This brief proposes that the keys to internet cross-layer optimization
are the development of non-standard implicit primal-dual solvers for
underlying optimization problems, and design of jointly optimal network
protocols as decomposition of such solvers. Relying on this novel
design-space oriented approach, the author develops joint TCP congestion
control and wireless-link scheduling schemes for wireless applications
over Internet with centralized and distributed (multi-hop) wireless
links. Different from the existing solutions, the proposed schemes can
be asynchronously implemented without message passing among network
nodes; thus they are readily deployed with current infrastructure.
Moreover, global convergence/stability of the proposed schemes to
optimal equilibrium is established using the Lyapunov method in the
network fluid model. Simulation results are provided to evaluate the
proposed schemes in practical networks.