How to choose the ideal connectivity technology for an IoT project

Many communication technologies are currently available, making choosing one for an Internet-of-Things project potentially daunting. For example, several LP-WAN options exist, including Wi-Fi, Ethernet, LoRa, Zigbee, Bluetooth, and cellular technologies like NB-IoT, LTE-M, and 5G. Every connectivity solution has pros and cons, and there isn’t one ideal for all projects.

Wi-Fi might seem like the best choice for an application until realizing it’s dependent on 100% uptime. Selecting the proper connectivity solution for an IoT project must occur on a project-by-project basis.

A few factors to consider:

Connectivity. What cellular technology is ideal? Is a hybrid option possible, where a connected device can push and pull data if Wi-Fi or the primary communication technology fails or goes down? Is Bluetooth required?
Data requirements. Are there high bandwidth data requirements, like with audio or video streaming? Or will data only be exchanged infrequently and in small chunks?
Power consumption. Will the device(s) run on battery, solar power, or mains supply — or a combination? Devices deployed outdoors could potentially use solar energy and batteries.
Uptime. Will the device(s) spend most of their time in sleep mode or must they always be alert?
Range. What range is required? Does the device need line-of-sight, or how close must it be to the gateway?

The nature of data communication should be a primary factor in deciding what connectivity solution is best. In this article, we’ll discuss different communication technologies for IoT and IIoT (Industrial Internet of Things) projects, their pros and cons, and how they compare.

Wi-Fi

Wi-Fi is a common solution for connecting IoT devices indoors. It’s readily available and affordable, making it ideal for smart home devices and office automation. Wi-Fi is reliable and supports high-bandwidth, low-latency communication. However, it’s not the most power-efficient option for battery-powered devices, as Wi-Fi modules typically consume 50 to 200 milliamperes.

Battery-powered devices typically spend most of their time in sleep mode, only connecting to Wi-Fi intermittently to push or pull data. So, these devices must be programmed to use sleep modes and connection settings effectively. Additionally, the router must remain on to ensure reliable internet access.

Deploying IoT devices with a Wi-Fi network also presents certain challenges. One issue is network management: Wi-Fi credentials must be hardcoded into the devices, or a hub must manage their connection to the router. For end-users, configuring a Wi-Fi network can be daunting.

Security is another concern. Devices handling sensitive data need protection to avoid connecting to unmanaged networks and must use proper encryption. This requirement can be intensive for microcontroller or microcomputer devices. Nevertheless, Wi-Fi is suitable for high-bandwidth communication and non-battery-powered devices, so long as the system is properly designed and programmed for secure power optimization.

Bluetooth

Bluetooth Low Energy (BLE) is a common technology for connecting IoT devices, primarily for short-range device-to-device communication. However, it cannot directly connect devices to the Cloud or a remote server, as its range is limited to 20 meters. This means BLE is not suitable for devices deployed over long distances. Additionally, connecting devices via Bluetooth can be unreliable and is only sometimes automated. It supports peer-to-peer communication but does not allow multi-casting.

Bluetooth is ideal for short-range, low-power, low-latency device-to-device communication. Devices using BLE for connectivity require a user interface for manual configuration and management.

Ethernet

Generally, Ethernet is only used for IoT deployment in select situations. It’s not typically used because it’s costly, requiring extensive cabling and complex network management. Ethernet modules consume a lot of power, with routers and switches continually running, so it’s also unsuitable for systems where power consumption is a concern. One more disadvantage: mobile devices cannot connect via Ethernet.

Nevertheless, Ethernet can be a good choice for indoor applications requiring high-bandwidth, low-latency communication, such as streaming audio-video data from CCTVs or computationally intensive industrial applications. It’s also a deceny option where RF interference is an issue. If power consumption is not a concern and the devices are stationary, Ethernet offers more reliable data communication than Wi-Fi.

LoRa

LoRa is becoming a popular solution for low-power, long-range IoT communication, supporting device-to-device communication up to 15 km. Many LoRa modules offer selectable ranges, though developers must compromise between the data rate and the range.

LoRa features AES encryption for secure data communication. However, it cannot directly connect devices to the Cloud or a remote server. And despite its excellent range, LoRa signals can be interrupted by buildings and other obstacles. Reliable connectivity often requires gateways in a LoRa network.

Overall, LoRa enables simple, secure deployment of IoT devices for several applications. LoRa modules with Wi-Fi and Bluetooth functions are highly practical. They enable low-power, long-range device-to-device communication with LoRa, while Wi-Fi connects the devices to the internet. Additionally, the onboard Bluetooth function supports high data rate communication with nearby devices.

Cellular

Cellular technologies like NB-IoT, LTE-M, and 5G are ideal for outdoor and mobile applications. While 5G devices consume significant power, NB-IoT and LTE-M are low-power alternatives. LTE-M offers better data rates and supports devices in motion, making it suitable for battery-powered devices with intermittent data communication due to its power-saving modes.

Despite its lower power consumption and better indoor penetration, NB-IoT does not support connectivity with moving devices. So, 5G is ideal for applications where power consumption is not an issue and high-bandwidth or low-latency data communication with the Cloud or a server is required.

Cellular solutions provide global coverage and 100% uptime, along with location tracking. They’re the only viable option for devices that are mobile or scattered worldwide.

Going hybrid

Hybrid solutions leverage the unique advantages of each technology while addressing their respective limitations. Recognizing that no single solution is universally perfect, industries are increasingly adopting hybrid approaches. These solutions integrate complementary technologies to overcome drawbacks and enhance versatility.

For instance, combining LoRa modules with Wi-Fi and Bluetooth functionalities enables direct Cloud or remote server connectivity while facilitating low-power device-to-device communication across expansive distances using LoRa radio technology.

Due to the variety of communication technologies available, selecting the ideal one for IoT projects can be a challenging process. Careful consideration is essential for each project’s specific needs.