What is GPRS

With the continuous maturation of communication technology and the increasing demand of users for communication quality, the existing GSM network will inevitably evolve to W-CDMA (wideband Code Division Multiple Access), which is estimated to take about 2-3 years, and the main wireless network equipment suppliers will be the earliest It will be 2002 years before a commercially available W-CDMA system can be provided. But this does not mean that mobile operators can only wait, through the adoption of GPRS (Universal Packet Radio Service) technology, the existing GSM network can easily achieve with high-speed data packet easy access, so that operators can quickly respond to the demand for mobile market and gain competitive advantage. GPRS will be an important milestone to the 3G so what is GPRS? What advantages does it have? What will be the future of its development? To this end, the author of the following humble opinion, these content will be described in detail.

GPRS English is all called General Packet Radio Service, the Chinese meaning is universal Packet wireless services, it is the use of "Packet Exchange" (packet-switched) the concept of a set of wireless transmission display. The so-called packet Exchange is to encapsulate date into a number of separate packets, again, these packets are sent out in a similar form to send a package, the advantage of the package exchange is only when there is data need to be transmitted to occupy the bandwidth, and can be measured by the amount of data transmitted, which for users is a more reasonable billing method, Because most of the time bandwidth of data transmission like the Internet is between. In addition, in the GSM phase standard, GPRS can provide four different encoding methods, these coding methods also provide different fault protection (error Protection) capabilities. With four different coding methods, each slot can provide a transmission rate of CS-1 (9.05K), CS-2 (13.4K), CS-3 (15.6K) and CS-4 (21.4K), where CS-1 is the most secure and CS-4 is completely unprotected. Each user can use up to eight slots at a time, so GPRS claims the highest transmission rate of 171.2K.

In fact, in the GSM Phase standard not only the definition of GPRS, it also defines HSCSD (high-speed circuit-switched data service, high-speed circuit exchange information services), and HSCSD the highest transmission rate can be up to 57.6K (already faster than 56K), why no business people consider using HSCSD! Because HSCSD is a technology that uses "circuit switching," so users in the use of the same as the phone, regardless of whether you have to speak, the system will be in the upper and lower frequency band to retain a slot to the user, so the rate is to use the number of slots and the length of the use of time to calculate, for the user is really not cost-effective, Furthermore, its transmission rate is far less than GPRS, so many telecom users skip HSCSD directly into GPRS. However, regardless of the telecommunications industry decided to use the HSCSD service or GPRS service, the user's own mobile phone must be able to support a number of slots at the same time to send and receive the function and GPRS standards, the current use of the mobile phone most of us can not enjoy the high-speed GPRS, so if you want to enjoy the You have to buy a new type of mobile phone, of course, it also wants you to use the telephone service provider has been set up to complete the GPRS system and start to provide services. (Computer science)

GPRS is a new GSM data service, which provides a kind of connection between mobile user and data network, and provides high-speed wireless IP and X.25 packet data access service for mobile users. GPRS adopts packet switching technology, which allows multiple users to share some fixed channel resources. If the 8 slots in the TDMA frame on the air interface are used to transmit data, the data rate can be up to 164KB/8. The channel resource of GSM air interface can be occupied by voice or GPRS data service. Of course, under the condition of sufficient channel, some channels can be defined as GPRS dedicated channel.