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ABSTRACT: The increasing popularity of converged media services is promoting the deployment of a range of broadband networking technologies aiming at serving the increased bandwidth as well as service portability and user mobility demands. To optimally address the above requirements hybrid access network architectures coupling the benefits of optical (high capacity, robustness) and mobile/wireless networks (extended reach and mobility) are quite promising. In this paper we present the basic steps for converged network design and planning and evaluate algorithms for wireless backhaul optimization based on a PON architecture. Network optimization addresses the capacity requirements per access segment and optical backhaul segment, the physical layer limitations (e.g. power budget) and overall cost (in terms of CAPEX including number of nodes, active ports, civil engineering works etc. and OPEX mainly including real estate and power consumption) by means of both heuristic algorithms and stochastic optimization techniques.
Transparent Optical Networks (ICTON), 2011 13th International Conference on; 07/2011
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ABSTRACT: We benchmark OCS, OFCS, OBS and CANON against QoS parameters. The results demonstrate that sub-walength switching alone cannot guarantee efficiency. We show that CANON can simultaneously provide for both, statistical multiplexing gains and QoS guarantees outperforming the other paradigms.
Optical Communication (ECOC), 2010 36th European Conference and Exhibition on; 10/2010
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C. Politi,
A. Tzanakaki,
M. O'Mahony,
K. Katrinis,
P. Van Daele,
M. Pickavet,
D. Simeonidou, A. Stavdas,
G. Franzl,
J. Mitchell,
P. Castoldi,
S. Spadaro,
F. Callegatti,
P. Petropoulos,
K. Vlachos,
A. Pattavina
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ABSTRACT: Part of the activities of the ICT EU Network of Excellence "Building the future Optical Network in Europe" (BONE) project is the development of the European Roadmap on Optical Networking in the context of the "Network of the Future". This paper presents a summary of the views of the BONE consortium as they were developed in the framework of the Roadmap activity. The methodology followed in the development of the BONE Roadmap was firstly to identify and analyse the status of broadband access penetration as well as the availability of specific network and IT technologies in various European countries. The data collected were then processed and translated into the traffic volume (distributed across different European countries) that a Pan-European network would need to support. This information is then used as the basis of a WDM optical network dimensioning exercise performed with the aim of identifying the scale of the required optical network. In addition, based on estimations regarding the evolution of broadband access technologies and the degree of broadband penetration and network services and applications, extrapolations regarding the growth of traffic to be supported by the European Network of the Future were made in a systematic manner. These were also used to dimension and understand the requirements of the European Network of the Future. This paper presents the relevant results and also provides a discussion on the BONE consortium views on the Network of the Future from an architectural and technology perspective and an outlook of the relevant key research challenges and possible solutions.
Transparent Optical Networks (ICTON), 2010 12th International Conference on; 08/2010
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ABSTRACT: The lack of effective contention resolution mechanisms in the optical domain presents dynamic optical switching architectures with a hard dilemma between high loss (when adopting one-way reservations) and high delay (when using two-way reservations). In this work we evaluate an alternative hierarchical network architecture, which achieves a satisfactory compromise by partitioning the network into a number of geographically limited domains operating in slot and frame synchronous mode where two-way reservations are effective.
IEEE Communications Letters 12/2009; · 0.98 Impact Factor
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ABSTRACT: It is increasingly recognized that the Internet is transforming into a platform providing services beyond todaypsilas expectations. To successfully realize this transformation, the structural limitations of current networking architectures must be raised so that information transport infrastructure gracefully evolves to address transparent core-access integration, optical flow/packet transport, and end-to-end service delivery capability, overcoming the limitations of segmentation between access, metro, and core networks and domains. We propose and evaluate an integrated control plane for optical access and core networks, which addresses the above consideration. The proposed control plane can lead to a unified transport infrastructure integrating state-of-the-art components and technologies including wavelength division multiplexing, passive optical networking, and optical packet routers with inherent traffic grooming capabilities. The performance of the proposed architecture is assessed by means of simulation in terms of cost, resource utilization, and delay.
Journal of Optical Communications and Networking 08/2009; · 1.87 Impact Factor
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ABSTRACT: Todaypsilas core networks deploy wavelength division multiplexing (WDM) to offer high capacity of the order of 1 Tb/sec and long reach transmission of the order of 1000 km. In such systems, the information is transmitted optically on different wavelengths but it is transferred across the network through fibre links that are terminated by SONET/SDH equipment. In such networks, layer crossing is inevitable, requiring deep data inspection and complex protocol processing, resulting in limited scalability and high installation, operation and maintenance cost. It is however the only reliable end-to-end service delivery scenario available today that utilises the optical bandwidth and guarantees provisioning of resources. In this paper we review the alternative concept of CANON (clustered architecture for nodes in optical networks), a scenario that utilises clustering of nodes in ring topologies to create a hierarchy in transporting traffic in a dynamic, future proof and scalable manner. Here we emphasize on the optical crossconnect architectures that can serve such a network scenario.
