In a wireless network environment comprising first and second packet-switched access networks, each access network using a tunnelling-type micro-mobility protocol and a Quality of Service (QoS) routing protocol to route packet data to and from mobile nodes attached thereto, and each access network comprising an access router to which a mobile node may attach, a mobility agent with which said mobile node may register and a gateway, a method of facilitating network layer handover of said mobile node from said first access network to said second access network, said mobile node registered in said first access network with a serving mobility agent, which method comprises the steps of: said mobile node receiving a router advertisement from said second access network, which router advertisement comprises a network-layer address of a target mobility agent in said second access network with which said mobile node may register; and said mobile node forwarding said network-layer address to said serving mobility agent, whereby said serving mobility agent may communicate with said target mobility agent to facilitate network-layer handover of said mobile node to said second access network.