What are these for?

Does anyone know exactly what this is used for? Its on Roslyn St in Islip Terrace



http://ift.tt/1rXUSZ3







Then there's this. 2 boxes and a yagi on a pole. I have seen these on traffic lights but there are none around this and its in a residential neighborhood



http://ift.tt/12v7IYS







And these that are seen on the lie in nassau, and some of the interstates going in and out of the city.



http://ift.tt/1rXUV78

What are these for?