Wifi 4的意思

"Wi-Fi 4" is a marketing term used to describe the fourth generation of Wi-Fi, which is based on the IEEE 802.11n standard. This standard was introduced in 2009 and offered significant improvements in terms of speed, capacity, and coverage compared to its predecessors.

Here are some key features of Wi-Fi 4 (802.11n):

  1. Speed: Wi-Fi 4 supports maximum theoretical speeds of up to 600 Mbps, which is significantly faster than previous standards.

  2. MIMO (Multiple Input, Multiple Output): This technology allows multiple antennas to send and receive data simultaneously, improving overall throughput and range.

  3. Channel Bonding: Wi-Fi 4 can combine two 20 MHz channels into a single 40 MHz channel, effectively doubling the bandwidth.

  4. Improved Coverage: 802.11n provides better coverage and penetration through walls and other obstacles, thanks to its increased signal strength and MIMO technology.

  5. Support for Higher Modulation Schemes: Wi-Fi 4 supports up to 64-QAM (Quadrature Amplitude Modulation), which allows for more data to be transmitted in the same amount of time.

  6. Backward Compatibility: Wi-Fi 4 devices are backward compatible with older Wi-Fi standards, such as 802.11g and 802.11a.

It's important to note that the term "Wi-Fi 4" is used for marketing purposes and is not a technical term recognized by the IEEE. The IEEE standard for Wi-Fi 4 is 802.11n. Later generations of Wi-Fi, such as Wi-Fi 5 (802.11ac) and Wi-Fi 6 (802.11ax), have also been given similar marketing names for easier consumer understanding.