WPAN technologies for your next IoT project

Text written by Jan Nyrén, Product Manager IoT technologies, at IAR Systems

What should you consider when choosing a wireless protocol for an application with WPAN? There is a plethora of standards in this area and each one constantly evolving which can cause confusion. But don’t fret; the decision is not that hard.

First of all, what is a WPAN? WPAN stands for Wireless Personal Area Network and is a personal, short distance area wireless network, which is centered on an individual person's workspace. There is no unison definition when it comes to range so I choose to define it as a wireless network with a range up to 100 m between a transmitter and receiver. To name a few protocols and standards, there is Thread, Bluetooth, Bluetooth Low Energy a.k.a. Bluetooth Smart, a.k.a Bluetooth Version 4.0, Z-wave, 6LoWPAN, Zigbee, WiFi, proprietary protocols, and more. All protocols have their merits. Although confusing at a first glance, the critical criteria for selecting the right protocol are not that many and the selection is in fact quite straight forward.

The decision boils down to a selection among three main technologies, Bluetooth Low Energy, IEEE 802.15.4 or WiFi, simply because these all rely on dedicated hardware. Most of the other protocols are variants based on any of these and can be upgraded to or changed to by updating the software. For instance, if you have a Zigbee protocol (which is based 802.15.4) and necessarily need to upgrade it to IPv6 (required for Thread), then as both run on 802.15.4, adding software components such as 6LoWPAN will do the trick. The point is: The decision does not necessarily get you stuck, as long as you have made the right choice between Bluetooth Low Energy, 802.15.4 and WiFi.

Then how to select between Bluetooth Low Energy, 802.15.4 and WiFi? Consider the following criteria:

  • Range — Bluetooth Low Energy for range up to 10 meters. 802.15.4 and WiFi up to 100 meters
  • Throughput — 802.15.4 up to 250kbps, Bluetooth LE up to 3mbps and WiFi up and beyond 20mbps
  • Power consumption — Bluetooth Low Energy has the lowest power consumption and WiFi the highest
  • Topology — 802.15.4-based protocols for mesh networks, WiFi and Bluetooth Low Energy for star- and p2p networks

Some IoT applications examples:

  • Healthcare, such as activity monitors, smart watches and similar products — use Bluetooth Low Energy.
  • Audio applications that require high bandwidth such as wireless speaker systems, or process measurements with continuous monitoring where external power source is available, wireless image transfer from camera — use WiFi.
  • Products for home automation such as HVAC/Climate lighting — use 802.15.4.

Then a final word; if you have an idea that you want to realize today, go for it. Don’t wait for the standards to mature and some to become the prevalent, because if you do competition will get there first.