Mauro Brunato, Roberto Battiti and Elio Salvadori

Dynamic Load Balancing in WDM Networks}

Università di Trento,
Dipartimento di Informatica e Telecomunicazioni,
via Sommarive 14,
I-38050 Pantè di Povo (TN),
Italy
Email: brunato|battiti|salvador@dit.unitn.it

Optical Networks Magazine, 3Q 2003, to be published.

In this paper new load balancing techniques are proposed
based on IP-like routing, where the forwarding mechanism
is only driven by the destination address. The aim of this
work is to consider the applicability of this approach in
the context of optical networks.

The proposed algorithm (RSNE - Reverse Subtree Neighborhood
Exploration) implements a local search technique where the
basic step is the modification of a single entry in the
routing table of a node. A randomized method with reduced
computational complexity (fRSNE - fast RSNE) is also
presented and analyzed. Both schemes allow an incremental
implementation where local search steps are continuously
performed as traffic conditions change.

Experiments under static and dynamic (time varying) traffic
scenarios show a rapid reduction of the congestion. The
performance of the incremental scheme while tracking a
changing traffic matrix is comparable to that obtainable
through the complete re-optimization of the traffic, while
the randomized implementation is particularly efficient when
scaling properties are considered.