Li-Fi Internet of Things
Transferring data using fluorescent lights
With the Internet of Things set to become a mainstay of the digital world, device manufacturers and telecoms companies must ensure that their products are not using large amounts of power. One solution is through using Li-Fi, a new technology with speeds that surpass Wi-Fi hundreds of times over by utilising light instead of radio waves. The technology is currently being trialled by a number of universities and companies and has received substantial investment from EPSRC.
Light Fidelity or Li-Fi is a Visible Light Communications (VLC) system that enables wireless communications at very high speeds. Using binary code and a subset of optical wireless communication (OWC), it is 100 times faster than Wi-Fi and 250 times faster than super-fast broadband. Both Li-Fi and Wi-Fi transmit data electromagnetically. However, Wi-Fi uses radio frequency (RF) while Li-Fi runs on visible light between 400 and 800 THz. Transferring data using light increases the bandwidth by around 10,000 times, allowing for greater capacity.
One of the benefits of Li-Fi is that the infrastructure is already in place as 14 billion fluorescent lights are replaced with highly energy-efficient LEDs. Li-Fi uses these LEDs to transmit information through imperceptible changes in light. Rapid on-off keying enables the ultra-fast data transmission.
Li-Fi potentially eliminates access and bandwidth problems across the entire globe, connecting an almost limitless range of devices. It requires less power to operate than Wi-Fi, reducing costs. Li-Fi also builds increased security into local networks as the signal gets blocked by walls and cannot be intercepted by non-authorised users.
Why Li-Fi Matters
There are more than 1.4 million cellular radio masts and 3.5 billion mobile phones worldwide transmitting 600 TB of data every month. For future growth to continue at the same pace – and bring billions of more devices online – telecom providers need to consider a new challenge: energy efficiency.
Radio base stations consume vast amounts of energy and most of it is used for cooling the stations, not to transmit the data. Li-Fi represents the possibility to do away with this huge expense and energy drain. Installing new radio base stations comes with a large cost. Instead, Li-Fi uses wireless communication on the back of lighting which is already installed across the country.
Li-Fi has the potential to allow for tens of billions of securely connected devices while using a vastly reduced power outlay. Smarter home appliances that talk machine-to-machine are already being tested, where LED lights on electronics function as Li-Fi access points. Instead of installing radio base stations in cities, street lamps could provide both illumination during night, and high speed data communication 24/7. The Dartmouth Systems Lab’s prototype defied assumption that visible light communication requires the lights on at all times such as during a sunny day. Their DarkLight enables a special mode that the LEDs switch to, so that the light can still beam data to devices even when it’s not on.
Progress so far
Research into Li-Fi is currently focused on enhancing the performance of Li-Fi alone as well as on finding reliable Wi-Fi and Li-Fi coexistence solutions. There are many startups and universities researching to bring the technology into people’s homes, and Samsung is the top patent filer in the Li-Fi domain.
In November 2014, Li-Fi pioneer, a spin-out from the University of Edinburgh pureLiFi, joined forces with French lighting company Lucibel aiming to bring out Li-Fi enabled products by the end of 2015. PureLiFi offers full duplex, extensive range communication beyond existing Wi-Fi, mobility, and flexible deployment for multiple users. In the same year Li-Fi made its way out of laboratories to live trials. In 2016, pureLiFi has secured £7 million of funding from investment company Temasek to scale up the technology.
The EPSRC is currently funding a consortium of five UK universities, led by University of Strathclyde, to develop tiny, micron-sized LEDs that could communicate one million times as much information as one 1mm-squared LED.
Li-Fi has already been tested at places such as museums and shopping malls in France, Belgium, Estonia, China and India. Oledcomm is currently looking to instal Li-Fi in hospitals in northern France. It is reportedly being tested in Dubai, by UAE-based telecommunication providers Du and Zero1. Du has successfully provided internet, audio and video streaming over the Li-Fi connection. The speed record for information dissemination still belongs to researchers at the University of Oxford, who achieved a rate of 224 Gbps.
