SC445 - Visible Light Communications — the High Bandwidth Alternative to WiFi
Monday, 20 March
13:30 - 16:30
Short Course Level: Advanced Beginner
Instructor: Harald Haas; LiFi Research and Development Centre, The University of Edinburgh, UK
Short Course Description:
The visible light spectrum is 1000 times larger than the entire radio frequency spectrum of 300 GHz, and this simple fact provides the motivation to use visible light as a high bandwidth alternative to radio. The applications range from gigabit interconnects in data centers, through mobile networking in homes and offices to point-to-point long range wireless backhaul links outdoors.. We will set the scene by looking at existing conventional wireless access technology and state clearly its limitations. Then we will go on to provide a general background to the subject of optical wireless communications, followed by a brief summary of the history of visible light communication VLC). We will discuss the relationship between VLC and LiFi (light fidelity), introducing the major advantages of VLC and LiFi and discuss existing challenges. Recent key advancements in physical layer techniques that led to transmission speeds greater than 10 Gbps will be discussed. Moving on, we introduce channel modelling techniques, and show how this technology can be used to create fully-fletched cellular networks achieving orders of magnitude improvements of area spectral efficiency compared to current technologies. The challenges that arise from moving from a static point-to-point visible light link to a LiFi network that is capable of serving hundreds of mobile and fixed nodes will be discussed. An overview of recent standardisation activities will be provided. Lastly, we will moot commercialisation challenges of this disruptive technology.
Short Course Benefits:
This course will enable you to:
Understand the limits to conventional WiFi technology and how light can provide massively higher bandwidth.
Describe key visible light technologies sucvhc as VLC and LiFi.
Explain practical limitations of VLC communication links such as strong sun light and non-line of sight conditions.
Compare different digital modulation techniques used in intensity modulation / direct detection systems in terms of spectrum efficiency and energy efficiency as well as various environmental conditions.
Discuss pros and cons of angular diversity and multiple input multiple output techniques in VLC systems.
Summarise methods to achieve multiuser access and to support mobility in LiFi optical attocell networks.
List practical co-channel interference mitigation techniques in LiFi attocell networks.
Explain how the downlink capacity of optical attocell networks could be obtained taking into account that effects such as fading do not exist unlike in RF.
Discuss how LiFi could lead to a merger of the lighting and wireless communication industries.
Short Course Audience:
This advanced-beginner course is intended for a diverse audience including lightwave system researchers and engineers as well as photonic device researchers and engineers and optical sub-system designers. The course should also be of interst to reseachers and practitioners in fibre optic communication who see an all-optical future where light also plays a major role in wireless access networks. Some basic knowledge of intensity modulation and direct detection techniques will be useful, but is not a prerequisite. The same applies to basic knowldege of wireless access networks.
Harald Haas holds the Chair of Mobile Communications at the University of Edinburgh, and is the Director of the Li-Fi R&D Centre. He is founder of pureLiFi Ltd. He first coined Li-Fi and was an invited speaker at TED Global 2011 and 2015, and his talks have been watched online more than 4 million times. In 2014, he was selected by EPSRC as one of ten RISE (Recognising Inspirational Scientists and Engineers) Leaders in the UK.