Good WiFi Design, the journey from Pre to Post Install

Steve Jobs once said ‘Design is not just what it looks like and feels like. Design is how it works’ which is exactly why having good structure and design for a WiFi network can dramatically affect how it performs.

When deploying a WiFi network, thought has to go into the design months before it reaches installation stage. There are many questions that need to be discussed before a customer considers budgets, hardware and vendors as good WiFi design can dramatically change based on these factors. Below are a few examples of what needs to be understood at the design stage.

• What is the primary purpose of deploying a new WiFi network?
• How many devices can I expect to be using the network simultaneously?
• What devices will be using my network? Laptops? Smartphones? Tablets? Barcode Scanners?
• What applications will be in use & which warrants a higher priority?
• What environment is my network being deployed in? Office? Warehouse? External Coverage?

Once these questions are answered, a design engineer can start to consider how best to implement a wireless network. Scalable floorplans or maps are required at design stage, as visualising the network is integral to show how communications are taking place and how channelization is addressed. The engineer will need information from the site itself such as building materials, girder locations and ceiling heights, this will allow attenuation to be calculated and any propagation issues should be highlighted at this point.

The building will now be drawn, scaled and 3d modelled. The engineer can then consider how many devices will be communicating across the network. This number does not have to be exact, however the more accurate the number, the better network performance can be optimised to meet the needs. If we know that 100 laptops, and 100 smart phone users need to be accommodated, then this number is input into the survey software. This then means the software understands the capacity needs, which is important when we look at distributing clients across multiple access points and ensuring an access point isn’t ‘swamped’ with too many devices whilst maintaining high data rates.

We now have a virtual building, with a set of criteria for our WiFi network to meet, so the design engineer can now start the process of physically plotting access points on the floorplans. This will always be done alongside cross checking that the network criteria are being met. The ideal WiFi network will have smaller coverage cells, with high data rates configured so that devices can communicate effectively, the physical position of the AP’s will change depending on where the network is being deployed, and the restrictions and challenges that individual buildings offer. These can generally be worked around by adding or taking away access points or introducing different types of access point antenna.

After the process of physically putting the AP’s on to the floorplan, and checking propagation and other network criteria, the design engineer will have a full design which considers coverage and capacity. This can then be handed to the installation team to run infrastructure and mount the AP’s before the design engineer is called upon again, this time to optimise and commission the network to ensure device connectivity matches the predictive design put in place. It is always recommended to have a verification/optimisation survey done in case any misconfiguration or hardware issues are addressed before the network is pushed live.