Major industry participants include PureLifi, GE, Philips, Oledcomm, and LVX. GE has recently partnered with ByteLight to demonstrate “LED infrastructure” that will be available in the next generation of GE LED luminaries. It will use combination of VLC and Bluetooth for communication with smart phones, cameras and tablets. GE has also collaborated with Qualcomm to combine big data with location to offer engaging shopping experience and increased value to customers. In May 2016, LVX teamed up with NASA in order to introduce Li-Fi for space missions and enhance it with features such as Global Positioning Satellite Routing Systems architecture. A future manned spacecraft making a trip to Mars and a deep-space habitat operating on the planet could be candidates for the Li-Fi communication system. Li-Fi is gaining popularity with big companies like Apple, who is making code in the iOS firmware to incorporate its capabilities, whilst Cisco’s focus is on access networks in a multi-gigabit range for the IoT and Internet of Everything (IoE).
Challenges and advantages
The biggest challenge so far has been to provide an uplink from the receiving device back to the ceiling fixture. All devices need to have Li-Fi compatible receptors to be Li-Fi enabled. This may entail the use of a different wavelength in the infrared or radio frequencies. VLC is currently only a broadcasting technology.
The initial use is likely to be in places where Wi-Fi connections are limited, i.e. hospitals (for modern medical instruments), theatres, aeroplanes, and dense urban environments. Traffic lights will be able to communicate with cars’ LEDs to prevent accidents. Submarines and remotely operated vehicles (ROVs) configured to work in deep ocean will benefit from the connectivity as well as chemical and power plants where RF use is prohibited. Smart devices typically use GPS location, but the digital compass for positioning and orientation may not work for indoor apps, and Li-Fi can easily provide necessary reliable data inputs instead.
Li-Fi Cloud will bring broader accessibility. Smartphones will soon be able to download traffic information from traffic lights or apps related to new films at the cinema. According to Global Insights, Li-Fi is set to become $2.6 billion technology in the healthcare sector by 2023, owing to the absence of dangerous radio waves and better data management across hospitals. Hospitals are a specific case of environment where sensitivity and security of data are issues. Li-Fi will provide a smart means of secure connected medical instruments and patients’ records.
In the future, shops’ light fixtures will transmit product offers to your phones as you pass by and every light in an aeroplane will be a data transmitter. Both Li-Fi and Wi-Fi will work well in parallel to create more efficient networks. People will benefit from high signal-to-noise ratio stemming from an illuminated room instead of forcing the radio base station to send the RF signal through multiple walls. Interference between the indoor and outdoor user is entirely avoided and a radio base station can serve the outdoor users with reduced power resulting in greener, more efficient mobile networks
The reason behind the Cisco’s forecast for a drastic increase in data traffic in 2018 compare to 2013 is a fast growing number of devices connecting to the networks. The obvious limitations of RF put huge constraints on the demand for ubiquitous connectivity and high capacity. In wireless communication that requires low latency and high bandwidth, the use of RF is not suitable and beyond a certain limit is bad for your health. Today, VLC is preferred for a number of applications because of its large bandwidth, zero interference, low power usage, and low cost deployment.
Operators say that 80% of mobile traffic occurs indoors; therefore, the combination of Li-Fi and Wi-Fi is on the track to become an integral element in future heterogeneous networks (HetNets) including the 5G mobile telecommunication systems. 5G visible light communication, which can run on the back of lighting devices is an exciting breakthrough that will have a transformative impact on many traditional markets.
Potential vulnerability to a bug in the Li-Fi communication system has been assessed as very low, given authenticate hardware, software and encryption scheme integrated by lighting manufacturers. As Li-Fi cannot be hacked remotely, early adopters are likely to be hospitals, transport, company headquarters and security agencies, where safety and data security are paramount. Adoption may be slow at first as it is still quite new technology, with companies only developing the receivers necessary to implement it at large scale.
You can already see that all the internet giants are aiming to shape Li-Fi towards their own technology, with Google, Apple and Verizon working to implement the technology and take advantage of the 10-gigabit internet speeds. Li-Fi offers immense possibilities using SaaS, cloud, Google, and tools like the Chromebook to stretch the exploration of cyberspace. The communication, which the world sees as a market disruption today, might well be the standard devices are connected and data transmitted in the near future.
Gabriela Salejova, IoTUK Principal Analyst, Digital Catapult