The theoretical speed of each protocol can be referred to in the following table:
| Wireless Standard | Frequency band | Wireless Rate |
|---|---|---|
| 802.11a | 5GHz | 54Mbps |
| 802.11b | 2.4GHz | 11Mbps |
| 802.11g | 2.4GHz | 54Mbps |
| 802.11n | 2.4GHz、5GHz | Up to 600Mbps |
| 802.11ac | 5GHz | Up to 6.93Gbps |
| 802.11ax | 2.4GHz、5GHz | Up to 9.6Gbps |
| 802.11be | 2.4GHz、5GHz、6GHz | Up to 46Gbps |
In everyday use, the actual wireless throughput you experience is often significantly lower than the advertised theoretical maximum. This gap is primarily due to two key factors:
1. Link (Negotiated) Rate
Your Wi-Fi client (e.g., laptop, phone) and the access point negotiate a connection speed based on current conditions. This negotiated rate is always less than or equal to the maximum theoretical rate listed for your devices.
However, this negotiated rate isn’t fixed—it dynamically change based on several real-world conditions:
Physical Interference and Obstructions
During transmission, wireless signals can be degraded by:
• Electromagnetic noise from other Electronic devices
• Physical barriers like walls, furniture, trees, or large metal objects (e.g., refrigerators)
These factors reduce signal range, strength, and quality—causing the negotiated rate to drop accordingly.
Hardware Capabilities
Every wireless device has its maximum wireless speed. If the maximum wireless rate supported by the Access Point or the wireless client is relatively low, the maximum negotiated rate between the AP and the client will also be correspondingly low.
In ideal conditions—such as when your device is just a few meters from the router with a clear line of sight—the negotiated rate can reach the theoretical maximum.
2. Real-World Throughput Losses
Even when the negotiated rate is high, the actual data throughput you experience is typically only about 60–75% of that rate under good conditions. In environments with significant interference, real throughput may drop to 30–50% due to overhead and retransmissions.
Key factors affecting real-world performance include:
Number of Connected Users
Wi-Fi bandwidth is shared among all devices on the same network. The more active users consuming data simultaneously, the less bandwidth is available per device.The actual rate will be slower.
Co-Channel and Adjacent-Channel Interference
If other nearby access point are using the same channel or overlapping channels , they can introduce interference that degrades your Wi-Fi performance.
Necessary network communication is lost
The following is a simplified OSI Reference Model:
| Application Layer |
|---|
| Transport Layer |
| Network Layer |
| Link Layer |
The data used by users is application - layer data, but the remaining data in network transmission is also essential. In addition, the control data and management data required by the coding mode used in 802.11 wireless technology also occupy a part of the wireless bandwidth, resulting in a further reduction in available bandwidth.
Considering the above two main factors, in a wireless environment with little interference or when the hardware supports a high wireless rate, the actual rate of the wireless client is about 75% of the maximum theoretical rate. However, when there is strong wireless interference or the hardware does not support a high wireless rate, the actual rate of the wireless client will be further reduced..
