Priority-based Content Dissemination And Caching In A Content Centric Vehicular Networks

Content centric networks smooth the way for vehicular ad hoc network and increases network reliability that robustly delivers information using any available medium.It allows network to easily send and receive digital content from multiple locations,mobile devices,and diverse networks.CCN is a hot research topic that attract so much attention of researcher due to the unique characteristics of content caching and naming based content retrieval.Content centric vehicular networks(CCVN)performs best in content retrieving so far,different content-based content dissemination models have been proposed to retrieve and disseminate content in CCVN,but most of them are unable to explain the priority-based content dissemination.Usually,vehicle apply the same forwarding strategy in CCN.However,the application of data dissemination in CCVN are different in term of critical and non-critical.Safety content belong to the human life and should be broadcast prior than non-safety contents.Non-safety contents shared to consumers based on the request volume of interests.Hence prioritization law for the contents are highly appreciated at this level.Additionally,CCVN provides the facility of in-network caching which helps the content to be cached while being transferred to the subscriber.However,challenges exist in in-network caching such as limited cache storage space,inefficient cache management and content redundancy.Hence,cooperative caching is essential to provide an admittance chance to more contents.The main contributions of this dissertation are listed as follows.1)To guarantee the prompt and reliable delivery of the contents,a priority-based content dissemination(PCD)scheme is designed for CCVN.In the proposed scheme,content provided to vehicles are broadly classified into safety and non-safety.Safety contents always have higher priority than non-safety contents as it's relates to the life of humans.The priority of the safety content is assigned based on the content expiration time.Contents that have smaller deadline and distance will have assigned greater priority to ensure that content sent over to the destination in limited time.The priority of the non-safety contents is assigned based on the request volume of contents.For the non-safety contents,supremacy have been considered based on the number of interests received from consumer and size of content to be shared.2)To tackle the drawbacks of limited cache storage space and in-efficient cache management,a cluster-based cooperative cache scheme is proposed in CCVN.In this scheme,the vehicles are grouped into clusters and each cluster has a cluster master(CM)that would take the content cache decision cooperatively.When content received,a CM make the decision of whether or not to store the contents,relying on the interrogate outcome of cache summaries of cluster members.If any of the cluster member has a content,the content has not been cached in a cluster.The workflow of the proposed scheme are illustrated.The simulation results have proved that the proposed schemes can reduce the transmission delay of all safety contents,the popular non-safety contents,enhance the cache hit ratio in the network and reduce the content access delay.