Single-mode fiber's physical capacity boundaries will soon be reached; hence, alternative solutions are much needed to overcome the multiplying and remarkably large bandwidth requests. Space division ...multiplexing (SDM) using multicore fibers (MCFs), multielement fibers, multimode fibers, and their combination; few-mode MCFs; or fibers based on orbital angular momentum are considered to be the propitious stepping-stones to overcome the capacity crunch of conventional single-core fibers. We critically review research progress on SDM fibers and network components, and we introduce two figures of merit aiming for quantitative evaluation of technologies such as amplifiers, fan-in/fan-out multiplexers, transmitters, switches, and SDM nodes. Results show that SDM fibers achieve a 1185-fold (18-fold) spectral-spatial efficiency increase compared with the 276-SMF bundle (single-core fiber) currently installed on the ground. In addition, an analysis of crosstalk in MCFs shows how SDM concepts can be further exploited to fit in various optical networks such as core, metro, and especially future intra-data center optical interconnects. Finally, research challenges and future directions are discussed.
A large number of factors generate uncertainty on traffic demands and requirements. In order to deal with uncertainty optical nodes and networks are equipped with flexibility. In this context, we ...define several types of flexibility and propose a method, based on entropy maximization, to quantitatively evaluate the flexibility provided by optical node components, subsystems, and architectures. Using this method we demonstrate the equivalence, in terms of switching flexibility, of finer spectrum granularity, and faster reconfiguration rate. We also show that switching flexibility is closely related to bandwidth granularity. The proposed method is used to derive formulae for the switching flexibility of key optical node components and the switching and architectural flexibility of four elastic optical node configurations. The elastic optical nodes presented provide various degrees of flexibility and functionality that are discussed in the paper, from flexible spectrum switching to adaptive architectures that support elastic switching of frequency, time, and spatial resources plus on-demand spectrum defragmentation. We further complement this analysis by experimentally demonstrating flexible time, spectrum, and space switching plus dynamic architecture reconfiguration. The implemented architectures support continuous and subwavelength heterogeneous signals with bitrates ranging from 190 Mb/s, for a subwavelength channel, to 555 Gb/s for a multicarrier superchannel. Results show good performance and the feasibility of implementing the architecture-on-demand concept.
A multidomain optical transport network composed of heterogeneous optical transport technologies (e.g., flexi/fixed-grid optical circuit switching and optical packet switching) and control plane ...technologies (e.g., centralized OpenFlow or distributed GMPLS) does not naturally interoperate, and a network orchestration mechanism is required. A network orchestrator allows the composition of end-to-end network service provisioning across multidomain optical networks comprising different transport and control plane technologies. Software-defined networking (SDN) is a key technology to address this requirement, since the separation of control and data planes makes the SDN a suitable candidate for end-to-end provisioning service orchestration across multiple domains with heterogeneous control and transport technologies. This paper presents two different network orchestration's architectures based on the application-based network operations (ABNO) which is being defined by IETF based on standard building blocks. Then, we experimentally assesses in the international testbed of the STRAUSS project, an ABNO-based network orchestrator for end-to-end multi-layer (OPS and Flexi-grid OCS) and multidomain provisioning across heterogeneous control domains (SDN/OpenFlow and GMPLS/Stateful PCE) employing dynamic domain abstraction based on virtual node aggregation.
This paper proposed and evaluated a programmable ROADM system for MCF-based SDM/WDM networks. The proposed ROADM system employing both bypass connection and Route-and-Select wavelength switching ...enables adaptable virtual topology in optical networks by dynamically configuring bypass connection cores. The simulation results confirmed this ROADM system could provide acceptable performance with an around 10–20% reduction in the total cost including the number of ports and WSSs by comparing with a fully flexible SDM/WDM ROADM system, which cannot be implemented due to the required extremely high-port-count WSSs.
Along with the adoption of 5G, the development of neutral host solutions provides a unique opportunity for mobile networks operators to accommodate the needs of emerging use-cases and in the ...consolidation of new business models. By exploiting the concept of network slicing, as one key enabler in the transition to 5G, infrastructure and service providers can logically split a shared physical network into multiple isolated and customized networks to flexibly address the specific demands of those tenant slices. Motivated by this reality, the H2020 5GCity project proposed a novel 5G-enabled neutral host framework for three European cities: Barcelona (ESP), Bristol (UK), and Lucca (IT). This article revises the main achievements and contributions of the 5GCity project, focusing on the deployment and validation of the proposed framework. The developed neutral host framework encompasses two main parts: the infrastructure and the software platform. A detailed description of the framework implementation, in terms of functional capabilities and practical implications of city-wide deployments, is provided in this article. This work also presents the performance evaluation of the proposed solution during the implementation of real vertical use cases. Obtained results validate the feasibility of the neutral host model and the proposed framework to be deployed in city-wide 5G infrastructures.
