The Design And Implementation Of MAC Layer On Emergency Communications System's Base Station

In recent years, disaster and emergency events have occurred frequently around the nation and even around the world, which makes the research and development of emergency communications system urgent. This thesis is the analysis of the MAC layer technology on the base station of a broadband emergency communication system which is based on the project of "The implementation and application of the next-generation broadband wireless access systems and network".This is a project of the Ministry of Education of Guangdong province.The system is designed and optimized based on IEEE 802.16e MAC protocol. The IEEE 802.16e standard is one of the access technologies of metropolitan area wireless network. It provided data, voice and video transmission services, and it meets the needs of emergency communications systems well.The main features of Emergency communication system's MAC layer include:network access and initialization,MAC PDU construction and delivery, service establishment and release, bandwidth request and grant, resource scheduling and allocation, re-transmission processing, handover process and power control. In this thesis,we have detailed study and analysis of the MAC layer in emergency communications systems.First, we introduced the structure, function and main features of the IEEE 802.16e standard MAC-layer protocol, followed by the of the system's overall structure and the framework of the MAC layer's programming, also we have a brief introduction of the programm's main modules.Then, we put focus on the initialization and access processes of the base station, and the process of service establishment, and the bandwidth scheduling algorithms.At last, all the features of the base station have been tested on the picochip pc205 developmentboard, and we have an analysis and summary on the test result.