Table 2. The list of symbols and notations in this article.

Symbol	Description
G	Bi-directed Graph
V	Network size
E	Two-way communication links
C	Direct links
$\gamma$	Noise power
$\eta$	SINR value
$\sigma$	Energy at node
M	Data packet set
d	Distance between the nodes
$\rho$	The energy dissipated in the source and sink
$\alpha$, $\beta$	Space and multipath fading coefficients
$\varpi$	Size of optimal CHs
$\vartheta$	The distance among CHs and CMs
$\tau$	Two CHs distance