Wireless Connectivity Options for IoT Applications

- Overview

The success or failure of Internet of Things (IoT) projects is dependent on many things, but without a reliable connection between devices, sensors and your IoT platform, your project won’t even get off the ground. However, connectivity is not a matter of simply choosing a preferred wireless technology. It’s equally important to understand the requirements of your application—and then choose the network technology that’s the best fit. 

Below are the four general types of IoT networks and some of the top IoT wireless protocols within each category. Keep in mind there’s no “winner” here; all the below technologies have advantages and disadvantages in terms of cost, power, and battery size—three key differentiating features of IoT networks. 

No matter which technology you choose, you’ll inevitably have to make a trade-off somewhere. Negotiating the right balance of the three elements for your project will ensure it starts off on the right foot.

- Cellular Networks for Massive IoT

Enabling low power wide area applications. Today’s cellular networks, covering the globe with standardized mobile access, provide the ideal platform for a proliferation of IoT devices and applications. New radio access technologies are available specifically targeting the connectivity requirements of Massive Internet of Things (IoT) applications. Commercial devices span various types of meters, sensors, trackers and wearables in many different industries, including utilities, automotive, transport, logistics, agriculture, manufacturing, healthcare, warehousing and mining.

A typical 5G network will support millions of devices per square mile. Unlike the massive cell towers used by 4G networks, 5G towers are sometimes called “small cells” because of their size and ability to transmit data over a different part of the radio spectrum. Designed for interconnectivity, multiple 5G towers are deployed across a network to create additional connection points and relay data faster than the centralized cell towers of previous generations. 

This tower density will allow 5G networks to support far more IoT devices than is currently possible. While today’s 4G networks can accommodate a few thousand devices per square mile, 5G will provide fast network connectivity for millions of devices, opening up tremendous possibilities for industrial IoT applications and the sensor networks of smart cities.

- Local and Personal Area Networks (LAN/PAN)

PAN stands for Personal Area Network. It is sometimes referred to as Wireless personal Area Network (WPAN).  It’s a network covering a very small area, typically a small room. It enables computer devices to communicate with other nearby computers and exchange information and data. Devices in one PAN network can establish connection with other devices in other PAN network when in the same range. PAN network can be wireless or wired. The most popular wired PAN is USB whereas the most popular wireless PAN is Bluetooth. 

LAN stands for Local Area Network. It is sometimes referred to as wireless local area network (WLAN). The network connects computer over a small distance such as within a building or a single computer lab consisting of many computers. The network does not contain more than one subnet because they are controlled by one administrator. Ethernet and Wi-Fi are the two most common technologies in use for local area network. 

PAN and LAN networks are considered to be fairly cost-effective, but the transfer of data can sometimes be unreliable. Wireless personal and local area network technologies that are commonly incorporated into IoT connectivity solutions are WiFi and Bluetooth. WiFi can be used for applications that run in a local environment, or in a distributed setting if there are multiple access points integrated into a larger network. 

One downside to Wi-Fi is that it works only if the signal is strong and you’re close to the access point. Also, WiFi is generally more power-hungry than people think, but it is possible to operate it in a way that’s a little more power-efficient (for example, your device only connects periodically to send data, then goes back to sleep). Bluetooth Low Energy (BLE) is a more energy-efficient wireless network protocol - if you’re not receiving data constantly, a single battery running BLE could last up to five years. 

However, compared to WiFi it is slower to transmit and is more limited in the amount of data it is capable of sending. Both Wi-Fi and Bluetooth are easy to connect in most cases, although Wi-Fi does have some security challenges that may be difficult to overcome.

- Low Power Wide Area Networks (LPWAN)

IoT devices that run on LPWANs send small packets of information infrequently and over long distances. This type of wireless network was developed in response to the early challenges of cellular connectivity. Proponents of LPWAN position it as longer-range than Wi-Fi and Bluetooth, but using less power than cellular. 

A well-known and commonly used IoT network protocol in this category is LoRaWAN (long range wireless area network), which runs on the LoRa (long range) communication network. Advantages of LoRaWAN for IoT devices are its low power requirement (for long battery life) and relatively low-cost chipsets. 

Plus, under the right conditions, a single base station or gateway running on a long-range network is capable of providing service to a very large area - a few kilometers in dense urban areas and up to 15 - 30 kilometers in rural areas.

- Mesh Networks

A wireless mesh network is an infrastructure of nodes (a mesh topology) that are wirelessly connected to each other. These nodes piggyback off each other to extend a radio signal (like a Wi-Fi or cellular connection) to route, relay, and proxy traffic to/from clients. Each node spreads the radio signal a little further than the last, minimizing the possibility of dead zones In mesh networks, all the sensor nodes cooperate to distribute data amongst each other to reach the gateway. 

Zigbee is one example of an IoT wireless network technology. Mesh networks are very short range and may require extra sensors throughout a building or the use of repeaters to get the coverage your application needs. Also, the nature of the way these networks communicate can result in high power consumption, especially if you need instant messaging, such as for a smart lighting application. 

(IoT applications that require only occasional information updates use less power.) However, mesh networks are also fairly robust, able to find the fastest and most reliable paths to send data, and easy to install, making them a popular choice for in-building use.

[More to come ...]