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In current networks, large flows often co-exist with small flows and consume a significant proportion of the network bandwidth. This imposes a challenge on network resource management. Various hybrid switching architectures have been proposed in recent years aiming to address this challenge and improve efficiency and resource utilization. However, there is still a need for means for design and dimensioning...
To date, most resource allocation proposals in elastic optical networks have focused either on routing and spectrum assignment (RSA, assuming fixed coding scheme and modulation format) or routing, modulation level and spectrum assignment (RMLSA, assuming a fixed coding scheme). Recent research has studied the impact of adaptive assignment of the code rate, without adapting the modulation format (RCSA...
This paper evaluates the performance of partition scheme with first-last fit spectrum allocation for elastic optical networks. The scheme intends to increase the number of contiguous aligned available slots, and hence suppresses the blocking probability. The partition approach creates more aligned available slots by separating the spectrum allocation of the non-disjoint connections. The first-last...
Modern IP/Optical transport networks are seldom jointly operated and optimized, and do not cater to the usually implicit requirements of applications, which ultimately drive network traffic. In this concept paper we propose a Software Defined Networking (SDN) based Network Orchestrator to manage multi-layer transport networks while taking explicit application requirements into account. We discuss...
The spatial superchannel (Sp-Ch) allocation that is enabled by newly developed switching nodes supporting spatial group switching is anticipated to show significant cost savings in future SDM networking deployments. In this paper, we compare the performance of different spatial Sp-Ch switching paradigms, under different spatial and spectral granularities. The spatial granularity is related to the...
Sliceable Bandwidth-variable Transponders (SBVTs) enhance the configurability and flexibility of Flexgrid optical networks. A single SBVT can be used to transmit and receive several optical signals each modulated with a specific format. A SBVT can be seen as a set of sub-transponders that can be specifically configured to end a specific lightpath, by defining, among other parameters, the modulation...
In order to face the steady growth of the optical networks, network operators are now moving to elastic optical networking, with the challenge of optimizing the spectrum usage through the so-called routing and spectrum assignment (RSA) problem. It is a much more difficult problem than the classical routing and wavelength assignment (RWA) problem, for which practical algorithms are now available for...
In this paper we propose an online method for routing and spectrum assignment (RSA) in flex-grid optical networks, which aims at maximizing of a definable reward objective (e.g. carried traffic, economic revenue). The method is based on the theory of Markov Decision Processes (MDP). Connections are admitted and established depending on the traffic load (network state) and on the expected reward increase...
This paper proposes a lightpath threshold adaptation algorithm for dispersion-adaptive first-last fit spectrum allocation scheme in elastic optical networks in order to improve the performance in terms of call blocking in the network. The proposed algorithm adapts the suitable lightpath threshold value, denoted by β, according to the traffic condition in the network. The dispersion-adaptive first-last...
We focus on a routing, spectrum, transceiver and regeneration allocation (RSTRA) problem in elastic optical networks (EONs). In the RSTRA optimization problem, in addition to classical RSA constraints, the assignment of transceivers to lightpaths and selection of regeneration sites is taken into account. Moreover, we assume a full flexibility of modulation and spectrum conversion in regeneration sites...
The Elastic Optical Network (EON) architecture has been proposed in response to the large capacity and diverse traffic granularity needs of the future Internet. By breaking the fixed-grid spectrum allocation of WDM networks, EONs increase the flexibility in terms of connection provisioning. The appropriate-sized optical spectrum is allocated to each connection depending on its requested bandwidth...
Spatial Division Multiplexing (SDM) arises as the only solution to overcome the capacity limits of single-mode optical fibres (SMFs). Among the different SDM flavours, Multi-Core Fibres (MCFs) are gaining interest thanks to their low inter-core crosstalk (XT). In this context, Flex-Grid is envisioned as the technology that enables the efficient allocation of connections in SDM-based optical networks...
This paper proposes two wavelength overprovisioning strategies that can be used to improve the performance of path restoration in optical core networks under dynamic traffic conditions while considering single fiber link failure scenarios. The study presented in the paper shows that with the two proposed schemes it is possible to achieve nearly the same level of average connection availability and...
The paper proposes a resources allocation method for EON based on a modified RDM using squatting and kicking strategies in order to prioritise the usage of channels and enhancing the total utilisation. It can also be used as an admission control. The mechanism is described and compared to existing proposals, regarding the flexibility in the allocation per class. The strategy regards the EON constraints...
This article introduces an energy efficient heuristic that performs resource provisioning and Virtual Machine (VM) migration in the Disaggregated Server (DS) schema. The DS is a promising paradigm for future data centers where servers' components are disaggregated at the hardware unit levels and resources of similar type are combined in type respective pools, such as processing pools, memory pools...
We verify by system analysis that in a multi subcarrier radio over fiber system, the error vector magnitude (EVM) as a function of the subcarrier input power (Pin) is independent of the channel selection if our new channel allocation scheme is used.
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