V-Soft Communications Newsletter: 11/09/05

In this Newsletter:

Canadian Broadcast Corporation (CBC) chooses V-Soft

International Telecommunications Union (ITU) Propogation Model

Airport Tower Database Soon to be Available Once Again

2004 Census Estimate Now Available

What are the 2005 Map Update Datasets???

Microwave Frequency Search Program

V-Soft 101: D/U Tutorial Study in Probe 3

CBC Chooses V-Soft

The Canadian Broadcast Corporation has purchased V-Soft Communications’ allocation software package to be used for in-house AM standard-band allocations analysis. V-Soft Communications’ President, Doug Vernier said, “After a thorough examination of their options we're proud that the CBC has selected V-Soft as their AM allocations software provider.” Vernier and V-Soft’s Director of Research and Development, John Gray, will be traveling to Montreal, Quebec to train personnel of the Canadian Broadcast Corporation. The training, to begin in mid-November, will include a comprehensive review of AM allocations analysis in Canada and the U.S. and will feature V-Soft’s versatile AM software package, AM-Pro™. In 2004, Canada’s broadcast regulatory group at Industry Canada purchased AM-Pro and other V-Soft software for use in their analysis program. Top

ITU Propagation Model

V-Soft is pleased to announce a new propagation model based on the International Telecommunications Union (ITU) rules and regulations. This is a significant propagation breakthrough that will allow Probe 3 to be used globally to predict signal propagation in accordance with the ITU standards. V-Soft plans to release the ITU model option by late-November. The ITU model can be used either as a contour method or grid/area system that uses colors to differentiate between signal levels, similar to the current Longley/Rice propagation model. If you are interested in the new ITU propagation model option, email Adam Puls. Top

New Feature in Probe 3- User Defined Obstacles

A new feature has been added to Probe 3 that allows a user to create and apply user defined obstacles to the terrain database. The feature, in version of Probe (3.34) is still in beta testing, but is available in the current download for those on the technical support program. The feature allows the user to integrate obstacles of a certain height into the terrain database so that the obstacles are reflected when coverage studies are performed. The feature works with both propagation coverage and interference studies. The obstacle, however, as it is currently configured, will not be reflected in terrain profiles. You will notice that in this new version of Probe, there is a new button called "User Obstacles" just below the terrain setup dialogs. This button will allow the importing of a pre-made polygon set having defined locations and obstacle heights . Additional details about this feature will be addressed in future newsletters. Top

Coming Soon: Airport Tower Database Updates

V-Soft will once again be offering online updates for the airport tower databases. After 9/11, for reasons we believe to be security related, our source for this data ceased offering the service and, at the time, we were unable to find another provider. Now, a new source has been located and we will be providing this data again. The airport database updates will be available for all programs using the Geofiles overlay data. This includes: IDAir, and as an option in FMCommander, InterDLG, and Probe 3. The new data, to be updated weekly, contains the current registered airports, geographic coordinates, city name, and other details. As opposed to the old airport databases, the new data will not show ownership (private, public, military, etc.) or the 3 letter airport identifier. Instead, the database lists the first 4 letters of the airport name. To those who were previous subscribers of the airport database, and are interested in subscribing again, or those who wish to be new subscribers, please email Adam Puls or call 1-800-743-3684. Top

New Census Estimate Now Available

The latest U.S. Census estimate, just released by the U.S. Census is now available for Probe 3 and AM-Pro. For those who currently own the 2003 U.S. Census estimate database, the new 2004 Census estimate will be available at a discounted price. To acquire the 2004 U.S. Census estimate, please email Adam Puls or call 1-800-743-3684. Top

Reminder: 2005 Map Update Datasets

The optional Probe 3 2005 updated map datasets include, year 2000 Tiger Census based U.S. county boundaries, 1999 Metropolitan Service Area (MSA), 2000 state lines and polygons, and 2000 urban area datasets. The year 2000 and 1999 are the latest releases available. To apply the new datasets (once installed) draw your map, go to "Map Features," click on the "Datasets" tab as shown in the picture below. Use the drop-down menu to choose your desired dataset.

