April 13, 2021 by Maura
Basic knowledge of wireless smart home communication
Wireless smart home products are gradually welcomed by the market due to the fine adjustment and flexible function expansion. Faced with many wireless smart home products, various communication protocol terms are emerging one after another, and it is difficult for ordinary people to distinguish between the pros and cons. In fact, the underlying basic principles of these wireless products are common. Understanding the basics of wireless communication can help us better understand and get started with wireless smart home products.
Purpose and meaning
The purpose and meaning of any communication are to safely and accurately transmit information from one node to another. And wireless communication is the dissemination of information through radio without physical conductors or cables.
Modulation: The process of combining data and carrier is called modulation. There are many types of modulation. The simplest is that analog modulation is amplitude modulation, frequency modulation, and phase modulation (AM/FM/PM). Similar digital modulation is ASK. /FSK/PSK.
Amplitude modulation is the multiplication of carrier and data. When the data waveform is high, the carrier is also high, and when the data waveform is low, the carrier is also low. The amplitude of the carrier wave carries the data information, so it is called amplitude modulation, and similarly, the frequency modulation that carries the data information through the frequency of the carrier wave is called frequency modulation.
The amount of information generated by amplitude modulation and frequency modulation is relatively small, and it is also susceptible to communication interference, which cannot meet the needs of many wireless scenarios, and there are much more advanced wireless modulation technology.
Demodulation: The process of decomposing data from the modulation information is the reverse process of modulation.
Antenna: The function of the antenna is to turn the modulated electrical information into electromagnetic waves and send them out and receive electromagnetic signals in the air. Wireless communication equipment must have an antenna, and the quality of the antenna has a great influence on the quality of wireless data transmission.
Communication Channel: What if there are many devices communicating wirelessly in a space? Communication channels can be divided, devices can be grouped and classified, and they can run on different channels in a balanced manner. Similar to the road, there are many cars on the road. After dividing multiple lanes, the traffic flow runs on different lanes, which improves the overall high-speed carrying capacity.
In summary, a process of wireless communication: the data is modulated by combining with the carrier, and the antenna becomes an electromagnetic wave radiated into the air. The antenna on the other side receives the electromagnetic wave signal, and uses the demodulation technology to remove the data from the carrier, and get data.
Common wireless communication
At present, our most commonly used wireless communication is Wi-Fi. From life to office entertainment, Wi-Fi is inseparable. The second is Bluetooth. Bluetooth speakers and Bluetooth headsets are more commonly used in life. LTE is the 4G we currently use in mobile phones. NB-IoT is a low-power IoT standard promoted by operators in recent years. It is characterized by a large number of devices that can be connected, and power consumption can be made relatively low, which is suitable for some IoT sensing devices. There are also BLE Mesh, ZigBee, Z-wave, and so on for smart homes.
As developers and manufacturers, after years of development, we have inevitably developed and manufactured many protocol products. However, our main product line for the smart home system is GoSS and BLE Mesh, RS485 mixed systems.
About Communications Protocol
Radiofrequency is a general term for radio waves. Wireless communications such as Wi-Fi, Bluetooth, ZigBee, Lora, 4g, 5g, NB-IoT, etc. can all be classified as radio frequency communications.
These familiar RF names are communication solutions designed by different expert groups for specific application scenarios. For example, wifi is mainly used for wireless Internet access for indoor devices, and nb-iot is mainly used for low-power IoT base station communication. The fundamental differences in these radio frequency designs are mainly in wireless communication methods, communication base stations, and communication mechanisms. Some are simple and effective, and some are complex and highly reliable.
At present, many of the radio frequencies used for remote control lights and remote control curtains are 315m/433m radio frequency remote controls with the simplest ask modulation method. The advantages of this type of remote control are low cost, but poor stability, ease to have interfered, and easy to string codes.
The Thinker host series of Geeklink has the ability to learn and control the 315m and 433m radio frequency remote controls of the above ask debugging method.
Geeklink is also the first company in the line to support ask RF remote control learning and control (The second generation of remote control in October 2013 has been supported).
In addition to being compatible with the third-party ask315m, 433m radio frequency remote control, the connection method used by the Geeklink Thinker host and its peripheral accessories is a two-way radio frequency communication method. The main features are:
- Divide channels, avoid radio frequency co-frequency interference during dense installation by dividing different communication channels. Solve the communication instability that may occur in the dense installation of the entire cell. For example in a community like the picture below, if don’t make a divided channel, the user experience will not be good.
（community with massive use）
Two-way confirmation response mechanism, the host sends the device to the slave device, and the slave device receives a response reply. When there is no response, the host repeats sending for confirmation. Ensure the accurate delivery of control instructions.
Encryption, to ensure the security of wireless communication data through data packet encryption.
In addition, Geeklink’s series products based on Bluetooth Mesh-based have also been launched. The Bluetooth Mesh series is seamlessly compatible with the original GoSS series.