A subscription server (10, 11) for handling establishment and maintenance of wireless communication sessions, and for handling handover of a user equipment, UE, between a first and a second wireless communication network, comprising: - a processing unit; - a memory unit; - at least one communication interface (204, 205); wherein the processing unit is arranged to operate instructions stored in the memory unit for tranceiving information control messages, the control messages relating to connection status of the UE in relation to the first and the second wireless communication network, wherein at least one wireless communication network is a 3GPP type and at least one is a non-3GPP type, through the at least one communication interface (204, 205), wherein the subscription server (10, 11) is configured to: - receiving a request for information of IP address from a first mobility management device (7, 8) of the first wireless communication network; - sending a response to the first mobility management device (7, 8) of the first wireless communication network with the IP address; - sending information about connection status of the UE to a second mobility management device (7, 8) in the second wireless communication network, wherein the connection status comprises that a Mobility Management, MM, state in the MME and/or SGSN is modified such that the UE is classified as in state IDLE_non_3GPP_access, or the registration status in AAA server is modified such that the UE is classified as in state IDLE_3GPP access, enabling that the UE is prevented from being detached. - a processing unit; - a memory unit; - at least one communication interface (204, 205); wherein the processing unit is arranged to operate instructions stored in the memory unit for tranceiving information control messages, the control messages relating to connection status of the UE in relation to the first and the second wireless communication network, wherein at least one wireless communication network is a 3GPP type and at least one is a non-3GPP type, through the at least one communication interface (204, 205), wherein the subscription server (10, 11) is configured to: - receiving a request for information of IP address from a first mobility management device (7, 8) of the first wireless communication network; - sending a response to the first mobility management device (7, 8) of the first wireless communication network with the IP address; - sending information about connection status of the UE to a second mobility management device (7, 8) in the second wireless communication network, wherein the connection status comprises that a Mobility Management, MM, state in the MME and/or SGSN is modified such that the UE is classified as in state IDLE_non_3GPP_access, or the registration status in AAA server is modified such that the UE is classified as in state IDLE_3GPP access, enabling that the UE is prevented from being detached. - receiving a request for information of IP address from a first mobility management device (7, 8) of the first wireless communication network; - sending a response to the first mobility management device (7, 8) of the first wireless communication network with the IP address; - sending information about connection status of the UE to a second mobility management device (7, 8) in the second wireless communication network, wherein the connection status comprises that a Mobility Management, MM, state in the MME and/or SGSN is modified such that the UE is classified as in state IDLE_non_3GPP_access, or the registration status in AAA server is modified such that the UE is classified as in state IDLE_3GPP access, enabling that the UE is prevented from being detached.