In this day and age, many people have grown fond of the concept of WiFi – and for good reason. WiFi has invaded virtually all facets of human society – from the domestic setting and business, to basic government services such as ICT and transportation. Due to this heavy dependence on WiFi, many are stuck on this concept as the best mode of wireless communication. For this reason, people seem to remain unfamiliar to a similar concept known as LiFi – even though the concept has been around for many years.
The terms WiFi and LiFi possess similarities (both are wireless methods of data transmission) but are fundamentally different in that WiFi uses radio waves whereas LiFi uses light. But their differences do not end there. Here, we go into more detail on both concepts and explore the many differences, as well as the benefits and disadvantages of both in order to provide a clearer picture of these concepts.
What is WiFi?
WiFi, meaning Wireless Fidelity, is the name of the wireless networking technology that uses radio waves to create wireless network connections, provide internet access, or transmit data. It is very popular because it allows users to access networks without the need for a physical wire between the device and the transmitter. When a radio frequency (RF) current is supplied to an antenna, an electromagnetic field is created, which propagates through any space. This creates an access point in which users can connect and gain access. These access points are accessible up to 20 to 50 meters away. However, in order to connect to an access point, the user will need to have a wireless network adapter installed on the accessing device.
The Radio Spectrum
WiFi operates within the radio spectrum. The radio spectrum is part of the electromagnetic spectrum that have frequencies from 3 Hz to 3,000 GHz. Waves emitted within this frequency range, called radio waves, are widely used especially in telecommunication, making it prone to interferences occurring at various frequencies. That is why the generation and transmission of radio waves is strictly regulated by national laws in coordination with the International Telecommunication Union (ITU).
Advantages of WiFi
The use of WiFi brings many advantages. Before WiFi was created, users were required to physically connect to a modem through an Ethernet cable in order to connect to the internet, which was bulky and inconvenient. Accessing the internet from across a distance, e.g. the far end of an office, would require extremely long cables, which can be costly. Additional connections will also require additional cables, which is equally costly. WiFi eliminated the need for physical connections to servers in order to gain access to local networks and the internet. Because connections established through WiFi are wireless, users are given access from virtually anywhere within range. And because radio waves are able to penetrate through walls, users can enjoy WiFi connections within a 20 to 50-meter radius from the source.
Additionally, internet access through WiFi is easy to implement. All you need is an internet service provider (ISP) that supplies the internet connection and a WiFi Router, which supplies the access point. This ease in implementation is the main reason for the ubiquity of WiFi internet access. In fact, nowadays, you will need to travel far just to find an area that does not have any WiFi hotspots.
Disadvantages of WiFi
WiFi also has many disadvantages. For one, WiFi connections tend to be unsecure. Its lack of security generally comes from its wide signal range, allowing the network to be accessed within a 20 to 50-meter radius. This allows others to access the network as long as they remain within range. Even when the connection is protected with a password, others may attempt to hack into the network, leaving all private data vulnerable. In order to counter this, most employ sophisticated techniques using high-end technologies to protect their data. However, such techniques also have their own weaknesses that can be exploited to gain access. They are also very expensive to implement.
Another disadvantage of WiFi connections is that signals tend to be unreliable. That is because radio frequencies are still subject to various external interferences. These interferences can cause a variety of connection problems such as providing weak signals, poor reception, or even loss of connection. Add to that the fact that WiFi connections are inherently slower than wired connections. Typically, wireless connections have speeds ranging from 1 to 54 Mbps whereas wired connections have speeds of 100 Mbps or higher.
What is LiFi?
On the other side of the spectrum, there lies LiFi. LiFi, which means Light Fidelity, is an emerging piece of technology that makes use of Visible Light Communication (VLC) technology instead of radio waves to transmit data. In LiFi, solid-state lighting (SSL) such as LED bulbs are used in the transmission of data and provide access to the internet or a wireless network. This is done by modulating the light given off by the light source (the transmitter) and is received by a photodiode (the receiver). The signals received from the transmitter are then translated into usable data forms that are readily consumed by the end user. Connections provided by LiFi are typically confined within the space where they are provided due to the nature of visible light.
The Visible Light Spectrum
In contrast to using radio waves, LiFi makes use of visible light. This allows LiFi to have access to a greater range of available frequencies as the visible light spectrum is 10,000 times larger than the entire radio spectrum. The visible light spectrum covers frequencies from 430,000 to 770,000 GHz and colors from near ultraviolet to near infrared.
Advantages of LiFi
There are many different advantages offered by using LiFi. One of its biggest benefits come with its efficiency. Since LiFi makes use of VLC technology, which in turn makes use of highly-efficient LED bulbs, users are able to enjoy lower costs in terms of energy consumption. Additionally, they only require working LED lights, which are already available within most households and other establishments, allowing for additional savings in terms of installation costs.
Another big advantage of LiFi is that the usage of light allows LiFi connections to occur almost instantaneously because light travels at extremely fast speeds. This results in faster transmission of data and faster internet connections – about 100 times faster than speeds achievable by WiFi.
Because there are already 14 billion light bulbs all over the entire world, its availability is never in question as there can be as many LiFi networks available as there are light bulbs.
Lastly, the nature of visible light is that it cannot penetrate opaque walls. This means that as long as rooms are covered by opaque walls, light is confined within the space in which it is shone, thereby confining the connection to the space in which it is shone. This prevents unauthorized access to the LiFi connection, adding another layer of security to the network.
Disadvantages of LiFi
There can be many disadvantages to LiFi, as well. Its biggest drawback comes in the form of infrastructure (or lack, thereof). Since LiFi technology is a relatively new concept and is currently in its introductory stage, the infrastructure necessary to implement the technology in a large enough scale is still virtually non-existent. This means that plenty of time is still required before the general public can enjoy LiFi technology.
Another disadvantage is that the light source will need to be constantly turned on in order to provide network access. This problem can be solved by dimming the light enough to levels that the human eye can perceive as turned off, but are actually still on. In cases where dimming the light is out of the question, however, this could be a problem.
Another perceived disadvantage of LiFi connections is that because it relies on light to transmit data, it becomes highly susceptible to outside interference. Photodiodes are able to pick up light from competing sources of light such as sunlight and other forms of illumination. This could potentially create noise within the receiver and cause disruptions to the network. In most LiFi systems, an optical filter has been installed on photodiode devices in order to filter noise so that the receiver can only pick up signals coming from the transmitter.
Lastly, users are rendered immobile when using LiFi systems due to the limited range of the signal given off by light bulbs. This is, of course, countered by installing multiple LiFi systems within large spaces, creating as many connections as there are light bulbs.
When looking at the comparisons between WiFi and LiFi, it would be very difficult to choose one over the other as both have their own merits – and their own disadvantages. That is why a different mind-set needs to be adopted and look at these pieces of technology in a different way.
A big misconception about LiFi systems is that it was created to replace WiFi altogether. Considering that most of the existing infrastructure has already been built to accommodate RF technology, it would be very costly and tedious to replace all of that infrastructure to give way to a newer technology. For this reason, LiFi needs to be looked at as a complementary technology that aims to improve the performance of the existing technology and provide relief to the already congested radio spectrum used to provide WiFi connections.