An Orthogonal Frequency Division Multiplex (OFDM) base station transfers a wideband measurement request for a wideband OFDM spectrum to User Equipment (UE). The base station receives a wideband signal metric from the UE, and if the wideband signal metric is below a threshold, the base station transfers a sub-band null request to shield a sub-band of the wideband spectrum to an adjacent base station. The base station also transfers a sub-band measurement request to the UE. The base station receives a sub-band signal metric for the shielded sub-band from the UE, and if the sub-band signal metric is above a threshold, then the base station authorizes use of the shielded sub-band for the UE. The base station receives a communication request for the UE, and in response, transfers another sub-band null request to the adjacent base station and exchanges wireless data over the shielded sub-band with the UE.