Traffic Partition Grooming in the Mixed Granularity
and Multi-domain Optical Networks
Weigang Hou, Yue Zong, Lei Guo
College of Information Science and Engineering, Northeastern University, Shenyang, China
Correspondence email: guolei@ise.neu.edu.cn (L. Guo)
Abstract—The demands mixed with the coarse and fine
granularity cause the poor resource utilization and the port
thirsty of previous grooming techniques in Wavelength-Division-
Multiplexing (WDM) optical networks. Furthermore, with the
large scale of the backbone, the optical network has been divided
into multiple domains to achieve the scalability in the real world.
In this paper, we study the gra-diversity problems and facili-
tate the novel traffic partition grooming with the Granularity-
Layered Graph (GLG). Our heuristic is composed of three basic
components: a) the traffic grooming of fine-grained demands,
b) the waveband switching of coarse-grained demands, and c)
the demand migration functioned through the interconnection of
different granular layers in GLG. Extensive simulation results
demonstrate that our method is an alternative option of solving
the gra-diversity problems in the mixed granularity and multi-
domain optical networks.
Index Terms—Mixed granularity, Multi-domain, traffic parti-
tion grooming, demand migration.
I. INTRODUCTION
In recent years, various high-speed network architectures
have seen widespread deployment. At the fiber-level, Dense
Wavelength Division Multiplexing (DWDM) has gained favor
as a terabit solution. The next-generation SONET/SDH has
provided flexible “sub-rate” aggregation. Consequently, the
demand granularity tends to be diverse in the future optical
networks [1]. Though the bandwidth demand does not fill up
an Entire Wavelength Capacity (EWC), there usually exist
two grain levels, “coarse” and “fine”. Coarse-Grained (CG)
demands require the large bandwidth close or equal to an
EWC, while the required bandwidth of Fine-Grained (FG)
demands is far smaller than an EWC.
Currently, prior works on grooming techniques overlooked
gra-diversity problems in mixed granularity optical networks.
On the one hand, the traffic grooming [2-4] multiplexes several
demands into a lightpath. However, once carrying a CG
demand, the lightpath will not be able to hold other demands,
which leads to the poor resource utilization. If we only use
the waveband switching [5, 6], the more demands (especially
for FG demands) in the waveband tunnel, the more consumed
ports in cross-connects, which results in the port thirsty.
Meanwhile, the scale of the future optical networks keeps
enlarging. To ensure the scalability, the optical network has
been divided into multiple domains [7, 8]. Each domain is
a local automatic system managed by an independent vendor
and only distributes partial information to others. In a single
domain, the interior nodes cannot obtain the global topology.
Fig. 1. The mixed granularity and multi-domain optical network structure.
Therefore, the previous grooming techniques in the single
network cannot be applied into the multi-domain scenario.
The aforementioned future network trends contribute to a
mixed granularity and multi-domain network. This new net-
work structure is embodied by the interconnection of multiple
horizontal domains, each of which has two vertical granular
layers. In most situations, the granular layer accounts for
routing demands with the corresponding grain level. As shown
in Fig. 1, the dark nodes denote border nodes, and the other
nodes are interior nodes. The curve between two border nodes
from different domains denotes the inter-domain link. The
dashed line between two border nodes from different granular
layers denotes the migration link. The other links are intra-
domain links.
For this new network, we propose a novel mechanism
referred to as traffic partition grooming. The main idea of the
traffic partition grooming is described as follows: 1) traffic
grooming can handle only FG demands, which ensures that
the resource utilization will not become worse; 2) waveband
switching can handle only CG demands, which effectively
mitigates the port thirsty.
Fig. 2. The TPG-OXC structure.
2013 2nd IEEE/CIC International Conference on Communications in China (ICCC): Optical Communication Systems (OCS)
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