The Multi-layer data mining model for IoT is divided into four layers: data collection layer, data management layer, event processing layer and data mining service layer. Among them, the data collection layer adopts devices, e.g. RFID Reader and sinks etc., to collect various smart object’s data, which are RFID stream data, GPS data, satellite data, positional data and sensor data etc.
Different types of data require different data collection strategies. In the process of data collection, a series of problems, e.g., energy-efficiency, misreading, repeated reading, fault tolerance, data filtering and communications etc., should be well solved. The Data management layer applies centralized or distributed database or data warehouse techniques to manage collected data. After object identification, data abstraction and compression, various data are saved in the corresponding database or data warehouse. Take RFID data as an example, the raw format of RFID data stream is (EPC, location, time), where EPC marks smart object’s ID.
Comparing with the common data, data in IoT has its own characteristics. For example, the data in IoT is always mass, distributed, time-related and position-related. At the same time, the data sources of IoT are heterogeneous, and the resources of nodes are limited. We can pre-process the raw data in the distributed nodes, and then send the necessary data to the receiver. The distributed data mining model for IoT is not only able to solve the problems brought by distributed storage of nodes, but also decompose the complex problems into simple ones. Thus the requirement of high performance, high storage capacity and computing power is reduced.
Grid computing is able to implement heterogeneous, large scale and high performance applications. Just like IoT, Grid computing is receiving increased attention both from industry and the research community. The basic idea of Grid is that users can make use of the computation resources of Grid as the same as power resources. Various computing resources, data resources and devices resources can be accessed or used conveniently. The basic idea of IoT is to connect various smart objects via internet. Thus smart objects become intelligent, context-aware, and long-range operable.