When speaking with mobile operators, their primary concern regarding the use of Wi-Fi for indoor coverage and additional capacity is the Quality of Experience (QoE) for their subscribers. While this concern is understandable, it can also be seen as somewhat irrational—and even ironic. Many of these same operators have already implemented Wi-Fi Calling, which utilizes any available Wi-Fi network for voice services. This means they are willing to deliver voice—one of the most latency-sensitive services—over Wi-Fi networks that they do not control. Yet, they remain hesitant to use secure Wi-Fi networks under their own management for services like web browsing, downloads, and video streaming, which are far more tolerant of variable network conditions.

In fact, the need to backhaul traffic to the mobile core for session continuity has diminished as devices and applications have become more adept at maintaining a positive user experience when transitioning between Wi-Fi (with local traffic breakout) and cellular networks. For instance, if you step out of the range of your home Wi-Fi during a Microsoft Teams session, you might experience a brief disruption as the device switches to the mobile network. This minor interruption is similar to what can happen during a cellular call when the user moves between different base stations.

The simple explanation may lie in the differing perspectives: while devices—and many users—operate in a Wi-Fi-first world, mobile operators naturally adopt a cellular-first mindset. They fear that a user could unintentionally switch to a Wi-Fi network with a lower QoE than the cellular network they previously connected to.

This fear is further reinforced by common misconceptions about Wi-Fi, which we have addressed in a previous post Top Five Myths About Wi-Fi. Another reason could be that mobile operators are less concerned about Wi-Fi Calling, as it utilizes external networks, they neither manage nor fund. In such cases, we recommend leveraging the free Wi-Fi networks available through the OpenRoaming federation for Wi-Fi offloading. These networks are managed by reputable Wi-Fi access providers, offering reliable connectivity. For more details, refer to the OpenRoaming in Wi-Fi Offloading chapter.

Ultimately, some mobile operators’ concerns about Wi-Fi stem from the perception that it is outside their area of control. While we have emphasized throughout this paper that many of these concerns are unwarranted, we also recognize the importance of addressing them seriously.

With expertise spanning both the 3GPP ecosystem and Carrier Wi-Fi, Enea is uniquely positioned to offer practical solutions that increase mobile operators’ control over Wi-Fi offloading. We are actively looking at a concept for QoE-based communication across mobile and Wi-Fi networks. For more details, refer to the More Intelligent Network Selection chapter.

Factors Behind Poor Wi-Fi QoE

The user experience in Wi-Fi networks is influenced by a mix of persistent and intermittent factors, and each type requires a different resolution approach. Here’s a deeper look at these factors.

Persistent Network Deficiencies

These are typically structural issues that remain constant unless the underlying design or hardware is improved. Addressing them often involves network redesign or hardware upgrades:

• Insufficient Backhaul Capacity: This is when the connection between the Wi-Fi access points and the internet or core network is too limited, creating a bottleneck. No matter how good the Wi-Fi signal is, the user experience will be poor if the backhaul is under-provisioned.
• Poor Radio Network (RAN) Design and Channel Interference: Inefficient placement of access points or poor channel planning can lead to overlapping channels and signal interference, especially in environments with many Wi-Fi networks. This can result in slow speeds and high latency.
• RAN Installation Not Done According to the Original Plan: Sometimes, the real-world installation of access points doesn’t match the design plan, which can cause gaps in coverage or overlap which results in interference and degraded performance.
• Old Wi-Fi Access Points or Outdated Firmware: Older Wi-Fi standards and devices (Wi-Fi 4 and 5) lack the advanced features of Wi-Fi 6/6E and Wi-Fi 7, such as OFDMA, MU-MIMO, and better handling of dense environments.

Intermittent Issues

These factors can cause performance fluctuations that come and go, often influenced by changes in the environment or network load. Managing these requires ongoing monitoring and dynamic adjustments:

• Wi-Fi RF Channel Congestion: Temporary spikes in Wi-Fi traffic, particularly in busy environments, can cause congestion on specific channels, leading to a temporary slowdown in performance.
• High Number of Concurrent User Sessions: A surge in the number of active users can overwhelm an access point, reducing the available bandwidth for each user. This is common in public spaces or during events.
• Current Uplink/Downlink Load: High data transfers in either direction can cause intermittent slowdowns for other users sharing the same access point.
• Interference from Other RF Sources: Devices like Bluetooth gadgets, cordless phones, or microwave ovens can temporarily interfere with Wi-Fi, particularly in the 2.4 GHz band.
• Weak Signal / UE Too Far from the Wi-Fi Access Point: Users at the edge of an access point’s coverage area can experience weak signals, leading to slower speeds and dropped connections.
• Environmental RF Interference (primarily outdoors): External factors like weather conditions or nearby construction using heavy equipment can cause fluctuations in Wi-Fi performance, especially for outdoor access points.
• Insufficient DHCP Capacity and Other Back-end Issues: When the DHCP server is unable to provide IP addresses due to a limited pool, new devices cannot connect, causing intermittent connection issues.
• Poor QoS Enforcement, Some Devices Monopolize the Available Bandwidth: If quality-of-service (QoS) rules aren’t set up properly, certain devices or applications can consume too much bandwidth, causing others to experience slower speeds.
• Sticky Devices: Devices that hold on to a connection with a distant or weaker access point even when a stronger one is available can cause performance issues.

