Explain the principle of sending and receiving text messages.

Short message is text or digital information sent or received directly by users through mobile phones or other telecommunication terminals. The number of characters that users can send and receive SMS at a time is 160 English or numeric characters or 70 Chinese characters.

Short message is a telecommunication service in digital mobile communication system. It is a non-real-time and non-voice data communication service to transmit text or digital short messages through the signaling channel and signaling network of mobile communication system.

SMS can be initiated by mobile communication terminals (mobile phones), SMS platform servers of mobile network operators, and network service providers (including ICP and ISP). ) interconnected with the SMS platform of mobile operators.

In the technical means to realize the function of short message service, sending and receiving point-to-point messages through mobile terminals occupies the mainstream position, but it is not the only form. Fixed telephone, PHS and Internet are becoming new tools and carriers.

At the beginning of the development of short message service, the sending and receiving of short messages started from mobile phones, and finally went to mobile phones, passing through GSM network /CDMA network, short message center and other network elements; With the emergence of short message on demand and customized services, mobile phones, Internet sites and short message value-added service systems can send short messages to each other. Internet sites and short message value-added service systems have become new network elements, while GSM/CDMA networks and short message centers still maintain the core position of short message networks. With the emergence of PHS mobile phone based on fixed telephone network in China, the short message service has been extended to fixed network, and the terminal is no longer limited to mobile phone. PHS mobile phones or dedicated fixed terminals can be used as the sender and receiver of short messages, and the network foundation is no longer limited to digital mobile networks such as GSM/CDMA networks. Fixed network can also become the network foundation of short message, and the elements of short message network have changed significantly.

With the extension of short messages from mobile phones to PHS and fixed terminals, and from digital mobile communication network to fixed telephone network, people's understanding of short messages is no longer just regarded as the "patent" of digital mobile phones. Business forms are changing, network elements are changing, and information content is rich. In this process, only two things remain unchanged:

First, the message length of short message is always less than 160 English or numeric characters or 70 Chinese characters, which is closely related to the mechanism of short message transmission based on the signaling network of communication system. The second way is to send short messages-store and forward. When the user does not receive it, the short message will not be lost and will be temporarily stored in the short message center. When the user logs on to the network again, the short message will be quickly submitted to the user's mobile phone.

These innate characteristics make short messages have the advantages of accuracy, reliability, rapidity and timely delivery, and make short messages have the basic conditions that affect people's habits!

As a kind of service on mobile phone, SMS has turned the mobile phone with language transmission function into a telegraph-style interpretation tool, which makes the ears idle and the words show greater role; As a way of transmitting information and communication by words, SMS makes the thumb sensitive and developed, and gives the mouth a rest. Modern telecommunication services have dual colors of technology and culture.