A method performed by a network node, for managing a transmission of one or more Cell-specific Reference Signals, CRS, subframes, wherein the network node operates one or more cells (130, 131, 132), the method comprising: identifying if a cell out of the one or more cells is actively serving a set of User Equipment, UEs, or not; when the cell has been identified as not actively serving a set of UEs, sending CRS over a first frequency bandwidth in one or more CRS subframes which are transmitted during a paging occasion and/or in one or more CRS subframes where system information is sent, sending CRS over a second frequency bandwidth in one or more CRS subframes which are not transmitted during a paging occasion and/or in one or more CRS subframes except subframes where system information is sent, which second frequency bandwidth is reduced in relation to the first frequency bandwidth; and when the cell has been identified as actively serving a set of UEs, which set of UEs is configured for a Discontinuous Reception, DRX, sending CRS over the first frequency bandwidth in one or more CRS subframes which are transmitted in the cell during an onDuration interval of the DRX pattern and/or in the one or more CRS subframes where system information is sent and/or in one or more CRS subframes where downlink, DL, data is sent, sending CRS over the second frequency bandwidth, in CRS subframes which are not transmitted in the cell during the onDuration interval of the DRX and/or in the one or more CRS subframes except CRS subframes where system information is sent and/or in the one or more CRS subframes except CRS subframes where downlink, DL, data is sent, which second frequency bandwidth is reduced in relation to the first frequency bandwidth. identifying if a cell out of the one or more cells is actively serving a set of User Equipment, UEs, or not; when the cell has been identified as not actively serving a set of UEs, sending CRS over a first frequency bandwidth in one or more CRS subframes which are transmitted during a paging occasion and/or in one or more CRS subframes where system information is sent, sending CRS over a second frequency bandwidth in one or more CRS subframes which are not transmitted during a paging occasion and/or in one or more CRS subframes except subframes where system information is sent, which second frequency bandwidth is reduced in relation to the first frequency bandwidth; and when the cell has been identified as actively serving a set of UEs, which set of UEs is configured for a Discontinuous Reception, DRX, sending CRS over the first frequency bandwidth in one or more CRS subframes which are transmitted in the cell during an onDuration interval of the DRX pattern and/or in the one or more CRS subframes where system information is sent and/or in one or more CRS subframes where downlink, DL, data is sent, sending CRS over the second frequency bandwidth, in CRS subframes which are not transmitted in the cell during the onDuration interval of the DRX and/or in the one or more CRS subframes except CRS subframes where system information is sent and/or in the one or more CRS subframes except CRS subframes where downlink, DL, data is sent, which second frequency bandwidth is reduced in relation to the first frequency bandwidth.