Li-Fi replacing Wi-Fi: multipoint-to-multipoint-capable optical data transmission for automation

Researchers around the world are developing light-fidelity (Li-Fi) technology (the use of light to exchange large amounts of data) to augment, or sometimes replace, the widely used Wi-Fi. Developers at Fraunhofer IPMS (Dresden, Germany) are working on Li-Fi systems specifically for use in industrial environments. The use of Internet of Things (IoT) technology in industry is known as Industrial Internet of Things (IIoT) or Industry 4.0.

In addition to allowing different users in an industrial setting to simultaneously use an access point, the IPMS-developed optical transmission technology enables each user to communicate with several access points. As a result, Li-Fi is no longer limited to stationary applications. Fraunhofer IPMS specialists will present this multipoint-to-multipoint-capable technology to the professional public for the first time at the 2017 SPS IPC Drives Trade Fair for Electric Automation (Nuremberg, Germany; November 28-30, 2017).

In the age of smart production, more and more users rely on wireless data transfer between devices used in logistics, industrial manufacturing, and machine maintenance. However, those radio solutions (Wi-Fi), which have proven themselves in the consumer sector, quickly reach their limits in highly automated production environments. Wi-Fi networks are susceptible to interference because other wireless methods, such as Bluetooth, partially transmit in the same frequency ranges, causing multiple channel assignments and overlapping frequency usages. They also slow down as the increased number of users and larger volumes of data to be transferred decelerate both the data rate as well as communication cycle times. And Wi-Fi networks are susceptible to abuse, as it is relatively easy for skilled hackers to crack even encrypted networks.

According to Fraunhofer IPMS, its Li-Fi optical data transmission performs far better than Wi-Fi in every respect. Its Li-Fi hotspot transceiver system uses the optical spectrum of light, which is available free of regulations worldwide, and which eliminates interference with and from radio-based systems. Net bandwidths of up to one gigabit per second are much faster than today's Wi-Fi. IPMS also claims that Li-Fi networks offer security against hacker attacks.

The multipoint approach

But optical data transmission also has a systemic vulnerability: the visual axis between transmitter and receiver must remain unobstructed—a significant shortcoming, especially in mobile applications. In order to not be limited to stationary applications when using Li-Fi technology, Fraunhofer IPMS specialists are working on so-called multipoint-to-multipoint solutions.

"Our communication modules allow multiple users to act simultaneously in the same spot," says Alexander Noack, project manager at Fraunhofer IPMS. "At the same time, each user can switch between different, overlapping access points along a production line. Provided the coverage is adequate, we are in a position to guarantee mobile users a free viewing axis at all times to accommodate uninterrupted data exchange—faster, more stable, and more secure than possible with radio-based infrastructures."

The Fraunhofer IPMS driverless transmit/receive modules combine an optical transceiver and a protocol controller with a gigabit Ethernet interface. To allow potential users to test the equipment, Fraunhofer IPMS is providing its clients with Li-Fi customer-evaluation kits.

GigaDock to replace stationary cables

Fraunhofer IPMS scientists will present the multipoint-to-multipoint-capable Li-Fi HotSpot as a prototype for optical wireless communication at distances of up to 10 meters, as well as the so-called GigaDock technology for smaller distances, at the 2017 SPS IPC Drives Trade Fair. November. GigaDock has bandwidths of up to 12.5 Gbit/s and is intended to complement or replace stationary cable connections in highly automated production environments. Fraunhofer IPMS will be exhibiting this technology at its Booth 246 in Hall 7a.

Source: https://www.ipms.fraunhofer.de/en/press-media/press/2017/2017-11-08.html