Wired or wireless
The communication systems of smart homes are mainly divided into two categories: wired communication and wireless communication.
While wired smart home systems are relatively stable, their drawbacks include complex wiring, high workload, high cost, and difficult maintenance. Wireless solutions offer a glimmer of hope for smart homes, eliminating many of these hassles. Wireless smart homes do not affect the aesthetics of the interior, save on the manpower and resources required for integrated wiring, and are convenient and fast, making them ideal for smart homes.
What are wireless communication technologies?
Wireless communication technologies mainly include Zigbee, Z-Wave, RF, Bluetooth, Wi-Fi, EnOcean, LoRa, NB-IoT, etc.
01 WiFi technology
Wi-Fi is a long-range wireless transmission technology that allows electronic devices to connect to wireless local area networks. Its biggest advantage is the convenience of accessing the internet anytime, anywhere. However, its drawbacks are also apparent for smart home applications. High power consumption: a fatal flaw for deploying low-power sensors anywhere; Low security: Wi-Fi account passwords can be easily cracked by purchasing a random network card, posing a threat to home security.
While WiFi is widespread, this technology is only suitable for small, standalone smart devices and struggles to achieve scenario-based applications. It tends to become sluggish when there are more than eight WiFi-connected devices in the home, thus limiting its role to a supplementary function in smart home applications.
02 Bluetooth Protocol
Bluetooth is also one of the most common protocols in daily life. The most frequent example is pairing a mobile phone with a Bluetooth speaker. Through short-range wireless communication, it can transmit large amounts of data, bringing many conveniences to life. However, Bluetooth consumes less power than Wi-Fi, but its transmission distance is also relatively short, generally less than 10 meters, so it cannot be used for internet connectivity. Furthermore, the Bluetooth stack is prone to crashing.
Bluetooth nodes are relatively few, and its stability and interference resistance are not very strong, making it unsuitable for smart home systems. In the smart home industry, Bluetooth technology is generally only considered for single products or small local smart products.
03 RF433
The RF433 uses low-frequency signal transmission. The lower the frequency, the stronger its wall-penetrating and diffraction capabilities. Therefore, the RF433 has excellent wall-penetrating and diffraction capabilities. Like Wi-Fi, the RF433 only supports star network topologies, achieving network coverage and spatial expansion through multiple base stations.
Radio frequency (RF) technology is particularly suitable for renovated homes and apartments. Installation is easy and won't disrupt the existing decor. The control module can be installed directly on the wall, inside a box, on the ceiling, or wherever you prefer. Installation is flexible and customizable.
04 z wave
Z-Wave is a wireless network protocol spearheaded by the Danish company Zensys, focusing on interconnectivity and standardization. Z-Wave offers a data transmission rate of 9.6kbps and effective signal coverage of up to 30 meters indoors (over 100 meters outdoors). It is suitable for narrow bandwidth applications and provides a degree of security and stability. However, currently, it is only used in home automation.
Its main drawbacks are: First, it has a limited number of nodes; the theoretical maximum is 256, but the actual number is likely only around 150, which is the upper limit of the number of devices it can accommodate. In fact, many manufacturers can accommodate 20 or 30 devices. Second, it has a tree-like network structure. Once the upper end of a branch loses connection, all devices at the lower end will be unable to communicate with the gateway. Third, it lacks encryption methods, resulting in poor security and vulnerability to attacks. (The frequency band used by Zwave is non-civilian in my country, and Zwave smart home technology is not yet common in China, but it is still widely used abroad.)
05 ZigBee Protocol
The ZigBee standard protocol is currently recognized as the most suitable communication technology for building IoT intelligent systems. It is a short-range, low-complexity, low-power, low-data-rate, and low-cost bidirectional wireless communication technology. Its security is widely recognized as good, employing AES-128 encryption. Furthermore, ZigBee networks have strong self-organizing and self-healing capabilities.
In summary, ZigBee is an inexpensive, low-power, short-range wireless network communication technology. In terms of network capacity, it can be expanded to 65,000 devices, more than enough to meet the access needs of smart home products. With a speed of 250Kbps, it's more than sufficient for home devices that don't require large data transfers. Currently, most new smart home products use ZigBee for control and networking.
