Two of the most used and now mature IoT networks are LoRa and LTE-M, the attractive aspect of both technologies is that they are ‘Low Power’ networks. This is important for IoT devices with a limited energy supply. In this article we take a closer look at both techniques and what the differences are between the two networks.
What is LoRaWAN?
LoRa stands for ‘Long Range’ and it is a wireless network protocol for low power IoT applications. It is therefore a ‘Low Power Wide Area Network’ (LPWAN). This is ideal for applications that are located in remote or isolated places such as lampposts, dikes, quay walls or trash bins. When used, LoRa messages are very similar to SMS traffic, as long as nothing is sent, the cellular module is not active. As soon as a message is sent, the cellular module is active and a transmission takes place on the correct frequency with the correct network keys. Nearby LoRa gateways then receive this signal and process it towards the cloud.
Advantages of LoRa
The two biggest advantages are, on the one hand, the extremely energy-efficient consumption and the long distance that the message travels from device to the LoRa gateway. In addition, the hardware is compact and the costs are usually very low. Due to the low energy consumption, sensors can be made that can send information every day for three to five years on 2 AA batteries. The exact battery life of course depends on several factors, such as network coverage, the antenna of the device and the amount of information sent per message.
The LoRa network is separate from ‘the internet’, because messages are first received on the LoRa network itself and only then are they forwarded to the cloud via a LoRa gateway. As a result, LoRa modules are not vulnerable to cyber attacks. Within the LoRa protocol, encryption has also been applied to various layers to increase security.
Disadvantages of LoRa
There are also a number of disadvantages to using LoRa. In the Netherlands there are two rules that are enforced by the Radiocommunications Agency. The first rule means that each module may not send radio signals too often, this is called the ‘duty cycle limitation’ and the second rule means that the intensity of the radio signal may not be too strong, a maximum of 20 mW. Another disadvantage can be the amount of data that can be sent, which is about 54 bytes with LoRa. This is not a problem if you only want to send sensor information.
What is LTE M?
The LTE-M network has been specially developed for Internet of Things applications and is based on the reliable and secure 4G networks of the providers. LTE-M is also based on the GSMA’s global 3GPP standard, which offers possibilities for roaming abroad. The coverage of LTE-M is stronger than a 2G network and has the advantage of a deeper degree of penetration, which means that the coverage in buildings is many times better. Via LTE-M, data can be sent quickly in an energy-efficient manner and it is suitable for various applications that currently work with 2G. In addition, it is also suitable for applications that are not yet ‘smart’.
Advantages of LTE-M
LTE-M has good coverage, a high data rate and can also be set to be energy efficient, so this is interesting for applications that run on a battery. Furthermore, LTE-M is more cost efficient than a standard 4G device. The amount of data is compact and this keeps your data consumption low (MBs). Another advantage is that there are roaming agreements with neighboring countries and there is international LTE-M coverage in progressively more and more countries. It is also possible to send messages via LTE-M, VOICE and SMS and depending on the type of module you can also have a fallback to another network (2G).
Disadvantages of LTE-M
Even though LTE-M is promoted as an energy efficient technique, the module still consumes a lot of power as long as there is a connection to the network and data is being sent. It is many times more energy efficient than standard 4G, but you still need large batteries if your device often has to send data and wants to last longer than a year. A frequently heard wish for IoT devices is that they should be practical and compact in design, LTE modules are currently still large in size and you need quite a few additional components.
LTE-M and LoRa are two different techniques with similarities in how they are used, both networks are energy efficient and transmit device information. The choice is best based on where you want to implement your solution and the requirements for power consumption. Even if international use is your main requirement, then you should go for LTE-M. But when power consumption is critical, go for LoRa.