Abstract: In a heterogeneous network environment a method of selecting an access router (20) among a number of available access routers (20, 22, 24) for a group of mobile network nodes (14) attached to a mobile router (12), each access router (20, 22, 24) providing access to packet-switched resources in a respective network domain (26, 28, 30) and each mobile network node (14) having a desired QoS level at the network layer, which method comprises the steps of: (a) determining a group QoS level acceptable to substantially all mobile network nodes (14) in said group; (b) using said group QoS level to query at least one of said number of respective network domains (26, 28, 30) to determine whether or not it can meet said group QoS level; and (c) using a response from said at least one network domain (26, 28, 30) to decide whether or not to perform a network layer handover of said group of mobile network nodes (14) to one of said number of available access routers (20, 22, 24).