06 NB-IoT Technology
NB-IoT is an emerging technology in the Internet of Things (IoT) field, supporting cellular data connections for low-power devices in wide area networks (WANs), also known as Low Power Wide Area Network (LPWA). Compared with traditional IoT technologies such as Bluetooth and Wi-Fi, NB-IoT technology has significant advantages. The national push for IoT development largely relies on NB-IoT.
When applied to smart homes, NB-IoT technology offers numerous advantages beyond just deep coverage, large connection capacity, fast data transmission speed, ultra-low power consumption, enhanced security, and greater stability. It also adds functionality to smart devices, such as supporting efficient connectivity for devices with short standby times and high network requirements. Furthermore, it provides comprehensive indoor cellular data connectivity coverage, simplifies terminal complexity, reduces power consumption, and enables real-time, high-capacity, efficient identity authentication and access control.
How to choose a communication protocol?
How to choose a smart home communication protocol?
In fact, whether it's NB-IoT, ZigBee, or WiFi, they are all protocols for automatic control in certain scenarios. The choice depends on the specific circumstances, such as the type of apartment, its size, the number of walls, and so on.
Rongshida Smart Home primarily utilizes NB-IoT and Zigbee, but also possesses significant expertise in WiFi, RF433, and other areas, demonstrating its strong technological capabilities. In Rongshida's smart whole-house system, NB-IoT, ZigBee, and WiFi technologies are perfectly integrated, forming a comprehensive smart home solution based on their respective network structures and communication protocols.
Currently, NB-IoT is mainly used in niche areas such as smart door locks and security alarms, such as Rongshida NB smart locks and Rongshida NB combustible gas detectors, solving the problem of network connectivity failures caused by high bandwidth. However, it has high power consumption and limited Wi-Fi network coverage. Direct connection to the operator's base station without a gateway or router ensures more stable linkage between the door lock and sensors, building a series of IoT home scenarios. ZigBee primarily controls smart systems, such as Rongshida smart curtain systems and Rongshida smart lighting systems. Devices based on the ZigBee protocol can be easily added to the network and communicate with each other. It has very strong compatibility, supporting a large number of devices to better meet the needs of each family. Wi-Fi primarily controls smart items, such as smart doorbells, background music systems, and smart mirrors—most popular electronic devices on the market are equipped with Wi-Fi modules.
Rongshida Smart Home seamlessly integrates and distributes these protocols to provide users with personalized smart home systems and create a customized smart living experience. The use and combination of basic protocols demonstrate the completeness and powerful capabilities of the smart whole-house system. Based on a thorough understanding and mastery of various technical protocols, it can be extended to multiple fields such as smart hotels, smart villas, and smart apartments, ensuring the long-term operation and continuous iterative upgrades of the smart system.
Smart home technology has undoubtedly been a hot research topic in recent years. Various protocols are constantly being updated and their shortcomings addressed, resulting in the current lack of a truly internationally standardized communication protocol for smart homes and smart lighting. This article primarily compares the principles, technical characteristics, advantages, and disadvantages of various solutions and uses this comparison to envision the future of the smart home market.
We will now introduce these protocols one by one:
ZigBee protocol:
Zigbee is short for IEEE 802.15.4 protocol. It originates from the figure-eight dance of bees, which uses flight and a "buzzing" (zig) wing-fluttering "dance" to communicate the location of pollen to their companions. The ZigBee protocol's characteristics are similar, hence the name ZigBee. ZigBee is primarily suitable for automatic and remote control applications, and can be embedded in various devices. Its features include short transmission distance, low power consumption, low cost, low data rate, self-organizing networking capability, and a simple protocol.
The main advantages of ZigBee are as follows:
1. Low power consumption
Compared to WiFi, Bluetooth can support a device for six months to two years with the same amount of power (two AA batteries), while Bluetooth can only work for a few weeks and WiFi for only a few hours.
2. Low cost
ZigBee is royalty-free, has a lower transmission rate, and a simpler protocol, which greatly reduces the cost of ZigBee devices.
