## 4 Energy Conserving Solutions in Wireless Networking-Based IoT
### Energy Conserving Solutions for WPAN-Based IoT  
WPANs are expected to play a crucial role as an energy efficient connectivity for battery-powered constrained IoT devices, with Bluetooth being one of the widely deployed WPANs. We will discuss the use of Bluetooth and Bluetooth Low Energy (BLE) implementation for energy efficiency in IoT scenarios. We will also discuss Z-Wave, a widely used technology in home environments.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Category** & **Solution** & **Approach** & **Scheme** & **Metric** & **Control** & **Evaluation** \\ \hline \multirow{8}{*}{Overload control} & [63, 96] & Calculated offset listen interval spread among devices & Duty cycling & Energy efficiency & Centralized & Analysis, simulation \\  & & Higher channel access priority to low energy level devices & Device power & Energy efficiency & Distributed & Algorithm, simulation \\  & & Frame slotted alba and tree & Frame slotted alba and tree & Energy efficiency, end-to-end delay & Centralized/ & Analysis, simulation \\  & [65] & splitting algorithm based duty & Duty cycling & Energy efficiency, end-to-end delay & Centralized/ & Analysis, simulation \\  & [66, 67] & PSR and traffic announcement extension for IEEE 802.11 & Duty cycling & Energy efficiency, end-to-end delay & Distributed & Simulation \\  & [68] & Mobility supported PSM & Duty cycling & Energy efficiency, end-to-end delay & Distributed & Simulation \\ Power Saving Mode & [70] & Schedule-aware PSM & Duty cycling & Energy efficiency & Centralized/ & Analysis, simulation \\  & [69] & IEEE 802.11 android power & Transmit power & Energy efficiency, end-to-end delay & Distributed & Experimental test bed \\  & [71] & New low power WiFi & Transmit power & Energy efficiency, interference, communication range & Distributed & Real time experiment \\ \hline \hline \end{tabular}
\end{table}
Table 2: Energy conserving solutions for wireless local area network-based IoT.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Category** & **Solution** & **Approach** & **Scheme** & **Metric** & **Control** & **Evaluation** \\ \hline  & [72] & Virtual grouping for contending and non-contending STAs & Contention alleviation & Energy efficiency & Distributed & Algorithm, simulation \\ Solutions for IEEE & [73] & Performance analysis of IEEE & Transmit power & Energy efficiency, transmission & Distributed & Real time experiment \\
802.11/802.11 ah multi-hop communication collision & [74] & Packets buffering strategy for TIM and non-TIM devices & Duty cycling & Energy efficiency & Centralized/ Distributed & Simulation \\  & [75] & Restricted access window mechanism & Duty cycling & Energy efficiency, throughput, end-to-end delay & Distributed & Analysis, simulation \\  & [69] & Low power radio based interface energy management & Duty cycling & Energy efficiency & Centralized/ Distributed & Simulation \\ Energy saving management & Middleware based on overlay of heterogeneous radio & Duty cycling for devices in & Energy, end-to-end delay and & Energy, end-to-end delay and & Centralized & Simulation \\ interfaces & [77] & Ambient management & overlay network & capacity & Centralized & Simulation \\  & [78] & ZigBee assisted WiFi transmission & Congestion control & Energy efficiency & Centralized & Simulation \\ \hline \hline \end{tabular}
\end{table}
Table 2: _Cont._