On the roof of the student residence at Halbauer Weg 19/21, between all the Telekom-owned sites, there are two o2 LTE antennas.
the student residence seen from west (Brieger Str.): Presumabely, the two separate o2 antennas are left and in front of some Telekom mast.
seen from north (Kamenzer Damm): Telekom owns everything on this roof, except two o2 antennas, that could be second from right