Digital All-Optical Physical-Layer Network Coding

Network coding (NC) has recently attracted intense research focus for its potential to provide network throughput enhancements, security and reduced network congestions, improving in this way the overall network performance without requiring additional resources. In this chapter, the all-optical physical-layer network coding (AOPNC) technique is presented, focusing on digital encoding schemes that are based on optical XOR logical gates. It is also discussed how digital AOPNC can be implemented between sub-carrier-modulated (SCM) optical signals in radio-over-fiber (RoF) networks, circumventing the enhanced complexity arising by the use of SCM signals and the asynchrony that might exist between the data arriving at the encoding unit. AOPNC demonstrations are described for simple on/off keyed (OOK)-SCM data signals, as well as for more sophisticated higher-order phase modulation formats aiming to further improve spectrum efficiency and transmission capacity

Transition technologies towards 6G networks

[EN] The sixth generation (6G) mobile systems will create new markets, services, and industries making possible a plethora of new opportunities and solutions. Commercially successful rollouts will involve scaling enabling technologies, such as cloud radio access networks, virtualization, and artificial intelligence. This paper addresses the principal technologies in the transition towards next generation mobile networks. The convergence of 6G key-performance indicators along with evaluation methodologies and use cases are also addressed. Free-space optics, Terahertz systems, photonic integrated circuits, softwarization, massive multiple-input multiple-output signaling, and multi-core fibers, are among the technologies identified and discussed. Finally, some of these technologies are showcased in an experimental demonstration of a mobile fronthaul system based on millimeter 5G NR OFDM signaling compliant with 3GPP Rel. 15. The signals are generated by a bespoke 5G baseband unit and transmitted through both a 10 km prototype multi-core fiber and 4 m wireless V-band link using a pair of directional 60 GHz antennas with 10 degrees beamwidth. Results shown that the 5G and beyond fronthaul system can successfully transmit signals with both wide bandwidth (up to 800 MHz) and fully centralized signal processing. As a result, this system can support large capacity and accommodate several simultaneous users as a key candidate for next generation mobile networks. Thus, these technologies will be needed for fully integrated, heterogeneous solutions to benefit from hardware commoditization and softwarization. They will ensure the ultimate user experience, while also anticipating the quality-of-service demands that future applications and services will put on 6G networks.This work was partially funded by the blueSPACE and 5G-PHOS 5G-PPP phase 2 projects, which have received funding from the European Union's Horizon 2020 programme under Grant Agreements Number 762055 and 761989. D. PerezGalacho acknowledges the funding of the Spanish Science Ministry through the Juan de la Cierva programme.Raddo, TR.; Rommel, S.; Cimoli, B.; Vagionas, C.; Pérez-Galacho, D.; Pikasis, E.; Grivas, E.... (2021). Transition technologies towards 6G networks. EURASIP Journal on Wireless Communications and Networking. 2021(1):1-22. https://doi.org/10.1186/s13638-021-01973-91222021

Chapter Digital All-Optical Physical-Layer Network Coding

Network coding (NC) has recently attracted intense research focus for its potential to provide network throughput enhancements, security and reduced network congestions, improving in this way the overall network performance without requiring additional resources. In this chapter, the all-optical physical-layer network coding (AOPNC) technique is presented, focusing on digital encoding schemes that are based on optical XOR logical gates. It is also discussed how digital AOPNC can be implemented between sub-carrier-modulated (SCM) optical signals in radio-over-fiber (RoF) networks, circumventing the enhanced complexity arising by the use of SCM signals and the asynchrony that might exist between the data arriving at the encoding unit. AOPNC demonstrations are described for simple on/off keyed (OOK)-SCM data signals, as well as for more sophisticated higher-order phase modulation formats aiming to further improve spectrum efficiency and transmission capacity

Analog radio-over-fiber 5G fronthaul systems:blueSPACE and 5G-PHOS projects convergence

The fifth generation (5G) mobile systems can be considered the way to ubiquitous Internet, pervasive computing paradigm, and a revolution in industries like automotive, media and entertainment, and eHealth. New 5G fronthaul systems based on centralized radio access networks will eventually use technology enablers such as reconfigurable optical add-drop multiplexers, space-division multiplexing, ribbon fibers, software-defined networking, multiple-input multiple-output signaling, analog radio-over-fiber signals, and beamforming. In this context, this paper addresses the principal technology enablers of the 5G PPP phase 2 projects blueSPACE and 5G-PHOS and their potential interoperability. The convergence of 5G key-performance indicators (KPIs) along with methodologies and usage scenarios is also addressed. Furthermore, the 2020 European championship is perceived here as a unique opportunity to leverage a 5G pan-European trial platform. The technologies developed in both projects are seen as potential candidates for next generation mobile networks, where ultra-low latency, energy efficiency, and millions of connected devices are major network KPIs requirements

Analog radio-over-fiber 5G fronthaul systems: blueSPACE and 5G-PHOS projects convergence

The fifth generation (5G) mobile systems can be considered the way to ubiquitous Internet, pervasive computing paradigm, and a revolution in industries like automotive, media and entertainment, and eHealth. New 5G fronthaul systems based on centralized radio access networks will eventually use technology enablers such as reconfigurable optical add-drop multiplexers, space-division multiplexing, ribbon fibers, software-defined networking, multiple-input multiple-output signaling, analog radio-over-fiber signals, and beamforming. In this context, this paper addresses the principal technology enablers of the 5G PPP phase 2 projects blueSPACE and 5G-PHOS and their potential interoperability. The convergence of 5G key-performance indicators (KPIs) along with methodologies and usage scenarios is also addressed. Furthermore, the 2020 European championship is perceived here as a unique opportunity to leverage a 5G pan-European trial platform. The technologies developed in both projects are seen as potential candidates for next generation mobile networks, where ultra-low latency, energy efficiency, and millions of connected devices are major network KPIs requirements