Comparison of Various Wireless Technologies in Smart Home

Smart home solutions need to comprehensively consider many factors, such as technology, cost, convenient construction, beauty and so on. The traditional smart home network wiring mode is wired network, which is inconvenient for construction and affects the beauty. Manufacturers are mainly promoting smart home solutions based on wireless technology. The wireless network does not need wiring and will not affect the indoor beauty. It saves manpower and material resources in generic cabling, and has the characteristics of convenience and speed. It is very suitable for smart home.

1、 Overview

Smart home solutions need to comprehensively consider many factors, such as technology, cost, convenient construction, beauty and so on. The traditional smart home network wiring mode is wired network, which is inconvenient for construction and affects the beauty. Manufacturers are mainly promoting smart home solutions based on wireless technology. The wireless network does not need wiring and will not affect the indoor beauty. It saves manpower and material resources in generic cabling, and has the characteristics of convenience and speed. It is very suitable for smart home.

At present, there are many wireless solutions for smart home in the market. On the one hand, it can provide users with more choices, but it also brings confusion to users. I don't know which wireless technology to choose to build the smart home system. Although there are many smart home wireless solutions, the mainstream smart home wireless technologies can be summarized as ZigBee, Z-Wave, KNX RF, WiFi, Bluetooth, etc.

2、 Comparison of several mainstream smart home wireless technologies

This paper compares the above mainstream smart home wireless technologies from the aspects of wireless transmission technology, power consumption, number of nodes, security, openness, standardization and interoperability, industry applicability, available software and hardware resources, etc.

1. Wireless transmission technology

ZigBee: Based on IEEE 802.15.4 standard, the operating frequency is 868mhz, 915MHz or 2.4GHz. It mainly uses 2.4GHz and 250kbps (2.4GHz) in China. The modulation mode is BPSK / OQPSK. It supports star, tree and mesh network topology and 16 communication channels (2.4GHz).

Z-Wave: there is no standard for wireless transmission technology. The operating frequency is 908.42mhz (USA) and 868.42mhz (Europe). The modulation mode is FSK (BFSK / GFSK). The data transmission rate is 40kbps. It supports mesh network topology and single channel.

KNX RF: Based on EN 50090-5-3, working frequency is 868mhz, modulation mode: FSK, data transmission rate is 16kbps, supports peer-to-peer network topology, does not support mesh topology, and supports three fast channels and two slow channels.

WiFi: Based on IEEE 802.11 standard, the main operating frequency is 2.4GHz, the modulation mode is MIMO-OFDM / DSSS / CCK, the data transmission rate is more than 11Mbps, supports ad hoc and infrastructure topology, and supports 14 communication channels.

Bluetooth: Based on IEEE 802.15 standard, the main operating frequency is 2.4GHz, the modulation mode is GFSK, the data transmission rate is more than 1Mbps, supports point-to-point and peer-to-peer network (AD HOC) topology, and supports 79 channels.

2. Power consumption

ZigBee / Z-Wave / knxrf are designed for low power consumption, typically 1MW (0dbm). KNX RF even supports electromechanical energy acquisition (similar to enocean mode); WiFi power consumption is large, and external power supply is required, typical 36mw (16dbm); Bluetooth power consumption is between low power consumption and WiFi power consumption, typically 2.5 MW (4dbm).

3. Number of nodes

ZigBee: theoretically, it can support more than 60000 nodes.

Z-Wave: more than 232 nodes.

KNX RF: about 4000 more nodes.

WiFi: there are 254 nodes in theory, but the actual support is far lower than the theoretical value, generally no more than 20.

Bluetooth: generally 8 nodes.

4. Security

ZigBee: AES – 128 and other security mechanisms.

Z-Wave: it has a security layer and provides a key mechanism.

KNX RF: provide authentication, encryption and other security mechanisms on the application layer.

WiFi: WPA / WPA2 security mechanism.

Bluetooth: it can provide security mechanisms such as authentication, encryption and key management.

5. Openness

ZigBee: ZigBee alliance, open to members.

