This article reports the work on next generation transponders for optical networks carried out within the last few years. A general architecture supporting super-channels (i.e., optical connections composed of several adjacent subcarriers) and sliceability (i.e., subcarriers grouped in a number of independent super-channels with different destinations) is presented. Several transponder implementations supporting different transmission techniques are considered, highlighting advantages, economics, and complexity. Discussions include electronics, optical components, integration, and programmability. Application use cases are reported

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/userguides/explore-bristol-research/ebr-terms/ 1932-4537 (c)Abstract-Datacenter (DC) design has been moved towards the edge computing paradigm motivated by the need of bringing cloud resources closer to end users. However, the Software Defined Networking (SDN) architecture offers no clue to the design of Micro Datacenters (MDC) for meeting complex and stringent requirements from next generation 5G networks. This is because canonical SDN lacks a clear distinction between functional network parts, such as core and edge elements. Besides, there is no decoupling between the routing and the network policy. In this paper, we introduce Residue Defined Networking Architecture (RDNA) as a new approach for enabling key features like ultra-reliable and low-latency communication in MDC networks. RDNA explores the programmability of Residues Number System (RNS) as a fundamental concept to define a minimalist forwarding model for core nodes. Instead of forwarding packets based on classical table lookup operations, core nodes are tableless switches that forward packets using merely remainder of the division (modulo) operations. By solving a residue congruence system representing a network topology, we found out the algorithms and their mathematical properties to design RDNA's routing system that (i) supports unicast and multicast communication, (ii) provides resilient routes with protection for the entire route, and (iii) is scalable for 2-tier Clos topologies. Experimental implementations on Mininet and NetFPGA SUME show that RDNA achieves 600 ns switching latency per hop with virtually no jitter at core nodes and submillisecond failure recovery time.

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The recently created ITU-T Focus Group Network 2030 is leading network operators to identify the requirements and use cases that networks are expected to fulfill for the short, medium, and long term within the current decade. Essentially, network operators need to evolve their networks to meet strict performance requirements in several dimensions, including a large bandwidth to support foreseen beyond-5G (B5G) services, such as digital twins and volumetric video. To provide such a bandwidth requirement in a sustainable and scalable way, multi-band (MB) optical networks are expected to gradually extend legacy optical network capacity by exploiting bands beyond C+L. In this paper, we present a traffic analysis methodology to help network operators to compute expected traffic demand to be supported in their networks as a result of combining well-known mass market services with foreseen B5G service scenarios. Numerical results based on inputs and forecasts from major European network operators show that MB will be required at all network segments, including metro-aggregation, metro-core, and backbone, by the end of this decade.

A software-defined IoT network is integrated with fibre-based QKD technology to provide the IoT devices with quantum-secure keys to enhance their battery lifetime. Experimental demonstration reveals an 18% energy efficiency improvement compared to the standard device key generation.