## 5 Data Communication Phase  
The main objective of the setup phase is to improve the performance of the network in the data transmission stage. In this phase, CHs as the coordinators of the cluster transmit the aggregated data to the BS for further processing by the end user according to the type of the application. The transmission of a packet from sensor nodes to the CH (intra-cluster) and from CHs to the BS (inter-cluster) can be done through direct transmission (single-hop) or by assistance of other nodes in the path (multi-hop). While several algorithms use single-hop for intra-cluster and inter-cluster data transmission phases, some other schemes claim it inefficient or even infeasible in implementation, especially in scenarios with numerous number of sensor nodes scattered in large area field. However, according to [PERSON], _et al_. [124], multi-hop transmission is not always the most optimum and energy-efficient solution. By considering the energy transmission model [23] in Equations (21) and (22), the authors of [125] studied the energy-efficiency of single-hop _versus_ multi-hop data communication to find the threshold distance of which transition from single-hop to multi-hop transmission leads to saving energy resources. According to the Equation (21), when the distance to the destination meets the \(\mathrm{d}<\mathrm{d}_{0}\) condition, the communication cost  
Figure 9: Block matching algorithm: macro block moves to all vertical and horizontal displacements in the search area and data correlation is measured at each block.  
between two points is related to the distance by the power of two and it is called short-distance communication. On the other hand, for the condition \(\mathrm{d}\geq\mathrm{d}_{0}\), the transmission cost is related to the distance by the power of four which is called long-distance transmission. By exceeding the transmission distance from \(\mathrm{d}_{0}\), the paper [125] calculates in Equation (23) the threshold value \(\mathrm{d}_{1}\) in which the cost of communication using single-hop outstrips the multi-hop transmission. In this respect, data communication between two nodes can be grouped into three states: single-hop short-distance, single-hop long-distance and multi-hop transmission. While only the cost of transmission of packets are considered in calculation of distance threshold \(\mathrm{d}_{1}\), to achieve a more accurate threshold value, the cost of transition from sleep mode to active state and processing of packets in relay nodes (RN) are two other factors that should be counted:  
\[E_{\mathit{rx}}\left(l,d\right)=\begin{cases}\mathit{IE}_{\mathit{elec}}\,+ \mathit{l}\varepsilon_{\mathit{f}}\,d^{\,2},d\,<\mathit{d}_{0}\\ \mathit{IE}_{\mathit{elec}}\,+\mathit{l}\varepsilon_{\mathit{amp}}\,d^{\,4},d\,\geq\mathit{d}_{0}\end{cases} \tag{21}\]  
\[E_{\mathit{rx}}\left(k\right)=E_{\mathit{elec}}\times l \tag{22}\]  
where \(\mathrm{E}_{\mathit{elec}}\) is the energy consumed by the radio transceiver, \(l\) is the size of the message in bits; \(\varepsilon_{\mathit{f}}\)s and \(\varepsilon_{\mathit{amp}}\) are the parameters of amplifier energy consumption:  
\[\mathit{d}_{0}<d<\sqrt{\frac{\frac{\varepsilon_{\mathit{f}}}{2\varepsilon_{ \mathit{amp}}}+\sqrt{\left(\frac{\varepsilon_{\mathit{f}}}{2\varepsilon_{ \mathit{amp}}}\right)^{2}+4\times\frac{2E_{\mathit{elec}}}{\varepsilon_{ \mathit{amp}}}}}{2}}=\mathit{d}_{1} \tag{23}\]  
According to the number of hops and type of the nodes used to relay data, we classify the intra-cluster transmission into single-hop and multi-hop transmission schemes and inter-cluster transmission schemes into multi-hop by CHs and multi-hop by RNs. Figure 10 shows the taxonomy of the data communication phase.  
Figure 10: The taxonomy of the data communication phase.