WiFi Network Design: a practical guide for planning and implementation

Once upon a time, wireless network design planning involved grabbing a floor plan and plotting locations for access points with a protractor. This was a tedious and time consuming activity. Access points no longer require manual power and channel settings. Wireless planning has also become much more simple, thanks to great software options. However, the downside is that wireless devices and the world of WiFi continue to get more complex than ever.

Initially wireless network design involved a large emphasis on coverage, as only a select group of people used and relied on wireless on a regular basis. With more and more companies opting for BYOD, it is hard to find a regular user who does not rely on wireless every day and often on multiple devices. Needless to say, wireless network design has changed significantly.

This article provides engineering insight and practical techniques for designing, planning and implementing a wireless network that is robust, compliant and without borders.

Key elements of a robust and reliable network design strategy should include the following considerations.

Plan for capacity, not just coverage

Not that long ago, designing a WiFi network was pretty much focused around physical site surveys to determine the number of access points needed to provide enough coverage. Afterward, you would evaluate the results and compare the amount of APs against an acceptable minimum of signal strength, and the whole WLAN design would be deemed a success. Going down this road is suitable for WLANs that are planned for coverage but certainly is not the right approach to meet capacity requirements.

In this method, key elements like the number of concurrent users, applications’ bandwidth needs are left out. Wireless engineers and IT consultants need to fully understand the network design requirements to ensure a successful design. This will help reduce the need for further site surveys after deployment of the WiFi infrastructure in the long run.

Key points to consider:
  • Types of applications expected in the network, e.g., web browsing, VoIP calls, software, or video streaming.
  • Technologies that the WiFi infrastructure supports (802.11 a/b/g/n/ac).
  • Number of client devices that connect to the WiFi network simultaneously (helps to determine the number of spatial streams, technology, and access point types).
  • Key geographical areas you need to cover and provide WiFi in and the number of concurrent devices per area.
  • Power constraints. It’s way more useful to have an infrastructure equipped with PoE+ that allows you to support high performing access points.

Channel utilisation

The WiFi network management platform should have incorporated a tool to manage radiofrequency. So, it can dynamically assign access points channels, adjust the access point transmit power, and provide coverage lapse mitigation for the WiFi infrastructure.

For instance, for the 802.11ac wireless standard, radio frequency management should be executed at 20, 40, and 80MHz channel widths. Different client devices will support different channel widths for the 802.11 protocols. Client devices that support the wider channel widths will support higher bandwidth within the particular protocol.

Estimate how many client devices can be allocated per band. With newer technologies, more client devices now support dual-band operation, and hence using proprietary implementation devices can be steered to 5 GHz. A typical design approach is to do a 30/70 split between 2.4 GHz and 5 GHz.

To know more about how software managed WiFi is transforming businesses, read our article.

Think mobile – Again, think mobile

A good network design needs to be built up, also, for mobile – it is very crucial to the success of any WiFi network deployment in the recent times. The wireless design for deployment should be optimized for every device, from smartphones and IoT to computers and tablets. Having the right wireless design comes first, especially when ensuring elevated device performance and overall mobility for a better end-user experience. This also means considering features such as 802.11r/w/v.

SSIDs

To maximize performance in the wireless space and simplify deployment, try to minimize the number of SSIDs being broadcasted into the environment. The drawback of enabling more SSIDs is that it generates extra channel utilization due to overhead. A target of three SSIDs per access point provides for a flexible yet straightforward deployment model.

For example, you can have one open SSID for all unmanaged devices (daily guests, consultants, BYOD, customers..) with captive portal authentication. A second SSID for 802.1x authenticated users and devices. And a third SSID for particular use cases or specialized wireless devices, e.g., Wi-Fi-enabled VoIP phones, non-802.1x capable devices, or specialized network devices.

BYOD

Users want to connect their personal devices to public and private WiFi networks. It’s the standard. Just make sure that users are routed through a web content filter to provide a secure browsing experience to all users. Also since there are multiple devices involved, the BYOD solution should be compliant with local and global data privacy regulations. To understand how data privacy has changed digital businesses in the past few years, check out our latest report.

Lastly, a per-user bandwidth consumption limit is essential in the network to manage its performance. It is important to take into account that the BYOD trend has a direct consequence on the bandwidth and throughput requirement.

Bandwidth limitation

The final recommendation for a better WiFi network design is to put in place a per-client device bandwidth limit on all the WiFi network traffic. Priority must be given to applications such as video and voice. For instance, 5 Mbps is a good recommendation for a per-client bandwidth limit in a high-density environment.

With multiple connection modes and device types becoming a common norm at offices, hotels, guest houses etc. it won’t be wrong to say that a poorly planned and implemented network design can negatively impact the IT productivity of your entire organization. It might be even detrimental in some situations and could hamper critical business processes. Hence IT infrastructure teams must keep all these parameters in mind in order to think for the longer run and design a WiFi network that is robust, compliant and hassle free.