Massive MIMO is a technology where tens or even hundreds of antennas are used alongside technologies like beamforming to give a very large capacity gain to an area. It is most commonly deployed with TDD on high frequencies like 2600MHz. In the case of the installation below, 2300MHz TDD is used (Band 40) by O2 UK.
O2 UK Massive MIMO in near Marble Arch
Nokia AANA Massive MIMO
Nokia AANA B40 2300MHz LTE Massive MIMO panel near Marble Arch. The passive antenna is a Commscope CVV2NPX308.208R or similar.
The Massive MIMO panel with the Nokia FZNJ RRU for the previous 4T4R 2300MHz 4G visible behind the Commscope panel.
Field Test Screenshots
TM8-2L(P7,8) transmission mode with sa2 and ssp5 config. 40MHz bandwidth across two carriers.