Two commonly used IoT networks are LoRa and LTE-M / NB-IOT.
What is LoRaWAN?
LoRa stands for ‘Long Range’ and is a wireless network protocol that was originally conceived for low power IoT applications. It falls under the type of “Low Power Wide Area Networks” (LPWAN). These are networks whose core feature is that information can be communicated over long distances using very small amounts of energy. Ideal for devices that are in remote or isolated places or where you don’t want to make any changes to the installation. Think of things like lampposts, dikes, quay walls or garbage cans.
In use, sending LoRa messages is very similar to SMS traffic. As long as nothing is sent, the cellular module is not active either. In addition, unlike SMS, the cellular module does not need to set up or maintain a connection. As soon as a message is sent, the cellular module becomes active and sends the message on the correct frequency with the correct network keys. Surrounding gateways then receive this signal and process it towards the internet and ultimately the platform to which the sensor is connected.
Biggest advantages of LoRa
The most important characteristics and advantages are the extremely energy efficient consumption and the long distance that a message can travel from device to network. Thanks to the low energy consumption, sensors can be made that can send information every hour for multiple years (3-5) on 2 AA batteries. Exactly how long it works depends on a number of other aspects. Such as the coverage of the network, the antenna of the sensor itself and the amount of information that is sent per message.
Another big advantage is the security of the system. Many networks that we know, such as WiFi and 4G, have the property that you have a direct connection to the internet. You can use it to visit websites and request information. The LoRa network itself is separate from ‘the internet’. Only when the messages have been received on the network are they forwarded to an application via the internet.
As a result, LoRa modules themselves are not vulnerable to ‘typical attacks’ from hackers such as a DDoS or man in the middle attack. Within the LoRa protocol, encryptions have been applied to various layers, so that it is not possible to watch or imitate. Sensors themselves periodically and securely refresh their network keys, so that a permanent vulnerability never arises.
With a professionally installed and managed network, each module can also be located in the network. That way you know where you are, without needing an energy-guzzling GPS or WiFi module. Partly for this reason, there are quite a lot of trackers available on LoRa.
LoRa providers
LoRa depends on a LoRaWAN (Wide area network). There are various providers in the Netherlands: the public network of KPN, the community network of The Things Network and various private initiatives. The difference between these networks is often the coverage and uptime guarantee. Anyone can set a LoRa gateway and ‘live’, this is possible because the radio frequency on which the LoRaWAN protocol works is not covered by a license.
Disadvantages of LoRa
Of course there are also disadvantages to using LoRa. There are two rules in use in the Netherlands, which are imposed and enforced by the Radiocommunications Agency. The first rule is that each module should not send radio signals too often. This is the so-called duty cycle limitation. In addition, the intensity of your radio signal should not be too strong (maximum 20 mW).
Then there is the amount of data. This is very small with LoRa, namely about 54 Bytes. That is the same as a text message with 50 characters. This shouldn’t be a problem, as long as you just want to send some sensor information or locations. It works better if the messages are as small as possible. Then sending is faster and it costs less power.
What is LTE M/NB-IOT?
LTE-M / NB-IOT functions under 4G and 5G. You know this as the networks with which you can stream and scroll faster on your smartphone. LTE, or “Long Term Evolution”, stands for a whole series of increasingly faster network protocols based on increasingly powerful hardware. In addition to the fact that these connections are getting faster and faster, there are also connections that can be very economical, and work with the same radio masts, antennas and networks. This is possible because sending a small amount of information can be done quickly and efficiently, without requiring the entire network capabilities.
Biggest benefits of LTE-M and NB-IOT
LTE-M and NB-IOT offer very good coverage, has a high data rate and can therefore be set energy-efficiently. This makes it interesting for battery-powered applications. In addition, it is also more cost efficient compared to standard 4G hardware. You often send encrypted technical information, so the amount of data is compact. This keeps your data consumption low: it is often about MBs instead of GBs.
Other plus points are that there are roaming agreements with neighboring countries and that there are already many countries internationally with LTE-M or NB-IoT coverage. Depending on the choice for a type of cellular module, you can also have a fallback to other networks such as 2G. The advantage of this is that your hardware can get network connection at more locations worldwide.
Disadvantages of LTE-M and NB-IOT
Despite the fact that LTE-M and NB-IOT are promoted as an energy efficient technology, a device still consumes quite a bit of power as long as there is a connection to the network and data is being sent.
It is certainly twice as economical as standard 4G, but you still need large batteries if you want to send often and want to last longer than 1 year. The power consumption also depends on the interval with which you transmit. You can choose to completely switch off the device, or to put it in sleep mode. Reconnecting after power off costs a certain amount of power, but so does keeping it in continuous sleep and waking it up periodically. The optimum switching off and on is around once a day. If you want to receive data more often, it is better to go for the so-called Power save mode (the sleep mode with periodic wake-up). If you want less than once a day or only for a certain event, it is better to disable everything.
A frequently heard wish for IoT devices is that they are small, handy and practically designed. LTE and NB-IOT devices are currently often quite large in size, and you need quite a few additional components to make a complete sensor device.
Conclusion
LTE-M / NB-IOT and LoRa are two completely different techniques, which have a similarity in how they are applied. Both networks are energy efficient and wireless, and only transmit sensor and machine information. The choice is best based on where you want to implement your solution, and power consumption requirements.
When power consumption is your main design requirement, then you should go for LoRaWAN. If international use is your main requirement, go for LTE-M or NB-IOT.
For more information about LoRa, LTE-M and NB-IOT, you can contact us via telephone number 085-0443500 or by mail to info@thingsdata.com.