looking to the world, "wireless cable replacement" is the trend, and now people just stay in the wifi environment, or open the bluetooth function of the device, each other will be able to easily carry out data transmission. on the other hand, the continuous development of wireless technology, but also for the field of home networking has brought new opportunities for development, and home automation (smart home) is to become the arena of advanced wireless technology. turning to wireless technology, most people think of the first may be wifi, bluetooth, but in fact, in the smart home industry, the more mainstream wireless technology a total of four kinds: wifi, bluetooth, zwave and zigbee.
in fact, the concept of intelligent home as early as more than a decade ago, in 1998, bill gates built for himself a intelligent mansion. intelligent home furnishing early wired, which largely limits its own development: the first is the wiring problem, need to open the hole wall, the most decorated house to join in; secondly, the line lay buried in the wall, maintenance is very inconvenient, if there are problems, means to open a hole in the wall again; finally, it is not cheap, so smart home furnishing earlier only for high-end crowd of civilians, rather than consumer goods.
wireless solutions for home automation has brought the dawn, cut off the cumbersome lines, it lost a lot of trouble. for now, the wireless smart home based on the technology used is different, mainly divided into bluetooth, wi-fi, zwave and zigbee four, wireless technology allows people to realize the remote control of home. here we may wish to start from the daily contact with the most frequent wifi.
based on intelligent home furnishing wifi technology products is the most common, the advantages of fast transmission speed, and low cost, is the most popular in life, the most convenient for users, based on wifi intelligent home furnishing combination, purchase equipment directly to the network.
everything has two sides, although wifi fast transmission and popularization, but there are also technical disadvantage: the biggest problem is very low security, wireless power is weak stability; one of its weaknesses, will lead to its limited application in the field of home furnishing, such as intelligent lock, infrared transmitting controller, a variety of sensors and not suitable for use; in addition, the networking capabilities of wifi is relatively low, the actual size of the wifi network is generally not more than 16 devices, but the actual home furnishing environment, only the number of switches, lighting, household appliances have been far more than the 16, obviously the development space is limited.
compared with the wide popularity of wifi technology, it zigbee technology, the research and application of the threshold is relatively high, and not just what people can manage, like schneider, siemens, sony, general electric, matsushita and other fortune 500 companies, have been added to the zigbee camp, huawei iot sensor and other domestic enterprises in the zigbee camp.
first, the security of zigbee technology is very high, so far the world has not yet appeared together to break the precedent. the design of the safety due to the system of using aes encryption (advanced encryption system), strict degree equivalent to 12 times the bank card encryption technology; secondly, zigbee adopts honeycomb structure network, each device can pass through multiple directions and gateway communication network, high stability; in addition, the network node capacity theory 65300, enough to meet the needs of home network coverage, even the intelligent community, intelligent buildings can still full coverage; finally, zigbee has the capability of two-way communication, not only can send commands to the equipment, and equipment will put back the execution state of end use experience is essential, especially security equipment, if you click the door closed, but do not know whether it has been locked, will bring much of a security risk; in addition, the zigbee uses a low-power design, full battery supply electricity, in theory, a battery can be used for more than 10 years, energy saving and environmental protection.
we are familiar with bluetooth technology, i am afraid to belong to the bluetooth feature on the phones. between the power consumption and cost between wifi and zigbee, but the transmission distance is the shortest, belong to a point to point, short distance communication, because in a mobiles device or a shorter distance between the transmission, bluetooth products will provide some experience to use more personal, such as bluetooth headset, bluetooth speakers, intelligent scales so, because of its short transmission distance, so it is not suitable for the formation of large family network.
the data transmission rate of zwave is 9.6kbps, the signal coverage in indoor (outdoor 30 meters more than 100 meters), suitable for narrow bandwidth applications, and have a certain safety and stability, but currently only used in home automation. the main drawback of the three: one is less nodes and the theoretical value is 256, only about 150 actual value is the maximum number of equipment can accommodate, in fact many manufacturers can accommodate 20, 30 equipment is good; two is the tree network structure, once the branches broken end, all equipment the lower end will not be able to communicate with the gateway; three is not encrypted, poor security, vulnerable to attack. zwave in our country is not used in the frequency band, the domestic is not common zwave smart home, more or application in foreign countries. )