An apparatus and method for feeding back channel state information are disclosed. The method of providing channel state information for a wireless communications channel provided between a first network node having at least one transmission antenna and a second network node having at least one reception antenna comprises the steps of: estimating a current value of at least a first type of channel state information for at least one sub-channel within the channel from signals received by the at least one reception antenna over the channel from the at least one transmission antenna; determining whether the current value of the first type of channel state information varies from previously-transmitted value for the first type of channel state information by at least a predetermined amount; and if so, transmitting an indicator indicative of the current value for the first type of channel state information to the first network node.