# Towards Crowdsourcing Internet of Things (Crowd-IoT): Architectures, Security and Applications
## 3 Architectures of Crowdsourcing and Proposed Crowdsourcing Internet of Things
### Centralized Architectures of Crowdsourcing
The Social Internet of Things (SIoT) [22] is another approach to spreading tasks and expanding traditional crowdsourcing networks. Utilizing crowdsourcing in SIoT has advantages such as the advancement of large social networks leading to a larger group of workers. SIoT is usually organized according to mutual friendship and thus can be obtained without incentive issues. The authors in [23] proposed an architecture for crowdsourcing in SIoT. The authors proposed a trustworthy crowdsourcing model in SIoT. Their system model of crowdsourcing in SIoT is shown in Figure 3. The architecture contains three components called sensing entities, end-users, and social cloud. It is a 3-layered structure that includes the base layer, component layer, and application layer. The function of the base layer is to provide the infrastructure for computation and storage to support the upper-layer services. The component layer provides tools for basic component implementation such as owner control, ID management, object profiling, and so on. The function of the application layer is to serve as the interface for the sensing entities, human participants, and end-users. \begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt} p{142.3 pt}} \hline \hline
**Authors \& Ref** & **Year** & **Focus Areas** \\ \hline \multirow{4}{*}{[PERSON] et al. [17]} & \multirow{4}{*}{2014} & Crowdsourcing architecture/platform with a focus on distributed applications. It contains three contributions: (1) QoS requirements for requesters; (2) Strategies for platform management and execution; and (3) Human aspects and worker characteristics. \\ \hline \multirow{4}{*}{[PERSON] et al. [18]} & \multirow{4}{*}{2014} & A task-oriented crowdsourcing system was proposed to connect the worker, the requester. Authors focused on task management in crowdsourcing and complex tasks. Crowd tasks are classified into subtasks (e.g., partition, aggregation, qualification, and grading). \\ \hline \multirow{4}{*}{[PERSON] et al. [19]} & \multirow{4}{*}{2015} & The authors described two models for mobile crowdsourcing: (1) Internet-based and; (2) Local-based. In the Internet-based model, mobile users can be utilized as service providers. In the local-based model, users within the vicinity can provide cloud services in local-based crowdsourcing. \\ \hline \multirow{4}{*}{[PERSON] et al. [20]} & \multirow{4}{*}{2015} & Authors used crowdsourcing to exploit the sensors and other equipment for setting up IoT networks and focused on a more straightforward extension of Internet-enabled WSN to form IoT. \\ \hline \multirow{4}{*}{[PERSON] and [PERSON] [21]} & \multirow{4}{*}{2017} & Authors applied crowdsourcing to simplify and focused on reducing the dependency of IoT networks on the service gateways to reduce the cost of the system. Their work showed the potential of applying crowdsourcing in futuristic IoT. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._Figure 2: Centralized mobile crowdsourcing architecture for IoT [129].