Terabit Bidirectional Multi-user Optical Wireless System (TOWS) for 6G LiFi

Lead Research Organisation: University of Leeds
Department Name: Electronic and Electrical Engineering

Abstract

Given the unprecedented demand for mobile capacity beyond that available from the RF spectrum, it is natural to consider the infrared and visible light spectrum for future terrestrial wireless systems. Wireless systems using these parts of the electromagnetic spectrum could be classified as nmWave wireless communications system in relation to mmWave radio systems and both are being standardised in current 5G systems. TOWS, therefore, will provide a technically logical pathway to ensure that wireless systems are future-proof and that they can deliver the capacities that future data intensive services such as high definition (HD) video streaming, augmented reality, virtual reality and mixed reality will demand. Light based wireless communication systems will not be in competition with RF communications, but instead these systems follow a trend that has been witnessed in cellular communications over the last 30 years. Light based wireless communications simply adds new capacity - the available spectrum is 2600 times the RF spectrum.

6G and beyond promise increased wireless capacity to accommodate this growth in traffic in an increasingly congested spectrum, however action is required now to ensure UK leadership of the fast moving 6G field. Optical wireless (OW) opens new spectral bands with a bandwidth exceeding 540 THz using simple sources and detectors and can be simpler than cellular and WiFi with a significantly larger spectrum. It is the best choice of spectrum beyond millimetre waves, where unlike the THz spectrum (the other possible choice), OW avoids complex sources and detectors and has good indoor channel conditions. Optical signals, when used indoors, are confined to the environment in which they originate, which offers added security at the physical layer and the ability to re-use wavelengths in adjacent rooms, thus radically increasing capacity.

Our vision is to develop and experimentally demonstrate multiuser Terabit/s optical wireless systems that offer capacities at least two orders of magnitude higher than the current planned 5G optical and radio wireless systems, with a roadmap to wireless systems that can offer up to four orders of magnitude higher capacity.

There are four features of the proposed system which make possible such unprecedented capacities to enable this disruptive advance. Firstly, unlike visible light communications (VLC), we will exploit the infrared spectrum, this providing a solution to the light dimming problem associated with VLC, eliminating uplink VLC glare and thus supporting bidirectional communications. Secondly, to make possible much greater transmission capacities and multi-user, multi-cell operation, we will introduce a new type of LED-like steerable laser diode array, which does not suffer from the speckle impairments of conventional laser diodes while ensuring ultrahigh speed performance. Thirdly, with the added capacity, we will develop native OW multi-user systems to share the resources, these being adaptively directional to allow full coverage with reduced user and inter-cell interference and finally incorporate RF systems to allow seamless transition and facilitate overall network control, in essence to introduce software defined radio to optical wireless. This means that OW multi-user systems can readily be designed to allow very high aggregate capacities as beams can be controlled in a compact manner. We will develop advanced inter-cell coding and handover for our optical multi-user systems, this also allowing seamless handover with radio systems when required such as for resilience. We believe that this work, though challenging, is feasible as it will leverage existing skills and research within the consortium, which includes excellence in OW link design, advanced coding and modulation, optimised algorithms for front-haul and back-haul networking, expertise in surface emitting laser design and single photon avalanche detectors for ultra-sensitive detection.

Planned Impact

We will benefit the academic and industrial community engaged in research in OW design, and in turn the wider communications, IoT and ICT communities, in the UK and internationally. We would like particularly to point out the potential of TOWS in demonstrating new concepts and aiding standards bodies including ITU and IEEE where the applicants are particularly active in standards with 5 new IEEE standards recently approved through leadership of GreenTouch and its industrial partners and through a new OW standard currently being introduced through our work in the important IEEE 802.11 standard (LiFi in WiFi standard). To ensure that the potential academic and industrial communities identified above benefit we will engage in a range of impact activities. We have hosted extended industrial and academic placements in our groups, have found those to be far more effective than workshops in transferring knowledge and ensuring the engagement of industrial and academic researchers, and have reciprocated placements at partner locations. We plan to continue this successful impact activity and plan to arrange for researchers to rotate between our sites. We will disseminate the knowledge and bring awareness of TOWS through our IEEE distinguished lecturer tours, IEEE Teaching Courses, IEEE tutorials and through our leadership of initiatives such as the IEEE 5G initiative. The research will benefit the UK by ensuring that it maintains its world leading position in ICT infrastructure needed for beyond 5G / 6G, through the potential creation of new ICT systems, and services where the applicants have outstanding track records. For example, Cambridge has a track record in licensing to world leaders such as Avago with components already in production. In other cases, new spin-off companies will be set up to commercialise network architectures, systems and protocols, for example as in spinoffs PureLiFi in Edinburgh, Celltron Networks in Leeds and Zinwave (sold to McWane in 2014) in Cambridge.
 
