Business-critical applications aren’t connected by cables — they’re Wi-Fi-first and in many cases, Wi-Fi-only. Phones, tablets, laptops, barcode scanners … the devices you rely on day after day to run your business need a reliable wireless network and capacity is key to ensuring everything works flawlessly together.
Identifying your business’s Wi-Fi capacity requirements is one of the most important elements covered in the 3 Steps to Great Wi-Fi Every Day Guide. Here, we’ll expand on what goes into a capacity calculation and show how easy Ekahau makes it to design an amazing wireless network perfectly tuned to your coverage and capacity needs.
In this guide, we’ll cover:
What is Wireless Network Capacity?
Wireless network capacity or capacity utilization is a network design requirement detailing the number of Wi-Fi-enabled devices that can be supported concurrently on a wireless network based on the applications used, bandwidth being consumed, and the number of available Wi-Fi radios.
Along with coverage and channel utilization, understanding your network capacity needs is a key requirement for designing a wireless network. This capacity health heatmap shows a school floorplan that has been segmented into two different capacity requirement areas where we’ve optimized for higher device density in the auditorium based on the expected usage.
Think of wireless network capacity like the patrons at your local club (Wi-Fi-enabled devices) trying to place their orders and check out at the register (access point). When it’s early in the evening and the crowds are low, it’s easy to walk right up, place your order and pay. But as the night picks up and more patrons compete to place orders, the underequipped service staff has a hard time keeping up with all of the orders that need to be processed which leads to frustratingly long wait times for everyone in line.
When you design for business Wi-Fi, you need to make some careful considerations so that you can maintain the performance you expect under times of normal use as well as times of high utilization.
How to Identify Your Wi-Fi Capacity Requirement
Here is a quick overview of how to identify your Wi-Fi capacity requirement and how to use those requirements when designing a wireless network with Ekahau AI Pro.
The key takeaway here is that improper planning might result in excessive contention and congestion, and lead to poor performance on your network. Wi-Fi is a contention-based medium, meaning devices are competing for time to communicate on the network. When there are too many devices competing for airtime, throughput decreases as devices wait for an opening with an available access point or have to retransmit their data. More devices = more contention = more collisions = more retransmissions. Increased contention translates to low quality, buffering, latency, and frustratingly slow application use for end-users, and lots of help desk tickets for IT or the network owner.
3 Considerations for Capacity Planning
1. Devices being used on the network. The types of wireless devices that connect to your network can range from the latest generation Apple and Android phones to decades-old barcode scanners in warehouses. Take inventory of all business-critical devices and optimize for what is known while leaving room for the unknown.
Questions to ask: Will there be phones, laptops, handheld scanners, or printers, and how many of each device will be used? Can stationary devices like TVs, printers and other networked equipment be hard-wired instead of wireless? Cable it if it doesn’t move!
2. Applications and throughput. The range of applications and throughput is just as wide as the device types themselves. It’s important to consider how bandwidth-hungry your applications are when planning your capacity. Here’s a sample data usage table to really show the variances:
|HD Video Streaming
|4K Video Streaming
Just remember, it’s unlikely that every user will be running every application on every one of their devices at the same time. The human brain is only capable of so much multitasking.
Questions to ask: How will the devices be used on the network? Will they require voice, HD video streaming, etc? How much data is actually transferred on the network?
3. Future growth/needs. Step 3 of the 3 Easy Steps to Great Wi-Fi Every Day details the importance of performing periodic health checks to ensure your network continues to meet your needs. Most new network designs build in excess capacity for growth and health check surveys are a great way to visualize performance over time so you can be proactive about addressing capacity requirement changes before it becomes an issue. Also, remember that wireless interferers and interfering APs also affect your capacity — performing periodic health checks is extremely important in order to find and remove these interfering devices.
Questions to ask: If your requirements change, will your network be able to accommodate that growth with little or no changes? Do you have interferers you might not know about affecting the performance of your network? What is our plan for running periodic health check surveys?
