Manual

Recipe: Wi-Fi that keeps working as you walk

One SSID through the whole building, and a phone that follows you without dropping the call.

The goal: you walk from the ground floor upstairs while on a call or in a video meeting, and your connection stays up.

Roaming is not a feature you switch on. It is what happens when a few things are right: the same SSID with the same passphrase everywhere, access points that overlap just enough, channels that stay out of each other's way, and power that is not set too high. The decision to move is made by the client, always. Your job is to give it a good reason to.

What you need

  • Two or more access points, each with a network cable to the switch or router. A repeater does not do this well: it halves the throughput and the roaming mechanisms do not work in that setup.
  • A floor plan, or at least an idea of where the walls are.
  • A site in the configurator holding all your devices, so the SSIDs and the passphrase exist once. See Multiple devices.

Step by step

  1. Put your devices in one site. The SSID table belongs to the site and is copied to every device that broadcasts. That makes the name, security and passphrase identical everywhere by construction, which is the single most important condition. The site check tells you when two access points broadcast different SSIDs.
  2. Set the security to WPA2 + WPA3 and use one passphrase for the SSID on every access point. Different passphrases under one name means a phone gets refused when it tries to move and falls back.
  3. Draw the placement in the Wi-Fi plan. Put your access points down, draw the walls with their real material, and look at where you still get −67 dBm or better on 5 GHz. The plan tells you per room how much of it is good and where the weakest spot is. What you want is that everywhere you walk, a second access point is also reasonably audible, because then there is something to move to.
  4. Mount them high and in the open. Central in a room, not in a meter cupboard or behind a fridge. The plan warns you when an access point sits within a metre of something like that.
  5. Spread the channels. At 2.4 GHz only 1, 6 or 11 at 20 MHz; at 5 GHz a separate frequency per access point, preferably 40 or 80 MHz wide so enough channels remain. Fill the frequency in per device in the Wi-Fi section. See Channels, width and power.
  6. Do not leave the power at maximum. This is the step most often skipped and the one that helps most. An access point that shouts too loudly is heard in places where the phone itself can no longer be heard back, and the phone then stays attached to it. Set the TX power a few dB lower, or lower the EIRP per band in the plan and check that your coverage still closes.
  7. Switch on 802.11r fast roaming if your devices run the new wifi package. It saves a full reauthentication at every handover. With CAPsMAN it is on by default; on a standalone access point you turn it on in advanced.
  8. Switch on band steering on multi-radio devices with the wifi package, so clients that can do 5 GHz end up there instead of on the crowded 2.4 GHz band.

How to test it

  1. Start a ping to your router from a laptop or phone and leave it running.
  2. Walk the whole building, stairs included, and watch where the replies stop. A short stutter at a handover is normal, seconds of silence are not.
  3. On each access point, see who is connected with /interface wifi registration-table print (or /interface wireless registration-table print on the old package). With CAPsMAN you see all of it on the controller.
  4. Stand in a far corner of the building and look at which access point you are attached to. If it is not the nearest one, power is set too high somewhere.
  5. Walk the same route again on a Wi-Fi call. That is the test that actually counts.

What to watch out for

  • A phone that sticks is nearly always a power problem, not a missing setting. Turn down the access point it refuses to let go of.
  • Old IoT devices sometimes choke on 802.11r. If a thermostat or a smart plug stops working after you enabled it, give those devices their own 2.4 GHz SSID without fast roaming.
  • Roaming does not cross separated networks. Your guest SSID and your own SSID roam each on their own, which is exactly the point.
  • Carry the VLANs everywhere. An SSID on a VLAN only works on access points whose uplink carries that VLAN tagged. Present on one access point and missing on the next means your connection dies the moment you walk that way.
  • A repeater will not get you there. Same name or not, the fast-handover mechanisms do not work in that setup and the throughput is halved already. Run a cable, even if it costs you an afternoon.
  • The plan is an estimate, not a measurement. It works from typical figures per material. Walking around is the only real test.

Next

See Setting up Wi-Fi for the SSIDs, CAPsMAN if you want to manage it centrally, and The Wi-Fi plan for the placement.

Want to try it right away? Open the configurator