The adoption of software defined networking (SDN) within traditional networks has provided operators the ability to manage diverse resources and easily reconfigure networks as requirements change. ...Recent research has extended this concept to IEEE 802.15.4 low-power wireless networks, which form a key component of the Internet of Things (IoT). However, the multiple traffic patterns necessary for SDN control makes it difficult to apply this approach to these highly challenging environments. This paper presents Atomic-SDN, a highly reliable and low-latency solution for SDN in low-power wireless. Atomic-SDN introduces a novel synchronous flooding (SF) architecture capable of dynamically configuring SF protocols to satisfy complex SDN control requirements, and draws from the authors' previous experiences in the IEEE EWSN Dependability Competition: where SF solutions have consistently outperformed other entries. Using this approach, Atomic-SDN presents considerable performance gains over other SDN implementations for low-power IoT networks. We evaluate the Atomic-SDN through simulation and experimentation, and show how utilizing SF techniques provides latency and reliability guarantees to SDN control operations as the local mesh scales. We compare the Atomic-SDN against the other SDN implementations based on the IEEE 802.15.4 network stack, and establish that the Atomic-SDN improves SDN control by orders-of-magnitude across latency, reliability, and energy-efficiency metrics.
Efficiency gains in 5G softwarised radio access networks Gkatzios, Nikolaos; Anastasopoulos, Markos; Tzanakaki, Anna ...
EURASIP Journal on wireless communications and networking,
07/2019, Volume:
2019, Issue:
1
Journal Article
Peer reviewed
Open access
This paper proposes the concept of compute resource disaggregation in centralized softwarised radio access networks. This approach allows individual allocation of processing functions to different ...servers depending on the nature and volume of their processing requirements. The benefits of the proposed approach are evaluated through experiments analyzing the baseband unit (BBU) processing requirements of LTE PHY using an open source suite for wireless systems and a purposely developed multistage linear programming modeling framework. To address the high computational complexity of integer linear programming (ILP), limiting real-time services, a heuristic algorithm was also developed. Our results show that when using the proposed approach, the overall system power consumption is reduced by 40% under high loading scenarios compared to the traditional solution where all BBU functions are hosted in the same physical servers. The heuristic results achieve relatively good agreement with the ILP results (the gap is less than 5%), particularly for low and high loading conditions. At the same time, the heuristic requires less than 0.3 s to identify the optimal allocation policy.
The adoption of private 5G networks or Non-Public Networks (NPN) by industry verticals is igniting a digital transformation across various sectors and also leading to industry 4.0. This impetus comes ...from the integration of private wireless networks with 5G capabilities. Currently, a range of innovative applications and use cases are emerging and resulting in improved enterprise performance and solutions. The potential to boost revenue, stimulate cost reduction, and accelerate Return Of Investment (ROI) makes 5G NPN adoption attractive to industry verticals, network operators and other third-party stakeholders. However, a significant infrastructure upgrade is required, which demands understanding of the complexities of 5G NPN deployment scenarios and their economic implications. This paper addresses these needs by conducting a detailed techno-economic analysis on 5G NPN deployment. The study formulates a techno-economic model that focuses on; (i) Cost savings in support of ROI achieved by enabling Network Function Virtualization (NFV) technology and Neutral Host (NH) concept; (ii) The trade-off study between enterprise goals (cost vs deployment technologies) with a multi-objective sensitive analysis; And (iii) the trends of 5G NPN adoption worldwide. Analytical results confirm savings of up to 53% in Total Cost of Ownership (TCO) reflecting a significant reduction in Capital and Operation Expenditures (Capex and Opex). Simulation analysis identifies a ranking order of deployment parameters, which prioritise the use of Cost saving strategies and Deployment type. And finally, it offers a prediction of a starting annual average worldwide adoption rate of 82.2% with an expected height by 2026.
This paper reports all-optical, function programmable, transparent, intra- and inter-data center networking (DCN) using space and time-division multiplexing (SDM/TDM) within data centers and ...wavelength division multiplexing (WDM) between data centers. A multielement fiber is used for SDM transmission to provide a large quantity of optical links between the top-of-racks (ToRs) and the function programmable cluster switch. Beam-steering large-port-count fiber switches, used as central cluster switches and intercluster switch, provide a single hop optical circuit switching solution, and also enable network function programmability for DCN to support variable traffic patterns and different network functions. A TDM switch as a plug-in function provides intra-cluster communication with variable capacity and low latency. The flat-structured intra data center architecture, with a circuit-switched SDM and TDM hybrid network enables scalable, large-capacity and low-latency DCN communication. In addition, all-optical ToR-to-ToR inter-DCN is realized through metro/core networks. A highly-nonlinear fiber based all-optical SDM-to-WDM converter transfers three SDM signals to three-carrier spectral superchannel signals, which are transmitted to the destination DCN, through the metro/core networks. The all-optical ToR-ToR cross-DCN connections enable the geographically distributed DCNs to appear as one Big Data center.
A novel conceptual framework is developed that depicts a generic Freeport model underpinned by 5G technology. The framework is based on preliminary findings from a 5G testbed project and secondary 5G ...use cases from both practice and academic literature. We first provide a descriptive model of the current state of a port without 5G and Freeport status, identify the challenges and opportunities for logistics flows if Freeport status is attained and then prescribe how 5G may enable seamless logistics flows. With multiple challenges for ports generally, Freeport status increases the level of complexity of the core and support business processes that deliver goods from origin to destination. Despite that increased complexity, Freeports can attract investment and generate revenue, thus the enablement of Freeports is notionally beneficial in the long run. As complexity is anathema to smooth logistics flows, we develop a prescriptive model to exploit 5G to improve efficiency and effectiveness within a Freeport. We demonstrate the application of the prescriptive model with a 5G Freeport use case supported by simulation results, from which we aim to contribute to the overall adoption of 5G in Freeports.
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