As the development of connected devices continues to be driven forward, particularly by IoT (internet of things), more research is starting to focus on the technologies and architectures that will support network expansion in this area. At the moment, there is a lot of competition between technologies, each looking to dominate the market and come out on top as the favoured supporter of IoT and its growth.
Two technologies which have been talked about a lot in this race are LTE-M and LoRa. The focus on LPWAN (Low-Power Wide-Area Networks) as well as the soon-to-be absence of GPRS and its effects on businesses, have been the focus of the race in development of these two technologies.
LTE-M (Long Term Evolution Category M1) is a low-powered wide area network technology standard that looks to support IoT through simple devices and extended coverage, alongside reuse of existing installed LTE base. LoRa is a set of open standards for bidirectional devices.
This article will compare the two technologies, where their development is heading and ultimately which is more likely to go on to become the preferred technology for IoT.
LTE-M technology is designed for use by IoT devices that want to connect to a 4G network without a gateway and while using batteries. These low-powered devices are expected to make up the bulk of devices that operate within the Internet of Things over the next few years. They are likely to make up the majority of the predicted 50 billion connected devices estimated to be in operation by the year 2020. LTE-M products are exciting a lot of manufacturers because they are very cheap to build.
The low cost associated with manufacturing LTE-M devices isn’t its only positive either, with extended battery life also being a hugely significant factor in its popularity. LTE-M devices are able to enter power-saving mode, which means they can automatically “wake-up” when connections are made. This is known as Extended Discontinuous Reception or eDRX.
There is a substantial financial benefit from using LTE-M as well. With the maximum data rate for LTE-M devices limited to 100 kbit/s, they are much less taxing on 4G networks. This means that carriers can offer service plans with significantly reduced prices, even in some cases, at the same price as 2G M2M prices.
Within a LoRa network, LoRaWAN is the term used for all of the system architecture that is used as well as the communications protocols, and LoRa describes the physical layer of the network. Within a standard LoRa network, there are three key components: nodes & endpoints, gateways and network servers. A node could be, for example, a sensor which detects changes in the environment or a sensor that tracks and reports any changes that occur to the conditions around it. Nodes used within a LoRa network are linked with gateways to ensure that any data transferred from the nodes reaches all gateways before being sent on to a cloud-based server.
The server used in the LoRa network filters packets for duplicates, as well as performing security updates and sending acknowledgements back to the gateways.
LoRa networks have two different layers that operate security, the network layer and the application layer. This security makes LoRa networks very secure and is one of the key reasons why its development has been so popular.
Both LTE-M and LoRa have strengths. It is fair to say that LTE-M is likely to be preferred for national or international coverage because of it’s flexibility and ability to utilise existing infrastructure. However, for more focused connectivity in smaller areas LoRa is likely to be technology of choice. Of course, these are only two possible technologies that could be adopted, so we may even see something developed that could make both these technologies obsolete.