Wi-Fi generations at a glance
| Generation | IEEE standard | Bands | Key idea |
|---|---|---|---|
| Wi-Fi 4 | 802.11n | 2.4 / 5 GHz | MIMO; widely deployed, legacy |
| Wi-Fi 5 | 802.11ac | 5 GHz | Wider channels, MU-MIMO downlink |
| Wi-Fi 6 | 802.11ax | 2.4 / 5 GHz | Efficiency in crowded spaces (OFDMA), better battery life |
| Wi-Fi 6E | 802.11ax | 2.4 / 5 / 6 GHz | Adds the 6 GHz band: more channels, less interference |
| Wi-Fi 7 | 802.11be | 2.4 / 5 / 6 GHz | Multi-Link Operation, wider channels, lower latency |
Quoted maximum speeds are laboratory figures. Real throughput depends on client devices, distance, walls, channel width and interference. Clients must support the standard to benefit.
The 6 GHz band in India
India's Department of Telecommunications has opened the lower 6 GHz band (5925–6425 MHz) for licence-exempt Wi-Fi under defined power limits, announced in January 2026. Rules such as indoor-only low-power operation apply, and equipment must be approved for use. Check the current notification and your device's approval before specifying 6 GHz.
Design for capacity, not just coverage
- A signal bar is not a design. Plan for the number of simultaneous users and devices and what they do (video calls need far more than email)
- Common design targets: signal around −65 to −67 dBm at the cell edge and good signal-to-noise ratio
- As a rule of thumb, 25–40 active clients per access point; heavy video or dense rooms need fewer
- Place APs in or near the rooms they serve. A corridor AP has to push through walls
- Reinforced concrete, metal partitions, lifts and glass attenuate strongly. Do not assume open-office numbers
- In dense spaces (classrooms, auditoriums) use more APs on lower power rather than fewer on high power
Channels and widths
- 2.4 GHz: only channels 1, 6 and 11 are non-overlapping in a 20 MHz layout. Keep it for IoT and legacy, not primary capacity
- 5 GHz: use 20 or 40 MHz in offices with many APs; 80 MHz leaves too few channels and causes co-channel interference
- Let the controller manage channels and power, then review rather than hard-setting everything
- Avoid too many SSIDs. Each one adds management overhead on air. Three or four is plenty (staff, guest, IoT)
- Enable 802.11k/v/r roaming features where all client devices behave well
Wi-Fi security
- WPA3 where devices support it; WPA2/WPA3 mixed mode for transition
- WPA2/WPA3-Enterprise (802.1X with RADIUS) for staff, so each person has their own credentials
- Separate guest SSID with client isolation and bandwidth limits; separate IoT SSID
- Disable WPS; watch for rogue APs; change default AP admin passwords
- Put management interfaces on a management VLAN
Management models
| Model | Pros | Cons |
|---|---|---|
| Standalone APs | Simple, no controller | Hard to scale; no central policy or roaming tuning |
| Controller-based (on-premises) | Central control, works without internet | Controller to maintain |
| Cloud-managed | Easiest multi-site, remote monitoring, regular updates | Subscription cost; management plane depends on internet |
Site surveys
| Survey type | What it is | When |
|---|---|---|
| Predictive | Software model from floor plans and wall materials | Early budgeting, new builds |
| On-site (active/passive) | Walk the building with a survey tool and test APs in place | Before final AP placement or to diagnose problems |
| Post-install validation | Measure real coverage, roaming and throughput | Handover and troubleshooting |
For anything beyond a small office, an on-site survey almost always pays for itself.
Troubleshooting checklist
- Is the problem one room, one device or everyone?
- Check signal strength and SNR at the problem spot
- Look for channel overlap or high channel utilisation
- Check for sticky clients and old devices dragging a cell down
- Check DHCP pool exhaustion and VLAN configuration
- Check uplink port speed, PoE class and cable length
- Look for interference: microwaves, cordless devices, neighbouring networks
- Review firmware and known issues
Key takeaways
- Design for how many people and what they do, not just signal bars
- Use 20/40 MHz channels in dense 5 GHz deployments
- Use WPA3 and 802.1X where possible; keep guest and IoT separate
- Survey on site before final AP placement in complex buildings
An illustrative meeting-room example. A meeting room kept dropping video calls although the signal showed full bars. The access point sat in the corridor behind a reinforced-concrete wall and ran 80 MHz channels that overlapped with neighbours. Moving a ceiling AP into the room, reducing channel width to 40 MHz and lowering power on adjacent APs stabilised calls. (Illustrative example, not a client case study.)
References and further reading
General information for orientation; it is not legal or professional advice. Specifications, products and regulations change, so verify current details before acting. Product names belong to their owners and are mentioned only as examples.