Wavelength Router Functional Elements with Different Structures Enabling to Support VNF

Extended abstract: Notices of electric power consumptions in communication networks issued before now become big issues for sustainability, related on Sustainable Development Goals (SDGs) 7/9/11/13 due to tremendous use of a lot of information locally/globally which was produced/created, transferred, processed and compiled anytime anywhere.Power consumption of the global Internet analysis in 2016 showed some values that 4 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> W for data center, 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> W for core network, 5 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> W for access, plus 30 W × 3 billion users are required [1]. Estimated total power consumption of future homes in 2017 that are categorized by terminals/devices of a) communication ones; b) home appliances; c) sensors required several tenth W to several kW in a home [2]. Recent optical transceiver modules based on Multi-Source Agreement (MSA), e.g. 1.6T optical module roadmap @2023 requires around 20 W that equals to 10 – 20 pJ/bit [3]. Data center (DC)/enterprise network is a recent critical field on this issue that in DC, 219 GWh @2030 is expected. This is because the major part depends much on AI DC emergence [4].On the contrary, energy supply was about about 31 PWh/y in 2024 and is slowly increasing (2.6 % per annum) depending on new methods [5]. However, there would be not sufficient for growing consumption of electric power (about 27 PWh/y in 2024 with +4% [6]).For further reduction of power consumption, several technical challenges are under research/developing; Smart devices/modules/subsystems that use Silicon Photonics (SiPh), Photonic Integrated Circuit (PIC), Co-Package Optics (CPO) are current key technologies. However, as power consumption (e.g. in a system) is simply expressed by the notation of P [pJ/bit] × S [bit/s] × N where P; per device power, S; speed, N; the total number of devices (in a system), not only device enhancement but network architecture enabling to use much smaller number of devices (smaller N) have to be researched.This article discusses the following results;(1)The network configuration of wavelength routing networks with hierarchical structure in terms of wavelength (Fig. 1.) [7].(2)Then, its network performances are elucidated. Here, hierarchical, or non-hierarchical structures are compared for the number of lambdas, latency, and power consumption (Fig. 2. (a)(b)). As the hierarchical structure could create smaller segments, it showed possible reduction of the total number of lambdas, lower the latency and lower power consumption.(3)Wavelength router (WR) structures are then compared. They include two types of Thin Film Filter (TFF) based WRs, Arrayed Waveguide Grating (AWG) based WR, and proposed PIC based WR. They are already presented by the author [7–9].(4)As physical devices so far used have basically a pre-installed functionality/protocol, if such devices could also be one of virtualized network functions (VNFs) [10], much more flexibility and benefits will be obtained. Therefore, the proposed PIC based WR is considered to accommodate such functions (Fig. 3. and Fig. 4.). It enables the adjustment of CWDM filter bandwidth for dynamic requirements of the data plane programmability in terms of the wavelength uses to support VNF. Designing the CWDM/DWDM filters and preliminary system simulation results showed its feasibility and potential integration on the photonic circuits with other functions.