IoT is creeping closer to maturity, with technologies becoming increasingly robust and functional IoT implementations ramping up. IoT services and systems are entering the market on a daily basis with different architectures, feature sets and applications. There are many factors to consider when investing in IoT, but understanding the different protocol options available and which will fit the needs and scale of your business in both the short and long term is critical.
An IoT protocol is the network language that the nodes of an IoT system speak, dictating the range, format and complexity of the IoT system’s communications. Protocols also play a key role in determining cost and features. There are two primary considerations:
- How long will sensors need to stay in the field on battery power? How often will they need to report? What kind of devices being considered? Will replaceable or rechargeable batteries be used?
- What distance range must signals cover? How much data will they send in each message? Are you relying on cellular to maintain connectivity, or will you need to build your own IoT network?
The best protocol to use depends on these two factors, as well as the specific application at hand. The smallest and least-demanding IoT setups — connected homes or offices, for example — can run on simple Wi-Fi networks, with continuous power coming from the building’s electrical system. For areas such as a farm or a campus environment where small-volume data transmissions are required, self-contained low-power wide-area networks (LPWANs) such as LoRaWAN and Sigfox are a good choice. For larger regional areas, a cellular protocol like Narrowband IoT (NB-IoT) or Cat-M may be the best choice.
For networks that are larger than one small building, LPWANs usually make the most sense. These environments include such large-scale undertakings as construction projects, oil refineries or any type of operation where people, assets, such as equipment, and dangerous conditions need to be tracked across a large site. This also includes factories, warehouses, farms or ranches, and large school or government campuses.
Deploying an LPWAN like LoRaWAN in these types of scenarios means you will most likely pay the same or less as with cellular IoT, and you own more — all the devices, the network and the data that goes over the network. You’re responsible for monitoring, support, maintenance and repairs. Security is also your responsibility.
Another notable difference: unlike cellular data packets, LPWAN transmissions don’t always wait on reception confirmation. This can be a benefit and a liability — more traffic can be placed on the system without acknowledgements, but there are times data points will be lost due to network congestion.
The two most popular LPWAN protocols are LoRaWAN and Sigfox. Of the two, LoRaWAN and LoRa technology have experienced higher growth, as well as growth potential over the next five years. The simple case for LoRa and LoRaWAN is their widespread support, versatility and outlook. The LoRa Alliance is backed by more than 500 leading technology companies, and LoRa technologies are continuously evolving and improving to enable new use cases.
Cellular IoT is a good choice for larger environments, such as citywide or statewide hospitals, retailers or airports, or even environmental monitoring and disaster preparedness across a wide area — anywhere that needs a consistent, clear view of assets, shipments or conditions. No new network or gateways are required, as the cellular provider’s existing cell towers transport the IoT data. That also means, however, that the same dead spots in cellular coverage exist for IoT connectivity. If the network connection is interrupted, your IoT will also be impacted. Still, the costs and limitations of cellular IoT are often outweighed by the ease of deployment and size of coverage area.
Cellular protocols will lead the IoT discussion for those operating on a very wide scale, or in areas gateways can’t legally or logistically be erected. The two protocols with the most market share and mindshare are Cat-M and NB-IoT. Of the two, NB-IoT is more battery efficient and offers low-power communications and data size that match the LoRa profile more closely, making cross-sensor compatibility simpler for IoT providers that want to cover both LPWAN and cellular use cases.
Meanwhile, Cat-M allows for higher data rates and low-latency communications, critical if the organization needs to collect large files from its devices or push large updates to endpoints. Cat-M also allows for low-quality voice and is more appropriate for real-time applications such as smart vehicles.
Rollouts for NB-IoT and Cat-M are nascent but growing, and the availability of both will largely depend on cellular providers plans. Ultimately, it’s likely that NB-IoT will provide the right benefit at the right cost for most applications. However, LPWAN and LoRaWAN will find a sweet spot with companies that want to cover large areas or have private networks.
It’s possible that the future also holds a protocol-agnostic model where sensors support multiple protocols. In the interim, select an IoT protocol that best matches your scale, power and connectivity needs, with an eye keenly on your future requirements.
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