Z-Wave: zensys leads the Z-Wave alliance, which is open to members.

KNX RF: KNX Association, members are fully open.

WiFi: fully open.

Bluetooth: Bluetooth technology alliance, fully open.

6. Standardization and interoperability

ZigBee: no international standards have been established. The association's internal protocol specifications and regulations in different fields have been established. At present, there are interoperability problems with products of different manufacturers.

Z-Wave: no international standard has been established, and the internal agreement specification of the association has been established.

KNX RF: it has become ISO / IEC standard, en standard and GB / T standard. Products of different manufacturers can realize interoperability and be configured with unified software.

WiFi: there are international standards, but there is no protocol for the field of smart home, and the products of different manufacturers cannot interoperate.

Bluetooth: there are international standards, but there is no protocol for the field of smart home, and the products of different manufacturers cannot interoperate.

7. Industry applicability

ZigBee: it can face multiple application fields and is suitable for smart home applications, but it is mainly used for sensing, control and other functions.

Z-Wave: specifically for smart home applications, but mainly used for sensing and control functions.

KNX RF: specifically for smart home applications, it can be used in conjunction with KNX TP (twisted pair), but it is mainly used for sensing, control and other functions.

WiFi: for multi application fields, smart home applications can be used not only for sensing and control, but also for audio and video functions.

Bluetooth: for multi application fields, smart home applications can be used not only for sensing and control, but also for voice and other functions.

8. Available hardware and software resources

ZigBee: several chip manufacturers have provided solutions, such as Ti, Freescale, ATMEL, Nordic, etc., as well as communication protocol stacks based on different hardware platforms.

Z-Wave: zensys provides special chips.

KNX RF: at present, two hardware manufacturers and two software companies provide chip and protocol solutions.

WiFi: many manufacturers provide chip and protocol solutions, and the protocols outside the application layer are open protocols.

Bluetooth: many manufacturers provide chip and protocol solutions.

3、 Characteristic analysis

1、Zigbee

The wireless communication technology is advanced, the immunity and penetration are general (mainly working at 2.4GHz), the software and hardware development resources are rich, and the standardization and interoperability need to be improved. It is more suitable for the application of smart home industry.

2、Z-Wave

Wireless communication technology is relatively advanced, with good immunity and penetration, single software and hardware development resources, few third-party solutions, improved standardization and good interoperability. Suitable for smart home industry applications.

3、KNX RF

Wireless communication technology is simple but practical, with less software and hardware development resources, good immunity and penetration, and good standardization and interoperability. Wireless and wired can form a complete solution, which is suitable for applications in the smart home industry.

4、WiFi

The wireless communication technology is advanced, the software and hardware development resources are abundant, and the immunity and penetration are general (mainly working at 2.4GHz). The standardization and interoperability of smart home industry are poor. Due to high power consumption and limited number of nodes, its application in smart home industry is limited, but it has strong ability to integrate smart home applications into it network.

5. Bluetooth

Advanced wireless communication technology, rich software and hardware development resources, general immunity and penetration (mainly working at 2.4GHz). The standardization and interoperability of smart home industry are poor. Due to the number of nodes and topology, its application in smart home industry is limited, but it is convenient to integrate into smart terminals, such as mobile phones, pads, etc.

4、 Viewpoint

The above main objective is to make an objective comparison of smart home furnishing wireless technology. But for the company to choose which technology and what products the customer chooses, in addition to the contrast of advanced technology, we should also consider the maturity, reliability and engineering implementation of the technology.

Two more questions:

1) Is it necessary to support the wireless technology of mesh network? The wireless technology supports mesh topology, which means that its wireless technology is complex and can support more nodes and cover a wider area. However, in view of the complexity of mesh topology, it will increase the difficulty of development, and the network management is complex, and more routes are of little significance in practical application.

2) Should we adopt a pure wireless solution at this stage? Wireless technology does bring a lot of convenience to smart home, but at present, it can not solve all application problems completely by wireless technology, and the reliability and stability of wireless technology still need to be improved, especially for public construction applications. Wired wireless solution is still the right choice at this stage.