Research On Cross-layer Optimization Technology Based On Data Distribution System For Heterogeneous Converged Networks

With the rapid increase of mobile network users, the demand for data distribution services is growing fast and it becomes imperative to provide data distribution services for large scale users. It is an efficient way to ensure reliable transmission by using data distribution protocols for heterogeneous converged network and using Forward Error Correction(FEC) coding techniques in the data distribution system. From the perspective of the application of RaptorQ codes, the construction of data distribution system in the next generation broadcast wireless(NGB-W) network and the application of fountain code in the data distribution system are studied in this paper. The main points have been given, which can be listed as follow:(1) In order to fit the network architecture of the heterogeneous converged network, where terrestrial broadcast network is used for large-scale data broadcast and bidirectional access network is used for small-scale data repair, the basic composition of File delivery over Unidirectional Transport(FLUTE) protocol stack is studied. The application of FLUTE protocol stack in the data distribution system is proposed and the specific processes of FLUTE protocol stack are shown.(2) The data distribution system based on FLUTE protocol stack is designed and the specific functions and design details of each module are given. RaptorQ code is also used as the application layer FEC encoding module of the data distribution system and improves the data distribution mechanism based on the FLUTE protocol stack. Based on the rateless coding mechanism of the RaptorQ code, the data distribution scheme uses broadcast network for data pushing, broadcast network and cellular network together for data repair, which enhances the reliability of the data distribution.(3) As the RaptorQ code is used as the FEC encoding module of the data distribution system, the impact on the system design of the data distribution system, the wireless transmission and network coverage is studied. By using RaptorQ FEC coding, the utilization of radio resources is improved and precious radio resources are effectively saved.