Basis points for designing a stable Wi-Fi network
1. The best practice is to perform radio measurements before radio planning. Without measurements, radio planning will be based on theoretical calculations, which may differ from the actual situation.
2. When performing radio measurements, it is crucial to consider the SNR (Signal-to-Noise Ratio) parameter. A high SNR indicates that the signal is significantly stronger than the noise, ensuring reliable and high-quality communication.
| SNR (dB) | Signal quality | Commentary |
| 40+ | Excellent | High-speed, stable connection. |
| 25-40 | Good | Suitable for VoIP, video conferencing, cloud services, and large data transfers. Ideal for enterprise use with high connection stability requirements. |
| 15-25 | Low | Sufficient for email and small files. HD video playback (1080p) may be unstable. Suitable for general usage with moderate bandwidth needs. |
| 10-15 | Very low | The connection is extremely unstable. Only basic tasks like receiving text emails without attachments are possible. Not suitable for streaming, video conferencing, or large files downloads due to high latency and frequent disconnections. |
| Below 10 | Unusable | Unreliable connection, the noise level is too high to distinguish the signal. |
The SNR value is displayed in the WLC controller GUI:
The RSSI (Received Signal Strength Indicator) parameter is also important, but keep in mind that an access point typically has a more powerful transmitter and a sensitive receiver compared to client devices.
3. It is recommended to use specialized software for radio planning, such as Ekahau Pro Site Survey Tool, Tamograph Site Survey Pro, and similar applications.
Indoor Wi-Fi network design considerations
The optimal number of access points depends on the coverage area and the types of physical obstacles (concrete/brick walls, partitions, etc.).
Table of Wi-Fi signal efficiency loss when passing through different materials:
| Obstacle | Additional loss (dB) | Effective range* |
|---|---|---|
| Open space | 0 | 100 % |
| Clear glass window (no metallized coating) | 3 | 70 % |
| Tinted glass window (metallized coating) | 5-8 | 50 % |
| Wooden wall | 10 | 30 % |
| Interior wall (15.2 cm) | 15-20 | 15 % |
| Load-bearing wall (30.5 см) | 20-25 | 10 % |
| Concrete floor/ceiling | 15-25 | 10-15 % |
| Monolithic reinforced concrete floor | 20-25 | 10 % |
1. It is recommended to use both 2.4 GHz and 5 GHz bands, as hotel guests may have devices that support only 2.4 GHz, as well as smart home devices that do not support 5 GHz.
In the 2.4 GHz band, 3 non-overlapping 20 MHz wide channels are used: 1, 6, 11 (2412, 2437, 2462 MHz). The use of overlapping channels or 40 MHz wide channels is not recommended. It is also not recommended to use non-overlapping channels 1, 5, 9, 13 as many Wi-Fi clients do not support channel 13.
In the 5 GHz band, 17 non-overlapping 20 MHz wide channels are used: 36, 40, 44, 48, 52, 56, 60, 64, 132, 136, 140, 144, 149, 153, 157, 161, 165.
It is not recommended to use in 5 GHz channels 100-128, 165 (for compatibility with a large number of client devices).
If there are enough free channels available to avoid interference, it is recommended to increase the channel width to 40 MHz. This will improve wireless throughput by expanding the available bandwidth.
wlc-30(config)# wlc wlc-30(config-wlc)# radio-5g-profile default_5g wlc-30(config-wlc-radio-5g-profile)# bandwidth 40L
When selecting a channel, it is important to scan the air for third-party access points and choose channels that minimize interference from them. This scan can be performed using a client device (via InSSIDer, WiFiAnalyzer, or similar apps on Android, or via Airport utility on iPhone), or by using the scanning function built into the access point (web interface → Status → Rogue AP Detection). Scanning is also available via CLI:
WEP-30L(root):/# monitoring spectrum-analyzer
Interface: wlan1 last scanned channel: 64
Channel| CCA
1| 86%
6| 83%
11| 79%
36| 43%
40| 54%
44| 79%
48| 44%
52| 26%
56| 16%
60| 86%
64| 31%
2. It is recommended to enable band steering — when enabled, the access point will reject connection attempts over the 2.4 GHz band if it detects that the client device supports 5 GHz. This way, the 2.4GHz mode will be offloaded and the client will get higher throughput.
Enabling the mode on WLC:
wlc-30(config)# wlc wlc-30(config-wlc)# ssid-profile default-ssid [default-ssid - the name of your profile] wlc-30(config-wlc-ssid-profile)# band-steer-mode
3. It is not recommended to configure more than three SSIDs on an access point. Each SSID generates additional service traffic (beacon frames, Probe Request/Response), which consumes airtime that could be used for data transmission.
4. It is not recommended to place access points behind false ceilings or near household appliances. Wi-Fi signal strength will be reduced, negatively impacting connection quality. Additionally, household appliances can generate radio interference.
Access point placement options
Two typical access points placement options are used: in the corridor, serving multiple rooms and inside rooms, based on building characteristics and wall materials.
In older buildings with thick brick or concrete walls, it is recommended to place access points in each room:
In modern buildings with thinner walls, a checkerboard layout (alternating rooms and corridors) is acceptable:
Equipment selection
WEP access points
| Model | Standard | Placement | Number of actual users per access point | Commentary |
|---|---|---|---|---|
| WEP-3L | Wi-Fi 6 | Indoor | up to 40 | The AP is optimal for hotels and provides sufficient performance without being excessive. It supports up to 40 concurrent device connections and a maximum of 120 clients per radio. |
| WEP-3ax | Wi-Fi 6 | Indoor | up to 100 | The AP is suitable for hotel lobbies and conference rooms due to higher performance. |
WLC wireless access controllers
| Model | Number of supported access points | Number of clients | Client integration scheme |
|---|---|---|---|
| WLC-15 | 50, expansion up to 100 APs is available under the license | 2,000 | Сentralized forwarding, local switching |
| WLC-30 | 150, expansion up to 500 APs is available under the license | 5,000 | |
| WLC-3200 | 1,000, expansion up to 3,000 APs is available under the license | 30,000 |
Due to periodic changes in the air, it is recommended to use AirTune. Radio Resource Management allows to automatically optimize access point performance based on current conditions. Learn more about the service here: Configuring AirTune.