Using GPRS technology to implement mobile internet (1)

Introduction

Network technology is one of the most important technological advances in the 20th century. The rapid development of the Internet is a concentrated embodiment of the development of information technology, however, people are not satisfied with the fact that they can only sit in the office or at home and access the Internet through a fixed network. They are full of fantasies and hopes that they can access the Internet anytime, anywhere on their mobile devices, send and receive E-mails, and view information. How to Choose new technologies to make full use of and upgrade existing mobile communication technologies and devices has become a matter of concern to everyone.

1. GPRS technology

Many technologies are available for the transition from 2nd-generation mobile communication to 3rd-generation mobile communication, while GPRS (Universal grouping radio service) is one of the most eye-catching technologies. GPRS is a set of wireless transmission methods developed using the concept of block-based switching. Therefore, GPRS technology can save time, effort, and cost for accessing the Internet through mobile phones. To a certain extent, it satisfies users' requirements for information and allows users to enjoy surfing the Internet on their mobile phones.

The rapid development of modern information technology is changing our society. The rapid growth of mobile communication and the popularization of varnet are the two most important events in the information field, combining the two is a dream of people and has broad and attractive market prospects. GSM-based digital cellular mobile communication and Internet-based group data communication are currently the two most rapidly growing industries in the information field, and are showing a trend of mutual integration, GPRS can be seen as the 1st step of integration between mobile communication and grouped data communication. The original GSM dial-up method was the circuit exchange data transmission method, and GPRS was the group exchange technology. Because of the grouping technology, users can access the Internet without being interrupted. In addition, the advantage of GPRS is that the download of materials and calls can be performed at the same time. Technically, the voice transmission (CALL) continues to use GSM, and the data transmission can use GPRS, so that the application of mobile phones can be upgraded to a higher level. And the development of GPRS technology is also very economic, because in the original GSM network base _ Bu added a series of functional entities to complete the grouping data function, new functional entities constitute a GSM-GPRS network, as an independent network entity, GSM data is bypassed to complete the GPRS Service. The original GSM network completes the voice function, minimizing changes to the GSM network. Compared with the access speed of 9.6 kbit/s in GSM, GPRS has a access speed of 171.2.kbit/s. In terms of connection establishment time, GSM requires 10 s ~ 30 s, while GPRS only requires a very short period of time to access the relevant requests; in terms of cost, GSM is charged by the connection time, while GPRS only needs to be charged by the data flow meter; GPRS's utilization of network resources is much higher than that of GSM. It can be said that CPRS is the only way for GSM network evolution.

The main application fields of GPRS include E-mail, WWW browsing, WAP Service, E-commerce, information query, and remote monitoring.

2. Implement mobile Internet based on GPRS technology

GPRS is divided into MS (mobile station), BSS (Base Station Subsystem), including BTS (base station receiving and sending station), BSC (Base Station Controller), CSS (Circuit Switching subsystem) and PSS (group switching subsystem), including SGSN (Service GPRS Support Node), GGsN (Gateway GPRS Support Node), MSC (mobile switching center. Here, MS can be seen as an integrated entity for the functions of MT (mobile terminal) and TE (terminal device). It can be either an entity or two entities (TE + MT) physically ); SGSN is an important part of the GPRS network. It is mainly responsible for MS Access Control, mobility management, session management, recording the current location of MS, and other functions. The SGSN is used to establish the PDP (group data protocol) Context of MS to provide channels for MS to access the external Internet. GGSN is mainly used as a gateway to provide gprs plmn (Public Land Mobile Communication Network) interfaces with the external grouping data network can be connected to a variety of different data networks, and provide necessary network-related security mechanisms (such as firewalls); BG (Border Gateway) it is used for connection between GPRS backbone networks of PLMN. It should have basic security functions. In addition, it can also add related functions according to roaming agreements between carriers. DNS (Domain Name Server) there are two domain name servers in the GPRS network. One is the DNS between GGSN and the external network. The main function is to resolve the Domain Name of the external network, it serves exactly the same purpose as common DNS on a fixed Internet network, and DNS on a GPRS backbone network, 1. parse the IP address of GGSN Based on the specified APN (Access Point name) during the PDP context activation process, and 2. Update the routing area between SGSN, the IP address of the old SGSN is parsed based on the old routing zone number. This feature entity is not the proprietary device entity of GPRS.