ZigBee, Bluetooth, and Bluetooth Low Energy are often described as comparable network protocols. But aside from running on the the same frequency band, these Personal Area Network (PAN) wireless standards have more differences than similarities. Today we’ll be walking through what they are, which applications are suited for each, and how they differ in a specific use case.
What Is ZigBee?
ZigBee is a mesh network protocol. It is designed to carry small data packets over short distances while maintaining low power consumption. Like its competitor Z-Wave, it runs on a mesh topology network, meaning that information from a single sensor node travels on a web of nodes (each of which act as a data source and a repeater) until the transmission gets to the gateway.
It uses a version of the IEEE (Institute of Electronics and Electronics Engineering) 802.15.4 standard, and as such, is widely used in local area sensor data networks. ZigBee uses the 2.4 GHz ISM frequency band—and since this is a global standard, its applications can be used virtually anywhere.
(It’s worth noting that ZigBee has seen some issues with interoperability, because two ZigBee profiles can interfere with one another. This article from The Verge has more information on that topic.)
What Are Bluetooth & BLE?
Bluetooth is a wireless technology standard created and used for short-range wireless communication. It was developed in 1994 by telecom giant Ericsson, and it is now managed by the Bluetooth Special Interests Group (SIG).
Bluetooth was created to allow wireless data transmission with very short-range devices. That’s why many people immediately think of a wireless headset or wireless keyboard when they think of this technology. In technical terms, Bluetooth operates within the 2.4 GHz ISM frequency band (like ZigBee). Data packets are split and exchanged between one of the 79 designated Bluetooth channels, each of which have 1 MHz in bandwidth.
Bluetooth applications are ideal for device-to-device file transfers, headsets, speakers, and wireless computing additions like keyboards, trackpads, and printers.
Bluetooth Low Energy—abbreviated BLE—was originally branded as “Bluetooth 4.0” when it was created in 2011. Its primary benefit (and the difference from “regular” Bluetooth) is its low power consumption. This is ideal for M2M products, because a single battery running BLE in a product could last up to five years.
BLE operates in the 2.4 GHz ISM band, like Bluetooth 1.0. That being said, BLE has a very short connection time (only a few mS) with a high data rate (1 Mb/s), and then goes into “sleep mode” until a connection is reestablished.
BLE applications are ideal for sensor-level technology, public transportation apps, and health and fitness monitoring devices. Compared to Bluetooth, BLE is more closely related to ZigBee as far as applications are concerned, because it’s less costly than regular Bluetooth and draws low power.
ZigBee Vs. BLE: Vineyard Use Case
To illustrate the difference between ZigBee and Bluetooth Low Energy, we’ve created this comparison chart. Assume that a winemaker wants to wirelessly monitor his vineyards to address environmental conditions, so his next crop of Pinot Noir isn’t flat or lifeless. Below, we’ve broken down the outcomes that said winemaker can expect. Per this example, assume the environmental sensors are on the grapevines, and the antenna is on the roof of the pressing facility.
(We’ve also included Symphony in this chart. Symphony Link is the wireless protocol we implement for clients here at Link Labs.)
|TX Antenna Height (m)||6||6||6|
|TX Power (dBm)||4||18||18|
|TX Antenna Gain (dB)||0||0||0|
|RX Antenna Height (m)||1||1||1|
|RX Antenna Gain (dB)||-6||-6||-6|
|Structure Loss (dB)||11||11||11|
(Note: 11dB structure loss consistent with propagation through an 8″ masonry block wall.)
Based on this side-by-side comparison, you’ll find the Symphony has (by far) the best range. This means that the sensors on the grapevines would be able to run for many years on a single battery and still transmit information over several thousand meters. But between ZigBee and BLE, ZigBee comes out on top—it achieves better range for this use case.