In this article, we look at five ways you can use 7SIGNAL to analyze client device roaming. This includes using it to understand roaming behavior, interference issues, device specifications, and more.
Why is roaming so hard to track? Client roaming on Wi-Fi networks presents a challenge for tracking due to the decentralized decision-making process inherent to wireless devices. Each device autonomously decides when to disconnect from one access point (AP) and connect to another, based on its proprietary algorithms which consider signal strength, performance, and other factors.
This lack of a standardized criterion for roaming, coupled with the rapid nature of these transitions, makes it hard to monitor and analyze from a network perspective. Roaming events are not typically communicated to the network infrastructure, leading to a lack of visibility into the roaming behavior of devices. The diverse range of client devices, each with their own roaming thresholds and behaviors, further complicates tracking efforts. As a result, ensuring a seamless and optimized roaming experience becomes a complex task for network administrators who must cater to the idiosyncrasies of myriad devices.
Here’s how 7SIGNAL can help you optimize client device roaming:
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To begin, let’s take a look at how the 7SIGNAL client agent can be used to understand roaming behavior at the device level.
For those unfamiliar with Mobile Eye, it consists of two elements. The first is a software agent that’s downloaded onto client devices — like smartphones, laptops, and tablets — and used to monitor network connections from the perspective of end users. The second element is the Mobile Eye dashboard, which can be used to visualize and audit device and network performance based on data collected via the software agent. In essence, it helps network managers visualize what’s happening in their Wi-Fi ecosystems and enables them to make informed decisions regarding network optimization, device acquisition, and enterprise mobility strategy.
Related to the topic at hand, one way Mobile Eye can be used to optimize device and network performance is by leveraging the data it collects to analyze client roaming. Check it out:
The image above is from the Mobile Eye dashboard. More specifically, it’s the Roaming Analysis dashboard for a specific device operating within our Wi-Fi environment. It provides insight into a variety of roaming-related metrics, enabling us to monitor the device’s behavior as it operates within our network.
By mousing over the dots in the Signal chart, we can even see the signal strength of the access point the device was connected to juxtaposed with the signal strength offered by neighboring access points:
In the case above, we found that this particular device was operating at around -70 dBm. While that’s technically within the ideal range of Wi-Fi signal strength (which is between -55 dBm and -70 dBm), we also discovered that there were closer access points offering -53 dBm. It may seem like a small difference, but it’s one that could have a profound impact when extrapolated across our entire fleet.
In any event, what we can conclude is that the observed connectivity issues don’t stem from the Wi-Fi network, per se. Instead, it appears that the client is “sticky.” That is to say, it’s sticking to distant access points rather than roaming over to better options. The question then is: why is this happening? More investigation is required.
However, before we take that next step, it’s worth pointing out that there’s something suspicious happening related to roaming. Take a look at the Channel / Band chart. Mousing over the line, we discovered that as the device went from good signal strength to poor signal strength and back again, the channel and band switched:
The device was originally operating on the 2.4GHz band before switching first to channel 56, then to channel 100, then back to channel 1. This tells us that the Wi-Fi network is not designed for the 5GHz band. While this client was trying to move to 5GHz — perhaps being pushed to do so by band steering protocols — once it got onto a 5GHz network, it was clearly not very comfortable. So, it went back to where the signal was strongest, which was on 2.4.
As a prescription for this particular issue, we can increase the transmit power of 5G by a few dBms. Alternatively, we may need to do a complete redesign of our network to better accommodate 5G.
In any case, let’s move on to interference issues. Using Mobile Eye, you can identify which bands are suffering from the most interference and use this information to inform and direct future connections.
For example, examining the same network as above, we discovered that 5GHz connections were preferable to 2.4GHz connections on the grounds that 2.4 suffers from a good deal of interference.
Check it out, here’s what interference looks like on the 2.4GHz band:
Now look at what the device saw when it roamed over to the 5GHz band:
These charts indicate that devices are spread out and using different channels across the spectrum when connecting to 5G. In other words, there’s practically no interference!
So, we’ve already used Mobile Eye to identify two problems on this particular network. First, when devices in this environment are on 5G, they have roaming issues because the network is not set up to accommodate the 5GHz band. Second, when they use 2.4, they have co-channel interference issues because there are too many devices accessing channels on the 2.4GHz band. From here, we can come up with a strategy for improving 5G accommodations and reducing traffic on 2.4.
Now then, let’s return to that “sticky” client. We can actually use Mobile Eye to zoom in on relevant device specifications. Take a look at the Details section on the left-hand side of the Mobile Eye dashboard:
This is great for creating reports and detecting devices that perform poorly. In the example above, we've got an old device. It’s a Windows 10 tablet that uses an 8260 adapter.
Now, it’s worth pointing out that the vast majority of roaming issues stem from client adapters and drivers, since they’re the ones interpreting what’s going on in surrounding environments and making connection decisions based on what they find. So, to solve for stickiness, a good place to start is by looking at the Details section and scanning for old adapter or driver versions.
Let’s expand on this a bit. You can use 7SIGNAL to collect information on adapter and driver combos and run reports to analyze their performance. Check out the Client Adapters: Roaming Problems dashboard:
In the image above, we looked at the adapters accessing our network. We found that there’s a mix of devices using older adapters, like 8260s, and newer ones geared towards Wi-Fi 6. In addition, we noted that the only drivers that encountered roaming problems were the 22.40.07 drivers and the 20.70.23.1 drivers, which are both quite old.
Okay, one last thing. This isn’t a 7SIGNAL-specific tip, per se, but it’s still extremely helpful when trying to determine whether you need to update your client fleet.
To determine the latest versions of Wi-Fi drivers, or to estimate how old existing drivers are, you can go to Intel’s Wireless Wi-Fi Drivers pages:
They do a great job of providing adapter and driver information online; and because they make a significant portion of wireless LAN adapters for Windows, it’s an extremely useful resource.
For instance, if you scroll to the description sections of the various driver and adapter pages, you can see that they list version information and indicate any important information, like end-of-life details.
So, if you notice that you’re having roaming issues with a specific device, and that other devices with the same adapter / driver combo are having similar issues, you can look up the various specifications on Intel’s website and determine whether the roaming issues stem from their side. If so, you can use this information to plan your next steps.
There you have it. Those are five key ways you can analyze client device roaming to optimize performance across your enterprise Wi-Fi ecosystem.
Eric Camulli, VP and Customer Success Officer at 7SIGNAL, covered the subject above in a recent segment on our weekly webinar. You can watch the full recording here:
We’re always here to answer your Wi-Fi questions at 7SIGNAL. Our enterprise Wi-Fi optimization platform helps you plan and execute a healthier network. Contact us to learn more.
7SIGNAL® is the leader in enterprise Wi-Fi optimization, providing insight into wireless networks and control over Wi-Fi performance so businesses and organizations can thrive. Our cloud-based platform continually tests and measures Wi-Fi performance at the edges of the network, enabling fast solutions to digital experience issues and stronger connections for mission-critical users, devices, and applications. Learn more at www.7signal.com.