Wi-Fi signal interference test — simple trick to speed up your connection

It doesn’t take much interference to degrade the performance of a Wi-Fi network severely, a MyBroadband test has shown.

Using two home Wi-Fi routers placed right next to one another, we tested the impact on network performance with different channel configurations.

We also tested the impact of changing a Wi-Fi network’s channel without having a second router present to interfere with it.

Wi-Fi routers offer several settings to change how networks are broadcast and how different devices can connect.

While some of these settings are only manually adjustable on high-end routers, a few are available on even the most basic Wi-Fi routers.

Modern routers generally support at least Wi-Fi 5, which uses two frequency bands — 2.4 GHz and 5 GHz.

The 5 GHz band provides better bandwidth but usually has a shorter range. For connections from further away, the 2.4GHz band is used, which offers better object penetration and range.

Each of these bands is subdivided into channels.

Switching the channel on which a router communicates with Wi-Fi devices is one of the more commonly available settings.

Routers usually try to select an optimal channel during the initial setup automatically, but if there are multiple networks nearby, channels can overlap, which can degrade performance.

For testing purposes, we used two routers: a Netgear Orbi Pro Mini without the usual mesh satellite (pictured above), and a D-Link DIR-825.

The two routers were placed next to one another for a worst-case scenario.

D-Link DIR-825

The Orbi was connected to an Openserve 200/100 Mbps link, and we verified that we could reach our fibre’s maximum advertised speeds with a PC connected via Ethernet.

The D-Link router was used purely as an interfering network and not connected to the Internet.

A Microsoft Surface Laptop 3 was used for all the testing, positioned far enough away to prefer the 2.4GHz network from the Orbi, and to the point where performance dropped to around half the available speed.

We also used a free Wi-Fi analyser app on a smartphone to confirm which channels were being used and search for other interfering networks.

The performance was measured with five consecutive speed tests under each configuration to see the average download and upload speeds, and latency.

When setting up the routers, the D-Link defaulted to channel 3, while the Orbi automatically went to channel 13 — as far away from the D-Link’s interference as possible.

We tested four different scenarios to get a picture of how overlapping channels would affect network speeds:

• Only the Netgear router enabled, on channel 13
• Only the Netgear router enabled, on channel 3
• Both routers enabled, both on channel 3
• Both routers enabled, the D-Link on channel 3, and the Netgear on channel 13

This would show us the optimal performance on different channels, a worst-case scenario, and an improvement by selecting a better channel.

Wi-Fi channel visualisation

One of the biggest surprises from this test was the performance difference between channel 3 and channel 13 when running only the Netgear router.

Upload speed and latency remained consistent on different channels, but download speed varied significantly.

This could be due to another source of interference not detected by the Wi-Fi analyser app.

It shows that if your Wi-Fi performs poorly, it could be worth testing different channels.

As expected, when both routers were on channel 3, the performance took another hit. Download and upload speeds were degraded.

Moving the Netgear router back up to channel 13 while keeping the D-Link on channel 3 improved this substantially. However, download speeds remained much lower than our baseline.

During testing, we noticed that the routers tried to get as much channel separation as possible during the initial setup.

When both routers were set to the same channel, the laptop often tried switching to the 5GHz channel with less interference.

Therefore, an automatic setup of a modern router should get you pretty good performance right off the bat.

However, this can change if someone adds another network after your initial setup or if you are in a noisy RF environment.

Under those circumstances, it could make a noticeable difference if you select a channel with less interference.

Now read: We tested Wi-Fi 5 and Wi-Fi 6 to see if there is a big difference