Mysterious black antennas showing up on cell phone towers in my area

[ultimatebob]

I've been noticing that a bunch of the cell phone towers in my area (Western Connecticut) are starting to be topped with a black antenna on top of the tower. The antenna appears to be about 50% larger than the other white antennas on the tower, and it usually located in the middle of the pole instead of the ring of antennas near the top of the pole.

Are their any cellular engineers here who can tell me what these new antennas are? Is somebody rolling out 4G service in my area, or are these new antennas used for something else?

 

[gsaldivar]

One of the veterans on Howardforums should know this if you can't get an answer here.

 

[corkyg]

Can you take a picture of one of them? That would help ID the antenna.