Design Of Multi-environment Coding Cache Scheme Based On Bipartite Graph

With the rapid development of the mobile terminals,the amount of the transmissions,which has lots of the video business,in the wireless network growth significantly.However,the high temporal variability of network traffic results in communication systems that are congested during peak-traffic times and underutilized during off-peak times.The Caching technology can solve this problem.It reduce the congestion during the peak-traffic times,which can effectively utilize the off-peak times.In this thesis,we will focus on the dynamic networks and distributed networks.In the dynamic networks,it always happens that some new users join the existing network in a short time.In order to reduce the energy loss and to not shortens the life span of memories.effect to accelerate the service life of the equipment,based on the MN scheme and using the concatenating construction and matching in the bipartite graph,we design a coded caching scheme for dynamic networks with the following properties:(i)During the placement phase,the new coming user caches part of the content without updating the original user's cached content;(ii)During the delivery phase,the coded gains are generated as more as possible among the new coming users and the original users.So the rate is ordered optimal.In the distributed networks,it is sufficient to consider the scheme with symmetric request.The rate of the scheme is the rate of a scheme reduces when the ratio of unpaired messages transmitted in the delivery phase reduces.By the splitting technique of the combination number,we further reduce the the ratio of unpaired messages.It is worth noting our method can further reduce the ratio of unpaired messages by increasing the complexity of the scheme and can also be used to the many data servers and parity servers.The results show that the proposed code caching scheme for two types of network environments has good performance.