Tuesday, February 23, 2010

Pathloss 5.0 : Program Organization

Program organization

The figure below shows a diagram of the basic program organization. The PL50 main window is the network display and is referred to as such throughout the documentation. The network display shows the sites and links geographically and is the primary user interface.

An automatic export feature to Google earth is provided for sites, links, and the local and area studies. The sites and links can also be exported in the ESRI shapefile format.

GIS section

The network display is controlled by the geographic information system (GIS) which provides the following functionality:

  • Backdrop imagery in the form of raster data files (bmp, png, jpg tiff).
  • Vector displays using shapefiles or Planet type vector files.
  • Elevation and clutter views of the underlying terrain.
  • Datum and projection definition for the site coordinates.

Site and link lists

The site and link lists represent the user's data. As a minimum, a site is defined by its name and geographic coordinates and a link is defined by the end site identities. The user interface is the site list from which data can be imported by any of the following means:

  • Text files containing a list of sites.
  • Text files containing a list of links (two sites per line).
  • Existing pl5 files.
  • An ODBC interface to an existing data base.

Links and sites can be exported to a database using the ODBC interface or to a text file.

Network display operations

The following design operations are carried out in the network display:

  • Automatic link design - this is carried out for point to point and point to multipoint systems. In the point to point case, every possible combination of links are generated between two groups of sites. This includes the special case of all sites to all sites. Rejection criteria are used to determine the final link configuration.
  • Local studies - a base station is defined at a site and the signal strength is calculated for a specified distance from the site.
  • Area studies - a area is define which includes a number of base stations. The signal strength from each base station is calculated over this area. In addition to the signal strength displays, carrier to interference, most likely server and simulcast time delays displays are available.

PL50L integrated link design

When the user left clicks on a link in the network display, a drop down menu appears showing the following design sections of the integrated link design program:

  • Transmission analysis - includes data entry forms for radio antenna and transmission line equipment. This section calculates the link unavailability due to multipath and rain fading. An automatic link design feature including path profile generation, antenna height calculation and data entry is available in this section.
  • Terrain data - in this section path profiles are generated from a terrain database, imported from a text file or can be manually entered. Structures including off path structures and ranges of structures can be added to the path profile. If a clutter data base was used to generate the profile, the clutter heights can be edited.
  • Antenna heights - clearance criteria in terms of the earth radius factor (K), percent of the first Fresnel zone radius and a fixed height are used to calculate antenna heights. The analysis is extended to show diffraction loss at the minimum expected value of K and a user specified value. The feasibility of links operating in the VHF and UHF bands can be quickly determined with this feature.
  • Multipath - reflection analysis - section deals with terrain reflections and ducting. Ray tracing and reflective plane techniques are used to show the variations of receive signal using antenna heights, K, frequency and tide levels as variable parameters. The interactive display allows the optimum antenna spacing on space diversity applications to be simply determined. The elevated and surface duct characteristics are automatically determined for the specific path profiles using an ITU database.
  • Diffraction loss - although diffraction loss is automatically calculated in the antenna heights and transmission analysis section, this section provides diffraction loss calculations as a function of K, frequency, antenna heights and along the path profile. Interactive calculations can be carried out as a means of verifying the results.

PL50L standalone link design program

In the integrated link design program, the individual pl5 files can only be accessed from the network display. In particular the files menu only allows pl5 files to be saved. Although a pl5 file can be imported into the network display and subsequently worked on in the integrated link design program, there is no provision to directly open a pl5 file in this program.

To deal with the general case of pl5 files which are not included in the network display, a standalone version of the PL50L link design program is provided. This can be accessed from the network tool bar or from a desktop icon. The standalone program has its own GIS setup which does not include backdrop imagery or vector displays.

In the integrated link design, all site coordinates are expected to be referenced to the same datum as defined in the sites tab of the GIS.

In the standalone version, the GIS sites tab datum and projection are changed to that defined in thepl5 file when it is opened.

Data entry

In addition to the standard windows dialog boxes, the program uses two data entry forms. The standard data entry form is used for a fixed number of entries. The grid data entry form is used for a variable number of items. These are described below.

