Connecting your Smart Home with Sub-Ghz
Riley_S
What is Sub-GHz Communication?
Many of the newest sensors and devices from Tapo are able to take advantage of TP-Links Sub-GHz technology to bring new features, functionality, and product types to users everywhere.
The 2.4 GHz band is widely used by popular wireless devices such as Wi-Fi hotspots, wireless routers, ZigBee, Bluetooth, and some wireless phones. However, adding more devices to your network can lead to increased interference for each device. Fortunately, Tapo's new Sub-GHz frequency eliminates this issue by ensuring that your IoT devices are no longer affected by interference from other networked devices.
What is Sub-GHz technology?
Sub-GHz, also known as Sub-1 GHz or Sub-1G, is an innovative IoT solution to automate and control smart home devices through the lower-than-1Ghz wireless frequency characterized by its Long Range, Resilience to Interference, and Extremely Low Power.
In the United States, Sub-GHz uses the 922MHz frequency.
In Europe, Sub-GHz uses the 868MHz frequency.
Why Use Sub-Ghz Instead of Wi-Fi, Zigbee, or Bluetooth?
Increased Range
Sub-G boasts long-range transmission. It shows strong signals even in obstructed conditions in big cities. You are free to put sub-devices like wire-free cameras, motion sensors, or Tapo Sub-G devices anywhere within range of the smart hub’s signal. The narrowband operation of Sub-GHz networking enables transmission ranges up to several hundreds of meters indoors.
The rate of signal attenuation increases at higher frequencies; therefore, the 2.4 GHz signal weakens faster than a Sub-GHz signal.
As the frequency decreases, the angle of diffraction increases. Signals with frequencies below 1 GHz bend more around obstacles compared to signals with a frequency of 2.4 GHz, resulting in less blocking.
Using a frequency below 1GHz allows for the Sub-G devices to avoid the 2.4 GHz frequency used by most devices such as Wi-Fi, Bluetooth, and Zigbee. This means that as you walk through your home, your mobile phone is creating interference from the active Wi-Fi AND Bluetooth Connections.
Less Susceptible to Interference
Using a frequency below 1GHz allows for the Sub-G devices to avoid the 2.4 GHz frequency used by most devices such as Wi-Fi, Bluetooth, and Zigbee. This means that as you walk through your home, your mobile phone is creating interference from the active Wi-Fi AND Bluetooth Connections.
Extremely Low Power Consumption
All radio circuits running at higher frequencies, such as power amplifiers, mixers, or synthesizers, need more current to achieve the same performance as lower frequencies. Utilizing a frequency band under 1 GHz means sensor nodes use significantly less power than their 2.4 GHz equivalents. As a result, many upcoming Tapo Sub-G devices use watch-style or AAA batteries that could last a year or longer.
The Tapo C420S2 camera, which uses Sub-GHz, even offers a 180-day battery life thanks to its rechargeable battery pack. It can communicate motion detection events and receive commands through the included H200 Sub-GHz Hub.
Getting Started with Sub-Ghz Connections
Note: Sub-Ghz Networks and Devices Require a Central Hub to Operate as a Bridge to the Internet
Currently, the H100 and H200 may operate as your Sub-GHz Hub. These hubs connect to your network through Wi-Fi or Ethernet (H200 Only) and will broadcast a Sub-GHz wireless network available to other compatible devices and sensors.
Wi-Fi devices will not be able to communicate directly with your smart hub and will still connect directly to your router’s main wireless network.
Available Sub-Ghz Devices in the United States [Updated 4/13/23]
Sub GHz Compatible Smart Hubs:
Smart Hub with Chime (Tapo H100)
Smart Hub for Cameras (Tapo H200) (Sold with C420S2)
Sub-Ghz Compatible Sensors and Devices:
Wire-Free Camera (Tapo C420/C420S2)(H200 Hub Required)
Comment
Why not impletent these as Z-wave devices if you were wanting to operate in the 800/900 Mhz ranges and require a special hub?
@DataMeister Other IoT providers operating in the 800/900 Mhz range have also decided to use their own hubs rather than Z-Wave. I am particularly familiar with Yo Link, which operates at 923.3 Mhz. Yo Link has done an exceptionally good job, as their IoT devices can be up to 1/4 mile away from the hub. One particular reason a vendor may choose to go with their own hub rather than Z-Wave is that Z-Wave has its own protocol. Yo Link, for example, utilizes its own proprietary protocol, and thus decided on their own hub. I'd guess that Tapo may be in a similar situation, not wanting to be forced into using Z-Wave's protocol.
Based on my very cursory investigation, Z-Wave is designed for data rates of up to 100kbit/second. This would not be conducive to video streaming. It is mostly applicable to control and sensor applications. Clearly this would not be workable with the new Tapo wireless cameras.