# CATSWoTS: Context Aware Trustworthy Social Web of Things System
## 2 Background Study
### Preliminary Concepts  
One of the main ideas from which IoT evolved is Pervasive Computing. \"Internet of Things\" is the term behind the concept of making connections through networks. IoT is a paradigm which intends sensors, smart objects, and actuators to form a global network that can be uniquely identified based on standard communication protocols. It could be said that it is one paradigm having many visions including things-oriented and internet-oriented attributes [6]. IoT has great potential and is considered as one of the most important key areas for future technology [6]. Few examples of the applicability of IoT can be witnessed in safety protection, surveillance, logistics, and transportation, disaster management, etc. [6].  
An architecture for Social IoT was proposed by [PERSON] et al. [7]. The social relationship between the connected objects was identified. An integral component of this paradigm was Middleware (MW). Middleware architecture following the principles of SOA was proposed [8]. Web of things refers to the integration of web technologies with smart things including services provided by them. The architectural style Representational State Transfer (REST) was used for this purpose [9]. It made services abstract for the selection of best interface without going into technical details. REST has become popular among researchers and is their foremost choice for establishing a global architecture for smart things [1]. The era of the social object is the next phase of IoT [10]. A comparison was made between human and IoT revolution. It was described that a basic knowledge environment was translated into actions. Furthermore, they described different phases of IoT composition [10].  
An arrowhead framework [4] was proposed to facilitate the operations of interconnected systems. Based on SOA, it proposed three interoperability approaches which were interoperability layer, the translator system, and the translation as a service. In the interoperability layer, semantics and related technology were defined. The translator system consumed a service and then provided it on another technology, whereas the translation as a service had an extra service that could be consumed for translation purposes. In addition, it had core systems such as service registry, authorization, and orchestration which could be used by any other system. A service or a system could be easily designed and developed with the support of the arrowhead framework. Use cases were designed to evaluate the framework.  
[PERSON] et al. [11] reviewed the usage of semantics for facilitating interoperability in IoT. A comprehensive background study was carried out to give the answers to five major research questions. After that, data was extracted from 105 chosen studies. These scientific works were selected based on six criteria. It was identified that all studies except four discussed OWL (Web Ontology Language). Semantic Sensor Network (SSN) ontology was identified as directly related to IoT. The research concluded that the research area had become mature and ontologies were declared as standards for semantic descriptions. Linked data was projected as an emerging topic and multiple themes were found to exist. In short, it was a comprehensive review of the semantics in IoT. Another approach that addresses the semantic data integration, using the cloud based data as a service (DaaS) layer while ensuring the security of the system is presented in [12].