## 2 Materials and Methods
### Technical Discussions on Related Works
#### 2.1.1 Wireless Sensor Networks and Challenges  
WSNs are vastly used for establishing autonomous communication environments, Internet of Things (IoT) platforms and other distributed networks. As a collection of tiny sensor nodes is responsible for multi-path distributed communication, the effective utilization of medium, channel slot management and routing processes executed are expected to be optimized under limited energy-consumption practices. Generally, WSNs are categorized as static WSNs, mobile WSNs, deterministic WSNs, uncertain WSNs, single base station (BS) WSNs, multiple BS WSNs, direct-hop WSNs, multi-hop WSNs, homogeneous WSNs and heterogeneous WSNs (IoT), etc. The environment of various types of WSNs consists of crucial network properties such as energy optimization, network scalability, node responsiveness, communication reliability and node mobility. A wireless sensor node deployed in the field has internal components such as sensor units, data processing units, data communication units and optional software modules (operating system or system software). The sensor nodes used in WSNs are identified as generic, special purpose, gateway and other higher models. In this regard, [PERSON] et al. [1] proposed an energy-efficient data communication strategy for organizing the sensing, processing and data transmission tasks in each sensor node. The novel contribution of this work was identifying and managing disjoint connected dominating sets around the WSN. At the same moment, the nodes that were not participating in the communication were considered as disjoint entities. The connected dominating sets managed a logical association between various disjoint nodes in the network. The logical construction of connected dominating sets provided the optimal energy wastage spent from inactive sensor nodes. On the other hand, this work had not provided a crucial cross-sectional energy optimization model at different layers. [PERSON] et al. [2], [PERSON] et al. [3] and [PERSON] et al. [4] discussed various types of WSNs, wireless data communication and applications. Among these works, [PERSON] et al. explained the scenarios and practical difficulties of mobile sensor networks where the nodes are allowed to move around the geographical region. As discussed, each type of WSN architecture is important for appropriate field applications. Notably, mobile WSNs have the most flexible yet unstable network architectures against the uncertainties of wireless medium and network failures. In this situation, the responsibilities of channel allocation strategies, WMAC transactions and routing protocols are crucial compared to other types of standard WSNs. On behalf of these wireless network environments, [PERSON] et al. and [PERSON] et al. discussed the common functions of WSNs and the applications. These works deliver the recent needs of wireless communication technology and sensor platforms. The growth of WSNs is placed around the fields of agriculture, health monitoring systems, home automation systems, industrial automation systems, military security systems, ocean monitoring systems, wild animal tracking systems, underground sensor systems and other object surveillance systems. Each type of application-specific system needs a suitable set of wireless sensor nodes with various configurations. According to that, the processor model, memory model, signal transmitter, signal receiver, signal converters, sensor standards and the type of power source are selectively considered for managing overall network functions. On that note, this work provided the details of data collection techniques, coverage properties and other communication strategies. Figure 1 gives the internal components of a generic wireless sensor node. [PERSON] et al. [5] analyzed the problems of distributed sensor data collection and accumulation throughput rate.