A method for energy saving in a communication network is provided. The method is implemented by a first network device in a communication network. The first network device may be communicatively connected to a second network device by a FlexE group. The method may comprise measuring a traffic rate of one or more FlexE clients carried over the FlexE group, and determining whether one or more PHYs of the FlexE group is to be shut down or activated based on the measured traffic rate and a first shutdown threshold or a first activation threshold.