# Efficient and Secured Mechanisms for Data Link in IoT WSNs: A Literature Review
## 7 Research Gap in WSN Layers  
Table 1 presents the issues of WSN along with their limitations. The problems are mapped with their constraints, and gray areas are highlighted; we propose attendance to these current weaknesses in order to devise solutions. The table also includes recommendations and research development requirements in the context of WSN issues. A WSN node consists of various resources, such as power, memory, security, processing, network, and so on. Thus, according to the findings, significant problems are due to limited resources, and the required research developments reveal the need to build low-powered frameworks. Still, low power does not mean that security, efficiency, or reliability must be compromised. There is a demand for more reliable, trustworthy, efficient, and secure frameworks. Nevertheless, a low-powered operating system is necessary because WSN is deployed at locations where human intervention is not easily possible.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sr No** & **Issue** & **Limitation** & **Required Research Development** \\ \hline \multirow{2}{*}{1.} & \multirow{2}{*}{Limitation of resources [42; 43; 44]} & Power & There is a need to develop low-powered, low memory, controlled security, and reliable transmission mediums for functional, secure, and fast data communication, which will also prolong the lifetime of the WSN. \\ \hline \multirow{2}{*}{2.} & \multirow{2}{*}{Tampering [29; 45; 46]} & Physical tampering & Reliable network monitoring, network management, and network security protocols prevent or control physical and network attacks and ensure security. The WSN is impermetable, and the network’s performance is unaffected. \\ \hline \multirow{3}{*}{3.} & \multirow{3}{*}{Security [47; 48; 49]} & Network attacks & Researchers need to develop a solution to secure the network and ensure unapproved access, and the hub should maintain access control. The network needs to adapt to the various security conventions. \\ \cline{3-4}  & & Privacy & The OS of the sensor should be a less complex, simple programming environment that is fundamental to memory management. The application engineers should focus on validation activities such as planning, acquiring, and system administration. \\ \hline \multirow{5}{*}{5.} & \multirow{5}{*}{Quality of service [52; 53]} & Network management & The QoS application’s precise limits include organizational participation, dynamic sensors, efficiency, an estimate of sensor detail, dormancy, and delay accuracy. Further, the WSN’s QoS6 can sustain extension, cancelling nodes. It is challenging to track QoS6 boundaries for sensor networks as the geography of the enterprise tends to evolve and data management is unclear. \\ \cline{1-1} \cline{3-4}  & & Resource management & The QoS application’s precise limits include organizational participation, dynamic sensors, efficiency, an estimate of sensor detail, dormancy, and delay accuracy. Further, the WSN’s QoS6 can sustain extension, cancelling nodes. It is challenging to track QoS6 boundaries for sensor networks as the geography of the enterprise tends to evolve and data management is unclear. \\ \hline \hline \end{tabular}
\end{table}
Table 1: WSN issues, limitations, and required research development.