This is an update to the original article publisihed in June. The part with LoRaWAN has been updated.
This is an update to the original article publisihed in June. The part with LoRaWAN has been updated.
Needless to say, in the
Internet of Things, data transmission is critical. In this regard, LPWAN or low-power wide-area network is particularly suited for IoT connectivity. This article examines the main technologies under LPWAN, namely LoRaWAN, NB-IoT and Sigfox.
LPWAN stands for low-power wide-area network and is well suited in the IoT era. IoT devices transmit small data packets over long distances; this is especially the case in smart city or remote area applications where devices are distances away from receivers/routers. Most IoT devices are battery powered so battery savings are vital. In this regard, LPWAN, which transmits data at 0.3 to 50 kbits over a distance from 2 to 1,000 kilometers, has emerged as a popular IoT connectivity technology.
Currently, there are three primary standards under LPWAN: LoRaWAN, NB-IoT and Sigfox. Successful deployment of an IoT network requires a basic understanding of these technologies. Below we take a closer look at each.
LoRaWAN
LoRaWAN is a standard specified by the LoRa Alliance. According to the alliance, the LoRaWAN specification is a LPWAN networking protocol designed to wirelessly connect battery operated “things” to the Internet in regional, national or global networks, and targets key IoT requirements such as bi-directional communication, end-to-end security, mobility and localization services.
The major advantage of LoRaWAN is it consumes less energy overall. “Users can get up to 15+ years of battery life from devices connected to a LoRaWAN network. NB-IoT, on the other hand, only offers 10+,” according to a blogpost by Velos IoT. “This reduced power consumption also makes LoRaWAN ideal for devices that require higher refresh rates, as it will minimize the impact these higher refresh rates have on your battery usage.”
It’s important to point out that LoRaWAN communication is divided into three classes, and energy consumption varies with each class. In Classes A and B, the receiving channels or windows are open periodically, thus requiring less power. In Class C, the receiving windows are always open, requiring more power.
Security-wise, LoRaWAN relies on the Advanced Encryption Standard (AES) to secure devices, authenticate and enable end-to-end encryption. “LoRaWAN security uses the AES cryptographic primitive combined with several modes of operation: CMAC2 for integrity protection and CTR3 for encryption,” said the Center for Internet Security (CIS) in its whitepaper, “Internet of Things: Embedded Security Guidance.” “Each LoRaWAN device is personalized with a unique 128-bit AES key and a globally unique identifier (EUI-64-based DevEUI), which are both used in the authentication process.”
NB-IoT
Narrowband Internet of Things or (NB-IoT) is another LPWAN technology. It’s a brainchild of 3GPP and uses the existing cellular infrastructure. Because of this, NB-IoT is easier to deploy than the others.
NB-IoT also has other advantages. “While NB-IoT doesn't fare as well with battery life, it does provide better coverage and latency overall. And thanks to NB-IoT's low latency, you can send larger packets of data faster. So for devices that need to transmit a larger or more consistent data stream, NB-IoT is the way to go,” Velos IoT said. “Additionally, NB-IoT is more secure. It uses 256-bit 3GPP encryption versus LoRaWAN's AES 128-bit encryption. So if the data you're transmitting is sensitive, then NB-IoT is a more reliable option.”
Sigfox
According to Sigfox, it is a LPWAN protocol designed to connect sensors and devices securely at low-cost in the most energy efficient way to enable massive IoT. The technology is owned by UnaBiz, which has provided Sigfox solutions and services to over 1,500+ B2B customers, connecting over 11 million devices, Sigfox said.
Sigfox has certain advantages as well. “Sigfox boasts the most extended signal range of all three technologies. It has the lowest cost radio devices. The radio protocol does not require two way-communication to communicate with the network, which makes the technology more effective and efficient for applications that are not safety-critical,” said a post by IoT Solutions. “Sigfox technology bases its reliability on the repetition of signals from multiple base stations, which, if designed correctly, professionals argue may be more reliable than the two-way communication required in cellular networks and more efficient.”
Which one to choose
The three LPWAN protocols each have their advantages. In most cases they are relatively interchangeable. Yet in certain cases one outperforms the others.
LoRaWAN is known for being able to transmit small data packets over long distances using little battery power. As such it’s good for certain use cases. “LoRa devices and the LoRaWAN standard are flexible for rural or indoor use cases in a wide range of industries including smart cities, homes and buildings, communities, agriculture, metering and utilities, healthcare, environment, and supply chain and logistics,” the CIS whitepaper said. “LoRaWAN can be used when there is no other network connectivity and when power is constrained.”
The Velos IoT post agreed with the notion, saying LoRaWAN is particularly good at supporting static outdoor devices. “LoRa devices and the LoRaWAN standard are flexible for rural or indoor use cases in a wide range of industries including smart cities, homes and buildings, communities, agriculture, metering and utilities, healthcare, environment, and supply chain and logistics,” the CIS whitepaper said. “LoRaWAN can be used when there is no other network connectivity and when power is constrained.”
Conversely, the post said, NB-IoT works exceptionally well in dense settings. “It can penetrate walls, buildings, and more without little impact on service quality. For that reason, it's the better option in these situations: smart street lights, water and electric systems and
smart parking,” Velos IoT said. “As you can see, each use case is set in an urban landscape, with walls, concrete, and other wireless users to contend with. Even still, NB-IoT remains a reliable and successful solution in these instances."