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CROSS-LAYER DESIGN ISSUES
9.7.4 Stability
As already mentioned, a cross-layer design leads to several adapta-
tion loops. e complex interaction of these loops may endanger the
stability of the system. Although cross-layer design offers tremendous
opportunities, at the same time it has several critical disadvantages
that may hinder the proliferation of wireless networks. e cross-
layer approach should thus be used with caution. Much functionality,
like transmit power control and channel state estimation, is typical
of wireless networks and requires a cross-layer approach. In cases
where the cross-layer design is necessary, it should be ensured that the
implementation is not very aggressive (i.e., does not rely too much on
information excha ...