A method for wireless communications, comprising: operating a target master network element using a first radio access technology, RAT, in a wireless communication network to provide connectivity to a first core network; receiving, by the target master network element in a handover of a user device from a source master network element that uses the first RAT and provides connectivity between the user device and a second, different core network, information from the source master network element, wherein the information comprises properties of a source secondary network element using a second, different RAT that provides a secondary connectivity between the user device and the second core network, wherein the information comprising the properties of the source secondary network element is comprised in at least one container and explicit information elements which are decodable by the target master network element and intermediate relay nodes, wherein the information comprises configuration information of a primary cell and at least one possible secondary cell under the source secondary network element, wherein the number of the secondary cells is greater than or equal to 0, the configuration information comprising user plane configuration information, physical resource configuration information, and Medium Access Control, MAC, layer configuration of at least one cell under the source secondary network element, the information further comprising measurement information provided by the source secondary network element; and determining, by the target master network element, based on the information that identifies properties of the source secondary network element, whether to change a secondary connectivity network element from the source secondary network element to a target secondary network element that operates using the second RAT and provides connectivity to the first core network. operating a target master network element using a first radio access technology, RAT, in a wireless communication network to provide connectivity to a first core network; receiving, by the target master network element in a handover of a user device from a source master network element that uses the first RAT and provides connectivity between the user device and a second, different core network, information from the source master network element, wherein the information comprises properties of a source secondary network element using a second, different RAT that provides a secondary connectivity between the user device and the second core network, wherein the information comprising the properties of the source secondary network element is comprised in at least one container and explicit information elements which are decodable by the target master network element and intermediate relay nodes, wherein the information comprises configuration information of a primary cell and at least one possible secondary cell under the source secondary network element, wherein the number of the secondary cells is greater than or equal to 0, the configuration information comprising user plane configuration information, physical resource configuration information, and Medium Access Control, MAC, layer configuration of at least one cell under the source secondary network element, the information further comprising measurement information provided by the source secondary network element; and determining, by the target master network element, based on the information that identifies properties of the source secondary network element, whether to change a secondary connectivity network element from the source secondary network element to a target secondary network element that operates using the second RAT and provides connectivity to the first core network.