The GSM module can be further divided into a GPRS module, an EDGE module, a 3G module, and a pure short message module according to the provided data transmission rate. The SMS module only supports SMS service. GPRS, can be said to be a continuation of GSM. It is often described as "2.5G", which means that the technology is between the second generation (2G) and third generation (3G) mobile communication technologies. The transmission rate of GPRS ranges from 56K to 114Kbps, the theoretical speed is up to 171k, and the actual test downlink speed is around 25K. Compared with GSM's 9.6kbps access speed, GPRS has faster access to data communication speed. GPRS technology also has the ability to connect at any time and any place, always online, according to the flow rate. EDGE technology further increases the rate of data transmission to 270K, known as "2.75G", and the data transmission rate is twice that of GPRS. At present, the domestic GSM network generally has GPRS communication function, and the mobile and Unicom networks all support GPRS, and EDGE has also been covered nationwide.
The GPRS module is a GSM module with GPRS data transmission function. The GPRS module is a compact version of the mobile phone. The main function of integrated GSM communication is on a circuit board, which has the functions of sending short messages, calls, and data transmission. The GPRS module is equivalent to the core part of the mobile phone. If you add a keyboard and screen, it is a complete mobile phone. Ordinary computer or single-chip microcomputer can be connected to GPRS module through RS232 serial port, and control GPRS module through AT command to realize various GSM-based communication functions.
The GPRS module is different from the traditional pure short message module, both of which are GSM modules, but the short message module can only send and receive short messages and voice communication, and the GPRS module also has GPRS data transmission function.