# Survey on Power-Aware Optimization Solutions for MANETs
## 5 Challenges and Future Research Directions
### Future Directions
In a CA-MANET, cloud and MANET are formed in an overlay, while the MANET accesses the data centers of cloud servers via the super-peer nodes. Peer nodes are the mobile devices that are connected directly or indirectly within the MANET. Due to various causes (e.g., link failure, mobility, routing overhead, and even low battery power), the connection among the mobile nodes and peer nodes often renew. During this time, CA-MANET consumes a large amount of energy in seeking and connecting the mobile nodes. Therefore, in CA-MANETs, we must propose new energy-efficient routing mechanisms that will perform fast local route discovery between mobile nodes and peer nodes to minimize energy consumption. Such a scheme was proposed recently in [14]. Writing--review and editing, D.K. ; Writing--review and editing, V.K.S. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The authors declare no conflicts of interest. AD-TDMA: Adaptive and Distributed TDMA; AMC: Adaptive Modulation and Coding; AODV: Ad Hoc On-Demand Distance Vector; AODV_RR: AODV Range Routing; AOMDV: Ad Hoc On Demand Multipath Distance Vector; AOMR-LM: Ad Hoc On Demand Multipath Routing with Life Maximization; CEER: Color-theory based Energy-Efficient Routing; CH: Cluster-Head; CL: Cross-layer; CLD: Cross-Layer Design; CLI: Cross-Layer Interaction; CLSP: Cross-Layer Scheduling Protocol; CR: Cognitive Radio; CSI: Channel State Information; DARPA: Defense Advanced Research Projects Agency; DSDV: Destination-Sequenced Distance Vector; DMP_EOISR: Disjointed Multi-Path Routing Extended OLSR; DSR: Dynamic Source Routing; EAR: Energy Aware Routing; EELAM: Energy Efficient Lifetime Aware Multicast route selection strategy; ELBRP: Energy-Level Based Routing Protocol; ELGR: Energy-efficiency and Load-balanced Geographic Routing; EPAR: Efficient Power Aware Routing; ESAS: Energy-Spectrum-Aware Scheduling; ESDR: Energy Saving DSR; FANET: Flying Ad hoc Network; FAR: Flow Augmentation and Redirection; FF-AOMDV: Ad Hoc On Demand Multipath Distance Vector with the Fitness Function; GPS: Global Positioning System; GPSR: Greedy Perimeter Stateless Routing; HCN: Host-Centric Networking; LAER: Link-stability and Energy-aware Routing protocol; LAR: Location Aided Routing; LEAR: Local Energy-aware Routing; LEARN: Localized Energy-Aware Restricted Neighborhood; LEER: Location-aided Energy-Efficient Routing; LMT: Lifetime-aware Multicast Tree; MAC: Medium Access Control; MANET: Mobile Ad hoc Network; MDR: Minimum Drain Rate; MTPR: Minimum Transmission Power Routing; MEA-DSR: Multipath and Energy-Aware on-Demand Source Routing; MECOR: Minimal Energy Consumption with Optimized Routing; MILP: Mixed Integer Linear Programming; MIMO: Multiple-Input Multiple-Output; MPF-MH: Modified Proportional Fairness model with Multi-Hop; MP-OLSR: Multi-Path OLSR; OFDM: Orthogonal Frequency Division Multiplexing; OLSR: Optimized Link State Routing; OMM: On-line Max-Min scheme; PAMAS: Power Aware Multi-Access protocol with Signaling; PEERMR: Predictive Energy-Efficient and Reliable Multicast Routing; PEMA: Predictive Energy-efficient Multicast Algorithm; PHAODV: Power-aware Heterogeneous AODV; PLR: Packet Loss Ratio; PSO: Particle Swarm Optimization; QoS: Quality of Service; QoE: Quality of Experience; RERMR: Residual-Energy-based Reliable Multicast Routing; RI-MAC: Receiver-Initiated MAC; RSS: Received Signal Strength; SINR: Signal-to-Interference-and-Noise Ratio; SLR: Serial Linear Programming Rounding; S-MAC: Sensor-MAC; TORA: Temporally-Ordered Routing Algorithm; TDMA: Time Division Multiple Access; T-MAC: Timeout-MAC; VANET: Vehicular Ad hoc Network; WEEM: Weight-based Energy-Efficient Multicasting; WMSN: Wireless Multimedia Sensor Network; WSN: Wireless Sensor Network; ZCG: Zone-based routing with a parallel Collision-Guided broadcasting protocol.