本文將詳細介紹WiFi在眾多領域的應用. WiFi is a technology that enables electrical gadgets to link to a wireless local area network (無線區域網路) using the 2.4G UHF or SHF ISM RF bands.
1. What is WiFi technology
The WiFi Alliance owns the “WiFi” trademark for wireless network communications technology, which was created to increase the compatibility of IEEE 802.11-based wireless network devices. Wireless Fidelity, or wireless Fidelity technology, is another name for WiFi. 該技術可實現 PDA 和行動電話等便攜式設備與個人 PC 等終端之間的無線連接.
在無線的背景下, LAN是指“無線相容性認證”,」 這既是一個 無線網路技術 和, 從根本上, 商業認證.
現在, 兩個主要的 WLAN 標準是 IEEE802.11x 和 HiperLAN/X (歐洲無線區域網), 與中國的WAPI標準一起.
IEEE 建立了 802.11 無線網路通訊的業界標準 1997 用於無線區域網. 自那以後, 該標準經過定期擴展和增強，形成了 802.11x 標準系列. 802.11x bar 是 WiFi 的技術基礎，現已成為無限 LAN 的業界標準.
WAPI標準
中國寬頻無線IP標準工作小組制定了名為WAPI的安全協議, 無線區域網路認證, 和隱私基礎設施. 該標準主要是IEEE 802.11b相關的安全加密標準. 另外, 是中國WLAN安全的要求，並已獲得IEEE註冊機構的認可, ISO/IEC 認可的.
Information security technology
由於其物理結構的獨特性, 無線網路無法達到與有線網路相同程度的安全性. 因此, 無線網路應考慮安全因素, 包括加密和認證. 讓無線服務達到與有線服務相同的安全等級是無線區域網路部署加密技術的首要目標.
IEEE 802.11 使用 WEP (有線等效保密) protocol to provide a unique security method for traffic encryption and node authentication to accomplish this aim. 然而, WEP encryption has a lot of drawbacks and is simple to break. Thus the WiFi alliance eventually proposed more secure WPA and WPA2 protocols.
2. How does WiFi technology work
Wireless networks use radio waves that pass over the air and function at 2.4G and 5G frequencies, much like radio waves.
It’s congested on 2.4G. 2.4G is a decimeter wave technology that operates in the UHF frequency range. Due to the presence of Bluetooth, microwave ovens, 物聯網設備, ham radios, and other devices in this frequency range, 2.4G WiFi interference is a significant problem in everyday life. 然而, 2.4G has a broader coverage area than 5G, which is why you may scan the wireless signals of your neighbors’ right and left at home. 大部分只能偵測到2.4G訊號.
超高頻頻段, 使用厘米波, 是5G發揮作用的地方. 與2.4G相比, 5G 覆蓋範圍更加有限. 在日常生活中, 幹擾更少. 雷達, 例如, 是乾擾的主要原因.
傳輸時無線. 訊號衰減, 主要的無線衰減類型, 會因各種材料對訊號的吸收而引起. 物質的金屬含量越多, 密度越大，吸收的無線訊號越多. 這將導致無線訊號因反射而丟失, 散射, 折射, 繞射, 以及其他效果.
無線路由器內部CPU和無線晶片將有線訊號轉換為無線訊號，然後透過無線天線發送出去. 透過其內建的無線天線, 終端 (a computer, mobile phone, ETC。) picks up the wireless signal, and the wireless chip then transforms it into an electrical signal to complete the data transfer.
3. Architecture of WIFI technology
- Site: The most fundamental component of the web
- Basic Service Unit (BBS): The most fundamental service unit. Just two dynamically connected sites to the primary service unit may make up the most straightforward service unit.
- Distribution System (DS): To link several fundamental service units, the distribution system is employed. Although they may physically be the same medium, such as the same radio frequency, the distribution system’s medium and the basic service unit’s medium are conceptually separate.
- 存取點 (美聯社): An access point has access to the distribution system and the identification of a shared site.
- Extended Service Units (ESS): A fusion of basic service units and distribution networks. Distribution systems may use several technologies.
- Portal: Another logical element that links wired and wireless LANs as well as other networks.
4. WiFi應用程式有哪些?
The following WiFi application situations may all benefit significantly from WiFi, as shown by the technical study and accompanying WiFi characteristics:
There is a lot of traffic going on at once
This is particularly true in situations when upstream traffic is crucial. 例如, file transfer-related services in a wireless office setting, video playback on several home devices, a substantial amount of on-demand instructional video in smart teaching apps, ETC. WiFi can deliver an actual throughput performance of up to 6Gbps in this kind of application situation. WiFi can still handle the particular needs of 150 people for concurrent transmission of UHD video, 基於超高清視訊的具體傳輸需求, 大約20Mbps, 和計算 50% 多用戶實際吞吐時長.
High-demand scenarios for low-latency transmission
例如, 製造現場的機器控制, AR/VR傳輸, ETC. 根據上面的估計, WiFi 提供小於 1ms 的雙向傳輸延遲. 滿足高寬頻傳輸的標準以及低延遲情況下AR/VR資料流傳輸的相關要求.
M2M apps are less expensive and use less power than local applications
其主要關注領域為智慧家居, 其中包括創新建築環境的監控和控制需求. 與普通 WiFi 相比，WiFi 可以提供超過 15dB 的鏈路額外津貼, 通常相當於室內環境中傳輸距離的兩倍. It is equal to the terminal using a lower transmission power while maintaining the same transmission distance from the power consumption perspective. WiFi decreases the peak power consumption in this application mode from 100mA to 10mA, which is comparable to the peak power consumption of 藍牙. The TWT technology may also improve the terminal’s ability to sleep effectively. These adjustments will improve endurance and lower terminal expenses.
5.WiFi technology solutions
Wireless cashier: WLAN mobile system may achieve a “one-stop” shopping experience, sales and cashier one-stop operation, speed up the checkout process, and provide consumers a better shopping experience thanks to its convenience.
Guest wireless internet access: Shopping centers/merchants in department stores with their chain of agencies or manufacturers need to offer Internet services. But due to space restrictions, the Internet host distribution of the location of the business is very flexible and frequently needs to be adjusted. The current general practice is renting the ADSL, but it is expensive and often requires adjustment. Shopping centers may operate virtually by installing WLAN. Wireless can help shopping centers create a new area of economic development, turning their IT departments into successful ones.
Content push: By deploying a WLAN network and integrating it with the hotel’s website, services are pushed to visitors as they enter the building, creating an accurate one-to-one consumer wireless shopping guide.
Other wireless uses include wireless receipts, wireless speech, wireless video surveillance, and client Internet access.
6. Popular WiFi apps
- NetSpot
- InSSIDer
- NirSoft
- PRTG Professional WiFi Analyzer
- Solarwinds wireless analyzer
- Acrylic WiFi
- Wireshark
- WiFi Explorer
