Handover mechanisms in next generation heterogeneous wireless ...

CONCLUSIONS AND FUTURE RESEARCH WORK
Therefore, the thesis research can be extended to explore the QoS mechanisms for
smooth data transfer of seamless handover. QoS context transfer from the source to
target systems has been proposed in a tightly coupled interworking architecture.
However, this approach is not applicable to a handover from the source to target
systems without a trust relationship. In a multi-operator environment, such kind of
handover may occur, and will place new challenges because heterogeneous wireless
networks may lack necessary mechanisms for negotiating QoS.
� Network control over handover across heterogeneous wireless networks: All the
solutions proposed in this thesis are based on the assumption that individual mobile
users control their handover processes in heterogeneous wireless networks for the
clear advantages [123]. However, it may be necessary for network operators to exert
control over their network resources to be allocated to a handover. This requirement
will become more prominent when network collaboration is widely expected and
there is no central party in control. Hence, it will call for a network controlled
handover approach. Network controlled handover that relies on communications
between the source and target systems is available in homogeneous wireless systems
or tightly coupled heterogeneous wireless systems, but will be a challenging issue
for handover across heterogeneous wireless systems belonging to multiple network
operators. Future work may investigate the network controlled handover
mechanisms for such kind of handover.
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