by Mark Horsfield, Director, smirk
ZigBee and Bluetooth low energy (BLE, marketed as Bluetooth Smart) are communication protocols for transferring data over wireless networks. They are short-range technologies that automatically detect devices within range and set up ad hoc networks with detected devices. Devices only operate within their networks, and currently do not connect to the internet.
Both ZigBee and BLE have been designed to enable devices with low power consumption and as such, often have a battery life that exceeds the life-time of the product. They handle short bursts of data, like when a sensor control unit is queried and responds.
ZigBee is a wireless local area networking (LAN) technology designed to carry small amounts of data over a mid-range distance, such as inside a house. It’s also a mesh networking standard so the control units can carry other data along to the hub. ZigBee is a mature technology that’s been available for more than 12 years.
Bluetooth Smart (BLE) is a wireless personal area network (PAN) technology that was originally introduced by Nokia in 2006 to handle various scenarios that wireless technology at the time did not address e.g. healthcare, sensor control unit and fitness profiles. It maintains a similar communication range to classic Bluetooth and was designed as a star network around a portable device such as a mobile phone.
BLE has a quite simple network topology, with nodes dropping off or coming onto the network dynamically as they (or the central device) move in and out of range. It is easy to add nodes, since they all connect to the central device.
ZigBee has experienced some issues with interoperability, because two ZigBee profiles can interfere with one another. It also faces increased latency when it is used in an area with WiFi coverage and often fails in an automated industrial environment as it is affected by interference and can be easily jammed by heavy radio frequency activity.
BLE is better suited to sensor control unit applications and uses frequency hopping to counteract narrowband interference problems; this is inherently more robust to jamming.
There have been speculative predictions that BLE will eliminate the need for ZigBee, though we think the two technologies can co-exist as each have their strengths and weaknesses depending on the application, and there are some ‘perfect fit’ applications for each type of technology.
ZigBee works well in a home environment where it is used primarily for automation control, such as controlling lights, temperature and equipment. BLE offers the range and flexible connectivity of Bluetooth Classic and is better suited to industrial environments. It has out of the box compatibility with most smart devices, and works peer-to-peer.