Optimal Placement of Multiple Interconnected Gateways in Heterogeneous Wireless Sensor Networks

Data c ollec ted b y sensors of ten h av e to b e rem otely d eliv ered th rou g h m u lti- h op w ireless path s to d ata sink s c onnec ted to applic ation ser v ers for inform ation proc essing . T h e position of th ese sink s h as a h u g e im pac t on th e q u ality of th e spec i c W ireless S ensor N etw or k ( W S N ) . Ind eed , it m ay c reate ar ti c ial traf c b ottlenec k s w h ic h affec t th e energ y ef c ienc y and th e W S N lifetim e. T h is paper c onsid ers a h eterog eneou s netw or k sc enar io w h ere w ireless sensors d eliv er d ata to inter m ed iate g atew ay s g eared w ith a d iv erse w ireless tec h nolog y and inter c onnec ted tog eth er and to th e sink . An optim iz ation f ram ew or k b ased on Integ er L inear P rog ram m ing (IL P ) is d ev eloped to loc ate w ireless g atew ay s m inim iz ing th e ov erall installation c ost and th e energ y c onsu m ption in th e W S N , w h ile ac c ou nting for m u lti- h op c ov erag e b etw een sensors and g atew ay s, and c onnec tiv ity am ong w ireless g atew ay s. T h e proposed IL P for m u lations are solv ed to optim ality for m ed iu m -siz e instanc es to analy z e th e q u ality of th e d esig ned netw or k s, and h eu r istic alg or ith m s are also proposed to tac k le larg e-sc ale h eterog eneou s sc enar ios.