Our society is now wireless. More and more of us are streaming news, entertainment, sports and more on wireless devices. That’s a solid indication of where we can expect industrial development to go. Just as the factory floor followed the larger (consumer) society in the deployment of office Ethernet, it’s following the deployment of wireless connectivity, albeit at a much slower pace. We can expect more wireless Ethernet (802.11), improved 4G LTE, Bluetooth, WirelessHart, spread spectrum technologies and 5G communications on the factory floor in the coming years.
There are lots of good reasons for this. The newest generation of plant floor engineers and managers are much more comfortable deploying wireless communications than their predecessors who grew up without streaming communications. We’re also sensorizing the factory floor like never before to capture more operational data for our analytics and cloud tools. These sensors are more likely than not to be wireless. Depending on the application, wireless systems can be much less costly than purchasing and installing wired networks.
It’s not complex but many people seem confused as to what wireless technology really is. Wireless is just another communications media. A communications media is the physical medium that is used to move signals from your device to a destination. Ethernet cabling is a media, as is USB, RS232 serial cables, CAN (Controller Area Network) cables and air (wireless). Just as we have any number of different ways to send bits over physical media (RS232 vs RS485 vs Ethernet), we have different ways of sending bits over the air. This article describes the most important of these to the plant floor.
Wi-Fi / WIRELESS ETHERNET / WIRELESS LAN
What is it? Wireless Ethernet is the standard for over-the-air Ethernet communications. Known as Wi-Fi or IEEE 802.11, it is the standard used with our smartphones, laptops and other devices. Wi-Fi first found a home on the factory floor where environmental conditions or rotating machinery made wired Ethernet cabling difficult.
Security: Many popular security options exist including WEP, WPA, and others. It is inherently less secure, given the ease to connect to a wireless Ethernet network.
Strengths/Weaknesses: Strengths include scalability, reliability, and mobility. Weaknesses include deployment costs, lower network speeds, vulnerability to obstructions, and security vulnerabilities.
Specifications: 2.4 or 5 GHz communication bands; up to 150 meters; data throughputs of 11 to 54 Mbit/s. Specifications vary with the specific communication driver (802.11/a/b/g/n).
What is it? Bluetooth (IEEE 802.15.1) is the technology embedded in our phones, speakers and other consumer electronics. It is designed for short-range applications where small data packets need to be exchanged under low power at low cost. In manufacturing applications, Bluetooth sensors collect temperature, pressure and vibration data from pumps, motors, and other devices and send it to a Bluetooth receiver.
Security: Bluetooth offers multiple security modes, some of which offer authentication and encryption.
Strengths/Weaknesses: Strengths include widely accepted technology, low power, low-cost connectivity for devices with small data packets. Weaknesses include limited range, inability to support large data transfers, security vulnerabilities, and incompatibilities among various versions.
Specifications: 2.4 GHz, 10m Range, 1mW Power (Class 3 devices).
What is it? IEEE Standard 802.15.4 defines a wireless personal area network (WPAN) that provides low-speed, low-cost communication between devices. It is the base for wireless technologies like Zigbee, ISA100.11A, WirelessHART, 6LoWPAN, Thread, and SNAP. Each of these derivations extends the 802.15.4 standard by defining upper layers of the 802.15.4 communication infrastructure.
Security: The standard supports symmetric key exchange for authentication and encryption.
Strengths/Weaknesses: The strength of 802.15.4 is that it is an accepted standard and foundation for many WPAN networks. Weaknesses include low data rates and incompatibility among all the upper layer standards.
Specifications: 868/915/2450 MHz, 10m range.
What is it? 5G stands for fifth-generation cellular wireless; it’s the successor to 3G and 4G. 3G ushered in video calling. 4G provided high-speed video and gaming. 5G, unlike 3G and 4G, is a revolutionary technology that will enable fundamentally new applications from its increased connection density, lower latency, and higher speeds.
Security: To be determined.
Strengths/Weaknesses: The strength of 5G is the increased speed. A major weakness is that 5G signals offer limited range and may not penetrate much of anything.
Specifications: Up to 20 Gbps.
Hurdles to the full acceptance of wireless technology
Wireless isn’t the magic bullet that some vendors portray. It’s also not a set of technologies that you should ignore – it most definitely belongs in your technology toolbox. It’s likely that there will always be a mix of wired and wireless media in manufacturing plants. For wireless to significantly displace cable, it must overcome a few hurdles:
Security – Wireless is correctly perceived as riskier than other technologies. It not only seems riskier because the signals travel through the air, but it is also easier for an untrusted intruder to gain access through your network wirelessly. That’s truer with wireless Ethernet than it is for the more uncommon 802.15.4 networks discussed earlier.
Resistance to Change – There is always resistance to change. Older generation workers who didn’t grow up in today’s wireless, on-demand, streaming world are sometimes more reluctant to use wireless media.
“OverKill” Phenomena – When communications infrastructure costs are a fraction of the costs for a manufacturing machine, cell or factory, there is a tendency to specify the ultra-reliable, wired solution instead of an equally effective wireless solution.
Cost of ownership – There is a fear that the cost of ongoing ownership of a wireless system is going to be more expensive than maintaining the equivalent wired system. In practice, both users of wired and wireless systems incur cost of ownership issues. Maintenance, software upgrades, and training costs are a bit different but very similar in overall scope, no matter which media is deployed.