3. Low disconnection rate
Due to ZigBee's collision avoidance mechanism and the dedicated time slots reserved for fixed bandwidth in communication services, no competition or conflict occurs during data transmission. Its self-organizing networking function allows each node module to establish a connection, and received information can be transmitted through the lines between each node module, which greatly improves the reliability of ZigBee's information transmission, making it almost impossible to lose connection.
4. Strong networking capabilities
ZigBee has exceptional networking capabilities, with each network containing 60,000 nodes.
5. Security and confidentiality
ZigBee provides a set of security classes and software based on the 128-bit AES algorithm and integrates security elements of IEEE 802.15.4.
6. Flexible operating frequency bands
The 2.4 GHz, 868 MHz and 915 MHz frequency bands are all license-free.
The disadvantages of ZigBee are as follows:
1. Short transmission distance
Without a power amplifier, the effective propagation distance of ZigBee is generally between 10m and 75m, making it primarily suitable for small areas such as homes and offices. However, by sacrificing its low disconnection rate and using node modules as both receivers and transmitters, longer-distance information transmission can be achieved.
However, there are no problems with general office, home, and villa use. If it is a large single-level apartment, the signal inside can be strengthened to achieve offline linkage control.
2. Low data transmission rate
At the 2.4 GHz frequency band, ZigBee only has a propagation speed of 250 Kb/s. Moreover, this is only the link speed and does not include frame header overhead, channel contention, acknowledgments, and retransmissions. After removing these, the actual usable speed will be less than 100 Kb/s. When multiple applications are running on multiple nodes, the speed will be shared by them.
3. There will be a delay.
While ZigBee does not support time-division multiplexing channel access while randomly accessing the MAC layer, it will cause delays due to multi-hop transmission and collisions when supporting some real-time applications.
Bluetooth (Bluetooth protocol)
The Bluetooth protocol was created by Ericsson, which, along with other leading developers, finalized the Bluetooth technology standard on May 20, 1999, ultimately naming this wireless communication technology Bluetooth. Bluetooth technology is a wireless communication technology that enables electronic devices to establish network connections and conduct data transmission or voice calls within a spatial range of 10 to 100 meters.
The advantages of Bluetooth are as follows:
1. Low power consumption and high transmission rate
Bluetooth's short data packet feature is the foundation of its low-power technology, with a transmission rate of up to 1Mb/s, and all connections employ advanced sniffing subrated function modes to achieve ultra-low load cycles.
2. Short connection establishment time
Bluetooth can be turned on by an application and a connection can be established in just 3ms. It can also complete the authorized data transfer in a few milliseconds and close the connection immediately.
3. Good stability
Bluetooth Low Energy technology uses a 24-bit cyclic repeat check (CRC) to ensure maximum stability of all packets under interference.
4. High level of safety
CCM's AES-128 full encryption technology provides a high degree of encryption and authentication for data packets.
The disadvantages of Bluetooth are as follows:
1. Data transmission size is limited.
High-speed frequency hopping provides extremely high security for Bluetooth data transmission, but it also limits the size of data packets during transmission. Even in so-called high-fidelity Bluetooth headphones, the high and low frequency frequencies are severely compressed.
2. Few devices can be connected.
Compared to Wi-Fi and ZigBee, Bluetooth's ability to connect devices is indeed inferior. Theoretically, it can connect up to 8 devices, but in practice, it can only connect 6 to 7 devices.
3. Single connectivity of Bluetooth devices
If I connect a Bluetooth device to phone A, phone B cannot connect to it. Phone B can only connect to the Bluetooth device after the handshake protocol between phone A and phone A is broken.
WiFi (Wireless Fidelity) protocol
WiFi, short for IEEE 802.11, is a short-range wireless transmission technology that supports data, images, voice, and multimedia with an output rate of up to 54 Mb/s. It allows internet users to receive radio signals within a range of several hundred meters. The first version of WiFi was released in 1997, defining the physical layer and the Media Access Control (MAC) layer. It specified the basic transmission medium and network structure of wireless local area networks, as well as the characteristics of the MAC layer and the physical layer (PHY). The physical layer uses FSSS (Frequency Frequency Spread Spectrum), infrared, and DSSS (Direct Sequence Spread Spectrum) technologies. In 1999, the IEEE 802.11g and IEEE 802.11a standards were added to further refine the technology.
