What is SMS in mobile phones?

What is SMS?

The short message server enables mobile phones (including Pocket PC Phone) to send short messages using the GSM network. It has many interesting features:

An SMS message can contain up to 160 messages. characters (even binary).

SMS is a store and forward service. In other words, short messages are not sent directly from the sender to the recipient, but are always forwarded through the SMS center. If the recipient is not connected (perhaps the phone is turned off), the message will be sent when the recipient connects again.

SMS has the function of message delivery confirmation. This means that SMS is different from paging in that the user does not simply send a short message and then believe that the message has been sent successfully; rather, the sender of the short message can receive a return message informing them whether the short message has been sent successfully.

SMS messages can be sent and received simultaneously with GSM voice.

SMS messages are charged on a per-message basis and are therefore much more expensive (per byte) than data sent over IP-based networks (for example, using GPRS [General Packet Radio Service]).

To use SMS, the user needs to subscribe to a mobile network that supports SMS, and the use of SMS must be enabled for the user. Users need to have a destination to send or receive short messages. The destination is usually another mobile phone, but it can also be a server. Finally, users also need to have an SMS-enabled mobile phone and need to know how to send or read short messages using their specific model of mobile phone.