Hello, everyone!
As a supplement to the ONT basic knowledge, I begin to introduce a series of basic Wi-Fi knowledge.
Today, I will share knowledge about Wi-Fi rate.
Theoretical Rate
The Wi-Fi rate increases with the update of Wi-Fi protocols.
The initial theoretical Wi-Fi transmission rate is only 11 Mbps. The Wi-Fi rate is increasing with several protocol updates.
The Wi-Fi rate further increases with the application of the Multi-Input Multiple-Output (MIMO) technology.
An MIMO antenna system includes m transmit antennas and n receive antennas. Signals are transmitted and received by multiple antennas at the transmit end and the receive end, enhancing communication quality. The MIMO technology can implement multiple-input and multiple-output through multiple antennas. Under the same spectrum resources and antenna transmit power, MIMO doubles the system channel capacity, showing obvious advantages and being regarded as the core technology for next-generation mobile communication.
The following table lists the theoretical air interface rates supported by 802.11n/ac/ax with a different number of spatial streams.
MIMO (mxn) | 11n (Mbit/s) | 11ac (Mbit/s) | 11ax (Mbit/s) |
1x1 | 150 | 433 | 1201 |
2x2 | 300 | 867 | 2401 |
3x3 | 450 | 1300 | 3603 |
4x4 | 600 | 1733 | 4804 |
Wi-Fi Rate Factors
The theoretical Wi-Fi rate indicates the rate in ideal conditions, which is not equal to the actual data transmission rate. In practice, the Wi-Fi rate is affected by multiple factors.
The Wi-Fi rate is limited by the bandwidths provided by carriers and by the network adapter performance of a connected device.
Currently, the maximum bandwidths provided by service providers are not more than 100 Mbit/s. Commonly referred 300 Mbit/s and 450 Mbit/s wireless transmission rates are the transmission rates within a LAN. The Internet access rate depends on the bandwidths provided by the external network (that is, a service provider).
When wireless devices (such as mobile phones and laptops) connect to a wireless network, they determine a wireless transmission rate with the router through negotiation. A higher rate supported by the wireless network adapter of a wireless device will determine a higher negotiated wireless transmission rate.
The wireless network adapters of most mobile phones support a rate of 54 Mbit/s or 72 Mbit/s, and those of most laptops support a rate of 144 Mbit/s. That is, a laptop can reach the 150 Mbit/s theoretically at most even when it is connected to a 450 Mbit/s wireless router.
In addition, a new wireless network adapter may reach a higher wireless transmission rate than an old one.
The Wi-Fi rate is affected by Wi-Fi signal strength and quality.
The Wi-Fi rate is associated with Wi-FI signal strength. That is, stronger signal strength results in a higher Wi-Fi rate.
Therefore, MIMO can be used to improve signal strength when 802.11ac is used to increase the Wi-Fi rate. The system measures channel quality before each transmission attempt and selects an appropriate transmit rate from a modulation and coding scheme (MCS) table according to the channel quality for real-time rate adaptation.
That's all for today's basic knowledge sharing.
Welcome to leave a message at the bottom of the forum.
Thank you!
For more information about ONT basics, click the homepage of the topic.
