Multi-bemaforming advantage ?

I think there are many applications. It can be perimeter security sensor placed in the corner of building or area to form two beams using single transmitter. Or it can be simple old-designed roadside FMCW traffic counter, upgraded with two-beam antenna, so it can estimate vehicle speed with higher accuracy using time difference between beams. Data transmitters can use lower power oscillators and few focused beams, so power is still enough, which can be problem with some single wide-beam or monopole antenna. Some special radars can use multiple beams to scan certain areas as fast as possible. Here some advantages i can think of:
- can use single transmitter, obtain lower power and higher range of operation in certain directions.
- lower interference by isolating unwanted areas from radiation. In data transmission you obtain higher SNR. In radars it simplifies signal processing, although leads to more complex antenna design.