## 2 Energy Efficiency (EE) Studies in LAR of Ad Hoc Networks
The conclusion of the previous studies presents the aim and the directions of some interested researchers in MANETs. The majority focused on the reactive part of MANETs, and the energy part is the most important field. Table 2 summarizes the related studies. Therefore, this study focuses on the reactive part generally and LAR protocol particularly to enhance the performance and minimize energy consumption. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Author’s** & **Protocol** & \multicolumn{2}{c}{**Methodology/Disadvantages**} & **Proactive** & **Reactive** & **Hybrid** \\ \hline
[26] & \multirow{3}{*}{AODV} & **Method:** This study enhanced the performance of AODV based on the location information of the & & & \\  & & **LAS protocol to minimize energy consumption. & & & \\  & & **Disadvantage:** LAR protocol default setup lacking with redundant of flooding in the request zone. & & & \\  & & This might increase the overhead and EE deadly. & & & \\ \hline \multirow{4}{*}{[27]} & \multirow{4}{*}{LAR-1} & **Method:** LAR-1 developed with the association of the Power-Aware Dynamic Source Routing & & & \\  & & (PADSR) energy model. The concentration of the energy model was truly affected by the MANET & & & \\  & & & network. & & \\ \cline{1-1}  & & **Disadvantage:** referring to the simulation parameters in the environment if being increased and the number of nodes is the same. In this case, the distance between the nodes increased and the possibility to drop the packet is high when the node shutdown. & & \\ \hline \multirow{4}{*}{[20]} & \multirow{4}{*}{ALAR-DA} & **Method:** This contribution of this study by adding (ALAR-DA) to achieve and reduce the redundant & & \\  & & route discovery propagations by using both a scheme of restricted flooding and directional antennas. & & \\ \cline{1-1}  & & **Disadvantage:** assuming we have a smaller number of nodes in the simulation environment, the complexity to deliver packet into the destination node. & & \\ \hline \multirow{4}{*}{[28]} & \multirow{4}{*}{LAZARP} & **Method:** A new model, called Location-Aided Zone Routing Protocol (LAZRP), studies the mechanism that is used to seek for the route from the source node to the destination node with high probability. This method ball to create many idle paths in the network and cost the overhead. & & \\  & & **Disadvantage:** there’s no concern about energy consumption. & & \\ \hline \multirow{4}{*}{[29]} & \multirow{4}{*}{PA-LAR} & **Method:** use Linear Regression and curve intersection point are to minimize the request zone and organize node behavior on the base of the battery level. & & \\  & & **Disadvantage:** Does not consider energy for route computation. & & \\ \hline \multirow{4}{*}{[30]} & \multirow{4}{*}{CQRP} & **Method:** Consider two aspects. firstly, the path,bandwidth from the source node to the destination node. secondly, the routing,cost requirements to select the middle node (host) should be chosen the lowest cost as small as possible. & & \\  & & **Disadvantage:** High probability of route & & \\ \cline{1-1}  & & **Disadvantage:** High probability of route & & \\ \hline \multirow{4}{*}{[31]} & \multirow{4}{*}{QG-OLSR} & **Method:** Reduce the consumption of the network topology control and reduce the time delay for & & \\ \cline{1-1}  & & & EE delay packet transmission between the nodes by using new augmented Q-Learning algorithm. & & \\ \cline{1-1}  & & **Disadvantage:** Nodes do not exchange & & \\ \cline{1-1}  & & & their energy states information. & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of related work in MANET.