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| 2. |
- Furdek, Marija, et al.
(författare)
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Attack-aware optical networks planning: A cost analysis
- 2011
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Ingår i: 13th International Conference on Transparent Optical Networks, 2011. ICTON'11.. - : IEEE. - 9781457708817
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Transparent optical networks (TONs) based on Wavelength Division Multiplexing (WDM) are the only viable future-proof solution for supporting rapidly growing traffic demands. In TONs, optical signals are propagated transparently between edge nodes without any O/E/O conversion. In this way, it is possible to reduce cost and energy consumption in the network, as well as obtain transparency to signal bit rates, modulation formats and protocols. However, the absence of O/E/O conversion makes it easier for erroneous signals to propagate through the network and affect existing traffic. This can be utilized to realize attacks exploiting the physical-layer characteristics of network elements. An example of such attacks is high-power jamming, where a high-powered signal is injected in the network aiming to deteriorate the signal quality on other, legitimate optical channels (referred to as lightpaths), as described in [1] and [2].
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| 3. |
- Jirattigalachote, Amornrat, et al.
(författare)
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Design of Grouped Routing Entity (GRE)-based Optical Networks with 100% Signal Quality Guarantee
- 2014
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Ingår i: 2014 International Conference on Optical Network Design and Modeling, ONDM 2014. - 9783901882609 ; , s. 174-179
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Konferensbidrag (refereegranskat)abstract
- In bandwidth abundant optical networks it is important to develop design strategies that are not only cost effective but also able to account for the inherent characteristics of the optical transmission medium responsible for the signal quality degradation. With this objective in mind, the paper proposes a design algorithm able to determine an appropriate placement of regenerators in Grouped Routing Entity (GRE)-based optical networks. The objective of the algorithm is to guarantee a certain signal quality level to all connections while minimizing the number of fibers and switching ports required in the network The proposed design strategy relies on a physical-layer impairment model, specifically introduced in the paper for this purpose, able to estimate the signal quality of an optical path in a GRE-based optical network Simulation results indicate that compared with a single layer optical path network the proposed design algorithm can reduce at least 87% of the switch ports while the increment in the number of fibers is lower than 10%.
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| 4. |
- Jirattigalachote, Amornrat, et al.
(författare)
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Dynamic provisioning strategies for energy efficient WDM networks with dedicated path protection
- 2011
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Ingår i: Optical Switching and Networkning Journal. - : Elsevier BV. - 1573-4277 .- 1872-9770. ; 8:3, s. 201-213
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Tidskriftsartikel (refereegranskat)abstract
- Energy consumption in optical backbone networks is increasing due to two main reasons: (i) the exponential growth of bandwidth demands, and (ii) the increase in availability requirements in order to guarantee protection of the ultra high capacity optical channels provided by wavelength division multiplexing (WDM) networks. Although state of the art reliability mechanisms are very efficient in guaranteeing high availability, they do not consider the impact of the protection resources on the network's energy consumption. Dedicated (1:1) path protection (DPP) is a well-known mechanism that provides one extra link-disjoint path for the protection of a connection request. This secondary path is reserved and maintained in an active mode even though it is not utilized most of the time. This means that in-line optical amplifiers and switching nodes/ports are always consuming power even when they are not used to reroute any primary traffic. Moreover secondary paths are on average longer than their respective primary paths. These observations motivated us to investigate the energy savings, when all unused protection resources can be switched into a low-power, stand-by state (or sleep mode) during normal network operation and can be activated upon a failure. It is shown that significant reduction of power consumption (up to 25%) can be achieved by putting protection resources into sleep mode. Moreover, in order to enhance this energy saving figure, this paper proposes and evaluates different energy-efficient algorithms, specifically tailored around the sleep mode option, to dynamically provision 1:1 dedicated path protected connection. The trade-off between energy saving and blocking probability is discussed and an efficient mechanism to overcome this drawback is devised. Our results reveal that a 34% reduction of energy consumption can be obtained with a negligible impact on the network's blocking performance.
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| 5. |
- Jirattigalachote, Amornrat, et al.
(författare)
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ICBR-Diff : An Impairment Constraint Based Routing Strategy with Quality of Signal Differentiation
- 2010
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Ingår i: Journal of Networks. - : Academy Publisher. - 1796-2056. ; 5:11, s. 1279-1289
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Tidskriftsartikel (refereegranskat)abstract
- Latest advances in Wavelength Division Multiplexing (WDM) technology make it possible to build all-optical transparent networks, which are considered to be able to satisfy the rapidly growing capacity demand. However, in a transparent WDM network the optical signal transmitted from a source to a destination node might be degraded due to physical layer impairments induced by transmission through optical fibers and components. Several Impairment Constraint Based Routing (ICBR) algorithms have been proposed to consider physical layer impairments during the connection-provisioning phase in order to prevent selecting a lightpath with poor signal quality. However, these algorithms support only a single quality of transmission threshold for all connection requests, while next generation networks and the future Internet are expected to support a variety of services with potentially disparate QoS requirements. In this paper, we propose the use of bit error rate (BER) as a differentiation of service parameter for connection requests in optical WDM networks. This is achieved through the use of ICBR, whereby various BER thresholds are set depending on the QoS requirements for accepting/blocking the connection requests during the connection-provisioning phase. The evaluation results reveal that significant network performance improvement in terms of connection blocking can be achieved, compared to non-differentiated conventional routing and wavelength assignment (RWA) and ICBR algorithms.
