The smart home gateway is the heart of home automation, through which functions such as system information collection, information input, information output, centralized control, remote control, and linkage control can be realized. In other words, the smart home gateway is an important information transfer station that controls other devices to perform related operations after receiving instructions from the cloud server. From another perspective, when some smart appliance such light BLE mesh lighting cannot connect to the network server alone, the smart home gateway can act as a IoT bridge between the smart appliance and the cloud server to help smart home devices realize smart operations.
What is Smart Home?
Based on residential units, smart home connects various devices in the home (such as audio and video equipment, lighting system, curtain control, air conditioning control, security system, digital theater system, audio and video server, video cabinet system, network appliances, etc.) through the Internet of Things technology to realize a smart living environment. Smart Home is influenced by the Internet of Things. Smart home connects various home devices and offers multiple functions by home appliance control, lighting control, telephone remote control, indoor and outdoor remote control, anti-theft alarm, environmental monitoring, HVAC control, infrared forwarding and programmable timing control, and so on.
Compared with traditional homes, smart homes not only have living functions, but also add functions such as network communications and home appliance automation, providing a full range of information interaction, and even saving costs for various energy consumption.
Reasons to Require Smart Homes Gateway
The Networking Principle of Smart Home
To understand why a smart home needs IoT gateways, let’s first learn about the networking principle of a smart home. At present, smart home devices are interconnected through two kinds of IoT gateways and three connection methods. The 2 IoT gateways are Bluetooth gateway and ZigBee gateway, and the 3 connection methods are Bluetooth connection, ZigBee connection, and Wi-Fi connection (no IoT gateway required).
Why do you need an IoT gateway if you can network directly through the WIFI at home? Because the hardware devices connected by Wi-Fi are particularly dependent on the wireless network, the wireless network at home must be stable and reliable, otherwise the hardware device may encounter offline and lost connections. If you invited some friends at home and a lot of mobile phones connected to the router, the wireless network will be easy to stuck. In addition, if there is an accident such as a telecommunications broadband failure or a router power outage, the smart devices at home will also become useless. Now that the Wi-Fi network has flaws, are another two ways the better alternatives to home networking?
Yes, of course. Zigbee gateway and Bluetooth gateway has already been proved as two most popular smart home gateway.
From the Point of View of Protocols
- The communication distance of the Wi-Fi is much smaller than that of the Zigbee protocol. Generally, a wall will attenuate Wi-Fi signal seriously, which is not suitable for entire smart home system.
- The Wi-Fi protocol has high standby power consumption and is not suitable for battery-powered devices such as sensor switches.
- The working status or command execution of Wi-Fi protocol devices depends heavily on the network conditions. If smart home devices do not have the ability to receive signals like mobile phones, they tend to become unstable.
The Internet of Things gateway adopting Zigbee protocol can greatly increase the amounts of the devices it can carry. The number of smart switches, sensors and motors in a single home may reach dozens, which can be easily handled by the a Zigbee gateway.
If the Wi-Fi protocol is adopted, the router needs to have at least 100-200 carrying capacity of devices, and the performance of the panel AP should also be improved accordingly. Otherwise, with more and more smart devices connected in the home, later use of Wi-Fi hardware device will be seriously stuck. Therefore, smart homes need IoT gateways for reasons of reducing cost, wide application, great reliability, and the standardization.
From the Point of View of Data Transmission
Wi-Fi executes control commands on a completely different path from other protocols. For example, in a scene of human body sensing lighting, the sensor senses someone is here, it starts to generate data, and upload the data to the cloud server, and the cloud server then issues the command to turn on the light, which is transmitted by light, network cable, and then executed by the smart switch, the light will open.
If you use other protocols that require an IoT gateway, since the gateway has edge computing capabilities and logic design capabilities, all data only needs to be transmitted through the gateway in your home to complete this control command.
Unlike mobile phone watching TV, which can be cached and loaded, smart home scenes must be respond timely. It is impossible for people to wait for the sensor to turn on the lights and process the commands in the cloud when they pass by. What’s more, if using Wi-Fi, the situation also may get worse when the network at that time is bad.
In conclusion, the smart home gateway is actually an IoT bridge, which can not only connect to the personal area network, but also connect to other smart devices at home through its own network. Therefore, protocols of low latency and high stability are necessary for smart homes. This is the reason why Zigbee and Bluetooth protocols are superior to Wi-Fi protocols, and it is also the reason why smart home gateways must be used.
