With a growing number of IoT devices connecting wirelessly with their servers and applications there is also a growing number of technologies being developed to address specific IoT needs. While there is nothing wrong to use Wi-Fi to connect your refrigerator with the coffee machine or use 3G/4G mobile network to connect ATMs and vending machines to their servers, the number of IoT devices require simplified, cheap, power-saving technologies with extended coverage.
3GPP standards offer modified versions of 4G LTE radio technology (LTE-M and NB-IoT) to address those specific needs. NB-IoT in particular uses greatly simplified radio interfaces techniques and procedures to reduce device cost, increase coverage, and offer much more power efficient operation for devices that need to stay active for months or years. But NB-IoT has a serious competitor in this segment.
The NB-IoT is an adaptation of LTE radio interface, but it still uses a “complicated” protocol stack with many radio-level and core-network level procedures, which increase implementation cost. Number of device-related and connection-related parameters (“contexts”) need to be stored in various network elements for device to communicate successfully. On the other hand, being part of 3GPP standards, NB-IoT offers full mobility, roaming, and proven 3GPP radio-level security of data transmission.
Unlike NB-IoT, the LoRa was from the start designed to address specific class of IoT devices: cheap to produce, sending tiny amounts of data, using as little power as possible. There are no mobility related attach or update procedures, no connection setup or release, and so on. In the simplest deployment scenario, the preconfigured LoRa device can be powered on and immediately send a data packet using end-to-end AES-secured communication. Asynchronous radio reduces the power consumption, but then there is no quality guarantees of any kind.
NB-IoT devices communicate with the regular 4G base stations adapted for NB-IoT radio and the regular 4G core network forwarding device’s data to some application servers. The NB-IoT radio can be also provided by 5G base stations and communication with 5G core network is possible (after a software upgrade) making NB-IoT devices “future-proof” for years to come. Licensed radio spectrum, access and admission control offer a higher quality of radio communication.
In comparison, LoRaWAN networks are much simpler in structure: the base stations (known as “gateways”) communicate over a backhaul network to Network Server (NS) connected to the application server(s). The backhaul can be fibre, wired, or wireless with IP connectivity provided by 3G/4G/5G mobile networks which simplifies deployment of gateways as they only need a power supply. The LoRa radio uses unlicensed spectrum, with a danger of interference, but also simplified deployment: launching a private LoRaWAN network for own use or as a service to customers is pretty straightforward.
Both technologies target similar groups of applications: various smart meters, tracking devices, sensors, alarms, etc. Generally: IoT applications utilising small payloads, infrequent data transmissions, low power consumption, and possibly poor coverage conditions.
From gas meters, water meters, leakage detectors to reindeer tracking devices and moisture detectors for farmers – the number of applications for both technologies keep growing every month. There are more and more both NB-IoT and LoRa networks being launched all over the world with LoRa being in the lead when it comes to a number of commercially operational networks.
With lower device complexity and cost, lower power consumption and comparable or better coverage LoRa seems “better”, but the ongoing NB-IoT development, improvements added in each new 3GPP system release and support from large vendors and mobile operators will keep those technologies competing for quite some time with no obvious candidate for the winner. And these two are not the only ones out there…