Advantages of WiFi:
1. Wide transmission range
WiFi has a coverage radius of up to 100 meters, which can even cover an entire building. Compared to Bluetooth, which has a radius of only 15 meters, WiFi has a significant advantage.
2. Fast transmission speed
With a transmission rate of up to 54Mb/s, WiFi users can access the internet anytime, anywhere, and quickly enjoy a range of broadband value-added services such as online games, video-on-demand (VOD), distance education, online stock trading, telemedicine, and video conferencing. In this rapidly developing information age, the ever-improving speed of WiFi will undoubtedly meet the needs of social and personal digital development.
3. Health and safety
According to the IEEE 802.11 standard, the transmission power of WiFi devices cannot exceed 100 mW, and the actual transmission power is likely only 60-70 mW. In comparison, mobile phones transmit power at approximately 200 mW to 1 W, while handheld walkie-talkies can reach as high as 5 W. Therefore, WiFi products emit significantly less radiation compared to these two types of devices.
4. High degree of widespread application
Nowadays, more and more electronic devices are equipped with WiFi. Mobile phones, laptops, tablets, and MP4 players have almost all included WiFi as a mainstream standard feature.
Disadvantages of WiFi:
1. High power consumption
2. Expensive
3. Complex protocol encoding
UWB (Ultra Wideband):
UWB is a carrier-free communication technology that uses narrow, non-sinusoidal pulses ranging from nanoseconds to picoseconds to transmit data. By transmitting extremely low-power signals over a wide frequency spectrum, UWB can achieve data transmission rates of hundreds of Mbit/s to several Gbit/s within a range of about 10 meters.
Z-Wave protocol:
Z-Wave is a wireless networking standard spearheaded by the Danish company Zensys. While the Z-Wave Alliance is not as powerful as the ZigBee Alliance, its members are manufacturers with existing products in the smart home field. The alliance already comprises over 160 internationally renowned companies, covering virtually every country and region globally. Its application in China is currently limited.
RF radio frequency protocol:
Common applications include Radio Frequency Identification (RFID), often referred to as inductive electronic chips, proximity cards, contactless cards, electronic tags, or electronic barcodes. Its principle involves a scanner emitting radio waves of a specific frequency to a receiver, which then drives the receiver circuitry to send out its internal code. The scanner then receives this code.
EnOcean Protocol:
The International Electrotechnical Commission (IEC) adopted the EnOcean wireless communication standard as the international standard ISO/IEC 14543-3-10, which is the only international wireless standard in the world that uses energy harvesting technology.
ModBus protocol:
Invented in 1979 by Modicon (now a brand of Schneider Electric), ModBus was the world's first truly industrial fieldbus protocol. An industrial communication system consists of programmable logic controllers (PLCs) with intelligent terminals and computers connected via public or private lines. Its system architecture includes both hardware and software. It can be applied to various data acquisition and process monitoring applications.
KNX protocol:
In May 1999, the three major European bus protocols, EIB, BatiBus, and EHSA, merged to form the Konnex Association, which proposed the KNX protocol. Based on EIB, this protocol incorporates the physical layer specifications of BatiBus and EHSA, and absorbs the advantages of BatiBus and EHSA, such as configuration modes, providing a complete solution for home and building automation.
Weave Protocol:
Weave is a low-power, low-bandwidth, low-latency, and secure inter-device communication protocol. Originally developed by Nest and used in their own devices, Nest opened it up to developers worldwide. It has since been acquired by Google, which has decided to launch Weave, a JSON-based communication language. The aim is to create a universal communication and command transmission solution between smart devices, compatible with Android.
Thread protocol:
Developed jointly by Samsung, Nest, ARM, Big Ass Fans, Freescale, and Silicon Labs, it is an IP-based wireless network protocol used to connect smart home products.
