Designing and Maintaining WLAN for High Density Environments

Designing and Maintaining WLAN for High Density Environments

Wireless is no longer a luxury in most spaces. Today. access to a wireless network is almost expected. In an office environment, you will typically have a decent understanding of how the network will be used and by how many people. In public spaces or high density environments though, it’s an entirely different ballgame. A wireless network needs to be flexible, adaptable, and capable of handling a wide range of network pressures. Due to the massive influx in wireless and mobile devices using the incredibly narrow 2.4GHz bandwidth, Wi-Fi designers are feeling the pressure.

Below, we take a look at how network teams can intelligently design a wireless network for high-density public spaces such as lobbies, courtyards, and auditoriums.


High density WLAN typically refers to an environment where client devices will client devices are in densities greater than the coverage expectations of a normal enterprise deployment. Cisco writes “in a traditional office setting, access points may be deployed for 2,500 to 5,000 square feet with a signal of -67 decibels in millowatts (dBm) coverage and a maximum of 20 to 30 users per cell. That is a density of one user every 120 square foot (sq. ft.) and yields a minimum signal of -67 dBm.”

 

In a high density environment, the density of wireless clients increases significantly. Densities are also no exactly uniform across the environment. What affects connectivity in a high density environment is a degradation in the signal-to-noise radio. This interference can be cut down by improving proper spatial use. Furthermore, the variety in user behavior will also affect the overall performance of the network, and while this can’t necessarily be fixed, it can be prepared for with proper access point spacing.

When building a high density wireless network, it’s important to have a firm grasp of which applications will be used and how much throughput will be consumed per user. Generally, it can be expected that per-user throughput requirements for video applications vary between two and four Mbps while audio streaming ranges between 0.1 and 1 Mbps. As more users access the network, throughput per user decreases causing slower transmission
rates.

Here are six best practices for managing your high density WLAN:

Identify High Density Areas – start the design process by using a live RF tool to identify areas of high density.

Use Dual Band Access Points – use dual band concurrent access points (2.4GHz and 5 GHz radios) to maximize available throughput for users. Always enable both radios.

Design Access Point Overlap – Design the AP placement in high density areas such that each client always sees two to three access points.

Upgrade the Wired Network – Ensure that there is sufficient bandwidth on the wired network to support higher
throughput APs by deploying PoE Gig switches at the edge and 1G or 10G switches at the aggregation/core layer

Load Balance Traffic – Set the threshold on the AP to effectively utilize an over the air resource to ensure that you
load balance the traffic to all of the access points that can be seen by clients.

If you’re looking to deploy a wireless network in a school, consider it best practice to limit yourself to one access point per classroom.

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Doug Atkinson

President at Solutions Review
An entrepreneur and executive with a passion for enterprise technology, Doug founded Solutions Review in 2012. He has previously served as a newspaper boy, a McDonald's grill cook, a bartender, a political consultant, a web developer, the VP of Sales for e-Dialog - a digital marketing agency - and as Special Assistant to Governor William Weld of Massachusetts.
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