# An Automatic Embedded Device Registration Procedure Based on the OGC SensorThings API
## 2 Related Work
OpenIoT standard [22] is a European Union (EU) open source web service standard released by developers from industry and academia jointly in 2012, which uses semantic web technologies to connect physical and virtual sensors to the OpenIoT web platform. The OpenIoT utilizes the Extended Global Sensor Network (XGSN) [23] as a hub between the OpenIoT service and the physical world, which can collect and filter semantically annotated data streams from SW-IoT devices. On the other hands, some open standards focus on device layer protocols. OneM2M is an international standard organization composed of standard organizations from Europe, America, China, Japan, and South Korea, and was established in July 2012. The oneM2M standard designs a distributed software layer that provides an interoperable framework. This distributed software layer is composed of three entities, Application Entity (AE), Common Services Entity (CSE), and Network Services Entity (NSE) [24]. An AE is an application implemented on oneM2M nodes. A CSE provides a set of common services functions (CSFs) to other AEs, CSEs, NSEs. An NSE provides network service functions from underlying networks such as 3 GPP, 3 GPP2, and WLAN to the CSEs. Furthermore, OGC PUCK is a standard that aims at providing interoperable communications between devices and host computers through serial cables (RS-232) or Ethernet. PUCK defines several PUCK commands for hosts to discover PUCK-enabled devices and retrieve devices' metadata or drivers from devices. The hosts can parse devices' metadata by following the PUCK standard format and install drivers to communicate with devices. Another solution based on the OGC SWE ecosystem is Sensor Interface Descriptor (SID). The SID aims at solving the heterogeneity issue between the service layer and the device layer [19]. The SID defines a schema and an extension to the OGC SensorML, to describe a sensor's communication protocol, commands, processing steps, and metadata association. According to the SID, a SID interpreter (gateway) can translate a sensor protocol into the OGC web services interface. A similar work to the SID was proposed by [PERSON] et al. [25], where the authors defined the Sensor Deployment Files (SDF) describing the metadata of a sensor and designed a framework to retrieve SDF via PUCK and register information to OGC SOS. Universal Plug and Play (UPnP) [26] is a network protocol proposed by the UPnP forum, which aims at providing seamless connections for devices in the same Local Area Network (LAN). The UPnP is a distributed architecture based on the TCP/IP, HTTP, XML, and SOAP network. The UPnP provides \"Addressing\" and \"Discovery\" procedure for new devices and services to join the UPnP network. A control point can control devices or subscribe to events of devices according to the description provided by devices. As mentioned earlier, the objective of this study is to achieve automatic connections between the service layer and the device layer. The OGC SOS, SensorThings API, OpenIoT are standard service interfaces for the service layer. The HyperCat provides a catalog service and data semantic annotation for sensor data searching, where the annotation and publish should be manually finished. The OGC PUCK mainly defines commands for device communication, where an automatic registration procedure was not defined. Some manual work is still needed for sharing sensing and tasking capabilities to the service layer. The SID provides a complete data model for describing sensing and tasking capabilities. However, for the Plug and Play, their data model is verbose in XML schema and is complicated for devices to support. The SDF approach is also based on XML and only supports sensing capabilities. The UPnP operates on networks based on the TCP/IP, HTTP, XML, and SOAP, thus that the standard cannot be applied to devices on low-power wireless communication networks. The oneM2M provides an operating-system-like logic layer for various kind of devices.