How mesh APs & Topology Impacts Wi-Fi Performance in Large Homes

In today's expanding Wi-Fi landscape, one challenge I've faced is ensuring reliable coverage in large or multi-story homes where a single Wi-Fi router struggles to provide adequate connectivity. Enter mesh AP (Access Point), a solution designed to address these issues. ?

Some might ask: why not use multiple routers on each floor, all set with the same SSID and password? Or why not invest in a high-end router with better throughput? While these ideas seem promising, they introduce challenges like channel interference and latency.

In a traditional home network, one router connects to the internet and provides internet to its WLAN network wirelessly, which usually cannot cover every corner of the house. Other devices, such as range extenders or powerline adapters, can connect to the router to extend the Wi-Fi coverage, however, each device forms a separate network with different Wi-Fi settings. In a mesh Wi-Fi network, multiple network nodes work together to form a single, unified network that shares the same Wi-Fi settings. These settings include the network name, password, control settings, and more. This unified Wi-Fi system provides your entire home with Wi-Fi coverage. Compared with a traditional single-router network, a mesh Wi-Fi network uses multiple network nodes to cover every corner of your house. You can get a stable connection, whether you’re in the basement, garage, or yard.

That said, deploying a mesh network isn't just about plugging in devices. I came across an issue while testing: how can we ensure consistent throughput across all mesh nodes, especially in large homes with multiple devices? After implementing a mesh AP system, I set out to see if each node could reliably handle the traffic.

To simulate a large home, I created a test bed with three chambers representing different rooms. I connected the root node to the internet in Chamber 1, while the two child nodes were placed in Chamber 2 and Chamber 3. Using Candela LANforge, I emulated clients across the chambers to simulate varying levels of home usage (smart devices, gaming consoles, etc.).

Each client generated 20 Mbps of TCP download traffic, totaling 300 Mbps, simulating a typical home environment. This setup tested the mesh network’s ability to handle real-world scenarios such as streaming, gaming, and browsing simultaneously. The goal was to determine if the child nodes could consistently deliver 20 Mbps per client under load, particularly in high-usage environments, without compromising performance.

The primary goal of this testing was to ensure that both the root and child nodes consistently deliver a reliable throughput of 100 Mbps throughout the home at every node (root and the child nodes), regardless of location. While achieving gigabit speeds would be ideal, our focus is on ensuring a stable 300 Mbps in total, which is more realistic and sufficient for a typical home environment. Mesh networks are designed to extend coverage and enhance performance, but this can only be achieved if all nodes perform optimally. The results of this testing will be essential in determining the capability of mesh AP to meet everyday demands.

Here are few clips showcasing how the test setup was done:

?

Analysis made while testing mesh Access Point:

In my testing, I used a mesh access point, known for its high performance and market reputation. Initially, I ran tests with 3 clients (one at each node) to evaluate throughput but recognizing that a typical home environment would have more connected devices, I expanded the test to include 15 clients, evenly distributed with 5 clients per node. This approach provided a more realistic assessment of the APs’ capability to handle higher device loads, reflecting real-world usage scenarios.

And here are the results when the topology is set to a daisy chain topology.

Now, look at what happened when I switched to a star topology for the same AP. The results were both surprising and highly informative, showing a clear improvement in throughput and overall performance.

The results from the recent tests highlight a major improvement over previous tests, and the key factor driving this change, topology. Simply switching the topology dramatically enhanced the performance of the mesh access points (AP). This reveals that optimal performance isn’t just about choosing high-quality routers or access points—it’s about using the right topology. When I changed the topology, the difference in throughput was significant.

The assurance of delivering 100 Mbps was clearly achieved in both the topologies at the root node. Regardless of the number of clients connected, root node consistently achieved the 100 Mbps throughput target. Despite the well-established reputation of the router used in this setup for delivering high performance, the expected results were not achieved at the child nodes. The throughput at these nodes consistently fell short of 100 Mbps, raising concerns about the reliability of this mesh AP and topology configuration. This outcome highlights a significant limitation, raising doubt on the system’s ability to consistently meet the demands of users in environments requiring robust, high-speed connectivity. In star topology the results were somewhat better in contrast with the daisy chain topology as it did not offer the same level of consistent performance. This highlights the importance of selecting the right mesh AP and, equally important, configuring it in the correct topology to ensure optimal performance in your home. In the revised setup, both the root node and the child nodes showed marked improvement, delivering higher throughputs and performing more consistently. This underscores the importance of not only the devices you use but also how they’re arranged in your network.

For those unfamiliar with the concept of topology, I’ve included two images that show a multi-story house where mesh APs are arranged in both star and daisy chain topologies. These representations make it easy to visualize the difference.

If you're setting up mesh APs, understanding how your network is structured will make a huge difference in the overall performance.

In the star topology, each mesh AP connects directly to the main or "root" AP. This setup ensures that all data flows directly between the individual AP and the root, creating faster, more efficient communication. It helps minimize delays (latency) because the devices don't need to pass information through multiple AP before reaching the internet.

In contrast, the daisy chain topology shows a more linear setup. Here, one AP connects to the root, and then the other APs connect to each other in a chain-like structure. This means that data from devices connected to the furthest AP must pass through each AP in the chain before reaching the root. This can create bottlenecks and add latency, especially if more devices are connected to intermediate APs.

Below is another set of compelling findings from these assessments. This time I tested by both downloading and uploading at the same time by giving an intended load of 25 Mbps for each client, highlighting how topology influences overall network performance and the AP we’re using. ?This is a very good example that will give us a very brief view about how the mesh is performing in households when you’re in a meeting or when you browse social media, you download posts and videos, while uploading photos or comments at the same time or online games.

?

Performance Testing of mesh Access Point (AP) in different topologies:

During my tests with the mesh AP, the results explained its performance across different topologies. We can see that mesh AP in star topology has performed well giving comparatively better results than in daisy chain topology. So, what's the difference? What factors are influencing better throughput and making a big difference? Here are the key reasons for this performance difference:

• Latency Considerations: Each hop in a daisy chain adds delay, increasing cumulative latency and slowing down data transfer. Star topology minimizes latency with direct node-to-root communication, ensuring faster and more efficient data transmission. And with our Candela LANforge GUI, we’re able to observe the latency when I tested the AP with different topologies.

• Direct Communication: In star topology, all nodes connect directly to the root, reducing hops and congestion. This ensures faster data transmission, lower latency, and better overall throughput than topologies where data must pass through multiple nodes.
• Fewer Bottlenecks: In daisy chain topology, data from distant nodes must pass through multiple intermediaries, creating bottlenecks as intermediate nodes handle their own traffic and relay data, leading to congestion and reduced throughput.

In conclusion, are you making a wise decision when purchasing a mesh AP? It's important to consider not only the quality of the AP but also the topology of your mesh network, as we've observed how a well-chosen topology can significantly impact throughput and performance. I hope this post gives you a clearer understanding of how crucial it is to know about mesh APs and select the right topology when setting up your mesh network. Making informed choices will ensure you get the best out of your network and optimize your connectivity experience across all your devices.