a.Certain regions with weak even blind signal,such as underground or semi-underground places of business,basements,parking lots etc.
b.Small-scale areas with signal not strong enough,such as conference rooms,offices,small supermarkets,shopping malls and some special public places like public security system and road safety management.
c.Large-scale places with weak signal,such as hotels,bars,cafes,dance halls,clubs,KTV rooms etc.
d.Elevator,subway,tunnels,lift wells in particular,not in the lift cables laid.
e.Homes,luxury yards,private cars etc.