Standard data entry form


Set the focus to the desired cell with a left click or use the cursor / tab keys and enter the data.

Cells which cannot be accessed are shown in blue letters. This may be a calculated field or not editable for some reason.

  • Click the green check (OK) to accept the data entries. If the red X (Cancel) is selected, the data will change back to the original values.
  • To erase an entry, select the field and press the F3 key or click the eraser button. Note that some data entries are mandatory and cannot be erased.
  • To edit an existing entry, select the field and press the F2 key or double click on the cell.
  • On forms with two columns, a data entry can be copied from one side to the other. Select the field to copy to and press the F4 key.
  • The reset button resets add data to their original values.

Grid data entry display

The grid data entry display is used when a variable number of entries is required such as the site list in the Network display or in a lookup table. The following data types are used: numeric, text, boolean (e.g horizontal or vertical polarization) and drop down lists, check boxes, and color definitions.

To enter data or replace existing data, set the focus to the desired cell with a left click or use the cursor / tab keys and enter the new data.

To edit all other data types existing data double click on the cell or set the focus to the desired cell an press the Enter or F2 key.

Each data record has a minimum data entry requirement. For example in the case of a new site, the minimum requirement is the site name and the latitude - longitude.

Records can be edited and added using a list form. To edit an existing record, first select the record and then select Edit - Edit from the menu bar or right click on any field in the record and select Edit from the popup menu.

To add a new record, select Edit - Add on the site list menu bar. An existing item can be used as a template. Left click on the record number field to select an item to be used as a template before selecting Edit - Add.

The list form may contain additional fields which are not available in the grid data form. For example, in the Site list form, the following additional fields are available : projected coordinates, address, city, state, country and owner code.

The records in most grid data forms can be sorted. Click on the header of the field to sort by. The first click sorts in an ascending order. The second click sorts in a descending order.

To change column widths click on the column separator on the header bar and drag to the new width.

To change the column order, click on the column on the header bar and drag to the new location.

To reset the display to the default column widths and order, select

Right button menu

A right button click on a cell brings up a popup menu. The default menu selection consists of the edit list form and delete items; however, on others considerable functionality is available. An example of this is the DEM index grid data entry form.

Antenna configuration

All calculations and analysis in the program are based on an antenna configuration. The following terminology describes the antenna usage.

  • TR - The antenna is used to transmit and receive.
  • TX - The antenna is used to transmit only.
  • RX - The antenna is used to receive only.
  • DR - The antenna is used to receive only in a space diversity configuration.
  • TH - The antenna is used to transmit and receive in a hybrid diversity configuration.

Table 1: Antenna Configurations

Two way antenna configurations

TR-TR

A single antenna is used at each site to transmit and receive.

TRDR-TRDR

Two antennas are used at each site in a space diversity configuration. The TR antenna is used to transmit and receive. The DR antenna is the diversity receive only antenna.

TXRX-TXRX

Two antennas are used at each site to transmit (TX) and receive (RX).

TXRXDR-TXRXDR

Three antennas are used at each site to transmit (TX), receive (RX) and space diversity receive (DR).

TR-TRTH TRTH-TR

This is a hybrid diversity configuration which uses frequency diversity in both directions and space diversity at one end of the path only. At the space diversity end, the TR antenna and TH antenna each transmit and receive one pair of the frequencies. The two configurations determine which site is equipped with space diversity.

TR-TXRX

A single antenna is used at Site 1 to transmit and receive. Separate antennas are used at site 2 to transmit and receive.

TXRX-TR

This is the reverse configuration of the above TR-TXRX configuration.

One way antenna configurations

TX-RX RX-TX

Transmit at one site and receive at the other. The two configurations identify the transmit and receive sites.

TX-RXDR RXDR-TX

Transmit at one site and diversity receive at the other. The two configurations identify the transmit and receive sites.


These antenna types are combined into antenna configurations as shown in the following table

Select Configure - Antenna Configuration from the PL50L menu bar to change the antenna configuration. If the antenna configuration is displayed on the status bar, you can also click the left mouse button on the configuration box.