Addressing These Challenges

All of these challenges can be mitigated with effective network design, regular monitoring, and proper investment in modern infrastructure:

• The adoption of Wi-Fi 6/6E and Wi-Fi 7 access points and devices will address many of these issues by introducing better channel management, higher data rates, and more efficient handling of dense environments.
• AI-driven predictive and proactive Wi-Fi RAN management can play a crucial role in optimizing network performance. AI can predict peak usage times, identify and resolve interference issues in real-time, and ensure optimal configuration of access points to deliver a better user experience.

With the right planning and technology, Wi-Fi networks can achieve a much higher quality of service, making them capable of delivering a consistent, high-quality user experience.

How Wi-Fi 6/6E and 7 Improve Quality of Experience

Previous Wi-Fi generations (Wi-Fi 4 and Wi-Fi 5) can be compared to a chaotic cocktail party, where everyone tries to talk at once; the more people present, the harder it is to communicate effectively. As a result, many messages had to be retransmitted, leading to increased latency and reduced data throughput. As shown in the diagrams below, the critical parameters for a good user experience—latency and data throughput—deteriorate rapidly as more users connect to a single Wi-Fi access point in these earlier Wi-Fi versions.

In contrast, this degradation is significantly mitigated with the introduction of Wi-Fi 6/6E and Wi-Fi 7. Wi-Fi 6 introduced Orthogonal Frequency-Division Multiple Access (OFDMA), a scheduling mechanism also used in cellular networks, which allows for more efficient and organized use of the spectrum. Today’s Wi-Fi is more like a well-coordinated choir, where a conductor controls when each voice can sing, resulting in a smoother and more deterministic user experience.

Though Wi-Fi operates on unlicensed spectrum, there is growing interest in using unlicensed spectrum for cellular as well. This shift, along with the improved efficiency and performance of Wi-Fi 6/6E and Wi-Fi 7, has led to increased respect and acceptance from 3GPP proponents.

QoE: Beyond the Radio Network

It’s easy to blame the Wi-Fi radio network for a poor user experience since it’s the most visible part of the connection. However, based on our experience, backend systems often play an equally significant role in user satisfaction. The Enea Aptilo SMP has repeatedly improved existing Wi-Fi networks by addressing backend deficiencies.

A common example is an overloaded DHCP server. At large venues like stadiums or trade shows, where thousands of users try to connect simultaneously, an overwhelmed DHCP server can prevent users from obtaining an IP address, rendering Wi-Fi access impossible. Ensuring DHCP capacity to handle such surges—and implementing overload protection—is essential. It’s better to deny a portion of users than risk a situation where no users can connect or renew their leases.

Some VPN clients cause DHCP-related issues by modifying the routing table whenever a VPN connection is established. These clients retain only the route to the VPN server, rerouting the default pathway through the VPN tunnel. This configuration causes DHCP renewal requests to be sent through the tunnel rather than directly to the DHCP server, preventing the server from receiving and responding to them. Consequently, the client may lose its IP address when the lease expires and the gateway may mark the client as “inactive” due to its lack of response to pings. The DHCP server can then reassign the IP address to another device, potentially resulting in an
IP address conflict.

Other backend and network issues that impact Wi-Fi QoE include:

• DNS Resolution: Slow or failing DNS servers delay website loading and application connectivity, often perceived as Wi-Fi problems. Devices configured for Private DNS may cause failure to load the captive portal.
• Authentication Delays: Slow RADIUS/AAA servers can cause connection delays or timeouts, particularly during peak times.
• Captive Portals: Poorly optimized captive portals for guest Wi-Fi lead to slow logins and inconsistent access.
• Network Address Translation (NAT): High user volumes can overwhelm NAT, causing connection issues.
• Quality of Service (QoS) Misconfigurations: Incorrect QoS settings can inadvertently throttle certain types of traffic.
• Firewalls and Security Appliances: Overloaded or misconfigured firewalls may introduce latency or block legitimate traffic. For example, clients attempting to validate certificates provided by the captive portal using OCSP may time out before they complete the validation.
• Bandwidth Management: Ineffective bandwidth caps or fair-use policies degrade user experience.
• Core Network Congestion: Switches, routers, or core network misconfigurations directly impact user performance.
• ISP Issues: Problems within the ISP’s network can be misinterpreted as local Wi-Fi issues.
• Content Filtering: Aggressive content filterin slows down web access.
• Proxy Servers: Overloaded proxies can significantly delay browsing.

To effectively diagnose Wi-Fi performance issues, the entire network stack—from radio to backend systems—needs consideration. Furthermore, being able to troubleshoot individual sessions among potentially millions is critical and the trace should always be on otherwise it will be hard to capture intermittent issues.

Enea Aptilo SMP’s stability, scalability, powerful Distributed Tracing function, and overload protection are all vital to delivering an excellent user experience. Learn more in the next chapter.