Since the introduction of Wi-Fi technology in 1999, Wi-Fi has been pursuing higher transmission rates, from 11Mbps, 54Mbps, to theoretical values ​​of 600Mbps (11n), 6.9Gbps ​​(11ac), etc., and there are also higher speeds in the development. 11ax standard and so on. Although the competition between Wi-Fi and Bluetooth has intensified, it seems that the manufacturers of the Internet of Things do not intend to choose the side station, but support both. However, since the rise of the Internet of Things (IoT) concept, Wi-Fi has begun to develop another route, that is, it is the opposite, no longer pursues more antenna numbers, higher transmission rate, but is cheaper and more integrated. The development of the route, the new development of this line is not only to respond to the Internet of Things, but also to the needs of self-creaters, Maker. In the past, the implementation cost of Wi-Fi function was about 40 US dollars. However, in 2014, US chip vendors began to implement affordable solutions. For example, Qualcomm Atheros launched the Atheros 4004 chip, and Texas Instruments also launched 3200 chip. At about $3, it immediately reduced the cost of implementing Wi-Fi functionality to $30. Then MediaTek also followed up with the MT7681, which cost about $1.80, and also launched LinkItConnect for the Maker field, using the MT7681 chip. In addition, Shanghai's Lexin also launched the ESP8266 chip, the price is about 1.2 US dollars, while the implementation cost of the entire Wi-Fi function fell below 10 US dollars, ESP8266 is also welcomed by the Maker community. After that, chip makers in Taiwan and the mainland continued to follow up. For example, Ruiqi launched Ameba's RT8195 chip, or Shenzhen Southern Silicon Valley Microelectronics, Nufront, and Lianshengde Microelectronics, all of which have affordable Wi- Fi chip solution, Wi-Fi chip is likely to fall below 1 US dollar. Looking at these cheap Wi-Fi chips that take the Internet of Things and self-created routes, they will find that their specifications are quite simple. For example, most of them do not have 11ac capability. Only in the 11n class, the number of antennas is only one, and the channel bandwidth may be only 20MHz. It does not support the optional 40MHz, and can only operate in the 2.4GHz band, and cannot use the 5GHz band. At the same time, there are few transmission interfaces between the chip and other chips, and only relatively slow transmission such as UART, I2C, and SPI is provided, instead of high-speed transmission such as USB and PCI Express. In addition, it is invisible to the naked eye, but it is on the chip. It is also different from the past. For example, the processor core with a leaner architecture, such as MT7681, uses the N9 core of Andes, and ESP8266 uses Tensilica. LX106 core. Different from the ARM core and MIPS core used in general. Furthermore, the hardware acceleration design of Wi-Fi encryption and decryption is not necessarily available, and some are implemented in software. Therefore, the encryption transmission is actually performed, and the response speed of the chip is greatly reduced. The above is the cost and specification savings, but it has been avoided to talk about the power saving of Wi-Fi chips. In general, Wi-Fi transmission power consumption is several times or even 10 times that of Bluetooth, so wearable for short-distance transmission. Electronic devices prefer to use Bluetooth instead of Wi-Fi unless there is a large amount of data to be transmitted (such as maps, photos) to use Wi-Fi. However, the situation may have to change. In March 2016, the University of Washington studied passive Wi-Fi at a rate of 11 Mbps, which is about 11 b, but it is 10,000 times less than existing Wi-Fi, so it is at least 1 compared with Bluetooth. Thousands of times of power saving, the transmission rate of 11Mbps is also higher than the general Bluetooth transmission rate (1Mbps ~ 3Mbps), and claimed that the chip cost is less than 1 US dollar. Perhaps the next IEEE organization, Wi-Fi Alliance will actively standardize this technology to compete with Bluetooth technology in the wearable and Internet of Things fields. In fact, the Wi-Fi camp tried to compete with Bluetooth in an area, that is, indoor positioning applications. However, the Wi-FiAware technology proposed by the Wi-Fi Alliance has not been popularized as Bluetooth Beacon technology since its introduction in January 2015. Passive Wi-Fi can also help in this regard. Although the competition between Wi-Fi and Bluetooth is intensifying, it seems that it is not intended for the makers to choose the side station, but to support both. For example, the third generation Raspberry Pi (RPi3) released in March 2016 supports 11nWi- at ​​the same time. Fi and 4.1 Bluetooth, ArduinoTIan (TIan equals Chinese characters: day) published in November 2015 is also true. The same is true for Lexin's upcoming ESP32. Some AndroidWear smart meters are also the same. Many chip vendors do the same. It seems that the two technologies are strong. The development of competition and cooperation will continue for a while. Half-cell Monocrystalline Solar Panel Jiangsu Stark New Energy Co.,Ltd , https://www.stark-newenergy.com