Antenna combinations

Diversity and separate transmit and receive antenna configurations have several antenna combinations. Each combination must be analysed separately. Select Configure - Antenna Configuration on the menu bar. Alternately, if the current antenna configuration is displayed on the status bar, click the left mouse button on the antenna combination in the status bar to select a new combination. An antenna must be selected at each site to define the combination.

Color ramp

Color ramps are used for the following:

  • Elevation backdrop.
  • Color coding links in the auto link design section.
  • Signal level displays in local and area studies.

This section describes the common features using the elevation color ramp shown on the right as an example

The display shows the color ramp with markers for each range on the left side of the color ramp. The basic operation is as follows

  • Click on a range marker to select it. The range value will be displayed.
  • Click and drag a range marker to a new location to change the range value. Be sure not to drag the maker outside the border as this will delete the range. Alternatively, enter a new value for the selected range.
  • To remove a range, first select the range and then click the remove range button. Alternately click and drag the range marker outside the around the range maker border.
  • To add a new range, double click inside the range border, but not on a specific range.
  • To change the color of a range, select the range and click the change color button or double click on a range marker. If the ranges use solid colors, then you can also change the color by double clicking on the range display color. Note that the color selection dialog includes a transparency setting. Transparencies can be set for individual colors in local and area studies only. This feature can produce interesting effects for signal coverage. Elevation backdrops and the link color coding do not use the individual color transparencies.

Color schemes

Color schemes can be saved. The last scheme use becomes the default. To save a color scheme, enter and name for the color scheme and click the save button. To remove a color scheme, select the scheme from the drop down list and click the remove button.


Pathloss file types

GR5

The gr5 file contains the network data.

GR5ID

The gr5id file contains the next available numeric ID for sites, stations and links.

PL5

Pathloss 5 profile

PL4

Pathloss 4.0 profile

PL3

Pathloss 3.0 profile

LSY

Local study data file

ASY

Area study data file

P5G

GIS configuration file

ASD

Binary antenna data file

ADF, DAT

Commonly used for ASCII antenna data files.

RSD

Binary radio data file

RAF

ASCII radio data file

LD5

Link design file

TC5

Frequency plan file

IFR

Interference calculation results


Pathloss 5\cstmdata directory

This directory is used for custom data and contains the following file initially.

CIRCLEH.EMF, CIRCLEL.EMF

Files used to denote high and low frequency sites in frequency assignment operations.

PATHLOSS.EMF

Pathloss logo file

COMPROSE.BMP

Compass bit map used in the 3D terrain view.

HF1 -6.RTF

Rich text format files used to predefined headers and footers.

THSYMBOL.LST

Current list of thematic symbols - not initially present.

DEFAULT.LD5

Default link design file - not initially present.


Pathloss 5\equipmnt directory

This directory is intended for radio, and antenna data files. The following index files are saved in this directory:

PL50_ANT.NDX

Antenna data file index

PL50_RAD.NDX

Radio data file index

PL50_TXL.NDX

Transmission line lookup table

Profile displays

Profile displays are used in link design sections of the program. The basic operation of these displays is described below. The above display of the diffraction design section is a typical example of a profile display.

The terrain profile is preconditioned so that the minimum distance between profile points is one percent of the path length. Points are inserted to meet this requirement using linear interpolation. Most displays show the flat earth profile with a diagonal fill pattern and a second profile above this to represent the effective earth radius. The corresponding earth radius factor (K) will either be displayed on the status bar or as a selection in a drop down list on the control bar.

Profile displays use a cursor for various operations. The cursor is positioned on the display using the cursor keys or by clicking the left mouse button on the display. The cursor style and movement are described below.

Cursor style

The default cursor style is a red arrow. Press the letter A to change between an arrow and lines to the antenna. The latter is useful in assessing the clearance from some point to the antennas. The cursor style is also shown on the status bar as A of L. Alternately, left click on this letter to change the cursor style.

Cursor movement

Three cursor movement methods are used in the profile display:

  • P (profile) the cursor can be positioned on any point of the terrain profile.
  • S (snap) the cursor can only be positioned on peaks of the profile.
  • C (continuous) the cursor can be positioned anywhere on the display. This option is only used in the diffraction design section.

