By Madhukar Swayambhu
Introduce for the first time in MWC, Barcelona 0 2014, “Li-Fi” is the latest buzz word in the wireless technology for computer networking and communication. And people do get amused with the terminology “Li-Fi”.
Prof. Harald Haas (chairperson of society of mobile communications, UoE) of University Of Edinburg, UK is considered inventor of the technology and is the one who coined the term “Li-Fi”, as the name suggests it’s communication over light. A subset of Optical Wireless Communication (OWC) it sends & receives the data signals over the light emitted by LED diodes. Optical communication, as in OFC supports a higher bandwidth, but has its own limitations as well. For example, light can’t penetrate walls, thus its limited to an area without wall, like a cafeteria / restaurant / mall kind of a pace, but for sure can’t be used for home networking as usual home have lot of walls.
It all started with the music industry. The term “Hi-Fi” used in the sound industry, which stands for “high fidelity” was the inspiration for the term “Wi-Fi”, a short form of “wireless fidelity” and now we have the latest version “Li-Fi” for “light fidelity”. The term “High-Fidelity” was basically referring to low distortion and noise, resulting into better clarity and quality of sound. The noise in case of communication network would mean packet drops, thus breakage in communication, therefore it was termed as “wireless fidelity” and the same is the reasoning behind “light fidelity”.
The Bandwidth Capacity
In Wi-Fi, the communication is done on 2.4 & 5.8 GHz, and the standards are 802.11xx (a, b, g, n, ac). It started with 11 mbps for “802.11a”, and went up to gigabit on “802.11ac”, wherein both the bands were used, using MIMO technology. However in “Li-Fi” it is expected to go up to 224Gbps, but like Wi-Fi, this is also a broadcast technology, thus the available bandwidth would get divided into simultaneous concurrent users latching on to the network.
Moreover, as this is an access technology, thus we need end-points (phone, tablets, laptops & desktops) also to be compatible with the technology, which would mean the manufacturers to integrate the chipset during manufacturing of the products, which might take some more time.
The Key Advantage
The key advantage of optical communication over electrical communication, get translated here as well. That’s insulation from electromagnetic field. For example, if you are using copper wire on physical layer for communication, you can’t lay it next to the electrical cable, or near a transformer or in any region wherein you have strong electromagnetic field, like electric trains, aircrafts, mines etc. Thus for such areas, you can only use optical fiber cables. The same goes true for “Li-Fi” over Wi-Fi”.
As Wi-Fi is a communication over radio signals, a strong electromagnetic field results in weakening of the signals, even to the extent that the network drops / hangs / stops responding at all.
I remember a good case study in this regard; a corporate customer of mine, who had an open space sitting in a hall, separated by 4 feet wooden partitions had gone for a wireless network. As the space was open, the number of access point was limited. The network was installed and was working to the customer satisfaction, but after about 15-20 days, we received an escalation from the customer, saying – “Madhukar, your wireless network goes for a lunch break”. That was the craziest remark, I had ever encountered. Sent our engineers for camping in the customer premise for 2 days, just to find that the complaint was correct. The network did went off during lunch hour.
And finally after minute investigation, we came to know that the wall on which AP was installed was common with the cafeteria – pantry wall and during lunchtime, they used the microwave, which caused interference and the wireless used to get knocked off. So we changed the AP to a different wall, keeping a good distance from the microwave and the network was restored.
Such kind of interferences wouldn’t affect the Li-Fi network, which will be a good advantage to the trains, aircrafts, electrical transformer sites, mine area and other such industrial environments, wherein the electromagnetic field is high. Ultimate truth is that a wireless network always gives you an ease of mobility, which is desired by everyone, but wasn’t practically possible in industrial environment due to the Wi-Fi limitations, which will be uprooted with the advent of Li-Fi.
Though it has a long way to go, before it reaches your home, but conceptually it excites everyone that you would be using light to get connected to the internet. Till it gets accepted by the end point and the home router manufacturers, and till it reaches your home, enjoy the concept and try to innovate and improvise of the concept. Following links would be helpful in developing a better understanding of the concept.
(The author can be reached at firstname.lastname@example.org
Twitter gear :@mmswayambhu)