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| 6. |
- Jirattigalachote, Amornrat, et al.
(författare)
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Impairment-Aware Routing and Waveband Assignment for Efficient Optical Transport Networks
- 2012
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Ingår i: 2012 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference, OFC/NFOEC 2012. - Washington, D.C. : Optica Publishing Group. ; , s. 6192131-
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Konferensbidrag (refereegranskat)abstract
- We demonstrate the importance of considering physical impairments in waveband-based optical networks. We propose and evaluate an Impairment-Aware waveband-routing and waveband-assignment (IA-RWBA) algorithm achieving significant improvement in both impairment satisfaction rate and total network cost.
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| 7. |
- Jirattigalachote, Amornrat, et al.
(författare)
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Impairment aware routing with service differentiation in heterogeneous WDM networks
- 2009
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Ingår i: Network Architectures, Management, and Applications VII. - : SPIE - International Society for Optical Engineering. - 9780819480354 ; , s. 763307-
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Konferensbidrag (refereegranskat)abstract
- In transparent Wavelength Division Multiplexing (WDM) networks, the signal is transported from source to destination in the optical domain through all-optical channels, or lightpaths. A lightpath may traverse several fiber segments and optical components that in general degrade the optical signal. This effect introduces the need for considering physical layer impairments during the connection-provisioning phase. Physical layer impairments can be divided into linear and non-linear. Both types of impairments are highly dependent on the fiber characteristics, which in turn are sensitive to length, temperature and age. A close look at the fiber infrastructure of today's network operators reveals a situation where old and newly deployed fibers coexist in the network. This heterogeneous fiber plant presents a challenge. A tradeoff should be found between the QoS requirements of connection requests and the use of the available (old and new) network resources. This calls for a provisioning mechanism able to adapt to the various fiber composition scenarios. In parallel, given the need for service differentiation, the authors recently proposed an Impairment Constraint Based Routing (ICBR) algorithm, referred to as ICBR-Diff, supporting differentiation of services at the BER (Bit Error Rate) level in a network with a homogeneous fiber infrastructure. In this paper the ICBR-Diff algorithm is extended to heterogeneous network; particularly, it is evaluated in WDM networks with fiber links having varying Polarization Mode Dispersion characteristics, i.e., with old and new fiber coexisting. Simulation results show that the ICBR-Diff algorithm exhibits high adaptability in a heterogeneous fiber composition scenario. This translates into improved performance in terms of blocking probability, when compared to traditional impairment aware routing algorithms.
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| 8. |
- Jirattigalachote, Amornrat, et al.
(författare)
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Impairment aware routing with service differentiation in heterogeneous WDM networks
- 2009
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Ingår i: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009. - Washington, D.C. : OSA. - 9781557528773 ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- We evaluate an Impairment Constraint Based Routing algorithm with service differentiation (ICBR-Diff) applied in WDM networks with fiber links having varying Polarization Mode Dispersion characteristics. Simulation results show high adaptability of the ICBR-Diff approach to this heterogeneous fiber scenario when compared to conventional routing schemes.
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| 9. |
- Jirattigalachote, Amornrat, et al.
(författare)
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Impairment Constraint Based Routing (ICBR) with service differentiation in survivable WDM networks
- 2009
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Ingår i: European Conference on Optical Communication, ECOC. - 9781424450961 ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- We propose and evaluate a novel survivable impairment constraint based routing (ICBR) algorithm with service differentiation at the bit error rate level. Simulations show significant improvement in connection blocking compared to conventional ICBR solutions.
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| 10. |
- Jirattigalachote, Amornrat, et al.
(författare)
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Limiting physical-layer attack propagation with power equalization placement in transparent WDM networks
- 2010
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Ingår i: 2010 Asia Communications and Photonics Conference and Exhibition, ACP 2010. - 9781424471119 ; , s. 363-364
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Konferensbidrag (refereegranskat)abstract
- We propose and evaluate a Greedy Randomized Adaptive Search Procedure applied to minimize the number of power equalizers (GRASP-PE) needed to limit the propagation of high-power jamming attacks in WDM networks. Simulation results show that GRASP-PE significantly reduces the required number of power equalizers when compared to a greedy approach.
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