How fast can LiFi be?

LiFi can achieve data rates of 100 Gbps and higher, but this would require a change in the lighting technology.

Recent news report that LiFi is 100 times faster than WiFi. The assumption was that the average WiFi speeds are 10 Mbps, and that LiFi can be as fast as 1 Gbps. In this discussion, it is important to compare like-for-like, and it must be stressed that 1 Gbps from an off-the-shelf LED have not been demonstrated. The facts are:

  • The visible light spectrum is 1,000 times larger than the entire 300 GHz of radio, micro wave and mm wave radio spectrum, so there is a big untapped reservoir of resources for wireless systems.
  • Phosophor coated white LEDs which are mostly used in all commercial lighting devices can deliver up to about 100 Mbps.
  • Red, Green, Blue (RGB) LEDs can deliver up to about 5 Gbps.
  • Laser based white LEDs with a diffuser to create a broad light beam could transmit up to 100 Gbps (http://bit.ly/1TdI7Yg  and http://bit.ly/1AgcwAJ).
  • The fastest WiFi in the 60 GHz frequeny band, WiGig, can achieve a maximum data rate of 7 Gbps.
  • The experienced data rate in a network where multiple users must share the bandwidth is significantly lower than the maximum headline number for data rates in WiFi systems.
  • Therefore, a more important metric is the data rate per square meter, or area data rate.
  • The area data rate of a LiFi network compared can be 1,000 times higher than the area data rate of a WiFi network. The main reason for this is that while there can only one WiFi router in a room as interference would destroy the bandwidth, there can be tens and more light bulbs in a room as interference behaves entirely different when using light to carry data.

 

Envisaged light bulb technoloy roadmap
Roadmap of expected light bulb technologies