Description Introduced a cross-project link simulation tool.
Developed an optical wireless (OW) network resource allocation optimisation framework.
Optimised back-haul OW network architecture with fog and cloud processing.
Developed models for eye safety and for link design.
Developed free space OW AP-AP back-haul link designs.
Evaluated potential demonstrator options.
Guest edited a special issue of IEEE Vehicular Technology Magazine on 6G, 2019.
Guest edited a special issue of the Philosophical Transactions of the Royal Society on Optical Wireless Communication, 2020.
Four Invited talks and two White papers at IEEE 6G World Summit, 2020.
Exploitation Route N/A
Sectors Digital/Communication/Information Technologies (including Software)

Electronics

Healthcare

Leisure Activities

including Sports

Recreation and Tourism

Manufacturing

including Industrial Biotechology

Culture

Heritage

Museums and Collections

Retail

Security and Diplomacy

 
Description IEEE 802.11 standard IEEE 1927.1 Standard
First Year Of Impact 2022
Sector Digital/Communication/Information Technologies (including Software),Education,Electronics,Healthcare,Leisure Activities, including Sports, Recreation and Tourism,Manufacturing, including Industrial Biotechology,Culture, Heritage, Museums and Collections,Retail,Security and Diplomacy
Impact Types Societal

Economic

 
Title Data supporting "8.2 Gbps Optical Wireless Link using SiPM at NIR Wavelength" 
Description SiPM_JLT_data.xlsx has six sub sheets each containing different data sets. Sheet1: The data is measured values of fast output pulse responses of 10010 and 30020 OnSemi SiPMs. Sheet2: The data is measured SiPM bias current obtained at different irradiance values from a 850 nm source. Sheet3: The data is a frequency response of 10010 SiPM measured using 7.5 GHz 850nm VCSEL source. Frequency response values obtained using FFT of fast output pulse data (10010 SiPM) are also provided for comparison. Sheet4: The data contains normalized values for white LED spectrum and transmittance values of RG-780 colour glass filter. Sheet5: The data is the measured BER for 8.2 Gbps data rate obtained at various SiPM bias voltages. Sheet6: The data is measured achievable datarate at various irradiances for different SiPMs and conditions: i) 10010 SiPM with DFE in dark, ii) 10010 SiPM with DFE under 500 lux, iii) 10010 SiPM without DFE, iv) 30020 SiPM with DFE. 
Type Of Material Database/Collection of data 
Year Produced 2023 
Provided To Others? Yes  
URL https://www.repository.cam.ac.uk/handle/1810/357983
 
Title Dataset for "Linearisation Method of DML-based Transmitters for Optical Communications, Part III: Pulse Amplitude Modulation" 
Description Data related to the JLT publication: "Linearisation Method of DML-based Transmitters for Optical Communications, Part III: Pulse Amplitude Modulation" 
Type Of Material Database/Collection of data 
Year Produced 2023 
Provided To Others? Yes  
URL https://www.repository.cam.ac.uk/handle/1810/354787
 
Description Disseminating the projects in the Disruptive Wireless Communication Paradigms: The Road Towards 6G, Indian Institute ofInformation Technology Guwahati, India, 2021 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Presented the results of the project before a group of students and academics and professionals from in the Disruptive Wireless Communication Paradigms: The Road Towards 6G, Indian Institute ofInformation Technology Guwahati, India, 2021. The even was held virtually and sparked questions and discussions during and after the event.
Year(s) Of Engagement Activity 2021
URL https://sites.google.com/view/dwcp-6g/home?authuser=0
 
Description Disseminating the projects results before a group of students and academics from Beihang University, China in 2020. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Undergraduate students
Results and Impact More than 50 undergraduate and post graduate students attended along with a number of academics from Beihang university and that sparked questions and discussion afterwards. This event was held virtually.
Year(s) Of Engagement Activity 2020
 
Description IEEE 5G World forum, Montreal, Canada 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Delivered an invited talk on "Resilient Free-Space Optical Communication for 5G and Beyond" for professionals, acedemic and industrial audience attending the IEEE 5G World Forum held in Montreal, Canada. The invited talk was delivered in the OWC topical session of the IEEE 5G World forum. The talk was attracted interests on how a resilient design can be developed for the next generation of optical wireless communication systems.
Year(s) Of Engagement Activity 2021
URL https://attend.ieee.org/wf-5g/optical-wireless-communication-owc/
 
Description Invited talk, Elmirghani, J.M.H., "Future Internet Networks and Systems," Ofcom, UK, 21 Oct 2020. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Future Internet Networks and Systems
Year(s) Of Engagement Activity 2020
 
Description Invited talk, Elmirghani, J.M.H., "Terabit Optical Wireless Systems and Energy Efficiency," UK and Nordic-Baltic Countries 5G Forum, organized by 5G Testbeds and Trials Programme, Department of Digital, Culture, Media and Sport (DCMS), 8 Feb 2021. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact 5G Testbeds and Trials Programme
Year(s) Of Engagement Activity 2021
 
Description Invited talk, Elmirghani, J.M.H., "Terabit Optical Wireless Systems for 6G Networks," EPSRC Towards Ultimate Convergence of All Networks (TOUCAN) Programme Grant final workshop, UK, 4 November 2020. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Terabit Optical Wireless Systems for 6G Networks
Year(s) Of Engagement Activity 2020