A multiband antenna system comprises a first massive multiple input multiple output (mMIMO) antenna array comprising a plurality of first antenna elements for use in a first frequency band and at least a second antenna array comprising a plurality of second antenna elements for use in a second frequency band lower than the first frequency band. The second antenna array is at least partially interleaved with the first mMIMO antenna array. The multiband antenna system further includes a distribution network for distributing input and/or output signals of the antenna elements of the second antenna array arranged in a distribution layer, and a transition device.