Research And Implementation Of Access Protocol Analysis And Feature Identification For Heterogeneous Devices On The Internet Of Things

The IoT platform shields the differences of heterogeneous devices and supports the development of differentiated IoT applications.The adaptation of heterogeneous device access protocols and data formats is the main function of the IoT platform.The differentiation of IoT devices,diversified protocols,and inconsistent data formats lead to huge challenges in parsing and identifying multiple heterogeneous protocols.This thesis focuses on the design and implementation of heterogeneous device access modules for IoT platforms centered on application development,studies non-standard IoT protocol feature identification methods,and proposes IPaa S(IP & Port as a Service)method for adaptive access on the platform side of heterogeneous devices on the Internet of Things.The difficulty of the adaptation of the IoT access protocol on the platform side lies in the identification of heterogeneous protocols.Based on the mapping relationship between the TCP(Transmission Control Protocol)or UDP(User Datagram Protocol)service port and the network application protocol,an adaptive access method for IoT heterogeneous devices on the platform side is proposed,which called IPaa S in this thesis.Aiming at the problem of strong coupling between IoT applications and devices,a three-layer mapping method for application development and stable virtual device data model is proposed.Aiming at the problem that the standardization of data format standardization methods led by standards organizations cannot meet the needs of the IoT market with a large variety of devices and the emerging new IoT device marketization,an open source collaborative mechanism for a standard data model of virtual devices for application developers is proposed.Aiming at the problem of scalability of protocol mapping caused by limited TCP or UDP service port resources and the inability to distinguish between different types of devices under the same gateway,a feature identification method for non-standard protocols of the Internet of Things was proposed to realize the heterogeneous protocol identification and analysis,which called IPaa S + protocol features.Feature extraction is performed on nonstandard IoT protocols in JSON and binary form,respectively.Aiming at the IoT protocol in JSON format,based on the fixed key value part of the protocol,a method for identifying network protocol features based on key value extraction was proposed.Aiming at the binary form of the Internet of Things protocol,based on the fixed binary protocol frame header and frame tail,the rest is random within a certain range,a binary protocol feature identification method based on Naive Bayes classification algorithm is proposed,and the recognition accuracy rate is 99.64%.To meet the needs of IoT protocol feature identification.For the two platform-side identification methods of the above non-standard IoT protocols,IPaa S is suitable for scenarios where the platform's TCP or UDP service port resources are sufficient and the directly connected device.The feature identification methods of nonstandard IoT protocols are applicable to the devices can provide historical data or under the IoT gateway with heterogeneous data format.Through the analysis of the two methods' processing performance and applicable scenarios,through the design of the pocket switch when the system is implemented,the two methods are complementary.Based on the proposed methods and technologies,an application-centric IoT platform heterogeneous device access module is designed and implemented as an important part of the "Micro Things OS" IoT platform.In terms of device access,Adaptive protocol identification and analysis reduces the access workload to 1/5 of the original.This platform has been implemented in a university "smart dorm" project,a public security "electronic fence" project,and a mechanical equipment intelligent transformation project.