By ITU News
ITU’s standard for indoor Visible Light Communication (VLC), also known as ‘LiFi’ – ITU G.9991 – is the world’s first standard for high-speed wireless communications with visible light and infrared.
LiFi provides network connectivity within a premises, similar to WiFi, but using light rather than radio signals.
When Philips Lighting introduced Signify as its new company name in 2018, the choice was motivated by light’s value as ‘an intelligent language, which connects and conveys meaning’.
“The lighting world has changed completely,” says Jean-Paul Linnartz, Research Fellow and Senior Director at Philips Research.
“Lighting is becoming a high-tech product. LEDs are now an Internet of Things business.”
Signify became an ITU member in January 2019.
The company participated in the development of ITU G.9991 to be quick to market with standards-based LiFi solutions – the Signify ‘Trulifi’ range.
Signify is part of “Enhance Lighting for the Internet of Things” (ELIOT), an EU Horizon 2020 project participating in the standardization of lighting and telecom infrastructures in IEC, IEEE, IETF and ITU.
Driven by component and luminaire makers, ICT operators and vendors, industrial IoT players, and academic and research institutes, ELIOT is contributing to consensus on architecture choices for LiFi to support IoT applications in smart manufacturing, smart mobility and smart cities.
Learn more about ELIOT, LiFi and ITU G.9991 from ELIOT coordinator Fraunhofer HHI…
High security, no interference, spectrum saving
LiFi will provide a valuable complement to WiFi as digital transformation accelerates. LiFi and WiFi have different strengths, and LiFi is strong where WiFi faces challenges.
Light does not travel through walls, providing high security alongside the assurance of no interference with other communications. LiFi can also assist in saving radiofrequency spectrum, alleviating challenges faced by WiFi in navigating increasingly crowded spectrum.
“The ITU standard takes the LiFi market beyond prototype and trial hype, providing a plausible direction for the growth of the market,” says Linnartz.
Sectors such as financial services and healthcare are interested in LiFi’s offer of high security.
Industrial businesses are looking to LiFi for the connection stability and low latency required by connected machinery and collaborative robotics.
And when LiFi enters consumer markets, its low latency could support advanced gaming and Virtual Reality applications.
“We are working with professional markets such as office spaces, hospitality, retail, financial services and healthcare, and we are pursuing significant opportunities for LiFi in industrial settings. When we enter consumer markets, we expect that will be to enable interactive applications such as Virtual Reality,” says Linnartz.
A route to market
ITU’s LiFi standard ITU G.9991 aligns with the ITU G.hn family of home networking standards.
Signify’s Trulifi range of solutions entered the market using hardware available from the established G.hn market.
“LiFi must build on an open standard if it is to achieve widespread market acceptance,” says Musa Unmehopa, Head of Ecosystems and Alliances for LiFi, at Signify.
“Signify sees ITU’s LiFi standard in combination with available G.hn chipsets as a key route to market, and an essential enabler towards sustainable market growth.”
Signify shifted from its own proprietary solution to ITU G.9991.
“With the ITU standard we have succeeded in delivering LiFi solutions at a reasonable cost to Signify, and an attractive price to our customers,” says Unmehopa.
“Available G.hn hardware – and the economies of scale and associated cost efficiencies achieved by the G.hn market – accelerated Signify’s entry to the LiFi market and can accelerate the growth of the emerging LiFi ecosystem.”
A natural fit for LiFi
ITU G.9991 details the system architecture, physical layer and data link layer specification for high-speed indoor LiFi transceivers, the LiFi access points within LED and infrared lamps.
“The TDMA modulation scheme proved a natural fit for the properties of LEDs,” says Jean-Paul Linnartz.
The ITU G.hn series was developed to solve home networking challenges over any type of wiring available in a residential environment, typically powerline, coaxial cable and phoneline.
“The modulation needed for LEDs is not dissimilar to the modulation needed for powerline, coax and twisted-pair communication,” says Linnartz.
Linnartz highlights associated advantages in performance and quality of service (QoS).
“When we compare the throughput of 5G, WiFi and LiFi, we have shown the throughput of LiFi to be very stable.”
With light confined by boundary walls and the TDMA scheme of the ITU standard, explains Linnartz, “QoS is nicely defined and the standard gives us the link stability to provide each application with a guaranteed level of QoS.”
A basis for LiFi market growth
The growth of the LiFi market will be driven by many companies and two quite different industries, the connectivity industry and the lighting industry. LiFi could also support the very diverse Internet of Things marketplace.
“Standards are really the only way for these different worlds to speak to one another and collaborate successfully in stimulating the growth of the LiFi market,” says Marcos Martinez, MaxLinear, Associate Rapporteur for ITU’s working group for ‘technologies for in-premises networking and related access applications’ (Q18/15).
“We have seen a variety of proprietary solutions, but without standards it has been impossible to create an ecosystem.”
Q18/15 continues to add new features to ITU G.9991.
For all ITU standards under development in Q18/15, see the Q18/15 work programme
Learn more about ITU-T Study Group 15
The international standards developed by ITU-T Study Group 15 define networks, technologies and infrastructures for transport, access and home.
For all working groups (‘Questions’), see list of Questions and Rapporteurs.
To learn more about ITU-T Study Group 15, contact firstname.lastname@example.org.