Design And Optimization For Data Collection Mechanism In Internet Of Things Based On Named Data Networking

The Internet of Things(IoT) technology has been booming in recent years.Billions of IoT devices are generating massive amounts of data.The network architecture is the basis for the performance of IoT.However,faced with the flexible application scenarios in IoT,traditional TCP/IP architecture has shown various inherent deficiencies in address allocation and dynamic addressing due to its feature of host-oriented connection.Therefore,Named Data Networking(NDN) initiates a content-centric network architecture that can collect data actively without addresses,showing greater potential than IP architecture.And it has gradually become a hot spot in the research of next-generation IoT architecture.However,IoT based on NDN(NDN-IoT) still has many problems,especially in the large-scale data retrieval scenarios.The "Single-Interest to Single-Data"(SISD) transmission mode is severely limiting the efficiency of data retrieval.Therefore,how to design a "Single-Interest to Multi-Data"(SIMD) transmission mechanism is the key issue to improve the efficiency of NDN-IoT data collection.This thesis first proposes a PIT replacement strategy to realize the SIMD transmission mechanism,and designs and optimizes the former about congestion control and signature privacy protection.The specific research content of these is as follows.(1)A PIT replacement strategy based on historical contribution is designed,and congestion control mechanism is further optimized.In NDN,PIT entry records the routing information for the return data,which will be deleted immediately the return completes.To ensure the successful return of multiple data,long-live PIT entries must be established in SIMD,which will cause the increase of PIT entries,but resource-constrained IoT devices can only bear limited PIT entries.So how to solve this problem has become the key to accomplishing the SIMD mode.This thesis introduces the concept of retrieval contribution for PIT entry and proposes a PIT dynamic replacement policy(PRP-MC).In PRP-MC,PIT entry records the name prefix of target data,and will not be deleted when satisfied.At the same time,Timelist is maintained in the entry to record the return time of data packets.When a new interest arrives,NDN router will calculate the retrieval contribution of all PIT entries based on the Timelist,and then replace the PIT entry with the lowest retrieval contribution.The simulation results show that compared with SISD,Fixed-PEL and LRU,PRP-MC further improves the interest satisfaction rate of collector on the basis of reducing the data collection time.Although PRP-MC can obtain significant advantages on retrieval efficiency,a large amount of return data brings the hazard of network congestion.Therefore,this thesis further optimizes PRP-MC and presents a congestion control scheme(HCC-TRA) suitable for SIMD.This scheme establishes a congestion window based on NACK packet feedback and a delayed retrieval mechanism between adjacent node.The two mechanisms jointly coordinate the transmission rate between neighboring nodes and make full use of the link resources in the network.Simulation results prove that,compared with the ICP protocol,HCC-TRA can continue to retain the data retrieval efficiency in SIMD,and alleviate the impact of network congestion productively.(2)An identity privacy protection scheme based on dynamic broadcast encryption is proposed.When collecting data from a group of users,the leakage of user identity privacy is another challenge in NDN-IoT.The traditional digital signature uses the private key of the data provider for encryption,so the collector can identify the provider toward its public key when verifying the signature.This thesis designs an identity privacy protection scheme based on dynamic broadcast encryption(SPP-DBE) on the basis of SIMD.In this scheme,data nodes first join the user group established by the data collector.The nodes in the group use the session key of the collection activity to sign the data,then the data collector uses the same session key to verify the digital signature.Simulation result shows that compared with ring signature,SPP-DBE can validly prevent identity detection attacks,and can obtain lower verification overhead and network transmission overhead for the collector.