Recently, a series of innovative information-centric networking (ICN) architectures have been designed to better address the shift from host-centric end-to-end communication to requester-driven content retrieval. With the explosive increase of mobile data traffic, the mobility issue in ICN is a growing concern and a number of approaches have been proposed to deal with the mobility problem in ICN. Despite the potential advantages of ICN in mobile wireless environments, several significant research challenges remain to be addressed before its widespread deployment, including consistent routing, local cached content discovery, energy efficiency, privacy, security and trust, and practical deployment. In this paper, we present a brief survey on some of the works that have already been done to achieve mobile ICN, and discuss some research issues and challenges. We identify several important aspects of mobile ICN: overview, mobility enabling technologies, information-centric wireless mobile networks, and research challenges.

A Survey of Mobile Information-Centric Networking: Research Issues and Challenges

We review margins used in optical networks and review a formerly proposed margin taxonomy. For each category of margins, we review techniques that the network designer can use in order to increase the capacity of optical networks, extend their life, and decrease deployment cost (CAPEX) or total cost of ownership over their life duration. Green field (new network deployments) and brown field techniques (used after initial network deployment) are discussed. The technology needed to leverage the margins and achieve the aforementioned gains are also reviewed, along with the associated challenges.

Design of Low-Margin Optical Networks

Fiber-optic multi-band transmission (MBT) aims at exploiting the low-loss spectral windows of single-mode fibers (SMFs) for data transport, expanding by $\sim\!11\times$ the available bandwidth of C-band line systems and by $\sim\!5\times$ C+L-band line systems’. MBT offers a high potential for cost-efficient throughput upgrades of optical networks, even in absence of available dark-fibers, as it utilizes more efficiently the existing infrastructures. This represents the main advantage compared to approaches such as multi-mode/-core fibers or spatial division multiplexing. Furthermore, the industrial trend is clear: the first commercial C $+$ L-band systems are entering the market and research has moved toward the neighboring S-band. This article discusses the potential and challenges of MBT covering the ITU-T optical bands O  $\rightarrow$  L. MBT performance is assessed by addressing the generalized SNR (GSNR) including both the linear and non-linear fiber propagation effects. Non-linear fiber propagation is taken into account by computing the generated non-linear interference by using the generalized Gaussian-noise (GGN) model, which takes into account the interaction of non-linear fiber propagation with stimulated Raman scattering (SRS), and in general considers wavelength-dependent fiber parameters. For linear effects, we hypothesize typical components’ figures and discussion on components’ limitations, such as transceivers,’ amplifiers’ and filters’ are not part of this work. We focus on assessing the transmission throughput that is realistic to achieve by using feasible multi-band components without specific optimizations and implementation discussion. So, results are meant to address the potential throughput scaling by turning-on excess fiber transmission bands. As transmission fiber, we focus exclusively on the ITU-T G.652.D, since it is the most widely deployed fiber type worldwide and the mostly suitable to multi-band transmission, thanks to its ultra-wide low-loss single-mode high-dispersion spectral region. Similar analyses could be carried out for other single-mode fiber types. We estimate a total single-fiber throughput of 450 Tb/s over a distance of 50 km and 220 Tb/s over regional distances of 600 km: $\sim\!10\times$ and 8× more than C-band transmission respectively and $\sim\!2.5\times$ more than full C+L.

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Assessment on the Achievable Throughput of Multi-Band ITU-T G.652.D Fiber Transmission Systems

Many researches show that the power consumption of network devices of ICT is nearly 10% of total global consumption. While the redundant deployment of network equipment makes the network utilization is relatively low, which leads to a very low energy efficiency of networks. With the dynamic and high quality demands of users, how to improve network energy efficiency becomes a focus under the premise of ensuring network performance and customer service quality. For this reason, we propose an energy consumption model based on link loads, and use the network’s bit energy consumption parameter to measure the network energy efficiency. This paper is to minimize the network’s bit energy consumption parameter, and then we propose the energy-efficient minimum criticality routing algorithm, which includes energy efficiency routing and load balancing. To further improve network energy efficiency, this paper proposes an energy-efficient multi-constraint rerouting (E2MR2) algorithm. E2MR2 uses the energy consumption model to set up the link weight for maximum energy efficiency and exploits rerouting strategy to ensure network QoS and maximum delay constraints. The simulation uses synthetic traffic data in the real network topology to analyze the performance of our method. Simulation results that our approach is feasible and promising.

Energy-Efficient Multi-Constraint Routing Algorithm With Load Balancing for Smart City Applications

Bandwidth fragmentation, a serious issue in elastic optical networks (EONs), can be suppressed by proper management in order to enhance the accommodated traffic demands. In this context, we need an in-depth survey that covers bandwidth fragmentation problems and how to suppress them. This survey paper starts with the basic concept of EONs and their unique properties. This paper then moves to the fragmentation problem in EONs. We discuss and analyze the major conventional spectrum allocation policies in terms of the fragmentation effect in a network. The taxonomies of the fragmentation management approaches are presented along with different node architectures. Subsequently, this paper reviews state-of-the-art fragmentation management approaches. Next, we evaluate and analyze the major fragmentation management approaches in terms of blocking probability. Finally, we address the research challenges and open issues on fragmentation problem in EONs that should be addressed in future research.

Fragmentation Problems and Management Approaches in Elastic Optical Networks: A Survey

In this work, we propose and investigate a class-of-service-based multilayer architecture for traffic restoration in elastic optical networks. This architecture benefits from both data rate elasticity and low quality of service requirements of best-effort traffic in IP-over-WDM optical networks, combining 1 + 1 IP protection for gold traffic and optical restoration for best-effort traffic. Numerical simulations reveal that the proposed architecture can further reduce capital expenditures, even with the significant extra cost of elastic transponders.

Class-of-service-based multilayer architecture for traffic restoration in elastic optical networks

The ICT (Information and Communication Technology) sector has recently been identified as a growing contributor to worldwide greenhouse gases emissions and power consumption. This has triggered interest for more energy efficient ways to design and operate telecommunication networks. We present an overview of the solutions proposed within the European network of excellence TREND focusing on core and metro networks including data centers. Potential savings are presented and discussed with respect to their impact and applicability within the global picture.

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TREND big picture on energy-efficient backbone networks

Flexgrid technology is an interesting solution to improve network capacity. However, for a given spectral band, it gives rise to the increase of the number of channels, requiring more amplification power in respect with the conventional fixed grid technology. In this work, we demonstrate that re-engineering the link margins allows supporting this increase while keeping in use legacy amplifiers.

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On the legacy amplifier limitation in flexgrid optical networks

We review physical layer models to design and simulate open line systems, enabling vendor interoperability. An open algorithm that takes into account different engineering choices is presented and used to optimize power on a WDM link.

Open Design for Multi-Vendor Optical Networks

P-cycle design solutions are mostly limited to fixed-rate optical settings. To handle the increased heterogeneity of emerging optical links, this paper develops and evaluates a new solution for p-cycle design in mixed-line rate optical networks.

Esther Le Rouzic

Papers

Class-of-service-based multilayer architecture for traffic restoration in elastic optical networks

TREND big picture on energy-efficient backbone networks

On the legacy amplifier limitation in flexgrid optical networks

Open Design for Multi-Vendor Optical Networks

P-cycle design for mixed-line rate optical networks