A method of enabling handover of a communication session of a user device (106; 204) from an access network associated with unlicensed spectrum (108; 208) to a circuit-switched access network (110; 214) the method comprising: receiving, by a gateway device (102; 202), a measurement report from the user device, the measurement report including measurements associated with a plurality of access networks, the plurality of access networks including at least the circuit-switched access network and the access network associated with unlicensed spectrum; deciding, by the gateway device based at least in part on the measurement report, to initiate a handover of the communication session of the user device from the access network associated with unlicensed spectrum to the circuit-switched access network; determining, by the gateway device, a session transfer number identifying one or more telecommunication network components (114; 210) which maintain continuity for the communication session; providing, by the gateway device, a handover request to a server associated with the circuit-switched access network, the handover request including the determined session transfer number; requesting, by the server, the one or more telecommunication network components identified by the session transfer number to perform a session transfer; receiving, by the server, a response from the one or more telecommunication network components indicating completion of the session transfer; sending, by the server, a handover response to the gateway device, the handover response from the server indicating that the circuit-switched access network has been prepared for the handover; and upon receipt of the handover response, instructing, by the gateway device, the user device to connect to the circuit-switched access network to continue the communication session. receiving, by a gateway device (102; 202), a measurement report from the user device, the measurement report including measurements associated with a plurality of access networks, the plurality of access networks including at least the circuit-switched access network and the access network associated with unlicensed spectrum; deciding, by the gateway device based at least in part on the measurement report, to initiate a handover of the communication session of the user device from the access network associated with unlicensed spectrum to the circuit-switched access network; determining, by the gateway device, a session transfer number identifying one or more telecommunication network components (114; 210) which maintain continuity for the communication session; providing, by the gateway device, a handover request to a server associated with the circuit-switched access network, the handover request including the determined session transfer number; requesting, by the server, the one or more telecommunication network components identified by the session transfer number to perform a session transfer; receiving, by the server, a response from the one or more telecommunication network components indicating completion of the session transfer; sending, by the server, a handover response to the gateway device, the handover response from the server indicating that the circuit-switched access network has been prepared for the handover; and upon receipt of the handover response, instructing, by the gateway device, the user device to connect to the circuit-switched access network to continue the communication session.