A method in a network node for allocating to user equipments a respective carrier is provided. The carrier is a frequency carrier for wireless communication. The network node is comprised in a cellular network. The network node identifies (202) a set of carriers. The carriers in the set of carriers each are associated with a respective geographic handover region for handover between cells. The geographic handover regions of the carriers differ from each other more than a threshold. When the network node has identified (203) a group of user group of user equipments with correlated mobility pattern, it allocates (204) to at least two of the user equipments within the group of user equipments a respective carrier. The allocation is performed such that the at least two user equipments in the group are spread among the carriers in the set of carriers.