## 4 Proposed Protocol
### MST and Chain Construction Period
In this paper, we propose an EEGT protocol based on grid cells clustering routing mechanism in order to minimize energy consumption within data transmission paths in homogeneous and heterogeneous network models in WSN-based IoT applications. The proposal methodology concentrates on three core contributions. Firstly, EEGT reduces communication distance among nodes inside clusters by dividing the network zone into grid cells with a balancing distribution of sensing nodes; each cell depicts a cluster. Secondly, the proposal protocol considers the distance among nodes within the cell and the node's remaining energy before selecting CHN for each cell to have balanced energy consumption among nodes. Thirdly, EEGT constructs multi-hop data transmission paths for intra-cells and inter-cells based on the MST and ant colony algorithm, respectively, to avoid the long communication

\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Protocols**} & \multirow{2}{*}{**Rounds**} & \multicolumn{6}{c}{**The Percentage of Dead Nodes**} \\  & & **EE (Kbytes/Joule)** & **1\%** & **10\%** & **25\%** & **50\%** & **75\%** & **95\%** & **100\%** \\  & (s) & **(\%\%)** & **(\%\%)** & **(\%\%)** & **(\%\%)** & **(\%\%)** & **(\%\%)** & **(\%)** & **(\%)** \\ \hline \multirow{8}{*}{LEACH-C, [21]} & 10 & 611(2.5) & 321(28) & 12(24.7) & 506(3.7) & 588(2.5) & 683(3.1) & 773(3) & 900(6.8) \\  & 50 & 852(2.3) & 43(20.2) & 157(25.2) & 378(9.8) & 674(5.2) & 1150(3.3) & 1456(2.8) & 1569(5.2) \\  & 100 & 1078(3.2) & 42(20.8) & 201(27.8) & 526(12.2) & 1122(5.8) & 1376(2.2) & 1713(4.7) & 1784(4.8) \\  & 21 & 300 & 470(17.9) & 38(28.6) & 336(35.9) & 1094(9.4) & 14703(5.2) & 1698(4.8) & 2472(13.1) & 2669(9.6) \\  & 10 & 652(2.2) & 385(16.7) & 591(4.3) & 686(4.7) & 787(2.6) & 841(2.2) & 931(2.9) & 981(3.4) \\  & 50 & 849(4.2) & 117(6.1) & 629(18.6) & 880(2.5) & 948(4.5) & 1113(5) & 1315(2.8) & 1348(2.8) \\ \multirow{4}{*}{PEGASIS, [22]} & 100 & 925(4.6) & 93(70.4) & 809(15.9) & 956(18.4) & 945(21.7) & 1220(1.7) & 1509(1.8) & 1535(2.5) \\  & 20 & 1002(9.5) & 73(81.4) & 976(44.1) & 1016(1.4) & 1040(1.5) & 1412(1) & 1808(0.5) & 1833(1.6) \\  & 20 & 1004(1.7) & 378(13.6) & 556(7.4) & 704(2) & 907(7.2) & 1127(10.9) & 1462(11.2) & 1617(12.8) \\ \multirow{4}{*}{PEGCP, [25]} & 50 & 1069(1.7) & 349(22.3) & 557(8.7) & 706(1.5) & 906(4.8) & 1121(4.6) & 1467(11.9) & 1568(13) \\  & 100 & 1093(1.9) & 326(32.6) & 562(8.5) & 710(1.3) & 940(6.2) & 1169(6.7) & 1526(6.7) & 1569(6.8) \\ \multirow{4}{*}{[25]} & 300 & 1142(2.0) & 203(48) & 544(8.7) & 725(6.6) & 970(8.5) & 1234(6.9) & 1623(6.2) & 1702(6.6) \\  & 500 & 1238(22.5) & 184(30.1) & 536(24.9) & 715(22.7) & 1029(24.6) & 1435(28) & 1863(24) & 2041(25.4) \\ \multirow{4}{*}{EEGT} & 10 & 1025(1.6) & 478(9.5) & 673(9.9) & 792(3.1) & 1024(4.4) & 1197(7.6) & 1461(5.9) & 1481(5.8) \\  & 50 & 1091(24.4) & 485(14.9) & 667(10.4) & 787(6.6) & 1017(5.0) & 11978(8.8) & 1423(4.0) & 1431(3.8 distance between CHNs and the sink device. In addition, the simulation results show that the performance of EEGT is better than the LEACH-C, PEGASIS, and PEGCP protocols regarding energy efficiency and the network lifespan in heterogeneous and homogeneous network models. In future work, we would like to improve energy-efficient routing protocols based-clustering in deploying smart micro-sensor nodes underwater for warning unauthorized intrusion detection or tsunami applications. Conceptualization, N.D.T. ; methodology, N.D.T. and D.-N.N.N. ; software, N.D.T. ; validation, T.-T.-H.L. and N.D.T. ; formal analysis, N.D.T., D.-N.N. and H.-N.H.; investigation, N.D.T. and T.-T.-H.L. ; resources, D.-N.N. and H.-N.H.; data curation, N.D.T. ; writing--original draft preparation, N.D.T., D.-N.N. and H.-N.H.; writing--review and editing, N.D.T. and T.-T.-H.L. ; visualization, N.D.T. and D.-N.N.N. ; supervision, T.-T.-H.L. ; project administration, N.D.T. and T.-T.-H.L. ; funding acquisition, T.-T.-H.L. All authors have read and agreed to the published version of the manuscript.