How to Design Wi-Fi Capacity in Ekahau AI Pro
Ekahau AI Pro simplifies the capacity utilization formula down to a few simple device and usage profile inputs and gives you the ability to create your own unique custom profiles to match the exact devices and applications that you or your customer will be using on the Wi-Fi network.
It also lets you assign multiple capacity areas to account for networks that have a wide variance in capacity requirements for different parts of the floorplan. Here’s a quick overview of how to design a wireless network and strategically place access points (APs) for different capacity areas.
Create Wi-Fi Requirement Areas for Different Capacity Densities
A simple office floor plan with little to no variance in capacity requirements may only need a single requirement area. If your network has areas with significant changes in device density (like the auditorium of a school or warehouse facility with connected office space) you’ll want to set up multiple requirement areas.
Establish Device Profiles
Once you have imported your floor plan, scaled your map, and set your coverage requirements, you can enter your usage and device profiles to simulate a realistic view of your site’s capacity health. Click on the Project menu and select Device Profiles to define the devices you expect to be used on the network. Choose from predefined device profiles, or create your own.
Establish Usage Profiles
Your next step should be to define how those devices will be used on the network. Click on the Project menu and select Usage Profiles. For usage profiles, you can again choose from predefined profiles or create your own. Just make sure you define your requirements as precisely as possible because while it is not possible to model capacity perfectly, as you’ll never truly know the exact number of devices or their exact usage levels, by establishing and documenting your best estimate, you’ll have a far better resulting Wi-Fi design today and you’ll make it easier to optimize with periodic health check surveys over time.
Place Access Points for Wireless Network Capacity
If you’ve already designed your network for coverage, try switching your heatmap visualization to Capacity Health and see how well your capacity requirements are being met. Areas in Green are perfectly capable of meeting your defined capacity requirements, and red represents areas that don’t have enough Wi-Fi radios / bandwidth to serve a specified number of Wi-Fi clients and their expected capacity requirements. Address issues by modifying your design. You may need to consider APs with external antennas and a more focused coverage pattern so you can add more radios to a high-density area, ensuring a better spread of clients between radios while reducing overlapping and contention, therefore increasing capacity.
Best Practices for Designing High-Density Wi-Fi Networks
More APs Doesn’t Always Mean More Wi-Fi Capacity
One of the biggest misconceptions when trying to fix a capacity issue is to just add a bunch of additional access points (APs) to your network as needed to accommodate the additional devices. Unfortunately, just adding more APs is not the right answer. Whether you are designing for a new network or upgrading/adding on to an existing network, you need to design with capacity requirements to meet your business’s needs. The simple idea of just adding APs may help, but it may also reduce your capacity by increasing channel contention / overlapping.
Quick tip: when you add another AP in the same location on the same Wi-Fi channel, you do not increase capacity, you actually reduce capacity! Have no fear — stay tuned for our next blog and webinar, where we will be covering all things Wi-Fi channels and channel planning!
Capacity Planning Throughout the Lifecycle of Your Wireless Network
Once you have defined your requirements, you can start building your predictive design and then deploy your network. But capacity planning doesn’t stop once you have deployed your design. The optimization phase of the Wi-Fi lifecycle is the ongoing monitoring and maintenance required for a high-performing reliable wireless network. You should be constantly gathering data on your network to ensure your design is meeting the capacity needs. Identify trends on your network like peak traffic times, packet loss, or throughput performance and work optimizations into your ongoing network maintenance. The biggest thing to remember is that network demands can change over time, and you need to ensure your network is up to the task.
Want to Learn More?
For even more tips on Wi-Fi capacity planning best practices, check out the on-demand recording of our recent webinar, “Demystifying Wi-Fi: Capacity Planning Made Simple.” In this webinar, we dive deeper into Wi-Fi capacity planning by discussing:
- How to define capacity requirements for different areas in a floor plan
- The factors that play into setting Wi-Fi capacity requirements
- Why you can’t rely on formulas (users x average number of devices)
- Plus, best practices for how to increase the capacity of your wireless network