Transparent Optical Networks, 2008. ICTON 2008. 10th Anniversary International Conference on; 07/2008
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ABSTRACT: The explosion of current demand has brought the contemporary multidomain core network paradigm to its limit. In the quest for new approaches that exploit recent developments in optical technology, a novel network architecture that obviates most of the expensive and loss-prone centralized all-optical switches is described in this work. It is based on clustered architecture for nodes in optical networks and features a reconciliation between dynamic resource allocation and guaranteed end-to-end network performance in a multidomain network. This article enhances the distributed, collision-free slot aggregation inside domains of clustered core nodes with dynamic switching of slots/frames between the domains. Thus, it can support dynamic sub-wavelength allocations between network domains, using standard burst-switching techniques. This extends the high efficiency and multiplexing gain into the inter-domain network even under highly bursty traffic. It features both low-cost optical add/drop edge nodes exploiting WDM transmission and agile and modular centralized electro-optical switches that are presented in conjunction with the overall network architecture. Its performance exhibits very low burst loss probability traded for a higher but tolerable and bounded delay.
IEEE Communications Magazine 07/2008; · 3.79 Impact Factor
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ABSTRACT: In this paper we present a hybrid opto-electronic switch architecture, which can be enhance the performance of optical packet switching (OPS) schemes. The proposed architecture is based on the use of electronic line-cards and packet cross-connect to a limited degree utilizing the large buffering capacity available only by means of electronic subsystems. This hybrid architecture achieves efficient utilization of optical network resources, which can be assigned dynamically in small time scales, limiting loss probability with controlled average latency.
Transparent Optical Networks, 2007. ICTON '07. 9th International Conference on; 08/2007
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ABSTRACT: In this paper we evaluate a hybrid optoelectronic switch architecture, which can be used under optical burst switching (OBS) or even optical packet switching (OPS) schemes. The proposed architecture incorporates electronic switching equipment to a limited degree utilizing the large buffering capacity available only by means of electronic subsystems. This hybrid architecture achieves efficient utilization of optical network resources, which can be assigned dynamically in small time scales, limiting loss probability with controlled average latency. Thus, the proposed switch architecture is suitable for critical networking applications with high capacity and dynamically changing requirements like GRID networking.
Networking and Services, 2007. ICNS. Third International Conference on; 07/2007
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ABSTRACT: The novel core network architecture presented in this paper realizes distributed all-optical switching of payload by partitioning the network into a number of geographically limited domains, where two-way reservations are effective. Thus, inside each domain, loss is eliminated, while traffic from many nodes can be aggregated into single bursts, improving efficiency. Clustered nodes contribute contiguous optical slots, which are marshaled into composite optical frames destined for other clusters, under the guidance of a reservation-based control protocol. The lossless aggregation of traffic from several core nodes allows the use of cost-effective bufferless all-optical transport among the domains with electrical buffers employed at the periphery of the system. The end result is a triple improvement in loss probabilities, efficiency, and cost. This is achieved by exploiting three features of the architecture: the distributed switching functionality (as in early LANs when centralized switching was expensive), localized reservations (avoiding the intolerable delays of end-to-end reservations), and a reduced number of source-destination pairs (by means of node clustering into reservation domains)
Journal of Lightwave Technology 06/2007; · 2.78 Impact Factor
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ABSTRACT: New algorithmically simplified WRA that incorporate physical layer criteria in the path establishment procedure are suggested and applied in the Deutsche-Telecom network. Their blocking performance superiority and physical performance guarantee are discussed.
Optical Fiber Communication and the National Fiber Optic Engineers Conference, 2007. OFC/NFOEC 2007. Conference on; 04/2007
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ABSTRACT: In this work, a migration scenario of a family of OXC architecture is proposed. This migration is completed in discrete stages, which is plausible since the architecture is highly modular. This modularity is an essential asset for low initial cost. Also, the physical layer modelling of the proposed nodes is presented, allowing to identify how many nodes can be cascaded. The node scalability vs. cascadability issue is assessed, taking into account many considerations like the availability of two technological platforms (all-optical and optoelectronic), as well as other technological constraints like the modulation bandwidth of the corresponding WCs.
