1. A system for facilitating handover of a mobile device across heterogeneous access networks by ensuring response to queries transmitted by the mobile device, comprising: a) a mobile device having a plurality of wireless network interfaces for communicating over a plurality of heterogeneous access networks, having a media independent handover (MIH) entity to facilitate handovers between the heterogeneous networks, and configured to transmit queries related to handover operation between the heterogeneous access networks to MIH entities within said heterogeneous access networks; and b) said media independent handover entity of said mobile device being configured to transmit multiple queries in a single message exchange to an MIH entity in an access network with prioritization among said multiple queries, said prioritization identifying respective priorities of the queries of said multiple queries to establish which of said queries shall be responded to in a single query response message that has a response to a low priority query removed when said single query response cannot accommodate responses to all of said multiple queries.