2,082 research outputs found
Drop cost and wavelength optimal two-period grooming with ratio 4
We study grooming for two-period optical networks, a variation of the traffic
grooming problem for WDM ring networks introduced by Colbourn, Quattrocchi, and
Syrotiuk. In the two-period grooming problem, during the first period of time,
there is all-to-all uniform traffic among nodes, each request using
of the bandwidth; and during the second period, there is all-to-all uniform
traffic only among a subset of nodes, each request now being allowed to
use of the bandwidth, where . We determine the minimum drop cost
(minimum number of ADMs) for any and C=4 and . To do
this, we use tools of graph decompositions. Indeed the two-period grooming
problem corresponds to minimizing the total number of vertices in a partition
of the edges of the complete graph into subgraphs, where each subgraph
has at most edges and where furthermore it contains at most edges of
the complete graph on specified vertices. Subject to the condition that the
two-period grooming has the least drop cost, the minimum number of wavelengths
required is also determined in each case
Optimization in Telecommunication Networks
Network design and network synthesis have been the classical optimization problems intelecommunication for a long time. In the recent past, there have been many technologicaldevelopments such as digitization of information, optical networks, internet, and wirelessnetworks. These developments have led to a series of new optimization problems. Thismanuscript gives an overview of the developments in solving both classical and moderntelecom optimization problems.We start with a short historical overview of the technological developments. Then,the classical (still actual) network design and synthesis problems are described with anemphasis on the latest developments on modelling and solving them. Classical results suchas Mengerâs disjoint paths theorem, and Ford-Fulkersonâs max-flow-min-cut theorem, butalso Gomory-Hu trees and the Okamura-Seymour cut-condition, will be related to themodels described. Finally, we describe recent optimization problems such as routing andwavelength assignment, and grooming in optical networks.operations research and management science;
Power consumption evaluation of circuit-switched versus packet-switched optical backbone networks
While telecommunication networks have historically been dominated by a circuit-switched paradigm, the last decades have seen a clear trend towards packet-switched networks. In this paper we evaluate how both paradigms perform in optical backbone networks from a power consumption point of view, and whether the general agreement of circuit switching being more power-efficient holds. We consider artificially generated topologies of various sizes, mesh degrees and not yet previously explored in this context transport linerates. We cross-validate our findings with a number of realistic topologies. Our results show that, as a generalization, packet switching can become preferable when the traffic demands are lower than half the transport linerate. We find that an increase in the network node count does not consistently increase the energy savings of circuit switching over packet switching, but is heavily influenced by the mesh degree and (to a minor extent) by the average link length
Energy-Efficient Design of Wavelength-Routing Networks
We discuss the power-aware Logical Topology Design problem in wavelength routing net- works, and analyze the economical impacts of power-efficiency. Results show that energy-optimized logical topologies can bring significant economical saving
Time Shared Optical Network (TSON): a novel metro architecture for flexible multi-granular services
This paper presents the Time Shared Optical Network (TSON) as metro mesh network architecture for guaranteed, statistically-multiplexed services. TSON proposes a flexible and tunable time-wavelength assignment along with one-way tree-based reservation and node architecture. It delivers guaranteed sub-wavelength and multi-granular network services without wavelength conversion, time-slice interchange and optical buffering. Simulation results demonstrate high network utilization, fast service delivery, and low end-to-end delay on a contention-free sub-wavelength optical transport network. In addition, implementation complexity in terms of Layer 2 aggregation, grooming and optical switching has been evaluated
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