A Letter to OpenSensors on LoRaWAN vs. ZigBee

I came across a tweet about a blog post comparing LoRaWAN and ZigBee resulting in a Twitter interaction with the author and OpenSensors.io.

The post provides an excellent overview of LoRaWAN, a Low Power Wide Area Network (LPWAN) technology. What I could not comprehend was to suggest LoRaWAN is “better” than ZigBee in the title of the blog post!

Logic suggests that you do a comparison of better and worse with similar technologies. It is fair to draw compare and contrast between two dissimilar technologies to educate. The author does a great job of educating on LoRaWAN by contrasting with ZigBee. But my issue with the article is that I don’t see the logic behind calling LoRaWAN better than ZigBee. And not specifying the conditions under which it is better...

ZigBee and the underlying radio protocol IEEE 802.15.4 is a better choice for many other use cases — Smart Energy (e.g. Meters, D/R etc.) , Home Automation (e.g. Comcast Xfinity Home) and Lighting (Philips Hue). It also supports a mesh network capability — the point of mesh network is to increase the reliability of the network.

The use-case should define the technology to be used. If your use-case requires a range in kilometers or miles, with very low bit rate then absolutely you should look at all the different LPWAN offerings such as LoRa or SigFox.

However you want a sophisticated protocol mapped over a radio for short range then you should consider technologies like ZigBee, Thread, Z-Wave, Bluetooth and even Wi-Fi.

I simply don’t get the point of claiming in the title that LoRa is better than ZigBee (even if it is in quotes) that sounds misleading. I could understand a newbie making that comparison but a well-established IoT company — to me that sounds like click bait.

In addition to what Boris writes, here some additional info or rather nuances that I feel are important to know:

1. LoRaWAN, I think, defines both the radio technology and the protocol end to end. I have seen folks refer to LoRa as the radio technology (which was developed by a French company Cycleo and acquired by Semtech) and LoRaWAN as the protocol. Note that originally Semtech was the only manufacturer of chips, and it still owns the patents on the technology. Microchip and STMicro are also making chips. LoRaWAN is very well suited for long range, very low power, long-lasting battery operated, low bandwidth use-cases. It is especially fantastic for use-cases where you have more uplink (device sending to cloud or gateway) updates than downlink — for example reading Water Meters or getting temperature readings once a day.

2. ZigBee (ZigBee Pro) is a protocol that runs on IEEE 802.15.4 standard. Note that it is an IEEE standard. ZigBee (Pro) has the notion of profiles, kind of like, Bluetooth Profiles. That implies a ZigBee device can have specific use case protocol. I am not saying if that is good or bad — just clarifying that it has a software level that gives it specific profile — such as Home Automation or Smart Energy. It is important to note that IEEE 802.15.4 is also used by Thread and ZigBee IP (and would be used by ZigBee 3.0).

3. A Washing Machine is a relatively expensive appliance that runs on AC mains supply. Washing Machines, especially the ones designed for home, are a prime example of using Wi-Fi to provide IoT use cases. It does not make sense — business or technical to enable the washing machine with a radio like LoRa or for that matter ZigBee and expect the home to have a gateway or bridge to translate that so the Washing Machine can connect to the Internet. Also while it does not need to watch Netflix :), the Washing Machine is a complicated piece of machinery and needs almost symmetric bi-directional payload capabilities. That is an app, cloud-based or smartphone-based would need to carry out things like firmware updates, control operations in near-realtime etc. Point being the use-cases require bigger payloads than what LoRa could support.

4. The Things Network (TTN) was started as a Kickstarter project. It’s manifesto states the network is open. And indeed it is truly open source — but to nitpick — but it is just the software infrastructure that is open. The “physical network”, is tied to LoRaWAN — the patents for which are owned by a single company — Semtech. It has licensed the technology to Microchip and STMicro — and chips are subject to royalties to be paid to Semtech. In other words, no matter how open the source code for the network is, somewhere deep-down a single company controls the infrastructure of the company. This may change in future (and I hope so) but I want to point out that it is not “open” today.

To quote from the blog post:

To understand a little more in detail how one of the LPWAN standards works, in the following we are going to focus on LoRaWAN as it is really ‘the network of the people’ and because The Things Network -a world-wide movement of idealists who install and run LoRaWAN gateways- supports our idea of open data.

The blog post on OpenSensors.io suggests that TTN installs and runs the gateways which are necessary for LoRaWAN to operate — that is not true. TTN simply enables the software, and infact they are funding this activity the gateways they are going to sell via the Kickstarter project I mention above.

I disagree with the statement LoRaWAN is a network of people. Technically speaking LoRaWAN is a protocol introduced and promoted by Semtech and LoRa Alliance.

TTN, yes, that is work done by the people, for the people. The TTN development is truly open source (all code is published with an open source license, and it is well documented), and it is incredible amount of work that has already been made open and free!