It is not unusual for a wireless engineer to hear this question: “How many access points will I need to provide coverage for my users?” I consider myself lucky if a scaled floor plan accompanies this question. Sometimes there is an expectation that a wireless engineer can determine access point quantity and location just by looking at a map; if there is, I want that super power! The truth is there is no crystal ball that will determine a wireless design.
While there is no crystal ball, there are several methods we can use to develop a wireless solution such as: a Predictive Survey, Passive Survey, Active Survey and the AP-On-a-Stick Survey. One or a combination of several methods can be used. I’ll breakdown the extremes in this list, starting with the Predictive Survey.
Predictive Survey – Imagine you have a new building being constructed and as soon as your occupancy permit is approved, people will immediately occupy the space and expect to begin work. In a fast-paced scenario as this, there may not be an opportunity to physically walk the building to develop a wireless solution. This is where a Predictive Survey comes in. This method uses computer software to simulate a wireless environment to predict wireless coverage. We can also use one of the other (3) survey methods to validate the predictive survey models.
Heat Map with a Predictive Survey
AP-On-a-Stick Survey – On the other extreme is the AP-On-a-Stick (APoS) survey. This method uses an actual access point temporarily mounted at multiple locations with the signal level being tested around each location. This method is mainly used for a complete wireless redesign or a greenfield scenario. This tried and true method is also recommended for challenging and/or unique environments like warehousing, manufacturing, healthcare and higher education. Without using any of these methods, you might as well throw darts at your floor plan to determine AP locations.
AP-On-a-Stick (APoS) Kit
Alex Zeltmann is an ABS veteran and a rockstar Infrastructure Engineering Manager. With over 10 years of experience in networking technology, he leads ABS’ team of implementation engineers as they integrate the latest technologies for ABS clients.