Shure Wireless Workbench<sup>®</sup> 6: Scans and Exclusions
This post will discuss scan data and how it can be used in the frequency coordination tab to generate exclusions to inform the calculator.
One really cool feature of Wireless Workbench is that it can connect to live, networked Shure devices to capture scans directly and import them into the software. It can be neat to see the spectrum, which is otherwise invisible to the human eye; but these scans also serve a deeper purpose in Wireless Workbench. It can be used to generate exclusions.
Scan Data in WWB6
When we calculate frequencies in Wireless Workbench, if you're familiar with intermodulation products and such other considerations, one of the primary goals of the calculator is to make sure that the frequencies we choose for our systems do not interfere with one another.
There's another key aspect of Frequency Coordination, which is to ensure that the frequencies you find don't interfere with the environment around you. There are several ways to define your RF environment, with most of them listed in the spectrum tab in Wireless Workbench. You can see which TV stations are operating near you, avoid certain ranges, or choose to use certain ranges.
Scan data is also one of the best ways to classify your environment.
A quick scan informs Wireless Workbench exactly what it is that the antennas of your receiver system are hearing. Or if you want to scan with additional omnidirectional antennas, you can listen to the world around you and get a worst-case scenario of what the RF spectrum in your vicinity looks like.
When you look at data in Workbench, there will be thresholds in the coordination plot that are actually processing the data. They are taking the scan data, and based on the placement of the exclusion and the scanning thresholds, using that data to inform the calculator where would be a good, and where would be a bad place to put a particular frequency.".
Let's break these thresholds down.
The exclusion threshold is the red line at the bottom of "Frequency Coordination" tab.
If you zoom in to the exclusion threshold, you will be able to move the threshold by hand or use the controls to the right. As this threshold is moved, the blue halo bars will reflect where the scan data exceeds the threshold. This threshold will exclude any noise that goes above the exclusion threshold line.
This is a really good way to set the threshold for ping, as to what is too noisy for my systems.
The scanning threshold is the orange line at the top of the "Frequency Coordination" tab.
If a scan goes above that line, Wireless Workbench will not only avoid that spectrum, but it will assume the presence of an active transmitter there, like a handheld or a body pack that is not our own.
The important differentiation between the exclusion and scanning thresholds is that the scanning threshold will assign some generic spacing, like a channel-to-channel spacing or channel-to-intermod spacings, so that the calculator doesn't put any frequencies too close to this frequency.
This is quite significant, since it makes Wireless Workbench a friendly neighbor when it comes to frequency coordination. If you capture very loud carriers in a spectrum, such as with a sampling threshold, the frequencies that Workbench calculates will not violate that frequency, which is an important aspect.
All the blue bars and rhombus peaks detected are shown visually on the coordination plot. You can also go to the additional exclusions dialogue; this table shows exactly the same data, in a tabular format. But all the ranges and single exclusions correspond precisely to the detected scan, peaks, and ranges, which are in the coordination plot from the loaded scan.
You can always load multiple scans and choose whether or not to apply any of these scans by using the checkbox at the bottom. When you calculate frequencies, Wireless Workbench will then use the exclusions to automatically find the best frequencies for your systems within the defined exclusions.