Hello and welcome to another episode of Learn Technology in 5-minutes and this is Venkatesh, the founder of MAKERDEMY.
In this episode, we will learn about IoT gateways. If you are an IoT enthusiast, it is likely that you have across the phrase “IoT gateway”. What exactly is an IoT gateway? Well, you can think of an IoT gateway as a kind of a bridge that connects the sensor networks to the cloud IoT platform. You may ask why do we need this bridge in the first place? Can’t the sensor nodes not directly talk to the cloud? I have seen some IoT prototypes where the Raspberry Pi is connected to the sensors and through WiFi connects to some cloud IoT platform? Well, first of all, prototypes are just that - prototypes. Real-world IoT implementations come with a variety of challenges and constraints. Often, the sensor nodes are devices that run on batteries for years. In other words, they are energy-constrained. Because of our mobile phones, we are familiar with WiFi and cellular wireless technologies through which we connect to the internet. WiFi consumes a lot of power and cellular consumes even more power than WiFi. This is why you end up charging your mobile phone on a daily basis. Therefore, most IoT implementations use some kind of low power networks like the Zigbee or BLE mesh or LoRa. In case, you are unfamiliar with these technologies, check out the other videos in this series, where we have covered the above mentioned wireless radio technologies.
Here is where the IoT gateways come in. As explained before, the IoT gateway acts as a bridge between the sensor nodes and the IoT cloud. A typical IoT gateway is mains powered unlike the sensor nodes, which are battery-powered. An IoT gateway may take in sensor data and is able to “speak” multiple protocols. For example, there could be an IoT gateway that connects to hundreds of sensors using the LoRa network and then channel all this data to the cloud via WiFi/Cellular, ethernet or even satellite connection and may use MQTT/HTTP/CoAP or any other standard protocol. And how is it that the gateway can use these radio technologies? Well, it is because it is mains powered, and is not a constrained device. We just need one powerful mains operated device, the gateway, that can connect to Ethernet or Cellular, and can have several cheap constrained sensor nodes that connect to this gateway. In practice, there are multiple gateways in an IoT system.
Now that we know what an IoT gateway is, can you think of a device that can act as a basic IoT gateway? Well, if your answer is ‘The Smart Phone”, you are right. Most modern smartphones have multiple radio technologies for connectivity like the BLE, WiFi and cellular. With some ingenuity can act as a basic IoT gateway device.
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