Search Results

Now showing 1 - 4 of 4

Some of the metrics are blocked by your
consent settings
Spectrum Slicer Placement for Elastic Optical Network With Sparse Slicers
(2023-01-01)
Pavarangkoon, Praphan
;
Akaki, Kaito
;
Kitsuwan, Nattapong
This paper investigates spectrum slicer placement problem under a spectrum allocation scheme that considers the splitting process to minimize the blocking probability for elastic optical network with sparse slicers. Unlike the conventional elastic optical network without slicers, the elastic optical network with slicers is able to split a spectrum band into several spectrum components by replicating the original spectrum band and filtering out an unwanted signal on each spectrum band. The largest L-shape fit allocation algorithm, which allocates a request to available slot areas with L-shape, is utilized to reduce the request blocking probability. We evaluate the performance of our scheme with various centrality policies on elastic optical network with sparse slicers, where the number of slicers is given. Simulation results show that our scheme with betweenness centrality significantly outperforms that with random centrality, degree centrality, and closeness centrality in terms of bandwidth blocking rate.
Some of the metrics are blocked by your
consent settings
Spectrum allocation scheme considering spectrum slicing in elastic optical networks
(2021-07-01)
Kitsuwan, Nattapong
;
Akaki, Kaito
;
Pavarangkoon, Praphan
;
Nag, Avishek
Recent advances in physical layer optics have made slicing of optical bands into multiple subbands with different bandwidths possible. Due to this development, spectrum allocation has become easier in elastic optical networks (EONs). More specifically, owing to the slicing technology, the defragmentation problem in EONs can be addressed easily, i.e., more demands can be fit into empty spectrum slots by breaking the demands as needed using the slicing technology. This paper proposes a spectrum allocation scheme considering the slicing process at any nodes, e.g., source node and intermediate nodes, in EONs. Slicing-and-stitching technology is applied to break the contiguous-spectrum constraint in an EON so that spectrum fragmentation is reduced. While slicing a demand from one node to another, the following questions must be answered: (1) Which parts of the spectrum band should be sliced? (2) In which node(s) along the path of a demand should the slicings be done to reduce the bandwidth blocking rate? To answer the above questions, we formulate a mixed-integer linear programming (MILP) model that jointly addresses the above questions as well as minimizes the total number of slicers in a network. To measure the performance of the MILP, we used the bandwidth blocking ratio (BBR) of the network as a performance metric. Our results from the MILP show that introducing slicing at every node in the network improves the BBR by as much as 68% compared to a conventional case where slicing a demand is allowed only at the source node.
Some of the metrics are blocked by your
consent settings
Large L-shape Fit Spectrum Allocation for Elastic Optical Network with Spectrum Slicing
(2021-01-13)
Akaki, Kaito
;
Pavarangkoon, Praphan
;
Kitsuwan, Nattapong
A slicing and stitching technology has been invented to relax the consecutive constraint of spectrum slot allocation in elastic optical network (EON). This technology splits a spectrum band into several signal bands, called optical components, by making a copy of the original spectrum band and filtering out an unwanted signal on each spectrum band. The remaining optical components are injected into a transmission channel. At the destination, the optical components are recovered by using phase preserving wavelength conversion. Therefore, a request is able to allocate to dis-consecutive groups of slots. A conventional spectrum allocation scheme with this technology adopts slicing devices, called spectrum slicers, at only a source node. There is a problem of allocation patterns due to lack of flexibility since slicing at intermediate nodes is not considered. In this paper, we propose a spectrum allocation scheme considering slicers at both source node and intermediate nodes. Performance of the proposed scheme is evaluated by a computer simulation. The results show that the proposed scheme with 20 slicers reduces 45% of request blocking probability compared to the conventional scheme in COST239 topology when the traffic is 300 Erlang.
Some of the metrics are blocked by your
consent settings
Elastic optical network for fragmented bandwidth allocation with limited slicers
(2021-01-01)
Akaki, Kaito
;
Pavarangkoon, Praphan
;
Kitsuwan, Nattapong
A fragmentation problem increases bandwidth blocking in an elastic optical network (EON). A technique to reduce bandwidth fragmentation is important. The routing and spectrum allocation (RSA) approach is one of the techniques to reduce bandwidth fragmentation. A slicing-and-stitching technology is adopted in EON to relax a consecutive slot constraint for the spectrum allocation process. A slicer is used to split a signal of a spectrum band into several spectrum components, as a slicing process. The split spectrum components are transmitted to the destination before recovering the original signal at the destination, as a stitching process. An RSA algorithm for EON with this technology is applied. As a result, the request blocking is reduced. Slicers are applied to all nodes in the network. The implementation cost is high. Reducing the number of slicers in the network degrades the performance in terms of bandwidth blocking. This paper investigates bandwidth blocking when the number of slicers is limited. Some nodes in the network are selected to place slicers. A betweenness centrality (BC) value is used to select the nodes to place the slicers. The result from a simulation shows that placing a small number of slicers per node for a large number of nodes has better performance than placing a large number of slicers per node for a small number of nodes.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results