Research Article

Prolonging the Lifetime of Two-Tiered Wireless Sensor Networks with Mobile Relays

Table 1

Comparison of energy consumption between ILP-S and MILP-S for several grid sizes.

Grid size (nodes)
Energy conservation method 24 × 24
(576)
30 × 30
(900)
40 × 40
(1600)
50 × 50
(2500)
60 × 60
(3600)
70 × 70
(4900)
80 × 80
(6400)
90 × 90
(8100)
100 × 100
(10000)

Performance2,58%5,69%7,06%11,53%12,35%12,43%13,15%14,99%16,02%
4ILP-S0,007850,0129350,0249450,0439360,0723390,1029090,1380250,2094710,282038
MILP-S0,0076470,0121990,0231840,0388710,0634030,0901130,1198770,1780730,236846

Performance3,19%4,22%5,28%9,18%9,45%13,29%15,86%16,38%18,61%
9ILP-S0,0076150,0122120,0226970,0380560,0571820,0864480,1212810,1593430,220506
MILP-S0,0073730,0116970,0214980,0345620,0517800,0749580,1020470,1332370,179472

Performance8,88%9,63%9,80%10,44%11,19%11,56%11,95%12,90%14,31%
16ILP-S0,0075780,0120980,0219890,0357270,0544010,0766940,1034740,1386660,18038
MILP-S0,0069060,0109330,0198340,0319960,0483150,0678250,0911120,1207720,154576

Performance7,42%8,39%9,56%10,29%11,49%12,38%12,94%13,11%15,88%
25ILP-S0,0075370,0119540,0219170,0350730,0525460,0738130,1006760,1318260,168469
MILP-S0,0069780,0109510,0198210,0314630,0465080,0646770,0876520,1145410,141715