The context
Connection problems appeared as soon as the number of users and the network load increased, in other words as soon as the arena filled up. They affected the Wi-Fi network open to the public, and only that one: the venue’s other networks were not concerned. The integrator running the network called on TWN Consulting for an independent diagnosis.
Measuring when the problem exists
A Wi-Fi audit carried out in an empty hall would have shown good coverage. Measurements were therefore taken on match night: an Ekahau survey of access points and coverage, then continuous spectrum analysis on a tablet, courtside, before the game, during the game and after the crowd had left. Observations were compared with the controller configuration.
What the evening revealed
- 5 GHz channels 124 to 132 stayed saturated for the whole game.
- The 5 GHz channel width in service was 80 MHz, although 40 MHz had been configured on the controller: the setting was not being applied.
- The number of 5 GHz channels in use needed to be increased, DFS channels included.
- A high number of networks (SSIDs) was being broadcast, which makes the radio spectrum harder to manage.
- Some access points were not installed according to the original predictive design, and were badly oriented.
The actions
During the visit, TWN Consulting worked on site with the integrator to improve the controller configuration: 5 GHz channels moved to 40 MHz on match day, then minimum transmit power lowered the next day. As this 40 MHz setting was not being applied (the network stayed at 80 MHz), the report recommended checking it so that it actually took effect, extending the channel plan to DFS channels, reducing the number of SSIDs to four or five at most and remounting the badly oriented access points.
TWN Consulting continued to support the integrator on controller settings: PoE power for the new access points, channels set access point by access point. Four high-density access points were added in the busiest areas (press and VIP areas, corners of the arena).
Not blaming everything on Wi-Fi
The exchanges that followed the audit had also flagged points to check outside Wi-Fi: switch and PoE sizing, possible saturation on the carrier side, and a switchover observed between two internet links during incidents. After the access points were added, the problems persisted: work continued on the wired network and internet links, with monitoring of switch ports and links during games.
In an arena, Wi-Fi is judged on event night: it is the crowd, not the empty hall, that reveals saturated channels and settings that are not being applied.