Hardware and software disaggregation is a recognized strategy for achieving efficiency and cost reduction within datacentre warehouse. More recently this approach has been applied to high-bandwidth inter-datacentre connectivity at transport layer. Telecom Operators look with great interest at this approach which promises savings that could make the difference in years of ever decreasing margins on revenues. This paper presents and analyses the disaggregation models in the WDM transport layer to replace the established aggregated model based on single vendor systems. Three optical disaggregation models are considered implying different levels of involvement of the Telecom Operator in WDM system design, assembly and integration. The impact on network lifecycle of each model is then analysed with particular reference to the roles of the Operator, the equipment Vendors and the System Integrator. The issue of organizational changes and heavy redefinition of processes is addressed and a comparative techno economic analysis is also proposed.

Optical communications are the key enabler for the ever-increasing traffic growth as they allow multiplexing many carriers onto a single optical fiber. However, network deployments are becoming more challenging due to the massive bandwidth increments. Indeed, the fiber planning process is a slow, costly and strategic activity for network operators, who must decide where to rent or deploy additional capacity. Depending on the long-term view, the network operator will define a fiber plan which may require high capital expenditure (CAPEX) investments to deploy additional multiple fiber pairs between central offices. During the last few years, C&L-band technologies have evolved to a point where they are now strong candidates to extend the fiber lifetime of these high capacity links. The aim of this article is to present the evolution of C&L-band systems from a network design perspective, covering transmission and optical amplifier capabilities, demand optimization phase, showing a record demonstration of 56.4 Tb/s C&L-band 800 km transmission using commercial C&L-band system technology.

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Network operators have deployed optical transmission systems in their production networks for several years. The transport technology for fiber-optic transmission systems in backbone networks has been a synchronous digital hierarchy. However, network operators started migrating such networks to deploy WDM systems to improve the utilization of the fibers. Network operators can migrate to 100 Gbps solutions that can cope with medium-term bandwidth needs. However, when evolving toward 400 Gbps or 1 Tbps, utilization of the optical spectrum is less efficient if the fixed-grid schemas are maintained. Elastic optical networks (EONs) are based on a flexible allocation of the spectrum and configurable transponders. There is an unprecedented flexibility at the optical layer, thanks to advances in the components to support EONs. To take advantage of such flexibility and unlock the potential of EONs, the control architecture plays a key role. This paper presents the architectural choices, including generalized multiprotocol label switching, path computation element, and software-defined networking using a transport application programming interface. Moreover, this paper presents how the open source Netphony suite enables the validation and testing of all previous control plane architectures for EONs.

We present a demonstration of software defined networking (SDN) services utilizing quantum key distribution (QKD) technology, fully integrated with standard telecommunication network connecting production facilities of Telefonica in Madrid. All communications “co-propagate” over the same fiber infrastructure.

In this Paper, we experimentally demonstrate highly flexible and intelligent interdomain coordinated actions based on adaptive software-defined networking (SDN) orchestration. An advanced multidomain multitechnology testbed is implemented, which consists of a 400-Gb/s variable capacity optical packet switching domain and a Tb/s-class flexi-grid wavelength division multiplexed optical circuit switching domain. The SDN-controllable transponders and the extended transport applications programming interface enable the congestion-aware provisioning of end-to-end real-time services. At the data plane level, different transponders based on orthogonal frequency division multiplexing are employed for inter/intradomain links in order to adaptively provision services with fine granularity. For adaptation, SDN-capable domain-specific optical performance monitors are also introduced. In the control plane, the applications based network operations architecture has been extended and addressed as an adaptive SDN orchestrator.