain at most 140 bytes of data, so one SMS message can contain up to:
- 160 characters if 7-bit character encoding is used. (7-bit character encoding is suitable for encoding Latin characters like English alphabets.)
- 70 characters if 16-bit Unicode UCS2 character encoding is used. (SMS text messages containing non-Latin characters like Chinese characters should use 16-bit character encoding.)
Besides text, SMS messages can also carry binary data. It is possible to send ringtones, pictures, operator logos, wallpapers, animations, business cards (e.g. VCards) and WAP configurations to a mobile phone with SMS messages.
One major advantage of SMS is that it is supported by 100% GSM mobile phones. Almost all subscription plans provided by wireless carriers include inexpensive SMS messaging service.
One drawback of the SMS technology is that one SMS message can only carry a very limited amount of data. To overcome this drawback, an extension called concatenated SMS (also known as long SMS) was developed. A concatenated SMS text message can contain more than 160 English characters. Concatenated SMS works like this: The sender’s mobile phone breaks down a long message into smaller parts and sends each of them as a single SMS message. When these SMS messages reach the destination, the recipient mobile phone will combine them back to one long message.
The drawback of concatenated SMS is that it is less widely supported than SMS on wireless devices.
SMS is a success all over the world. The number of SMS messages exchanged every day is enormous. SMS messaging is now one of the most important revenue sources of wireless carriers. What is so special about SMS that makes it so popular worldwide?
Some of the reasons are discussed below.
SMS Messages can be Sent and Read at Any Time
Nowadays, almost every person has a mobile phone and carries it most of the time. With a mobile phone, you can send and read SMS messages at any time, no matter you are in your office, on a bus or at home.
SMS Messages can be Sent to an Offline Mobile Phone
Unlike a phone call, you can send an SMS message to your friend even when he/she has not switched on the mobile phone or when he/she is in a place where the wireless signal is temporarily unavailable. The SMS system of the mobile network operator will store the SMS message and later send it to your friend when his/her mobile phone is online.
SMS Messaging is Less Disturbing While You can Still Stay in Touch
Unlike a phone call, you do not need to read or reply an SMS message immediately. Besides, writing and reading SMS messages do not make any noise. While you have to run out of a theater or library to answer a phone call, you do not need to do so if SMS messaging is used.
SMS Messages are Supported by 100% GSM Mobile Phones and They can be Exchanged between Different Wireless Carriers
SMS messaging is a very mature technology. All GSM mobile phones support it. Not only that you can exchange SMS messages with mobile users of the same wireless carrier, but you can also exchange SMS messages with mobile users of many other wireless carriers worldwide.