Is wifi wireless or wired?

Wifi is wireless. WiFi is a wireless LAN technology based on the IEEE 802.11 standard, which aims to improve the interoperability between wireless network products based on the IEEE 802.11 standard. A Wi-Fi network usually contains at least one wireless access point (which allows wireless terminals to connect to the Wi-Fi network) and one or more wireless terminals.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

wifi is wireless.

WiFi (Wi-Fi) is a trademark of the Wi-Fi Alliance and a wireless local area network (WLAN) technology based on the IEEE 802.11 standard. Since the release of the first generation IEEE 802.11 standard in 1997, the 802.11 standard has evolved through six versions. Before the release of Wi-Fi 6, the Wi-Fi standard was identified by version numbers from 802.11b to 802.11ac. With the evolution of Wi-Fi standards, the Wi-Fi Alliance chose to use numerical serial numbers to rename Wi-Fi in order to make it easier for Wi-Fi users and equipment manufacturers to understand the Wi-Fi standards.

History of Wi-Fi

Before introducing Wi-Fi, let’s first understand two organizations: electrical and electronic engineers Association (English full name: Institute of Electrical and Electronics Engineers, referred to as IEEE) and Wi-Fi Alliance (English full name: Wi-Fi Alliance, referred to as WFA).

As a standards organization, IEEE established the 802.11 working group as early as 1990 to formulate relevant standards for wireless LANs, and released the first standard 802.11-1997 in 1997. After that, every few years, the 802.11 standard will be upgraded and updated, and there have been six generations so far.

The evolution of the 802.11 standard

• The origin of the standard (802.11-1997): Defeated other standards and became the industry WLAN standard.

• Standard enhancement (802.11b and 802.11a): The 802.11b rate reaches 11Mbit/s, achieving large-scale commercial use. 802.11a introduces OFDM technology into the 802.11 standard in the 5GHz band for the first time, increasing the rate to 54Mbit/s.

• Standard extension and compatibility (802.11g): Extends OFDM technology to the 2.4GHz frequency band and is forward compatible with 802.11b equipment.

• MIMO-OFDM-based HT standard (802.11n): newly supports SU-MIMO and OFDM technology, with a rate of 600Mbit/s.

• VHT standard (802.11ac): Added support for downlink MU-MIMO, the maximum channel bandwidth is 160MHz, and the rate reaches 6933.33Mbit/s.

• HEW standard (802.11ax): For the first time, OFDMA (Orthogonal Frequency Division Multiple Access), uplink MU-MIMO, BSS Coloring and target time wake-up TWT (Target Wake Time) and other technologies have further improved the throughput rate in high-density scenarios, with the rate directly reaching 9607.8Mbit/s.

The other organization, the Wi-Fi Alliance, is actually a commercial organization. The original purpose of this alliance was to promote the development of the 802.11b standard and promote compatibility certification of products that comply with the IEEE 802.11 standard worldwide; by 2000, the organization adopted the term "Wi-Fi" as the name of its technical work. Proprietary name, and announced the use of Wi-Fi Alliance as the official name, that is, Wi-Fi Alliance. "Wi-Fi" is actually the trademark of this alliance.

So what exactly does “Wi-Fi” mean? There are currently two opinions: the first one is that Wi-Fi refers to Wireless Fidelity, which is similar to the classification of audio equipment: long-term high fidelity or Hi-Fi (High Fidelity); the other is that, Wi-Fi has no special meaning and no full name. Currently, there is no official organization that clearly states that Wi-Fi refers to Wireless Fidelity. In addition, many times "Wi-Fi" will be written as "WiFi" or "wifi". In fact, these writing methods are not recognized by the Wi-Fi Alliance.

The difference between Wi-Fi and 802.11

Although IEEE has developed and released the IEEE 802.11 standard, there is no implementation of the IEEE 802.11 protocol standard The equipment provides corresponding testing services; at the same time, because the IEEE 802.11 standard is very theoretical, once it is commercialized, the products produced by each manufacturer may be diverse. The Wi-Fi Alliance has well solved the production and equipment compatibility issues of products that comply with the IEEE 802.11 standard. At the same time, the Wi-Fi Alliance is also responsible for Wi-Fi certification of various wireless LAN devices and testing whether the products comply with IEEE 802.11 Protocol standard, after passing the certification, the "Wi-Fi" trademark can be marked on the device.

