We have seen long-haul communications cables move from copper to optical, we are seeing point to point wireless links starting to shift from microwave to free space optics. Short wired interconnects are also move towards optical links, and now VLC is continuing this trend with short range wireless.
So why has there been a shift towards optical technologies compared to copper conductors and wireless radio? While the reasons appear to be complex and varied, they do boil down to two key factors; cost and performance.
Long-haul fibre took a long time to be fully adopted. Initially in the late 1980s and early 1990s there was good supply of new fibre capacity and a lack of demand but then the Internet came along and changed that. Point-to-point links between buildings have traditionally been microwave, but there is now a growing shift towards free-space optical (FSO) links giving Gbit/s capacities using lasers.
In the local loop and interconnect we have seen low-cost plastic optical fibre (POF) interconnects widely used, initially for audio interconnects and now being widely proposed for future home networks.
If we now consider the problem we have today; there is massive demand for wireless data and the excess capacity using radio has dried up. In the early 1990s optical fibre was technology led until the Internet. The current demand for wireless capacity is insatiable and creates a market led demand for alternative wireless technologies. Looking at the contenders for short-range wireless in the Gbit/s range we seem to have 3 contenders; WiGig, GigaIR and of course VLC, or Li-Fi as we can now call it. You will notice that two out of these three are optical technologies. The trend continues!
In a second article I will look at these technologies in a little more detail.
