Case Study: Wi-Fi Experience Is Poor When APs Are Installed Too Densely or Sparsely
Symptom
Dense installation: In a higher education site outside China, APs are deployed at a distance of 5 m to 8 m. Since classrooms are separated by glass partitions, there is basically no signal loss. However, severe co-channel interference occurs on each channel. This causes unavailability of the channel and even the Wi-Fi network.
- At a higher education site in China, settled APs are deployed at the edge of an auditorium. Omnidirectional antennas cannot meet the coverage distance requirements in high-density scenarios, which results in insufficient coverage.
- At a site outside China, outdoor APs are deployed on the rooftop of a building to provide outdoor Wi-Fi coverage. However, no signal coverage is available near the building.
- At a site in China and a site outside China, indoor settled APs are deployed too far away from each other. As a result, some areas between the APs suffer from insufficient coverage, weak signals of STAs, and in-roaming STA disconnections.
Relevant Alarms and Logs
Co-channel interference alarm: WLAN_1.3.6.1.4.1.2011.6.139.16.1.1.1.5 hwAPCoInterfDetectedTrap
Cause Analysis
If APs are densely installed, signals between APs interfere with each other. If the AP is installed too far away from each other, the signal strength in the coverage area is weak or even no signal is available.
Procedure
- Plan the WLAN again based on scenarios and adjust the AP installation positions and layout. For details about network planning, see WLAN Network Planning Guide.
- If AP installation positions cannot be adjusted, disable some 2.4 GHz radios to reduce interference in scenarios where the APs are densely deployed. If the coverage is insufficient, adjust the transmit power of APs or add more APs to meet the coverage requirements.
Suggestion and Summary
According to the preceding case analysis, if APs are installed at improper positions, or are densely or sparsely deployed, Wi-Fi experience is affected. Proper installation positions ensure that APs can work better and STAs can roam between APs more smoothly, achieving better Wi-Fi network experiences.
The WLAN Planner can be used to plan proper AP installation positions and simulate signal coverage. In outdoor scenarios where APs with directional antennas are used for Wi-Fi coverage or Mesh backhaul scenarios, WLAN planning is necessary because there are strict deployment requirements and coverage distance restrictions.