How SMS works (II)

Despite the popularity of text messages, the text message service has been criticized. It has the following Disadvantages: You must use it in advance. Most wireless devices plan to charge a certain amount of text messages each month. Some users are only charged for sending text messages, while others are also charged for Receiving text messages. If the number of messages sent exceeds the limit, you must pay an additional 10 cents for each message that exceeds the limit, and the amount of these small payments will be less   The short message cannot be quickly transmitted. During peak hours, it may take several minutes or even hours to send a text message.   Send text messages only. SMS does not support sending images, videos, or music files. Other short message services allow you to send a variety of complex short messages. UseEnhanced Short Message Service (EMS)You can send text, sound effects, small images, and photos.Multimedia Short Message Service (MMS)In addition to text messages, you can also send animations, audios, and video files. If your mobile phone has EMS or MMS functions, you can use these standards, just like using SMS. However, the cost of each text message will be higher. Another alternative tool for SMS is instant messaging, such as aol im on your mobile phone. You can use pre-installed software on your mobile phone orWireless Application Protocol (WAP)Access the Internet, and then log on to your IM account. WAP is a protocol that provides small and simplified web pages. It can be easily navigated on a mobile phone or PDA (for more information, see the working principles of the Wireless Application Protocol (WAP ). You can use it to send instant messages or emails from your mobile phone. The common dissatisfaction with the text message service is that its transmission structure is inefficient, that is, it takes longer to reach the Sending target when the text message center has been backed up. Some networks are using more new-generation technologies, suchGeneral grouping wireless service system (GPRS).