Network Management

How accurate are the Airwave heatmaps?  We have a small trailor that only has 3 AP105s.  Airwave shows that there should be proper coverage except for a small area in an office.  We performed a survey at the site and the coverage was worst then what Airwave is showing. We have seen the same issue at another bigger site as well.

 

If we add all the wall in Airwave for the trailor, the coverage shows worst then our survey results, but at least it shows where coverage holes might be.  How can Airwave be more accurate?  We have the floor plan up to scale, we even use a laser measurement tool to make sure. 

It really depends on the accuracy of the data and that accuracy comes with more APs.  I am not sure of this trailor but with only 3 APs in there, you may not get as accurate a picture of this coverage hole as you would with more APs as there are then more data points to collect in terms of inter-AP signal quality.  Now, in your example, the AP may be at the edge of the deployment and this other area may be off to the side.  In this case, with no other data in terms of wall type and RF obstacles, VisualRF is predictive in nature.  As such, your mileage may vary in terms of accuracy

If we had more APs in the area for better accuracy we wouldn't have a coverage hole :smileyvery-happy:

Agreed, and that comes back to other factors with which to establish better data like adding in walls, etc...  

 

 

Hmm, I was informed that the walls are not needed in Airwave, but it's looking like it would be more accurate to have them.

Only on the edges of the floors or where there are "edges" for the APs

I have also created regions within AirWave VisualRF (In fact, conducted a passive site survey with a multi-story concrete structure this past weekend) and I found that regions in combination with walls provide a more accurate depiction of what an actual deployment will be. The region can be set to the environment (open space, cubicles, offices, etc.) that best suits your environment. When regions are used instead of walls, you have the option to assign an attenuation (i.e. concrete, drywall, wood, etc.) to the walls of the region. There is no longer a need to create additional walls.

You are using the region for planning, but I'm talking about to see how the actual signal is already at a deployed location. We need to see where there is potential holes at locations that were deployed a long time ago.

 

What do you mean the edge walls and the edge of APs?

I misunderstood your situation, but the same can still apply. For locations that have already been deployed, import your floorplan into Airwave and set up your regions. Given that the site has already been deployed you also know where holes within your network exist. You can then set up regions within one building with the environment settings that best suits the different environments within the building. Then you can perform a better comparison between what you saw on site and what VisualRF (on Airwave) shows. From the comparison you can better determine the accuracy of VisualRF.

 

 Playing with Airwave, it looks like adding a region 100% attenuation and client probability to High.  Also added all the walls within the building. This matched our survey almost 100%.

I am glad that the regions helped you. When generating heatmaps with VisualRF I set my target signal strength to -65 dBm. My only problem is that signal strength for anything worse than -65 bleeds through the concrete walls. Before I posted this issue on Airheads I was concerned that the signal at actual sites would just bleed through all walls. One contributor stated that when configuring access points, set the minimum power level to 12 and the maximum power level to 18. The discussion thread is attached via hyperlink below.

Alternative to Probe Response Threshold

I hope that helps as well 

Hi Salvi,

 

From my experience of using Airwave VisualRF so far is:

1) For office environment (in real life), the predictive heatmaps are pretty similar in shapes. But, there is around 10dB difference between what we see in a real site survey compared to the predictive heatmap in Airwave. The predictive heatmap in Airwave is set at default environment (office). 

2) Draw walls to the best knowledge will give more accurate predictive results

3) Places where we see coverage less than the light blue (lower than -75db) are place of concern. This gives a good idea on how big is the area that we are trying to cover and where we are lacking in coverage without having to send someone to do a physical site survey. 

4) We have done around 3-4 physical site survey in different locations and compare it with the predictive heatmaps and they are pretty close (i would say consistently with about 10dB difference). 

 

Besides this, we are compiling our own metric to determine Access Point which might indicate problems with coverage using the client sessions data by looking at the client signal strength. 

 

 

Accurate location data • Determines GPS location coordinates for APs and controllers on any floor plan by setting latitude and longitude coordinates, and displays altitude as floor number.

 

Could you advise me on how accriate the GPS signal is on the software?