Due to the close connection between the two systems, Wi-Fi and IEEE 802.11 are often confused. In fact, there are differences between the two. In summary, IEEE 802.11 is a wireless LAN standard, and Wi-Fi is a product implementation of the IEEE 802.11 standard. In addition to Wi-Fi, product implementations of the IEEE 802.11 standard also include WiGig, among which Wi-Fi is the most developed product implementation.

The difference between Wi-Fi and WLAN

Wi-Fi refers to the trademark of the Wi-Fi Alliance and is a wireless network communication technology based on the IEEE 802.11 standard. The purpose is to improve the interoperability between wireless network products based on the IEEE 802.11 standard.

The full name of WLAN is Wireless Local Area Network. The Chinese meaning is wireless local area network. There are two definitions of WLAN: broad and narrow: Broadly speaking, WLAN is a wireless network based on various radio waves (such as laser, infrared, etc.) A network composed of channels that replace some or all of the transmission media in a wired LAN; the narrow definition of WLAN is a wireless LAN based on the IEEE 802.11 series of standards that uses high-frequency wireless radio frequencies (such as radio electromagnetic waves in the 2.4GHz or 5GHz frequency band) as the transmission medium. . WLAN in our daily life refers to the narrow definition of WLAN. In the evolution and development process of WLAN, there are many technical standards for its implementation, such as Bluetooth, Wi-Fi, HyperLAN2, etc. Wi-Fi technology has become the mainstream technical standard for WLAN due to its relatively simple implementation, reliable communication, high flexibility, and relatively low implementation cost. Wi-Fi technology has gradually become synonymous with WLAN technical standards.

To put it simply, WLAN is a network system, and Wi-Fi is a technology in this network system. Therefore, there is an inclusive relationship between WLAN and Wi-Fi, and WLAN includes Wi-Fi.

Types of deploying Wi-Fi networks

A Wi-Fi network usually contains at least 1 wireless access point (Access Point, (referred to as AP), one or more wireless terminals, wireless access points allow wireless terminals to connect to Wi-Fi networks, wireless routers (integrated wireless access point functions) and wireless access points and other Wi-Fi devices have these Function.

In home scenarios, the most common way to achieve Wi-Fi network connection is through a home wireless router. In enterprise scenarios, there are usually the following Wi-Fi network deployment types.

FAT AP independent deployment

FAT AP, also known as fat AP, independently completes Wi-Fi coverage and does not require the deployment of additional management and control equipment. However, since the FAT AP alone controls user access, users cannot implement wireless roaming between FAT APs and can only use Wi-Fi networks within the coverage of the FAT AP.

Therefore, FAT AP is usually used for small-scale Wi-Fi coverage in homes or SOHO environments. In enterprise scenarios, it has been gradually replaced by the "AC FIT AP" and "Cloud Management Platform Cloud AP" models.

AC FIT AP centralized deployment

The "AC FIT AP" model is currently widely used in Wi-Fi network deployment in large and medium-sized campuses, such as shopping malls, supermarkets, Hotels, corporate offices, etc. The main function of AC is to manage and control all FIT APs through CAPWAP tunnels. The AC delivers configurations to FIT APs in batches, so there is no need to configure APs one by one, which greatly reduces WLAN management, control and maintenance costs. At the same time, because user access authentication can be managed uniformly by the AC, users can achieve wireless roaming between APs.

For small-area Wi-Fi coverage scenarios, the number of APs required is small. If an additional AC is deployed, the overall wireless network cost will be higher. In this scenario, if there is no user requirement for wireless roaming, it is recommended to deploy a FAT AP; if you want to meet the user's wireless roaming requirement at the same time, it is recommended to deploy a cloud AP.

Cloud deployment

The function of cloud AP is similar to that of FAT AP, so it can be applied to small networking in home WLAN or SOHO environment; at the same time, the "cloud management platform" The networking structure of "Cloud AP" is similar to that of "AC FIT AP". Cloud AP is managed and controlled by the cloud management platform, so it can be applied to large and medium-sized networks.

Cloud AP supports plug-and-play, is simple to deploy, is not limited by deployment space, and can be flexibly expanded. Currently, it is mostly used in scenarios with many branches.

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