Here is my result
Router Name: TP-Link MR600
Proximity to Mobile Tower: 200 meters
External Antenna: Yes , 2 x 12 DBi LPDA antenna.
Fastest Speed: 100 Mbps. Usual 4G+ speed is 45 Mbps
Internet Speed depends on various factors but I get steady network with router. With antenna it is more stable speed and faster.
Similar result I got with Airtel network.