  Traffic grooming is a major issue in optical networks. It refers to grouping
low rate signals into higher speed streams, in order to reduce the equipment
cost. In SONET WDM networks, this cost is mostly given by the number of
electronic terminations, namely ADMs. We consider the case when the topology is
a unidirectional ring. In graph-theoretical terms, the traffic grooming problem
in this case consists in partitioning the edges of a request graph into
subgraphs with a maximum number of edges, while minimizing the total number of
vertices of the decomposition. We consider the case when the request graph has
bounded maximum degree $\Delta$, and our aim is to design a network being able
to support any request graph satisfying the degree constraints. The existing
theoretical models in the literature are much more rigid, and do not allow such
adaptability. We formalize the problem, and solve the cases $\Delta=2$ (for all
values of $C$) and $\Delta = 3$ (except the case C=4). We also provide lower
and upper bounds for the general case.
