The Design And Development Of IOT Gateway And Research Of Outlier Detection

Internet of Things (IoT) is an Internet to connect things, those devices which don’t integrated with IP make gateway become indispensible in IoT. There are still existed some problems in IoT Gateway:The nowadays studies mainly focused on the interconnection between sensor nodes and Internet, there are still a big gap to achieve the requirement of IoT applications on architecture, functional implementation; Data quality issue has always been one of the challenges in IoT, necessary data handling mechanism is lacked in gateway; With the increasing of users and sensor nodes, traditional request/response communication mechanism can’t meet the needs of users, which may lead to the collapse of the gateway.Solving these three problems were the main purpose of this paper. By analyzing the design principles of IoT gateway, an architecture with three layers was proposed. Besides, some of the important function modules such as device configuration management and interface service were studied to design an IoT gateway with low coupling, high reusability and high access speed which could meet the demand of IoT applications.In order to ensure the data quality in IoT, the outlier detection mechanism in gateway was studied in this paper. By analyzing the characteristics of IoT data and the specific application scenario, this paper studied outlier detection of single-sensor data stream which could be categorized into point outlier and sequence outlier detection. This paper improved the distanced-based outlier for sliding windows detection algorithm to detect the outlier points in data stream, which reached low time complexity and space complexity. For sequence outlier, an algorithm OCSVM_KNN was proposed, it was a two-phased algorithm which combined the One-Class SVM with KNN classifier for step detection. The experimental results showed that the algorithm reached higher detection rate and lower false alarm rate.For the shortage of the request/response communication mechanism, the Pub/Sub system was designed in IoT gateway by studying mathematical model of Pub/Sub system to realize the asynchronous communication mechanism. Besides, multi-level indexing technology was adopted to achieve fast matching between events and subscriptions.Lastly, the gateway program was implemented on industrial computer and embedded device, and the gateway was applied to the smart home and smart agriculture scenario.