An invention to perform a method of cell measurement in a wireless network, wherein the wireless network comprises a plurality of frequency layers, the invention configured to: determine a Measurement Gap Length, MGL, for each one of the plurality of frequency layers operational in the wireless network; determine a gap bitmap to indicate a measurement gap availability in a time sequence for each one of the plurality of frequency layers of the wireless network; and transmit gap assistance information for each one of the plurality of frequency layers of the wireless network to a User Equipment, wherein the gap assistance information comprises at least the determined Measurement Gap Length and the determined gap bitmap.