The Research And Implementation Of Llc Protocol In Gprs Dial Test System

With the rapid development of social economic and mobile communication, mobile data services become more and more colorful, which bringing a huge amount of users and business opportunities to operators. Meanwhile, the mobile network structure is becoming increasingly complex, bringing great challenges to network maintainers. A system that can detect network conditions automatically is needed to improve the maintainment efficiency. GPRS dial test system can test the mobile core network periodically and automatically by emulating network elements and services, greatly reducing the time and manpower required for network maintenance.LLC Protocol (Logical Link Control Protocol) transmits data for upper protocols between MS(Mobile Station) and SGSN(Serving GPRS SUPPORT NODE) as a very important part in mobile data services dial test system. The main work of this paper is to study the LLC protocol, and then propose LLC module design, with program realizing and software testing. The test results show that the the LLC module is designed and implemented to meet the demand for dial test system well.First of all, from the overall research GPRS network and mobile dial test system, including GPRS network architecture, protocol, the application of the agreement, the basic process and GPRS mobile dial test system framework and working principle. Then, functions and processes of the LLC protocol conducted in-depth research, and combination the GPRS dial test system design requirements and software architecture, the LLC module design highlight LLC module main data structures, interfaces and procedures for processing flow. What’s more, implement LLC module according to the design, combined with the theory of software testing, to verify the correctness of the LLC module functions and processes to achieve the LLC module. The tests include unit module testing and system integration testing, and through the logs and outputing information, software tools crawl test packets to analyze the test results.Finally, summarize the work done on this article and give the direction of further work.