WiFi Site Surveys and AP Placement: Coverage, Capacity, Roaming and Validation

1. Define success before surveying

Record required applications, client types, expected density, mobility and critical areas. Voice roaming, warehouse scanners and ordinary office browsing have different design priorities.

2. Predictive design is a starting point

Floor plans and material assumptions can help estimate AP positions. They do not replace validation in the actual building. Concrete, metal, glass, shelving and neighbouring RF sources can change the result.

3. Pre-deployment survey

Where possible, temporarily place an AP of the intended type and measure from real client locations. Check signal, noise, channel use and practical application behaviour.

4. AP orientation and antenna pattern

Mount the AP in the orientation intended by the manufacturer. Ceiling and wall mounting can change how the antenna pattern covers the space. External-antenna systems require even more deliberate orientation.

5. Coverage and capacity are different

A client can see an AP but still experience poor service because too many clients share airtime. Dense areas may require more APs at controlled power rather than one AP transmitting at maximum power.

6. Roaming

Roaming is a client decision influenced by signal conditions and network design. Overlapping coverage must be sufficient for mobility without creating excessive co-channel contention.

7. Post-installation validation

Walk the intended areas and measure the deployed network. Test real applications, roaming, throughput and failure behaviour. Record the channel/power plan and final AP positions.

8. Survey handover

• Record the exact model and firmware/software level.
• Verify physical interfaces and supported media.
• Confirm power, cooling and environmental requirements.
• Test the intended workload, not only basic connectivity.
• Record baseline measurements and configuration.
• Label and document the installation for future fault finding.

Field application and acceptance

This section turns the technical concepts above into a repeatable procurement, installation and handover process.

Field design workflow

Begin with users and applications, then the building. Record client count, device types, mobility, critical rooms, expected throughput and voice/video requirements. Review floor plans, building materials and available cable routes. Perform predictive planning where useful, but validate the real RF environment before finalising positions.

The wired network is part of the design. Confirm switch-port speed, PoE class, VLANs, uplink capacity and controller or gateway requirements for every AP.

Questions to answer before ordering

• Which bands and WiFi generations do the important clients support?
• How many concurrent clients are expected in each area?
• Is roaming required for voice, scanners or mobile work?
• What Ethernet speed and PoE class does each AP require?
• What mounting orientation and environmental rating are required?
• Which SSIDs map to which VLANs and security policies?
• How will RF performance be validated after installation?

Fault-finding method

Separate RF, client, wired and service problems. Check whether the client can see the intended AP, then review signal, noise, channel use and association state. Confirm AP Ethernet speed and PoE mode, switch errors, VLAN path, DHCP, DNS and gateway reachability. Compare one failing client with another known-good client before changing the infrastructure.

Operational documentation

Record AP model, serial, switch port, cable ID, location, mounting orientation, channel, transmit power, SSID/VLAN mapping, PoE requirement and controller/site assignment. Keep survey results so later changes can be compared with the commissioned environment.

What correct looks like

Target areas meet the agreed application requirement, clients obtain the correct network and policy, APs receive full intended power and wired speed, roaming works where required, channels and power are controlled rather than chaotic, and post-installation measurements match the handover documentation.