An aspect of the invention is related to an apparatus comprising at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: determine a cell for guard period adaptation; define, for the guard period adaptation, at least two guard period portions of the cell with different guard period lengths within a frame the defining being based on at least one of the following: location of at least one network node in the cell and a propagation delay with respect to the at least one network node, and inform the at least one network node on at least one of the at least two guard period portions of the cell for transmission and/or reception.