The modulation formats preconized for PHY I and PHY II are the coding on-off keying (OOK) and variable pulse position modulation (VPPM). The Manchester coding used for the PHY I and PHY II layers include the clock inside the transmitted data by representing a logic 0 with a OOK symbol "01" and a logic 1 with a OOK symbol "10", all with a continue component. This is an important point because they continue component allows avoiding the light extinction in case of an extended line of logic 0.
The new high-speed optical wireless usage models both indoors and outdoors. The Li-Fi provides resources for OEM and ODM developers to create exciting new products. With the emergence of high-speed cable connections like Thunderbolt and USB 3.0, the stage is set for a wireless equivalent. While Wi-Fi is very popular for pervasive 100+ Mbps service, multi- Gigabit short-range optical wireless interconnects provide an alternative to the proposed WiGig Gigabit RF solution.
Some of the advantages of optical wireless communications include:
a) Scalability to 10+ Gbps,
b) A wide variety of beaming angles and distances,
c) No spectrum license required,
d) High physical link security, e) No RF interference and
f) No possible harmful RF radiation .
The technology is ideal for wireless docking, data links with kiosks and mobile displays, medium-range beaming, data showers and