Cainiao also understands Wi-Fi wireless technology

We have learned about Wimax wireless technology before Wi-Fi wireless technology. This article will introduce the Wi-Fi wireless technology. Wi-Fi wireless technology is a LAN, which has some limitations over Wimax. For more information, see the following section.

Overview of Wi-Fi wireless technology

WLAN standards mainly include 802.11b, 802.11a, and 802.11g. Currently, WiFiWirelessFidelity, a wireless fidelity alliance, the industry standard organization, is responsible for the promotion and authentication of WLAN. Therefore, WLAN technology is often called WiFi.

802.11b adopts a GHz band and supports 11 Mbps shared access rate. 802.11a adopts a 5 GHz band with a rate of up to 54 Mbps and uses OFDM orthogonal frequency division multiplexing, however, the Accessibility distance is reduced to 30-50 meters.

802.11b uses a 2-4 GHz band and supports 11 Mbps shared access rate, covering 100 meters.

802.11g is a hybrid standard that can adapt to both the 802.11b standard and the 802.11a standard. The speed is as high as 54 Mbps. It is 5 times faster than 802.11b and is compatible with 802.11b.

IEEE802.11n, which is waiting for approval, has a speed of up to 300 Mbps. At present, some manufacturers have already applied it to the market.

Wi-Fi wireless technology Advantages

Wi-Fi is a wireless LAN consisting of an AP (AccessPoint) and a wireless network card. The network is simple and can be independent from the wiring conditions. Therefore, it is very suitable for mobile office users.

Flexible application: flexible enough for a small network with only a few users to a large network with thousands of users.

With rich terminal support and economic savings, manufacturers have a low entry threshold in this field. WIFI networking costs are low.

Provides the roaming service: Provides the roaming features that cannot be provided by the wired network for your convenience.

Wi-Fi market positioning and development bottlenecks

Wi-Fi positioning-Wi-Fi is a LAN technology used to solve the "Last 100m" access problem. From its relationship with wired broadband networks, Wi-Fi can be used as a network extension to further expand the coverage area of Wired Access Networks and expand the applications of mobile communication networks.

Wi-Fi is an effective means to enhance the value of wired broadband users and provide differentiated services. It is also a powerful supplement to 3G data services in the future. 3G can use the features of WIFI high-speed data transmission to make up for the limited data transmission rate. Within the Wi-Fi network coverage, users can access the company's office network or the international Internet anytime and anywhere, and enjoy online securities, on-demand video streaming (VOD) anytime and anywhere), distance education, telemedicine, video conferencing, online games, and other broadband information value-added services, and mobile office.

Several aspects restricting the development of Wi-Fi wireless technology

The data transmission rate is limited. Although the maximum data transmission rate of Wi-Fi wireless technology can reach a nominal value of 11 ~ 54 Mbit/s, but the system overhead will reduce the application layer speed by about 50%.

There are mutual influences between radio waves, especially between the same frequency band and the same technical device. In multi-carrier environments, the frequency interference between different AP (AccessPoint) significantly reduces the data transmission rate, and the simultaneous high-speed data service for multiple users cannot be implemented in environments where three operators operate simultaneously.

In the process of transmitting radio waves, different obstacles may lead to refraction, reflection, diffraction, and signal penetration failures. The quality and Signal Stability of radio waves are not as good as that of Wired connections.

The biggest drawback of Wi-Fi coverage is the need for intensive wired transmission resources. The coverage of 3G/WiMAX base stations is 10 to times larger than that of WiFiAP.

Wi-Fi wireless technology itself does not support mobility, even if IEEE802.11s may enhance the mobility of Wi-Fi-FiMESH, it can only support walking speed at most. Both 3G and WiMAX support the mobility of over 120 km/h.

Wi-Fi air interfaces do not support QoS Assurance. They only support BestEffort services and are suitable for WEB browsing, FTP downloading, and sending and receiving emails. QoS for voice communication, video transmission, and other services is hard to be guaranteed.