Cell switch-off (CSO) methods for base stations (BSs) in a wireless network are provided. The CSO methods utilize quality of service (QoS) requirement information of user equipments (UEs) to determine which BS to switch off according to a pre-defined criteria. The criteria is defined so that impact of switching off a BS on the UEs may be reduced, and/or QoS requirements of at least some of the UEs may be satisfied if a BS was switched off.