Research Of Multimedia Broadcast Multicast Technology In LTE Broadband Trunking System RRC Layer

Long Term Evolution(LTE)broadband trunking system has the characteristics of high transmission rate,low transmission delay and fast call setup.It is widely used in transportation,public security,fire protection,forestry and government affairs.The Radio Resource Control(RRC)layer of the LTE broadband trunking system is mainly responsible for system broadcast,connection control,handover and measurement,control and management of the data link layer.The multicast technology is capable of performing multicast and broadcast of low-rate text messages,high speed Multicast and broadcast of multimedia services.It is the key technology of LTE broadband trunking systems.Therefore,the research on RRC layer multicast technology of LTE broadband trunking system is valuable for implementing.Based on the previous contributions of LTE broadband trunking system and its RRC layer multicast technologies at home and abroad,this thesis studies the RRC layer multicast technologies of LTE broadband trunking system.The main contributions are as follows:1.Based on the network architecture of Multimedia Broadcast Multicast Service(MBMS),the status and function of the RRC layer in the LTE broadband trunking system are analyzed.The signaling transmission process of the RRC layer is given,and the RRC layer MBMS signaling is described.2.Based on the research of RRC layer MBMS radio resource control,codec and multi-service parallel processing,a RRC layer MBMS radio resource scheduling mechanism for LTE broadband trunking system is proposed,which is capable of allocating radio resources more flexibly and scheduling efficiency.signaling procedures,i.e.,M2 interface establishment between the MBMS Coordination Entity(MCE)entity and the eNode B,MBMS session start,MBMS session update and MBMS session stop,are designed.3.An improved RRC layer MBMS multi-service scheduling algorithm is proposed.By combining the RRC layer MBMS multi-service parallel processing mechanism and the EXP/PF scheduling algorithm in the LTE broadband trunking system,the service delay and packet loss rate can be reduced.4.A RRC layer MBMS software architecture of LTE broadband trunking system is proposed.The software architecture combines the RRC layer MBMS function with real-time,parallelism and error tolerance.Based on the Ubuntu system,by utilizing the C language,modules such as RRC control,RRC process processing,and RRC Protocol Data Unit(PDU)processing are developed to implement multicast functions such as RRC layer session start,update,stop,and scheduling information control.5.The verification platform of MBMS function is built,and the verification scheme of MBMS functions is designed.The establishments of multicast interface connection,MBMS session start,MBMS session update and MBMS session stop are verified.The verification results show that the implemented RRC layer multicast function meets the design requirements.