Table 1 Notations for some metrics of the energy efficient barrier coverage

R _i

Sensing range of sensor _i i=1 …n

E _r

Remanning energy

t _i

The working time of sensor _i i=1 …n

A _{o i j}

Overlap area between sensor _i and

E _i

Initial energy reserve of sensor _i ,

D _{i j}

Distance between sensor i and j

i,j=1 …n

e _S , e _T , e _R

Energy required for sensing,

transmitting,receiving one unit data