Continuing our exploration of the Internet of Things (IoT) ecosystem, this week we focus on the short-range communication elements of the data flow that allow IoT devices to deliver their payload. We will cover the communication options that support up to a couple hundred meters/feet.
At the core of any IoT device is the connectivity between the device and the gateway, or cloud, that would allow the device to deliver their payload. The connectivity technology selection is closely tied to the data payload and the application requirement; some need an always-on comprehensive bi-direction data connection and others can be as simple as an occasional heartbeat message.
When it comes IoT device connectivity to the Internet there are dozens of protocols available, but we will focus on the most prominent:
Bluetooth is a proven technology that has been around for more than 30 years. It was initially introduced as a replacement to serial cables when connecting two personal devices together, usually a wireless mouse to a computer or a headset to a MP3 player. Today this has extended to many items surrounding us in daily life today, such as smartphones, tablets, wearables, etc.
Bluetooth Low Energy (BLE)
BLE is subset of Bluetooth technology introduced in 2011 as Bluetooth 4.0. The device remains in sleep state most of the time except when a connection is initiated; connection times are also reduced drastically. Although a different protocol, both classic Bluetooth and BLE can technically coexist on the same device.
Wi-Fi is another well-known technology that we have been using for more than 20 years in our everyday life to connect mobile devices to the Internet from any location, public and private. Used with IoT devices, it would be better suited for high-power consumption devices (plugged into a power source as opposed to battery-powered), requiring great response time and transmission rate to send a high volume of data over a long period of time, if not constantly. An example would be a static IP video surveillance camera, streaming data 24/7 back to a back-end server for monitoring and backup.
Z-Wave is an alternative to connect low power-consumption in a mesh network. Both Z-Wave and Zigbee require a central hub (access point) to connect devices to the Internet, however Z-Wave is a closed proprietary protocol.
Z-Wave uses different frequencies depending on the country where operated, thus devices purchased for the US market might not work in the EU and vice-versa. Virtually up to 200 devices can be connected in the same network.
Zigbee is a low power open protocol operating in the 2.4 GHz, license-free radio band in a mesh network configuration. Like Wi-Fi, it does require a central hub (access point) to connect devices to the Internet, although they can also communicate between them directly if needed, expanding the virtual the range. Virtually up to 65,000 devices can be connected in the same network.
Zigbee devices are battery-powered devices to be deployed in a mesh network to cover a small area. Typically found in home automation solutions, and more recently in commercial real-estate to monitor environments via Zigbee sensors.
Although it is an open protocol, vendors can configure their devices so that they are only fully compatible with own gateway. For example, a light bulb could be turned on/off using a gateway from any vendor, but only the one from the actual vendor can control all features, like dimming, color switching, etc.
Now that you have a better understanding of how these connectivity options fit into the IoT ecosystem, let’s highlight what each technology does best and how they may suit your specific needs.
When it comes to IoT communications, there is no “one size fits all” solution. However, you can select technology that covers most of your use-cases. At times you may be operating two IoT networks to cover all your use-cases and an IoT aggregator like ISEC7 SPHERE IoT can help. Please feel free to contact us if you have any questions or would like assistance in reviewing your IoT communications options.
(C) Rémi Frédéric Keusseyan, Global Head of Training, ISEC7 Group