LiFi Technology
1. What is LiFi?
LiFi, also known as "Light Fidelity" is a wireless optical networking technology, which uses light emitting diodes (LEDs) to transmit data. In 2011, professor Harald Haas made a LiFi demonstration at the TED (Technology, Entertainment, Design) Global Talk on Visible Light Communication (VLC). You can watch the demonstration on the link below;
VLC uses light as medium to deliver high-speed communication in a manner similar to Wi-Fi and complies with the IEEE standard IEEE 802.15.7. The IEEE 802.15.7 is a high-speed, bidirectional and fully networked wireless communication technology-based standard similar to Wi-Fi’s IEEE 802.11.
2. How does LiFi work?
LiFi is a high speed, bidirectional, and fully networked wireless communication of data using light. LiFi constitutes of several lightbulbs that form a wireless network.
When an electrical current is applied to a LED light bulb a stream of light (photons) is emitted from the bulb. LED bulbs are semiconductor devices, which means that the brightness of the light flowing through them can be changed at extremely high speeds. This means that the signal can be sent by modulating the light at different rates. The signal can then be received by a detector that interprets the changes in light intensity (the signal) as data. Also when the LED is ON, you transmit a digital 1 and when it is OFF you transmit a 0.
Fig 1. pureLiFi - How LiFi work?
The intensity modulation cannot be seen by the human eye, and thus communication is just as seamless as other radio systems, allowing the users to be connected where there is LiFi enabled light. Using this technique, data can be transmitted from a LED light bulb and back at high speeds.
3. Visible Light Communication
Visible Light Communication, also known as VLC, can be defined as the transmission of data through the use of light sources emitting at visible wavelengths between 400 and 800 THz (780–375 nm). It is a subset of optical wireless communications technologies.
Fig 2. Electromagnetic Spectrum
The VLC market is in its infant stage. There is a growing demand for an alternative wireless communication technology due to the crowding of the Radio Frequency (RF) bandwidth. This will result in the adoption of VLC technology on a global scale. As the VLC technology is based on LEDs, it does not face distortions or spectrum deficits and can transfer data at tremendous speeds.
4. LiFi vs Wi Fi
LiFi uses light for data transmission while WiFi uses electro-magnetic waves at radio frequencies for data transmission. Due to less interference incurred by light compare to radio frequency waves, it is used in more dense environments.
LiFi covers distance of about 10 meters while WiFi covers about 30 meters.
Tab 1. Differences between LiFi and Wi Fi
5. Cost of LiFi
Getting LiFi products from different LiFi companies can be very expensive for consumers. According to pureLiFi, they are currently working towards miniaturisation of LiFi technology as well as making affordable for consumers in the long run. Ultimately the end goal is to have LiFi in every mobile device. This means that the technology will be affordable for integration into handsets, tablets and laptops.
Ultimately the end consumer will see minimal or no cost associated with LiFi as the goal is to have LiFi embedded in every wireless mobile device. Today companies can speak to pureLiFi about working with us on proof of concept projects and other types of installations. These installations are priced based on individual requirements. PureLiFi only offers B2B services.
PureLiFi has just recently started to offer a LiFi starter kit for small businesses and institutions at the cost of £2500 excluding delivery and duties. The LiFi starter kit includes the following:
2x - LiFi Stations
USB (2.0) dongle that fits into device to send and receive data, to and from Access Point
Click here for accessing the datasheet for Li Fi XC Station
2x - LiFi Access Points and TX drivers
This help connecting to the LiFi-enabled lights to send and receive data.
2x - Lucicup II Luminaires
These are LiFi enables lights to send and receive data.
Click here to read the datasheet
PureLiFi also offers a LiFi Network Pack for IT resellers at the cost of £5000 excluding delivery and duties. This LiFi pack contains 4x LiFi Xc dongles, 4x Access Points and 4x Lucicup II.