Introduction of Zigbee and Bluetooth as Smart Home Protocol
Zigbee Smart Home Hub
ZigBee is a wireless network protocol for low-speed and short-distance transmission. Its main features include low speed, low power consumption, low cost, support for a large number of network nodes, and multiple network topologies. In addition, ZigBee has been released for more than ten years. Therefore, the application of ZigBee in the smart home field is quite mature, whether it is networking capability, connection capability, communication range, security performance, power consumption level, etc., have been tested by the market and accepted by mainstream smart home device manufacturers. Based on these facts, ZigBee is currently the most popular smart home protocol.
Bluetooth Smart Home Hub
Bluetooth is also a valuable smart home protocol where it is almost as ubiquitous as WiFi. These smart home gadgets can use Bluetooth to control: smart appliances, smart lighting, smart door locks, smart plugs, thermostats, motion sensors, contact sensors, smoke alarms, Air quality sensors, smart blinds, and more. Among them, Bluetooth mesh lighting control is becoming the more and more influential in both residential and commercial building automation.
According to the Bluetooth SIG 2022 Market Update, there is about 5 billion Bluetooth device shipments in 2022. Such a huge volume amortizes the hardware and software costs of the Bluetooth protocol and the Bluetooth chip, which makes the average cost of the Bluetooth module only half of that of other protocols or even lower, which can greatly reduce the price and cost of Bluetooth smart home devices. Therefore, although the early Bluetooth technology was not oriented to the smart home field, with the rapid adaptation of Bluetooth technology in the smart home field in recent years, there is great potential for Bluetooth to catch up from behind.
Zigbee vs Bluetooth Mesh as Smart Home Protocol
Bluetooth and Zigbee are two of the most popular personal area network technologies and both support Mesh networking. Zigbee is based on the IEEE 802.15.4 standard, while Bluetooth Mesh is a network technology based on BLE developed and released by SIG.
Advantages of Bluetooth Mesh as Smart Home Protocol
Direct Connected by Mobile Phones
A large number of consumer electronics products, especially mobile phones, integrate Bluetooth modules, such as earphones, speakers, bracelets, smart watches, Bluetooth blood glucose meters, Bluetooth light bulbs, etc., all have Bluetooth modules, so Bluetooth can provide a wider range of interoperability between brands. This is the uniqueness of Bluetooth, and is an unmatched advantage over ZigBee. That means every smart home devices in the Bluetooth mesh network can be connected to each other. In other wods, the smart devices in the network can directly send commands to control or link another smart device, which is much more closer to ideal “Internet of Things” .
Low Power Consumption
There are two device characteristics in Bluetooth mesh: one is Friend and the other is Low power node. These characteristics can guarantee the low power consumption performance of the nodes. The power consumption of Bluetooth mesh protocols is lower thanZigBee’s.
The Bluetooth Mesh communication speed is up to 2Mbps, while Zigbee is based on 802.15.4, which limits the data rate to a maximum of 250Kbps. Therefore, Bluetooth Mesh has a faster data rate compared to Zigbee.
Advantages of Zigbee Mesh as Smart Home Protocol
It usually takes only 15ms for Zigbee mesh to switch from sleep state to working state, and it only takes 30ms for a node to access the network. Right now, ZigBee mesh is still the preferred solution for smart home devices that require fast response. Of course, with the development of Bluetooth mesh, the response speed of Bluetooth mesh is also constantly improving.
Strong Wall-penetrating Performance
ZigBee mesh’s wall-penetrating performance is stronger than that of Bluetooth Mesh, and the effect is also better when there are fewer devices. However, when Bluetooth Mesh is deployed in a large area, it can make up for the weakness of wall penetration performance.
ZigBee mesh was produced for industry in the early days, so the anti-interference ability is much stronger than that of Bluetooth Mesh. For environments with large interference, ZigBee is more suitable for deployment.
To sum up, through the above comparison, we can see that both ZigBee mesh and Bluetooth mesh have their own advantages and disadvantages, but as a rising star, Bluetooth Mesh is much faster in popularity than ZigBee mesh. User experience and cost are the two most important factors when smart home devices want to get into thousands of households. The time that low-cost Bluetooth mesh user experience approaches or surpasses ZigBee mesh, Bluetooth Mesh will eventually replace ZigBee mesh as the first choice for smart home protocols. And ZigBee will be more used in some special fields and scenarios. Let’s wait and see.