Photonics in Switching, 2006. PS '06. International Conference on; 11/2006
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ABSTRACT: Clustering neighboring nodes of an all-optical core network into medium-sized rings featuring reservation-based control, allows lossless aggregation of bursts and a reduction of possible source-destination pairs. Both act towards reducing the system cost and burst loss creating an architecture that obviates most of the expensive and loss-prone all-optical switches by delegating the switching function to a medium access control protocol coordinating the distributed laser transmitters. This is in principle the approach taken in early LANs, but with the optical switches the incentive is not limited to avoiding their high cost but also the high burst loss arising from the very limited optical buffering. The end result is a core architecture with much lower losses than one-way systems, much lower delay than solutions employing two-way reservations end-to-end, still achieving multiplexing gain.
Photonics in Switching, 2006. PS '06. International Conference on; 11/2006
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ABSTRACT: Optical burst switching is a core architecture designed to reconcile the available optical technology with the increasing burstiness of traffic. However, disappointing performance in terms of high packet loss and/or low system utilization discouraged broader experimental implementations. A method to avoid these losses by first sending over the control channel a short scout packet that simulates the events that the actual burst will experience is proposed in this paper. Once the scout message detects a drop at any intermediate node, it returns back to the source to avert the payload emission and repeat the process. The way the control works results in essential service quality features, i.e., no loss of bursts, no out-of-order emissions, increased efficiency, much reduced delay variation, and graceful throttling of the load respecting the contracted rates.
Journal of Lightwave Technology 11/2006; 24(10):3616-3624. · 2.78 Impact Factor
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ABSTRACT: We present three cross-layer routing algorithms incorporating physical layer input with different performance-complexity tradeoffs. An example of their performance is given in a European scale network.
Optical Communications, 2006. ECOC 2006. European Conference on; 10/2006
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ABSTRACT: Wavelength conversion has been acknowledged as one of the most significant optical processing functions and various papers have been involved with investigating methods of translating very high bit-rate data into other wavelengths. This paper will give an overview of the recent advances in the area, with emphasis on methods that can be used as both wavelength and waveband converters, which can be used at higher bit rates without any configuration changes and are integratable and hence compact solutions. Four-wave mixing in SOAs is one of these techniques and we will elaborate on particulars of this technique. Switch architectures that benefit from wavelength and waveband conversion are presented
Transparent Optical Networks, 2006 International Conference on; 07/2006
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ABSTRACT: A novel algorithm that seeks the 'shortest-widest' path and assigns lightpaths according to their Q-factor is developed that exhibits better blocking performance, improved load-balancing and optimum physical performance when compared with 'shortest' path based counterparts.
Optical Fiber Communication Conference, 2006 and the 2006 National Fiber Optic Engineers Conference. OFC 2006; 04/2006
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ABSTRACT: The biggest disadvantage of optical burst switching lies in the high packet losses which are inevitable due to the lack of adequate optical buffering. Thus, the advantage of avoiding pay load translation into the electrical domain comes at the cost of dropping packets contending for the same output port whenever this contention persists for more packets than the limited fiber delay lines can accommodate. A method to avoid these losses is proposed in this paper by sending instead of a burst header a scout header over the control channel to simulate the events that the actual packet experiences. Once the scout message is informed in an intermediate node that a drop is inevitable, it comes back and prevents the sending of the actual packet, a new scout is issued instead. If all is okay, then the packet is launched with no loss certainty. To enable this, a slotted approach is adopted with all the necessary control tools. The penalty is the delay of the indirect reservations and the occasional repetitive attempts limiting the applicability of this approach to a couple of thousand kilometres
ELMAR, 2005. 47th International Symposium; 07/2005
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ABSTRACT: A system of slotted interconnected wavelength-division-multiplexing (WDM) rings controlled by a medium access control (MAC) protocol is shown to offer very high utilization within a queuing delay less than a few round-trip times, by means of a very-fast-reacting explicit reservation mechanism. The system can be used to provide interconnectivity in a metropolitan area transferring optical payloads on-the-fly without buffering or converting from the optical domain. All necessary control information is transferred on a dedicated wavelength and is processed in the electrical domain to provide both collision-free packet access at the ring nodes and contention resolution at the hub interconnecting the rings. The end result is a flexible and efficient metropolitan network suitable for bursty data services.
Journal of Lightwave Technology 05/2005; 23(4):1576- 1585. · 2.78 Impact Factor
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Optical Network Design and Modeling, 2005. Conference on; 02/2005
