# Survey on Power-Aware Optimization Solutions for MANETs
## 2 Related Work
### Energy-Aware Routing Protocols in MANETs
\begin{table}
\begin{tabular}{p{56.9 pt} p{142.3 pt} p{142.3 pt}} \hline \hline
**Year** & **Ref.** & **Focus** \\ \hline
2020 & [57] & It presents energy-based clustering algorithms. It proposes a cross-layer clustering framework and a hybrid self-organization clustering model that improves QoS in cluster-based MANETs. \\ \hline
2019 & [56] & It presents various types of scheduling techniques for MANETs. It analyses load-based queue scheduling and presents cross-layer schedulers for power control. Most of these techniques are related to power-efficient routing. \\ \hline
2018 & [23] & It exposes the critical view on why a HCN-based MANET is not energy-efficient by explaining the incompatibility of the HCN paradigm with the MANET itself. \\ \hline
2017 & [26] & It presents existing solutions on QoS routing and resource reservation methods to support multimedia communication over MANETs. It considers the limitations of existing QoS models. \\ \hline
2017 & [20] & It discusses the challenging factors in MANETs by focusing on power-based routing metrics. It classifies existing power-efficient routing algorithms in MANETs into six categories. It compares the routing schemes in each category, based on their merits and limitations. It also highlights their main features. \\ \hline
2015 & [55] & It considers diverse routing schemes investigating the benefits of multi-antenna aided relay nodes, the Frame Error Ratio (FER), the number of MAC retransmissions, and the number of hops on the performance energy consumption. \\ \hline
2013 & [53] & It classifies energy-efficient routing protocols in WSNs into four main categories. It surveys and analyses energy-efficient routing protocols for WSNs. \\ \hline
2012 & [54] & It presents energy-efficient routing techniques for WSNs. It discusses the design challenges of routing protocols for WMSNs and classifies current methods with their limitations. \\ \hline
2012 & [52] & It reviews only the PHY layer techniques for energy-efficient wireless communication, such as MIMO and OFDM, cognitive radio, network coding, cooperative communication, etc. \\ \hline
2011 & [58] & It presents cross-layer solutions for WSNs, including cross-layer energy-efficient routing protocols. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Previous surveys that summarize research into power-efficient routing in mobile ad hoc networks (MANETs). energy consumption state, the researchers have recommended the optional feature of actively adapting the operation mode of radio state (i.e., either to switch the operational mode into active/idle/sleep or simply shut the radio state off). Nevertheless, we cannot simply switch the operational modes blindly; instead, it involves efficient coordination and complex synchronization to guarantee efficient delivery. In conclusion, routing schemes based on the active and in-active energy consumption states focus on minimizing the individual node's energy consumption. In the next subsection, we analyze power-aware routing that can be used for determining optimum routes in energy-efficient MANETs.