The new U.S. county boundaries, state boundaries and polygons are taken from the 2000 U.S. Census data. These are high resolution, census based, boundaries. The 2000 U.S. Census urban areas dataset is typically used for studies involving moving a commercial FM station’s city of license. The dataset is useful in analyzing the new market of the station and to determine whether it becomes a part of the major urban area or not. If the new station is going to be licensed to a smaller city that borders a larger urban area, the FCC typically requires a showing of the new station's coverage of the urban area. If the coverage is at least 50% of the urban area, competing applications not serving the urban area will have the edge due to the fact that they are serving a "true" first service area. These datasets are being sold as a package set. The cost for this dataset package is $950. If you would like to order the new datasets, or have any additional questions, please contact us at 1-800-743-3684 or email Adam Puls. The map below shows the difference between the new urban areas and the high resolution 2000 Tiger-set metropolitan boundaries. Top

Microwave Analysis:

V-Soft continues its development of on a comprehensive microwave allocations analysis program. This program is ready for beta testing and V-Soft is looking for those knowledgeable in C/I microwave calculation methods to be beta testers. If you have such skills and are willing to beta test the new program please contact us. (1-800-743-3684). Top

V-Soft 101- D/U Studies (Available in Level 3 - Probe Professional)

Most Probe users know what a Desired to Undesired (D/U) ratio is, but not many know how to do a D/U study with Probe 3. V-Soft is committed to helping our users know all aspects of their powerful software.

How to create a D/U study using Probe 3.

From the starting screen in Probe, click on the new study icon, or select "New Study" from the drop-down File menu.
Click on the option to perform a D/U Study, as shown in the picture below, then click "Next". (Note

Select the terrain database to be used and define the geographic options as desired, such as the datum, cell spacing or land cover.
Edit the parameters of your Desired or reference station. (In this case we have selected a shortspaced station, KUNY.) You can look up an existing station from the FM database, as with any other study in Probe, or enter the parameters manually for a new station.

Click the "Edit" button to select the "Desired" station.
Select the Propagation model you wish to use from the drop-down box. (We have selected the "FCC Model".)
Adjust the calculation area or how far out you want the program to look. (see D/U Study Wizard above.)
Enter the threshold, or the smallest "desired" signal strength you want your cut-off to be. We have selected the "Desired" station's 54 dBu signal contour.
Type in the Front-to-Back ratio (if any), and click "Next"
Click "Force 10% time variable for interfering stations" to use the F(50-10) tables for the interfering station.
Click "Add" and repeat the selection process for the interfering station. Or, you may use the Cull feature as described in #12 below.

Click the cull function button (shown above) to display the drop-down menus of the Field names you with to match and logical operatives you wish to use to obtain a list of stations that have the specified matching factors and then click the "OK" button.

A cull using "City" Rochester and "State" as MN results in the following list:
Next, remove the unwanted stations from the list by highlighting a station and then clicking the "Remove" button until all have been removed.
Then click "OK" and Probe will perform the D/U study. Note that the resulting map, shown below, displays the band of D/U ratios between the cutoffs shown on in the Probe legend. You may need to adjust the D/U color band to configure the display to your liking. To do this, click the color assign legend area on the right-hand side of Probe's main screen. When this is done, the D/U color assign box will pop up. In this case, we changed the display to show red as the D/U band between 0 dB and +6 dB and green to display ratios that are less than zero.
Now you can add the 60 dBu F(50-50) contour of the "Desired" station, and the 54 dBu F(50-10) of the "Undesired" station. You will notice that interference area to the "Desired" station's protected 60 dBu does not consist of the entire contour overlap area.

One could argue that the Desired-to-Undesired studies are a more accurate way to determine D/U interference than the contour overlap method, however the FCC continues to require the overlapping contour method, except in cases of existing grandfathered shortspace. In narrative descriptions, the Commission expects you to refer to the overlap between station's signal contours as "overlap" and not "Interference". However, the term "interference" can be used when referring to shortspace areas where a D/U analysis has been made and the calculated D/U does not meet the FCC's minimums for the station channel relationships involved.

We selected the FCC model, in this case, because is uses the FCC's distance-to-contour curves. These curves typically result in uniform D/U signal band areas, where as Longley-Rice and other similar algorithms may result in widely varying signal areas depending on the intervening terrain.
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