Methods and network nodes of a wireless telecommunications system are disclosed. One method of controlling transmissions with a base station of a wireless telecommunications system comprises the steps of: determining a set of neighbouring base stations, each base station in the set of neighbouring base stations utilising an identical carrier and scrambling code to support transmissions with that base station; and allocating base stations in the set of neighbouring base stations different spreading codes for transmissions with those base stations. By allocating each base station in the set of base stations sharing the same carrier and scrambling code different spreading codes, interference in transmissions between the base stations can be controlled.