Legacy Wi-Fi networks are collapsing under the volume of simultaneous connections. Wi-Fi design must shift from coverage to capacity.
In an overwhelming number of organizations, Wi-Fi networks are struggling to support device density. In addition to large numbers of smartphones and tablets, networks are supporting growing fleets of IoT devices. Global wireless connections are on track to skyrocket from 21 billion to 39 billion by 2030, with Wi-Fi accounting for nearly a third of all global IoT connections.
Issues arise when Wi-Fi networks become seriously overcrowded. The proliferation of smart devices combined with the transition to remote and hybrid operations has fundamentally altered Wi-Fi usage patterns. Organizations must support more wireless users, devices and traffic than ever before, and it’s only getting worse.
As wireless demands continue to increase, density has become a central focus of Wi-Fi network design. The key is to ensure that the network can handle thousands of simultaneous connections.
Coverage Is No Longer Enough
Designing a Wi-Fi network for a high-density environment requires a transition from coverage-based planning to capacity-based planning. The number of APs cannot be based on square footage alone. The required bandwidth must be calculated mathematically, assuming that everyone occupying the space will carry an average of two active Wi-Fi devices.
Adding more access points (APs) might seem like a solution — after all, the closer a wireless device is to an AP, the better the data rate. It stands to reason that more APs would increase the raw capacity of a wireless LAN by reducing the distance between APs and devices.
It’s not that simple, however. Adding APs can actually cause oversaturation that degrades wireless LAN performance. Devices try to access multiple APs with similar signal strength, much as a car radio picks up signals from multiple stations that broadcast on similar frequencies.
Key Elements of a High-Density Design
The design constraints should be based on the least capable, most important device. In an entertainment venue, for example, the most critical devices might be legacy ticket scanners that only support older Wi-Fi standards. The network must be optimized around their limitations.
In high-density environments, the primary enemy is not a weak signal, but co-channel interference and airtime congestion. The key is to build many small, highly focused coverage zones called micro-cells. Focused directional antennas aim the RF energy precisely at specific sections of the facility. The facility’s structural elements can also help absorb competing signals.
For particularly high-density environments, planning should optimize the use of the wireless spectrum and consider load balancing and Quality of Service to accommodate variations in traffic patterns. The design should also allocate a realistic per-device bandwidth cap, such as 5MB per user for web browsing and social media.
The Importance of the Latest Wi-Fi Standards
Slow devices waste airtime, causing fast devices to lag. Enforcing network efficiency protocols helps keep traffic moving. Wi-Fi 6, Wi-Fi 6E and Wi-Fi 7 use Orthogonal Frequency Division Multiple Access (OFDMA), which allows a single AP to talk to multiple client devices simultaneously instead of waiting in a digital queue.
Ideally, capacity planning should also anticipate evolving standards and future requirements. For example, the Wi-Fi 7 standard was developed to provide ultra-low, predictable latency and vastly increased capacity, even when hundreds of devices are connected. However, reaping the benefits of Wi-Fi 7 will require upgrades to the core network backbone.
The best wireless design will fail if the wired components behind it choke on the traffic volume. Multi-gigabit switches supporting PoE+ or PoE++ to deliver both high-speed backhaul and the necessary wattage to enterprise APs.
Why It’s Best to Call in the Experts
Given the mission-critical nature of Wi-Fi, it’s important to get capacity planning right. That’s why it’s a good idea to work with a managed services provider (MSP) with demonstrated expertise in WLAN design and implementation.
An MSP will begin by assessing the types and numbers of devices and applications that are being used. This assessment is needed to get an idea of the aggregate bandwidth required in the coverage area. After that, the provider will usually conduct an onsite survey to identify signal strength and any sources of radiofrequency interference in various locations.
That information can then be loaded into design software to create visual representations of the environment, including heat maps that illustrate anticipated signal strength and application throughput. With this type of predictive modeling, the provider can simulate a variety of deployment scenarios to identify the most promising options.
Wi-Fi has become a business necessity, but many organizations are coming up against the limits of their existing Wi-Fi infrastructure due to rapid increases in device densities and bandwidth requirements.
