Page 64 - Security Today, July/August 2018

TECH BRIEF
By Andy Jimenez
COMPARING WIRELESS COMMUNICATION PROTOCOLS
i-Fi is a technology based on the IEEE 802.11 suite of standards that uses radio frequencies (RF) extend wired Ethernet-based local area networks (LAN) to Wi-Fi-enabled devices, allowing the devices to re- ceive and send information from the internet.
How does it work? Wi-Fi uses Internet Protocol (IP) to commu- nicate between endpoint devices and the LAN. A Wi-Fi connection is established using a wireless router that is connected to the network and allows devices to access the internet.
One disadvantage of Wi-Fi is that it may be prone to interference depending on the RF environment it’s operating in. Everything from other Wi-Fi signals to radio waves emitted by microwave ovens to cement walls can interfere with your data transmission. That’s where Wi-Fi’s two frequencies, 2.4GHz and 5GHz, come in. Wi-Fi can broadcast on both frequencies, helping its signal cut through all the noise and deliver a fast, strong signal from your wireless router to your device.
What applications is it best for? LAN video, e-mail, and web appli- cations requiring higher data rate network connections (1Mbps-1Gbps).
LI-FI
What is it? Li-Fi is a form of visual light communication that sees light waves from LED bulbs for high-speed wireless communication. It is used to exchange data quickly and securely at a much lower
power level compared to Wi-Fi.
How does it work? When a constant current source is applied to
an LED bulb, it emits a constant stream of photons observed as visible light. When this current is varied slowly, the bulb dims up and down. Since the bulbs are semiconductors, the current and optical output can be modulated at extremely high speeds that can be detected by a photodetector device and converted back to electrical current.
Li-Fi has fewer interference issues than RF technology, making it ideal for dense environments where Wi-Fi may fall short. It can’t penetrate solid materials, which makes it more secure, but also means a Li-Fi network in a building would need multiple transmitter bulbs, so a mobile user could experience seamless wireless coverage as they move between the illumination area of each LED bulb.
What applications is it best for? Li-Fi is still a long way from wide- spread commercialization, but it has potential applications for the In- ternet of Things in many industries, including aerospace, education, consumer electronics, healthcare, retail, security and transportation.
BLUETOOTH
What is it? A standard for the short-range wireless interconnection of mobile phones, computers and other electronic devices.
How does it work? Bluetooth sends and receives radio waves in a band of 79 different frequencies (channels) centered on 2.45 GHz, set apart from radio, television and cellphones, and reserved for use by
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