Due to the relevance of seamless mo

Due to the relevance of seamless mobility in future
networks, a significant amount of related work has
been published by the academic community until this
moment. In [9] and [10], vertical handover schemes
based on IEEE 802.21 are presented. Nevertheless,
both proposals lack interaction between the MIH
framework and the link layer access technologies QoS
specificities. Furthermore, performance measurements
are not given. In [11], a vertical handover scheme
between UMTS and WiMAX, employing the 802.21
framework, is proposed. To guarantee service
continuity, the authors define a new message for the
IEEE 802.21 framework, which supports passive
reservations during the HO preparation phase.
However, resource activation is performed only after
the physical handover is executed, delaying the packet
delivery to the target access technology. Finally, in
[12], a seamless mobility mechanism for
heterogeneous environments is proposed. Instead of
triggering events only from the MAC/PHY layers, the
authors enhance the MIH platform with the capability
to trigger events from the application layer as well,
delivering this information to the mobility decision
engine.