The ancients said: "There are no rules, there is no way to make a circle", the same is true in the field of smart home. Technically, the challenge for smart home construction is not equipment or implementation issues, but standards and protocol issues. Smart home is a multi-industry cross-coverage system project. Each equipment manufacturer produces equipment according to different interface standards and protocols. The result is that the interconnection and interworking between different equipment becomes very difficult. Therefore, establishing common standards and protocols is the first problem that must be solved in the development of smart homes. At present, the international standards in the field of smart homes are not yet mature, and major manufacturers and relevant organizations are beginning to establish and formulate network interface standards and data transmission protocols between the devices in the smart home system. Seizing opportunities and participating in the formulation of standards will bring endless opportunities to domestic manufacturers. Home bus system The home bus is an important foundation for the realization of smart homes, and it is the nervous system inside the house. Its main role is to connect various electronic and electrical equipment in the home, and is responsible for connecting various communication equipment (including security, telephone, home appliances, audio-visual equipment) in the home. Etc.) are connected together to form a complete home network. Japan is one of the countries that promoted the development of smart homes earlier. It earlier proposed the concept of the Home Bus System (HBS), established the Home Bus (HBS) research group, and established Under the guidance of the province, the HBS Standards Committee was formed to formulate the Japanese HBS standard. According to this standard, H Home intelligence requires that many home appliances and networks are compatible with each other. The bus protocol is the essence of it. Only when the interface is unblocked, home appliances can "understand" the instructions issued by people. Therefore, the physical layer interface form of the bus standard is important for smart homes One of the problems. At present, the bus standard protocols that are relatively formed are mainly proposed by American companies, including the LonWorks LonWorks protocol of Echelon, the CE bus protocol (CEBuS) of the Electronics Industry Association (EIA), the Smart House protocol of Smart House LP, and the X-10 company ’s X -10 agreement etc. Each of these agreements has advantages and disadvantages. The LonWorks protocol is a fieldbus technology developed by Echelon Corporation of the United States and jointly advocated by Motorola and Toshiba. It supports multiple physical media and is suitable for twisted pair, power line, optical cable, radio frequency, infrared, etc., and can be mixed in the same network. . LonWorks protocol supports a variety of topologies, you can choose any form of network topology, flexible networking. The application scope of LonWorks mainly includes building automation, industrial control, etc. It has good performance in setting up a distributed monitoring network. Currently, there are more than 500,000 LonWorks nodes established worldwide. Among the four protocols, X-10 is the longest and easiest to use. It was born in the United States in 1978 and is still the leading system for home automation in the United States. The reason why the X-10 protocol is simple is that it directly uses the residential power line as the control bus, connects the controllers to each function interface device through the power line and realizes program control, no need to punch holes in the wall, it is more conducive to changing the structural space, Users can install it by themselves, and the price is relatively low. CEBuS, as a promotion agreement for the electronics industry, is the recommended industry standard for European and American home automation electronics products, along with European EHS standards. Internal transmission interface The internal transmission interface of the smart home system can be realized by two transmission methods: one is the wireless transmission mode; the other is the wired transmission mode. At present, the internationally popular physical layer series interfaces mainly include radio frequency (RF), power carrier (PL), twisted pair (RS485, etc.), dedicated lines IEEE 1394, IEEE1394b, HAVI HAVI using IEEE 1394, and Bluetooth technology (BlueTooth) , Wireless communication Ethernet (IEEE802.11), X11, wireless communication HomeRF (Home Radio Frequency), infrared technology, etc. These interfaces cover the low-speed data link interface represented by smart device monitoring and home multimedia entertainment and video The high-speed data link interface represented by monitoring. The wireless transmission method is most suitable for home. At present, the wireless transmission technology used in the home is mainly wireless communication HomeRF, Bluetooth technology, WAP WAP, wireless Ethernet, etc., and people are more optimistic about Home RF and Bluetooth technology. HomeRF is mainly designed for home networks and is the product of the combination of IEEE 802.11 and DECT DECT. On January 5, 1999, the HomeRF working group announced the "Shared Wireless Access Protocol" SWAP 1.0 version specification. 13 companies (including IBM, Intel, etc.) promised to produce SWAP-based products. Bluetooth (IEEE 802.15) is the latest standard, it is more mobile than wireless Ethernet (IEEE 802.11), it can connect a device to LAN and WAN, and even supports global roaming. In addition, Bluetooth has low cost and small size, and can be used for more devices. Other technologies are more or less problematic. For example, the prospect of IEEE 802.11 technology in the home market is not very good; radio frequency (RF) technology has high maturity, low cost, and very good penetration, but the disadvantage is that there is no unified standard, and the communication protocols of various companies are different; Infrared technology is very mature, has good flexibility and mobility, and the cost is very low, but it is limited by obstacles, has no penetration, poor directivity, and no standard communication protocol. At present, because the radio frequency does not need to add additional wiring resources, the data transmission performance is reliable and the cost is low, so it has become one of the most realistic and popular physical layer interface forms. It is foreseeable that with the gradual maturity of wireless methods, it will replace wired communications in the future and become the best connection method for home networks. However, at present, home wiring is still heavily wired, mainly including the following three: The first is the home network wiring. This is currently the most widely used, but also the most troublesome technology. The problems to be solved in this way are the convenience of wiring and how to implement plug and play. The second is to use the phone line in the home for network connection, and the technology used is HomePNA (Home Phoneline Networking Alliance). HomePNA aims to introduce to home users as soon as possible easy to use, low cost, used to solve the problem of Internet access for families without network connection, the disadvantage is that the network speed is low. It supports Internet access, and the supported interface protocols include V.90, ADSL and Cable Modem. Currently, Home The third is to use the existing power line in the home to transmit data, using the power line carrier technology (Powerline Carrier Technology). The system transmits information through a 120V / 60Hz electric power distribution system in the home or equipment. The communication protocol currently used in this way is mainly X-10. The advantage of using the power line networking solution is that it does not require rewiring at home and can use the existing power socket, so it is also one of the directions of home network research and development. Especially worth mentioning is IEEE1394, which is a high-speed universal serial digital interface standard established by IEEE for connecting computers and peripheral devices. It focuses on cable connection applications. The standard defines the media topology and transmission protocol and is a hardware and software integration standard. IEEE1394 is likely to become the future universal interface standard for networks. It will be the latest interface standard for next-generation computer peripherals and consumer electronics products. The standard is still under further development. With the widespread use of digital equipment, the exchange of multimedia data between various digital home appliances, digital AV systems, digital set-top boxes and computers has adopted the IEEE1394 interface standard, making this standard a common interface between consumer electronics and computers. Fully automatic control of TV, movie, VCR, stereo and other systems, and can be connected with external ATM public network to realize the interconnection of home and outside information highway. Wire To Wire Connectors,Waterproof Connector,Electric Fan Connector,Photovoltaic Line Connector Zooke Connectors Co., Ltd. , https://www.zooke.com
The BS system consists of a coaxial cable and four pairs of twisted pairs. The former is used to transmit image information, and the latter is used to transmit voice, data, and control signals. All kinds of household equipment and electrical equipment are connected to HBS in a certain way. These electrical equipment can be controlled indoors or remotely by telephone in remote locations. In order to meet the needs of large residential communities, in early 1988, the Japan Housing Informatization Promotion Association launched the Super Home Bus System (Super Home Bus System, S-HBS for short), which is suitable for a larger range because of an S-HBS system. Can connect thousands of home intranets.
PNA's plan is still being worked out. The limitation of bandwidth is an unfavorable factor restricting the development of this technology, but due to the simplicity and practicality of its network media, it is still very attractive.