WLAN Frequency Planning

Overview

WLAN Frequency Planning involves the strategic allocation and management of radio frequencies to ensure optimal performance and minimize interference in wireless local area networks (WLANs).
Effective frequency planning is crucial for maintaining high network performance, reliability, and coverage.

2.4 GHz Band:
- Channels: 11-14 channels (depending on the region).
- Bandwidth: Each channel has a bandwidth of 20 MHz.
- Channel Overlap: Channels overlap significantly, leading to potential interference. Non-overlapping channels typically used are 1, 6, and 11.
5 GHz Band:
- Channels: More channels available compared to 2.4 GHz, with less overlap.
- Bandwidth: Channels can be 20 MHz, 40 MHz, 80 MHz, or 160 MHz wide.
- Regulations: Varies by region; includes additional channels for higher speeds and less interference.

Non-Overlapping Channels:
- For the 2.4 GHz band, use channels 1, 6, and 11 to avoid overlap and interference.
Channel Width:
- Wider channels (e.g., 40 MHz, 80 MHz) offer higher data rates but are more prone to interference. Balance between data rate and interference is necessary.

Adjacent-Channel Interference:
- Use non-overlapping channels to minimize interference from adjacent channels.
Co-Channel Interference:
- Ensure adequate distance between access points using the same channel to reduce co-channel interference.
External Interference:
- Identify and mitigate interference from non-WLAN sources (e.g., microwave ovens, cordless phones).

Density:
- Proper placement of access points (APs) to ensure sufficient coverage without excessive overlap.
- Avoid placing APs too close to each other to minimize interference.
Coverage:
- Ensure uniform coverage by considering the physical layout and potential obstacles (walls, furniture) that can affect signal propagation.

Site Survey:
- Conduct surveys to assess the physical environment, identify sources of interference, and determine optimal AP placement.
Tools:
- Use spectrum analyzers and WLAN planning software to analyze frequency usage and plan channel allocations.

DFS:
- Automatically selects channels to avoid interference with radar systems and other priority users.

Channel Bonding:
- Combine multiple channels to increase bandwidth (e.g., 40 MHz, 80 MHz, 160 MHz) while managing potential interference.

WLAN Frequency Planning is essential for optimizing network performance and reducing interference.
Key aspects include selecting appropriate frequency bands, channel allocation, interference management, and proper AP placement.
Utilize tools like site surveys and spectrum analyzers to ensure effective planning and deployment.