The Development Of CCN Protocol And Study On Caching Stratrgy For Content Centric IoT

Content Centric Networking(CCN)is a brand new future network architecture,which adopts the principle of separation of content from location.CCN use named content as the center of the network instead of host address,overcoming the disadvantages of content distribution in the IP network,which relies on end-to-end connections.In addition,CCN's natural support for in-network caching can effectively improve content distribution efficiency and reduce network load.With the explosive growth of the numer of Internet of Things(IoT)devices and the continuous penetration of IoT applications from individually deployed industrial scenarios to individuals and businesses,the IoT urgently needs to move towards a unified platform.The IoT with IP architecture has many deficiencies in terms of mass content distribution,requirements for lightweight protocol stacks,and mobility management.The IoT is naturally content-centric,and the application of CCN to the IoT has great development prospects.The current research on the content-center IoT is still in its infancy,and the development of the CCN transmission protocol for actual IoT scenario needs carried out.In addition,compared with the wired CCN network,the IoT has the characteristics that its content changes with time and energy consumption is tight.Therefore,the caching strategy for content-center IoT needs redesign.This thesis is based on the National Natural Science Foundation "The Research of Caching for Content Centric Mobile Social Networking".Considering the features of IoT,a CCN protocol for content-centric IoT is developed and the caching for content-centric IoT is studied in this thesis.The work of this thesis includes:1)This thesis introduces the architecture,key technologies and network protocols implement of CCN,analyzes the architecture needs of IoT,and summarizes the current research of IoT with the host center and content center architecture respectively.Next,the thesis introduces the cache research classification of the content-centric IoT,then focuses on the current research of cache placement strategy and analyses its shortcomings.This thesis introduces the basic concepts and key technologies of CCN,summarizes the current research of the host-centric and content-centric architecture of the IoT,and focuses on the research of cache strategies for the content-centric IoT.2)Aiming at the problem that classic CCN protocol does not support wireless network scenarios and the caching for time-varying content,this thesis designs and implements a CCN protocol,which supports content-centric IoT.First,we summariy the requirements of the content-centric IoT and modify the core components of the classic CCN protocol.We modify content storage and forwarding information base component and add a new neighbor component.Then,we design the frame structure of the network packet and implement the network processing logic by code.Finally,we implement the CCN protocol on hardware devices and verify its functionality.3)To improve the caching efficient of time-varying content in the content-center IoT,this thesis proposes a cache strategy based on content's freshness.First,we give a content-centric IoT cache model and calculates the content cache benefits.Then,we solve the optimization problem of gaining maximum cache benefits in the entire network through matching theory.We give a central cache strategy according to previous work.Furthermore,considering the adoption of cache strategy in actual IoT scenario,we propose a low complexity and convenient for deploying distributed cache strategy.Finally,software simulation and hardware experiments show that the cache strategy proposed in this thesis can effectively increase cache hit rate,reduce network delay and energy consumption.