A detailed description of WIFI functions on mobile phones (mobile phone Development)

I think there are still many people who do not know much about WIFI and raise a lot of questions about WIFI. Here I will describe WIFI, here we can regard WIFI as a wireless network card (the delayed notebook launched some time ago is the machine with the built-in wireless network card, which is the same as the built-in wireless network card of 838 ). It is similar to the bluetooth technology, but its wireless distance is farther and the speed is faster (it can reach 100 meters indoors, 300 meters outdoors, theoretical value ). A wireless network adapter is connected to a Wireless AP (a wireless HUB) and a wireless route (a wireless router) to share the internet. If a computer is equipped with a wireless network card, it can also be connected. In fact, WIFI is only a sign of wireless network authentication. To be precise, it is a wi-fi-certified wireless network product. 838 Supports Wireless Mesh protocols of 802.11g and 802.11b, and the former is 54M, the latter is 11 M. Any Wireless AP that supports either of the two protocols can be connected to 838, because they both use the 2.4G band. The difference is that the speed is different. There is also an 802.11a (also 54 M), but it is not compatible with the previous two protocols, it uses the 5G band. Currently, the latest 802.11n protocol is available, with a speed of over 400 M. It is backward compatible with 802.11b and 802.11g. The above M is Mbps. In fact, 11 M is enough for Internet access, because the theoretical limit of Internet access for ADSL is 8 M, the above 54M is useful for data transmission in a wireless LAN or high-speed broadband access through optical fiber. Using 838 to connect to the Internet via ADSL Wireless Network, 11 m is enough (the connection method is to buy a Wireless AP to connect to ADSL with a network cable, of course, some simple configuration is required ). I tried 838 using WIFI to access the Internet. The speed is indeed much faster than that of GPRS, but it still cannot be compared with the speed on the computer (the computer also uses WIFI to access the Internet ), this may be related to the CPU, memory, and operating system of the mobile phone. Connecting two computers with a wireless network card is like connecting two computers with a network cable (point-to-point, but a wireless network card can be a pair of many computers, a little like a HUB ), however, if you connect 838 to a computer, you can share files with your peers on the Internet, but you can share the internet. Licensed version 838 does not have WIFI, and is also related to failing to pass the Chinese certification, and is removed. If a laptop with built-in wireless NICs needs to enter the Chinese market, its built-in wireless NICs must be certified by relevant Chinese authorities. So some laptop manufacturers try their best to bring their laptops with built-in wireless NICs into the Chinese market, and some also take advantage of some wireless network vendors that have passed Chinese certification, use its certification to bring laptops to the Chinese market. The following is a Wi-Fi Certification Mark: