GPRS(General Packet Radio Service)

GPRS General Packet Radio Service abbreviation, it is GSM mobile phone available to a user of a mobile data service. GPRS is GSM continuation. GPRS and past continuous channel transmission in different ways, is a packet to transmit, so users of the burden of the cost is in the data transmission unit, does not use the whole channel, theory is comparatively cheap. GPRS transmission rate can be raised to 56 or 114Kbps.

GPRS is often described as "2.5G", that is to say the technology in the second generation ( 2G ) and third generation ( 3G ) mobile communication technology. It is through the use of GSM network unused TDMA channels, with moderate speed data transfer. GPRS broke through the GSM network can only provide circuit-switched mode of thinking, only by increasing the corresponding functional entities and to the existing base station system partial transformation to realize the transformation of the input packet switching, relatively little, but the user data rate but considerable. But, because no longer need the current wireless applications need intermediary converter, so the connection and transmission will be more easily. So, users can participate in online Internet, video conference and other interactive communication, and in the same video network ( VRN ) users, even without through dial-up Internet access, and continuous with the network connection. GPRS packet switching communication mode in a packet switched communication mode, data is divided into a certain length of the package ( packet ), each packet is preceded by a packet header ( in which the address identifies the packet sent to where ). Data prior to transmission does not require preassigned channel, to establish a connection. But in every data packet, according to the data in the header information ( such as the destination address ), temporary to search for an available channel resources of the datagram is sent out. In this type of transmission, data transmitting and receiving method with no fixed occupation relationship between channels, channel resources can be seen as composed of all users.

As a result of data service in the vast majority of cases have shown an unexpected business characteristics of channel bandwidth, large changes in demand, therefore the use of packet mode data transfer will be better able to use the channel resource. For example, a WWW browsing user, most of the time is in browse mode, and really for the data transmission time accounted for only a small proportion of. In this case the fixed occupancy channel way, will cause great waste of resources.