Li-Fi and Power over Ethernet (PoE)
According to a report from the GSMA (Group Special Mobile Association) Intelligence, the global Internet of Things (IoT) market will be worth $1.1 trillion (£856 million) in revenue by 2025 as market value shifts from connectivity to platforms, applications and services. By that point, there will be more than 25 billion IoT connections (cellular and non-cellular), driven largely by growth in the industrial IoT market.
Li-Fi is a very high-speed wireless technology using light waves instead of radio waves to transmit data. However, one popular question about Li-Fi is how the data gets into the LED light bulb. One answer to that is through Power over Ethernet. Power over Ethernet, also known as PoE, is a technology that allows network cables to carry electrical power alongside data.
How does PoE work?
Network cables, such as Cat 5e and Cat 6, are made of eight wires and are arranged as four twisted pairs. In 10 and 100BASE-T Ethernet, two of these pairs are used for sending data, and these are known as the data pairs. The other two pairs are unused and are referred to as the spare pairs (Gigabit Ethernet uses all four pairs). Because electrical currents flow in a loop, two conductors are needed to deliver power over a cable. PoE treats each pair as a single conductor, and can use either the two data pairs or the two spare pairs to carry electrical current. Power over Ethernet is injected onto the cable at a voltage between 44 and 57 volts DC, and typically 48 volts is used. This relatively high voltage allows efficient power transfer along the cable, while still being low enough to be regarded as safe.
Check out the following video for an explanation of PoE by Versa Technology:
5 advantages of PoE
PoE offers the following advantages:
1) Time and cost savings - PoE helps reducing the time and expense of having electrical power cabling installed. Network cables do not require a qualified electrician to fit them, and can be located anywhere.
2) Flexibility - Without being tethered to an electrical outlet, devices such as IP cameras and wireless access points can be located wherever they are needed most, and re-positioned if required.
3) Safety - POE delivery is intelligent, and designed to protect network equipment from overload, underpowering, or incorrect installation.
4) Reliability - POE power comes from a central and universally compatible source, rather than a collection of distributed wall adaptors. It can be backed-up by an uninterruptible power supply, or controlled to easily disable or reset devices.
5) Scalability - Having power available on the network means that installation and distribution of network connections is simple and effective.
Devices using PoE technology
There are currently many devices using PoE technology such as Ethernet extenders, LED Lighting systems, security access controls, smart clocks, wireless access points, PoS kiosks, industrial controls, network switches, digital signage, routers, IP/Pan Zoom cameras and VoIP phones.
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