Help Antenna for this scenario.

[Misterx1412]

Hello po! Ano po kaya magandang antenna para sa isang modem ZTE MF286RA na nasa 4th floor, no balcony nor windows (closed environment), low signal (due to the building siguro) pero super lapit sa cell tower?

Sabi po nila dapat daw po walang obstructions yung mga outdoor antenna like mimo antenna or hybdrid, so ano po dapat na antenna gamitin namin?