What are the most common problems we see with school Wi-Fi?

In the age of digital education – whether remote, on the playground, or in the classroom – managing connectivity is key to student success and staff satisfaction.

Shrinking budgets and scaling technologies, however, can thwart even the best efforts to deliver school Wi-Fi that underpins strong outcomes, and we commonly see a number of issues that repeatedly impact teaching, learning and socialising.

These are:
1. Slow speeds
2. Variable performance
3. Issues with guest networks…
4. And BYOD
5. Bandwidth limitations (1:1 learning, anyone?)

So what causes these problems, and what can schools do?

1. Slow or inconsistent performance

This is a really common one – the Wi-Fi is slow, or it’s slow in a particular classroom, or maybe it was fine yesterday but today the Wi-Fi is rubbish!

If you’re getting a weak signal, you probably need another AP to improve the Wi-Fi experience. But what about when the signal is good, but the performance is still bad? That’s where things get interesting. Here is a list of some of the common reasons why and how to address them.

What causes inconsistent or slow Wi-Fi in schools?

Cause: Too many users connected to the AP, generating too much traffic
Solutions:

• Bandwidth issues can sometimes be remediated by adjusting Wi-Fi configuration (see the section below on bandwidth)
• Often this will require new APs to spread the user count. Especially if you have a high number of users concurrently connected to a single AP

Cause: Overlapping channels
Solutions:

• Try reducing the channel width
• Move the AP to a less congested channel
• Allow more 5GHz channels to be used by enabling DFS

Cause: Transmit power too high
This can cause devices to gravitate to a single AP, hold onto an AP for too long (poor roaming) or suffer from asymmetric uplink/downlink data rates.
Solutions:

• Reduce the transmit power to match the transmit power of your lead capable most important device

Cause: External sources of interference
This is commonly from non-Wi-Fi device that operate in the same frequency.
Solutions:

• Identify the source of the interference with a spectrum analyser and either remove the interferer or move the AP onto a different channel

Lastly, don’t assume the Wi-Fi is to blame!
A switching issues or cabling issue could be the cause of the poor performance!

• Check that your cabling is running at the appropriate speed, a broken wire will cause the port to operate at 100Mbps
• Check the switchport settings are correct
• Check that the switch is not exceeding its PoE budget
• Check the switch logs for flapping ports or other errors

2. Guest Access

Traditional guest Wi-Fi access of accepting terms and conditions doesn’t work for schools. As it is often forbidden for students to connect their personal devices to the guest network. Here are the two most common method we see in schools:

What makes guest networks difficult for schools to manage?

Cause: SSID protected by a PSK (passphrase)
The issue with this approach is that the passphrase is often leaked and used for unintended purposes
Solutions:

• The PSK should be changed on a regular basis, so guest do not have continues access, but this doesn’t happen as often as it should

Cause: A RADIUS User is created for each new visitor.
This requires the schools IT team to manually create a new user account for each visitor, which is an inefficient use of time
Solutions:

• While there are many options available, one that we have found to work well for schools and is supported by multiple vendors is a voucher-based system
• This SSID directs users to a splash page that requires a voucher code to be entered
• The voucher can be generated in advance and in bulk, some systems event allow the vouchers to provide a limited amount of access, for example 1 day or 1 week
• This method requires little input from IT, and ensure visitors are only offer temporary access to the network

3. Bring your own device (BYOD)

BYOD is a challenge for many reasons, is the network able to support the influx of device? How will users authenticate? How can we identify which device belongs to which user? Can we limit which users connect to the BYOD network?

What causes problems with BYOD networks in schools?

Cause:
Your Wi-Fi network must be designed for capacity, not just coverage, or else the increased number of devices could grind your network to a halt. Ensure your AP to client ratio is appropriate for your planned usage. In addition, Wi-Fi 6 and Wi-Fi 6E APs are notably better in high density environments, when the network is designed correctly.

Solutions:

• User authentication with RADIUS is the clear winer for BYOD Networks. This allows us to identify which user is using which device and restrict access to only permitted users
• A word of caution when implementing RADIUS authentication, some devices require the user of a certificate from a trusted certificate authority, so self-signed certificates cannot be used

4. Bandwidth

Many schools operate with a 1Gbps internet connection if the school introduced BYOD or perhaps a one-to-one device scheme. Many schools could easily have 1000+ concurrent devices on the networks. Plus a few hundred wired devices on the networks.

When you consider that YouTube recommend 20Mbps for a 4K video stream. It’s easy to see how bandwidth can be easily exhausted if it’s not carefully managed. When the bandwidth is exhausted, it’s real-time applications like a Teams Meeting or a voice call that suffers most.

How can schools boost bandwidth?

• Implement bandwidth limits

This can usually be done on a per SSID basis, for example your guest SSID may have a lower bandwidth than the SSID used by school owned devices. Some vendors will allow you to limit bandwidth to certain applications, for example, don’t want students to watch YouTube in 4K? No problem, reduce their allowed YouTube bandwidth to 5Mbps and they’ll steam in 1080p instead

• Introduce Quality of service

QoS gives priority to certain types of device traffic, for example Web Meetings and Voice traffic can be given a higher priority than email or web generic traffic. For QoS to work properly it needs to be implemented on both your wired and wireless network.

As you can see, these common problems can have a wide-reaching impact on education, and although simple solutions can often be found, it’s vital to understand the knock-on effect of making changes when they can affect thousands of students, staff and visitors.

Has your school experienced any of these issues when it comes to wireless network performance?