Almost every IoT system requires a way to connect sensors/devices to the cloud so that data can be exchanged between them. IoT gateways are crucial in enabling this connection, but what exactly is a gateway?
A gateway acts as a bridge between sensors/devices and the cloud.
Many sensors/devices communicate with the gateway, which relays all the information and “conversations” to the cloud (what is the cloud?).
What is an IoT Gateway?
But why the extra step?
Now that you know what a gateway is, you may wonder what the benefits are of taking the extra step between sensors/devices and the cloud. There are several advantages:
Battery Life
If sensors/devices are located in remote areas, they may require a distant connection, such as satellite connectivity, to communicate with the cloud. As mentioned here, longer ranges often mean increased power consumption (and cost); this can be an issue for small sensors/devices with limited battery life.
If you are doing Smart Agriculture, you want your field sensors to last for years, not months or weeks. By using a high-altitude gateway installed near the periphery or the top of a barn, the sensors/devices only need to send data a short distance to the gateway, which can then relay the data back to the cloud via a single higher-bandwidth connection.
The gateway allows sensors/devices to communicate over shorter distances, thus extending battery life.
Different Protocols
A complete IoT application may involve many different types of sensors and devices. Again using Smart Agriculture, you may need sensors for temperature, humidity, and sunlight, as well as devices for automated irrigation and fertilization systems.
All these different sensors and devices may use different transmission protocols (essentially the rules and formats for transmitting information). Protocols include LPWAN, Wi-Fi, Bluetooth, Zigbee, and more.
The gateway can communicate with sensors/devices using different protocols and then convert that data to a standard protocol (like MQTT) for sending to the cloud.
Unfiltered Data
Sometimes, sensors/devices can generate so much data that it overwhelms the system or incurs extremely high transmission and storage costs. Often in these cases, only a small portion of the data is actually valuable. For example, security cameras do not need to transmit video data of empty hallways.
The gateway can preprocess and filter the data generated by sensors/devices to reduce transmission, processing, and storage requirements.
High Latency
In last week’s #askIoT article, I explained that timing can be crucial for certain IoT applications; sensors/devices cannot transmit data to the cloud and wait for a response before taking action. This is true for life-or-death situations in healthcare or for fast-moving objects like cars.
By processing data on the gateway and issuing commands locally, higher latency can be avoided. However, many sensors/devices in IoT applications are too small and have too low battery life to perform processing.
The gateway can reduce latency for time-critical applications by executing processing on the gateway itself rather than in the cloud.
Security
Every sensor/device connected to the internet is vulnerable to hacking. Compromised sensors/devices are bad news. Not just for the owner, but for everyone.
A few weeks ago, malware called Mirai was used to attack and control thousands of IoT devices. Then, these “botnet” devices were used to take down significant portions of the internet (more on Mirai).
The gateway reduces the number of sensors/devices connected to the internet, as sensors/devices only connect to the gateway. However, this makes the gateway itself a target and the first line of defense. This is why security needs to be a priority for any gateway.