GPRS working principle

GPRS work, is through routing management to address and establish data connection, and GPRS routing management performance in the following 3 aspects:

(1) The routing of data sent by mobile terminals is established.

(2). The route of the mobile terminal receiving data is established;

(3) and the establishment of the data route when the mobile terminal is roaming.

For the first case, when the mobile terminal produces a PDU (packet data unit), the PDU is processed by the SNDC layer, called the SNDC data unit. Then through the LLC Layer Processing for LLC Zheng through the air interface sent to the GSM network mobile terminals in the SGSN. SGSN send the data to GGSN. GGSN the received message into a format that can be transmitted in a public data network (such as a PSPDN PDU) and eventually sent to a public data network user. In order to improve the transmission efficiency and ensure the safety of data transmission, the data on the air interface can be compressed and encrypted.

In the second case, when a public data network user transmits data to a mobile terminal, the route between the data network and the GGSN is established through the standard protocol of the data network. A data unit emitted by a data network user (such as a PDU in PSPDN) that sends a data unit PDU to GGSN by establishing a good route. and GGSN the PDU to the mobile terminal on the SGSN GSN the PDU into a SNDC data unit, and then through the LLC Layer processing as the LLC frame unit, finally through the air interface to the mobile terminal. (Computer science)

The third scenario is that a data network user transmits data to a roaming mobile user. In this case, the data transfer must go through the GGSN of the place of attribution and then sent to mobile User A.