Industrial lighting control systems generally aim to maximize energy savings, satisfy building codes, or comply with green building and energy conservation programs. These Smart Lighting systems are fast becoming a staple in modern commercial architectural design. Today’s lighting components must be able to “talk” to one another, meaning they must use the same communication protocols to trigger specific actions, such as synchronizing and dimming light fixtures. Popular wireless protocols include Infrared, Bluetooth, Wi-Fi, Zigbee, Thread, Z-Wave and KNX. The number of wireless networking options is increasing.
With so many connection protocols available, it is essential for smart system designers and specifiers to understand the fundamental similarities and differences among various wireless protocol brands. This article identifies standard features as well as dissimilarities among three popular wireless protocols – Bluetooth®,Wi-Fi® and Zigbee– and outlines best industrial lighting applications for each technology.
Short for Wireless Fidelity, Wi-Fi® networking is a growing trend in smart building design. Wi-Fi® first gained popularity for media streaming gaming, browsing the web and other data-heavy activities because of its high bandwidth capability. Wi-Fi® uses radio frequency to transmit data through the air.[1] The communication protocol is stable and cost-effective, yet traditionally many designers avoided the technology in industrial applications because of its high power requirements. Recent improvements to Wi-Fi® power efficiency has prompted many designers to reconsider the technology for industrial lighting applications. Because of the limitations on the number of network-connected devices, the technology is more suitable for small commercial lighting applications.
Zigbee is an open wireless communication protocol based on the IEEE 802.15.4 technical standard. This openness leads to greater competition and innovation among developers. Its maximum speed of 250 kbps at 2.4 GHz makes it slower than other popular wireless standards. However, ZigBee shines in comparison to the other wireless protocols in power consumption efficiency. Zigbee was designed to transmit small packets of data at relatively infrequent intervals, making it easy to connect battery-operated devices such as LED lighting.
The Zigbee protocol supports star, tree and mesh networking topologies. Mesh-networked devices use each other to transmit signals; often referred to as many-to-many (m:m) communication. Single device malfunctions do not interrupt the network. Mesh networking topology strengthens connectivity and increases network scalability, opening the pathway for designers to incorporate the technology in increasingly sophisticated industrial lighting applications.
The newest version, Zigbee 3.0, further standardized the protocol, allowing for seamless compatibility among all Zigbee-certified devices regardless of branding. Zigbee aims to be the global standard for all “Internet of Things” (IoT) solutions. According to the Zigbee Alliance, the IoT market is expected to grow from $180 million in 2014 to more than $1 trillion by the year 2020.[2] It is no surprise, therefore that manufacturers, like GRE Alpha® Electronics, are jumping at the chance to get in on this technology. The company specializes in the design of solid-state lighting power supplies and lighting control accessories and is a trailblazer in the design of Zigbee-certified devices. Its SLD-SMARTDIM wireless dimming module, for example, is Zigbee-enabled and compatible with a wide variety of smart switches and controls. The module delivers flicker-free 0-100% dimming and a fast response time for easy control of constant voltage LED fixtures.[3]
Released in 2000 and originally designed to replace serial cables and support wireless audio applications, Bluetooth is arguably the most widely recognized wireless connectivity brand. The newest version, Bluetooth Low Energy (LE), uses very little power compared to the original variety. The addition of mesh networking support in the summer of 2017, opened the floodgates to sophisticated industrial lighting applications.
Often referred to as Smart Bluetooth, the mesh-based LE technology is not prone to signal loss like the Wi-Fi protocol. Like Zigbee, the technology supports complex many-to-many device communication, and networks can be designed to cover large physical areas. The technology is also interoperable across products from different vendors and is secure, scalable and upgradeable, making it a key player in the IoT market and especially suitable for large-scale industrial lighting automation applications.[4] GRE Alpha recently partnered with the EnOcean Alliance to further develop its wireless offerings to Bluetooth® LE-enabled devices and other wireless applications.[5]
Continued advances in these wireless technologies are ushering building design into an era of all-in-one facility automation, increased energy savings, greener construction practices and straightforward code compliance.
Table 1. Specification comparisons
|
Wi-Fi® |
Zigbee |
Bluetooth® LE |
Cost |
Medium |
Low |
Low |
Power consumption |
High |
Low |
Low |
Operating range |
150 feet |
35 feet |
330 feet |
Max. # of devices |
250 |
65,000 |
32,000 |
Data rate |
11 Mbps / 54 Mbps |
40 - 250 kbps |
1 Mbps |
Frequency |
2.4 GHz |
915 MHz/2.4 GHz |
2.4 GHz |
Network topology |
Infrastructure Ad hoc |
Star Tree Mesh |
Point to Point Broadcast Mesh |
Hub needed |
Yes |
Yes |
Yes |
Security |
Minimal |
128 AES plus application layer security |
64 and 128-bit encryption |
Proprietary |
Yes |
No |
Yes |
Scalable |
No |
Yes |
Yes |
Suitable applications |
Small Commercial |
Large Industrial |
Large Industrial |
[1] (Wi-Fi Alliance, 2017)
[2] (Zigbee Alliance, 2014)
[3] (GRE Alpha Electronics Ltd., 2017)
[4] (Bluetooth SIG Inc., 2017)
[5] (GRE Alpha Electronics Ltd., 2017)
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