1,720,965 research outputs found
Provisioning and Restoration With Sliceability in GMPLS-Based Elastic Optical Networks [Invited]
No full textImpact of SBVTS based on multi wavelength source during provisioning and restoration in elastic optical networks
No full textYANG Models for Vendor-Neutral Optical Networks, Reconfigurable through State Machine
No full textMulti-vendor interoperability can be achieved at node and network levels by relying on standard data modeling. YANG represents an attractive data modeling solution for network component definition. This article reports on the work done on YANG models for optical networks with particular reference to flexible-grid networks. In addition to a YANG model description for link, node, and media channels, YANG for a sliceable transponder is introduced given the importance of such a data plane device for the next generation backbone. Then a contribution is provided in proposing YANG models for events and state machine to further extend and increase the programmability of networks. This latter contribution is particularly relevant in the case of faults or physical layer degradation in a network. Finally, YANG models are validated in an experimental control plane testbed
Management of sliceable transponder with NETCONF and YANG
No full textNETCONF is emerging as Software Defined Networking (SDN) protocol for the control and management of optical networks. It enables data plane device configuration and access to monitoring information. NETCONF may exploit YANG data model to describe network elements to be controlled/managed. YANG and NETCONF are of interest for operators since they provide a standard way to control and manage network elements, independently from the vendor. This paper presents and demonstrates a management plane based on NETCONF protocol. In particular, a YANG model describing optical transponders supporting slice-ability, variable rate, and monitoring functionalities is proposed. NETCONF experimental demonstrations are carried out to validate the proposed model and to prove the control and management capabilities of these technologies applied to elastic optical networks (EONs)
YANG model and NETCONF protocol for control and management of elastic optical networks
No full textThis paper proposes a YANG model to describe a sliceable transponder with variable rate, code, modulation formats, and monitoring capabilities. The model is introduced into NETCONF, which is experimentally demonstrated in a testbed
Add and drop architectures for multi-carrier transponders in EONs
No full textThe elastic optical network (EON) is a paradigm for optical networks, based on the combination of a flexible grid, advanced transmission techniques, and bandwidth-variable optical switching. Recent studies on EONs have been focused on multi-carrier transponders with coherent detection. Such transponders can achieve high-rate (e.g., 1 Tb/s) lightpaths through super-channels. A particular case of the multi-carrier transponder is the sliceable bandwidth variable transponder (S-BVT) where the generated flows can also be routed onto different paths and toward different destinations. The add and drop (A&D) module connecting transponders to the optical cross connect plays an important role in the design of the network node. In particular, depending on the A&D architecture, the flexibility provided by the multi-carrier transponder and the S-BVTs may be partially limited. This paper gives first a technological overview of different A&D architectures. In particular, the coupler/splitter, multicast switch, and wavelength-selective switch technologies for A&D are reviewed. Then, we investigate how different A&D architectures influence the benefit of elastic spectral efficiency in a long-haul meshed network scenario, looking for a trade-off between costs and performance
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Routing, spectrum, and transponder assignment in elastic optical networks
No full textBackbone networks are evolving toward Elastic Optical Network (EON) architecture that allows a flexible and efficient use of spectrum resources. Flexibility in EONs is guaranteed also by emerging sliceable bandwidth variable transponders (SBVTs) that support the simultaneous generation of multiple optical carriers. Such carriers can be used to serve different lightpaths (i.e., slice-ability), or can be merged into a single high-rate super-channel. SBVTs typically use a dedicated laser to generate each carrier, i.e., multi-lasers SBVT (ML-SBVT). Alternatively, a multi-wavelength source can be used to generate multiple carriers using a single laser, i.e., multi-wavelength SBVT (MW-SBVT). Using MW-SBVT improves the super-channel spectrum efficiency. Indeed, MW-SBVT reduces the inter- carrier interference among the sub-carriers composing the super-channel, thus it is possible to reduce the guard bands among sub-carriers. With ML-SBVT, each sub-carrier suffers from unstableness of the related laser and inter-carrier interference may have a huge impact, thus higher guard bands are needed. On the other hand, the use of a MW- SBVT introduces specific constraints to the routing and spectrum assignment (RSA) because the spacing among the sub-carriers is limited to a range of specific values. To take into account the constraints introduced by transponders, this paper integrates the selection of the transponder into RSA thus proposing a dynamic routing, spectrum, and transponder assignment (RSTA) scheme sup- porting both ML-SBVT and MW-SBVT technologies, and aim- ing to combine the benefits of the two technologies. Simula- tion results show that the proposed RSTA scheme provides benefits in terms of achieved blocking probability compared to traditional RSA schemes. Moreover, the achieved results demonstrate that by jointly using both SBVT technologies provides significant benefits with respect to the utilization of any single SBVT technology.Peer ReviewedPostprint (author's final draft
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