The introduction of GPRS technology organically connects telecommunications networks and computer networks to the future all-IP network platform. From the GPRS structure, it can be seen that the connection between the base station and the SGSN standby is generally connected through a frame relay, and the SGSN and the GGSN device are connected through an IP network.
The GGSN can be translated by the router with NAT (network address translation) function between the internal IP address and the external network IP address. The MS can access the GPRS internal network, and can also access the external PDN/Internet through the APN (external network access point name). The internet.
In the identification of GPRS equipment, such as the identity of the mobile phone MS, in addition to the IMSI and MSISDN numbers used in GSM, an IP address needs to be allocated. The identifiers of the network element devices SGSN and GGSN are both the 7th signaling address and the IP address of the data GGSN. The communication between the GSN (SGSN or GGSN) uses the IP address, and the communication between the GSN and the MSC, HLR and other entities adopts 7 Signaling address. In the GPRS system, there are two important database records. One is the user mobility management context, which is used to manage the location information of mobile users. The other is the user's PDP context (packet data protocol context) used to manage the access from the mobile phone MS to the gateway GGSN and to the ISP (Internet service provider). Data routing information. When the MS accesses the GPRS internal network or an external PDN/Internet network, the MS sends an Activate PDP Context Request message to the SGSN, and the MS can contract with the operator to select a fixed service GGSN. Or according to the APN selection rule, the SGSN selects the serving GGSN, and the SGSN sends a PDP context request message to the GGSN again. The GGSN assigns an IP address (static, dynamic, public or private) to the MS. During the establishment of the PDP context, the user's identity and the required quality of service are required to be authenticated and demonstrated. After the PDP context is successfully established and activated, the MS Both the SGSN and the GGSN store the user's PDP context information. With the user's location information and data routing information, the MS can access the network's resources. The advent of the second generation of semi-product GPRS will encounter some new concepts in the development and deployment of GPRS services.
The GGSN can be translated by the router with NAT (network address translation) function between the internal IP address and the external network IP address. The MS can access the GPRS internal network, and can also access the external PDN/Internet through the APN (external network access point name). The internet.
In the identification of GPRS equipment, such as the identity of the mobile phone MS, in addition to the IMSI and MSISDN numbers used in GSM, an IP address needs to be allocated. The identifiers of the network element devices SGSN and GGSN are both the 7th signaling address and the IP address of the data GGSN. The communication between the GSN (SGSN or GGSN) uses the IP address, and the communication between the GSN and the MSC, HLR and other entities adopts 7 Signaling address. In the GPRS system, there are two important database records. One is the user mobility management context, which is used to manage the location information of mobile users. The other is the user's PDP context (packet data protocol context) used to manage the access from the mobile phone MS to the gateway GGSN and to the ISP (Internet service provider). Data routing information. When the MS accesses the GPRS internal network or an external PDN/Internet network, the MS sends an Activate PDP Context Request message to the SGSN, and the MS can contract with the operator to select a fixed service GGSN. Or according to the APN selection rule, the SGSN selects the serving GGSN, and the SGSN sends a PDP context request message to the GGSN again. The GGSN assigns an IP address (static, dynamic, public or private) to the MS. During the establishment of the PDP context, the user's identity and the required quality of service are required to be authenticated and demonstrated. After the PDP context is successfully established and activated, the MS Both the SGSN and the GGSN store the user's PDP context information. With the user's location information and data routing information, the MS can access the network's resources. The advent of the second generation of semi-product GPRS will encounter some new concepts in the development and deployment of GPRS services.