In a previous blog post we had approached the contentious topic of the use of Wi-Fi tracking in malls ( which had demonstrated the significant improvements that have been made to Wi-Fi technology in the past decade (even if used maliciously).

One of the other notable improvements emerged in the form of Wi-Fi detection and signal analysis, under the brand AirMagnet. This software, produced by Fluke Networks, detects the strength of Wi-Fi signals of your surroundings as you move through a building. The program allows you to upload floor plan drawings on which it will superimpose the readings from the frequency scan measurements.  The result: a colourful display of Wi-Fi signal frequencies present in the area, as shown above.

This program is immensely useful if your business or place of work is aiming to install a new wireless network or wireless access points (WAP) as having interference from existing Wi-Fi signals can slow a poorly placed or improperly calibrated new one.

Signal strength is measured in dBm (if you really want to know, it stands for the power ratio in decibels (dB) of the measured power referenced to one milliwatt). On the nifty colour spectrum in the picture, this range starts at 0, which is the relatively the strongest signal, and stretches to -100, which is relatively the weakest. However, the optimal signal strength range actually falls in the yellow, between   -30 and -40dBm. Higher values actually prevent a decent signal from being received, where lower values, understandably, cause the same problem. A useful fact to consider, different devices have different minimum dBm requirements in order to function, which is extremely important in regards to iPad functionality. One study showed that:

“The connectivity expectation by executives is the same as their laptops, though the performance of the iPad can make this an unrealistic proposition, since the iPad’s average 5GHz transmit power of 10mW (10dBM) does not compare with the 30mW to 50mW (15dBM to 17dBM) of a typical laptop. This means that the performance, range or both will be significantly diminished for the iPad or any device where these parameters have not been part of the design effort.”

In other words, iPads have a much higher minimum signal strength requirement than most laptops. So while one wireless access point may permit everyone to connect a laptop in your office, it is possible that only people within its vicinity will be able connect an iPad. This is an important consideration, especially for us here at Fancom, while designing your wireless infrastructure.

But if you’re not yet convinced that professional wireless design is important, take another look at the picture. Two WAP locations are easily identifiable in the yellow regions, where the increased strength highlights the signal’s origin. The immediate surroundings of these two WAPs offer decent signal strength to anyone nearby; however, a noticeable decline in strength, shown in blue, snakes its way between the expanses of the signals. Because the two WAPs were placed too close together, there is signal attenuation where their frequencies merge. Problems like this are easily avoidable when a Communications Consultant in involved in the design process.