  Topology is a fundamental part of a network that governs connectivity between
nodes, the amount of data flow and the efficiency of data flow between nodes.
In traditional networks, due to physical limitations, topology remains static
for the course of the network operation. Ubiquitous data networks (UDNs),
alternatively, are more adaptive and can be configured for changes in their
topology. This flexibility in controlling their topology makes them very
appealing and an attractive medium for supporting "anywhere, any place"
communication. However, it raises the problem of designing a dynamic topology.
The dynamic topology design problem is of particular interest to application
service providers who need to provide cost-effective data services on a
ubiquitous network. In this paper we describe algorithms that decide when and
how the topology should be reconfigured in response to a change in the data
communication requirements of the network. In particular, we describe and
compare a greedy algorithm, which is often used for topology reconfiguration,
with a non-greedy algorithm based on metrical task systems. Experiments show
the algorithm based on metrical task system has comparable performance to the
greedy algorithm at a much lower reconfiguration cost.
