# Energy-Efficient Opportunistic Routing Algorithm for Post-Disaster Mine Internet of Things Networks
## 2 Related Work
### Opportunistic Routing Protocols  
Opportunity Routing (OR) was proposed mainly to improve the packet delivery rate of wireless networks. The design of an OR protocol focuses on four aspects: \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
\begin{tabular}{c} balances node energy \\ consumption \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison of MIoT routing protocols. (1) construction of the candidate forwarding set, (2) selection of relay nodes and forward coordination, (3) data transmission and identification, and (4) dynamic adaptation to network topology changes. Currently, a plethora of OR protocols have been designed for various application scenarios [21]. [PERSON] et al. [22] proposed an opportunistic routing protocol based on trajectory prediction (EORB-TP) to deal with the dynamic topology and unstable links of the FANET. EORB-TP defines the trajectory metric value based on node movement distance, node direction, and node density. In EORB-TP, an energy-saving data forwarding strategy is designed to deal with the limited energy resources and storage space of UAVs. In [23], the Delay and Duplicate transmission Avoid CFS optimization algorithm (DDA) was proposed to reduce the transmission delay and duplicate transmission in opportunistic routing for wireless muti-hop networks. DDA divides the nodes in the CFS into different fully connected relay networks and chooses the most appropriate relay network based on the multi-attribution decision-making (MADM) theory. [PERSON] et al. [24] proposed an opportunistic routing algorithm based on trust relationships for wireless mesh networks (WMNs) to solve the problem of low message delivery rate and high network resource consumption when forwarding messages in opportunistic networks. [PERSON] et al. [25] proposed an efficient and reliable transmission power control-based opportunistic routing (ERTO) for wireless ad hoc networks to improve packet delivery probability and reduce energy consumption and network interference. In ERTO, the packet delivery probability, the expected energy consumption, and the relationship between transmission power and node degree are applied to optimize the transmission power and forwarding node degree jointly. [PERSON] et al. [26] proposed a Hierarchical learning-based sectionalized routing paradigm for pervasive communication and Resource efficiency (HiLSeR) in an opportunistic IoT network. HiLSeR enables message routing using a combination of controlled-parameterized flooding and opportunistic sector-based decentralized transmission. [PERSON] et al. [27] proposed a Sector-based Opportunistic Routing (SectOR) protocol for hybrid underwater optic acoustic networks. SectOR uses a variety of local and global metrics to evaluate the fitness of a candidate set (CS) and develops candidate prioritization techniques for various OR metrics. [PERSON] et al. [28] proposed a Network Coding Combined with Link Correlation (NCCLC) method to improve the energy efficiency in wireless edge IoT applications. In NCCLC, the link correlation was considered when calculating the number of required forwarding and selecting the forwarder set. In [29], the Community clustering Routing protocol based on information Entropy in mobile opportunity Networks (CREN) was proposed to deal with the different characteristics between communities and the inefficient nodes after community clustering. CREN reduces the transmission delay and routing overhead. [PERSON] et al. [30] proposed the detection of selfish nodes in a dynamic ad hoc network (DANET) via employing evidence-based detection. An Improved Self-Centered Friendship (ISCF) tree was constructed using Trust Authority (TA) to deal with security issues. The proposed method performs well in terms of selfishness detection accuracy and selfishness detection time. In [31], a Communication Trust and Energy Aware (CTEA) routing protocol was proposed to mitigate the effects of bad mouth and energy drain attacks.