What is LPWAN?
You may have heard the term LPWAN before, and you may be wondering: what is LPWAN, and what is its role in IoT?
In short, LPWAN stands for low-power, wide-area network.
It is a type of wireless telecommunication wide area network designed to allow long-range communication at a low bit rate among connected objects, such as sensors. All LPWAN technologies enable long-range transmission with low power consumption. LPWANs are unique in that they offer an efficient, affordable and easy-to-deploy solution for massive-scale IoT networks.
There are a variety of platforms that utilize LPWAN, so we will compare three of the most prominent: LoRa, Sigfox, and Behrtech.
LoRa – short for Long Range – uses sub-gigahertz radio frequency bands, varying in MHz depending on location. It has a wider band technology than some competitors, operating at 125kHz or more.
With either LoRa or LoRaWAN, you can use the same radio for a receiver on the basestation and the endpoint.
In the OSI model of computer networking, LoRa covers the physical layer, which is the first and lowest layer. This differs from many other competing technologies which cover the upper layers. The aforementioned LoRaWAN is one of several protocols that were developed to define the upper layers of the network. LoRaWAN defines the communication protocol and system architecture for the network, while the LoRa physical layer enables the long-range communication link. LoRaWAN is also responsible for managing the communication frequencies, data rate, and power for all devices.
Sigfox uses a 900MHz frequency band, and is a narrowband (or ultra-narrowband) technology. It uses a standard radio transmission method called binary phase-shift keying (BPSK), and it takes very narrow chunks of spectrum and changes the phase of the carrier radio wave to encode the data. This allows the receiver to only listen in a tiny slice of spectrum, which mitigates the effect of noise. It requires an inexpensive endpoint radio and a more sophisticated basestation to manage the network.
Sigfox communication tends to be better if it’s headed up from the endpoint to the basestation. It has bidirectional functionality, but its capacity going from the basestation back to the endpoint is constrained, and you’ll have less link budget going down than going up. This is because the receiver sensitivity on the endpoint is not as good as on the expensive basestation.
Behrtech’s MYTHINGS network is a wireless IoT connectivity platform purpose-built for complex industrial and commercial sensor networks. At the core of MYTHINGS is TS-UNB (MIOTY); a new low-power wide area network (LPWAN) protocol.
Recent tests comparing MYTHINGS to LoRa have shown that MYTHINGS experience less interference under dense interference conditions, which means it may have advantages for use in industrial environments which require high reliability in noisy environments. However, this does not have as great of an effect using small-scale networks in rural locations. This low interference rate is partially due to MYTHINGS being the only technology that implements Telegram Splitting, which is in the licensed-free spectrum.
In addition to Quality-of-Service, the characteristics of Telegram Splitting, at the same time, offer great power benefits. After the transmission of each sub-packet, there is a significantly longer transmission-free period in which the node goes into “sleep mode”. Short on-air time and longer off-air time minimize power consumption while giving the battery time to recover, which in turn significantly extends battery life.