The letters P, S or C appear on the status bar. To change the cursor movement press the letter for that movement or click the left mouse button on the letter in the status bar.

Selecting a Segment of the Profile

Many calculations involve the selecting a segment of a terrain profile. Several examples are:

  • Defining the end points of a reflective plane.
  • Terrain roughness calculations.
  • Inhibiting reflections over a portion of the profile.
  • Manual diffraction loss calculations.

The basic procedure, in all cases, is as follows:

  • Place the cursor at one end of the segment and press the F1 key or click the right mouse button. The cursor will change color to indicate that it has been selected.
  • To cancel the first point selection, press the F8 key or click the reset button on the display.
  • Move the cursor to the opposite end of the segment and press the F1 key again or click the right mouse button.

Terrain data point information


Press the Ins key for information on the point at the cursor location. The format will vary depending on the design module. Alternately, click the left mouse button on the cursor location box on the status bar.

Status bar functions

The status bar, on most displays, includes short cut operations to commonly used functions. Typical examples are as follows:

  • Click on either site name to access the site data entry form.
  • To convert between metric and miles-feet click on the measurement box.

The selections available on the status bar depend on the specific design section.Click on each box in the status bar to determine if additional functionality has been implemented.

Fresnel zone reference

Fresnel zone reference area is an essential part of any terrain profile analysis. In profile displays, the Fresnel zone dialog is accessed from the menu bar or with the F2 key.

The Fresnel zone reference can be expressed as a percentage of the first Fresnel zone reference or as a Fresnel number (e.g. F2 = 1.414 F1).

Several types of Fresnel zone references are available. On line of sight paths the Fresnel zone references are always drawn from end to end. On obstructed paths, a more meaningful representation is achieved by drawing the Fresnel zones between the horizons.

If a reflective plane has been defined, the Fresnel zones can be drawn to the reflection point. This provides a visual representation of the area along the profile required to support a specular reflection.

If the label box is checked, the Fresnel zones reference will be written at the mid point.

There is no limit to the number of Fresnel zone references. The Fresnel zone reference settings are common to all design sections

Reports

Pathloss reports use the TE EDIT CONTROL, a full featured word processor, licensed from Sub Systems, Inc. The program generates the basic reports in an RTF format and then invokes the word processor. These can be If the files are saved in RTF format, then these can be used with Microsoft Word or any other word processor that supports the RTF file format.

Each link design section includes a report menu item for the specific reports applicable to that section. Details of these reports can be found in the documentation for that design section. Composite report generation for multiple pl5 files is provided in the PL50L link design program and in the PL50 network display. Details of these procedures are given below

PL50L report generation

Select the Design - reports on the PL50L menu bar to access the Reports dialog. This is really a report summary for the selected link.

Click the blue arrow for a particular report to print that report only

Check the desired reports and then click the blue arrow for "Print all selected reports" to print a composite report.

Click the blue arrow for "Edit report formats" to set the page margins and header footer format for the report templates

To batch print reports for multiple pl5 files, first check the desired reports and then click the blue arrow for "Multi select files to print". An open file dialog is used to multi select the pl5 files to print. This can also be carried out in the network display using a selection or group of links.

Path profile format

A path profile drawing is included in the Transmission summary report and is available as a single page landscape report. The drawing options depend on the profile format and the state of the "use clearance criteria" check box.

  • The profile format can be a flat earth display, a curved earth display with straight axis or a curved earth display, with curved axis.
  • With the flat earth display and the "use clearance criteria" checked, all Fresnel zone setting and K values are inhibited. The values specified in the pl5 file clearance criteria will be used.
  • Four values of K can be shown using the flat earth display (with the "use clearance criteria not checked) or a single value with the curved earth displays.
  • Four Fresnel zones can be drawn between the main antennas or between the main to diversity antennas. On obstructed paths the Fresnel zones can be drawn end to end or between the horizons.

Use the preview profile button to display the results.

Company name - Project name

These fields will be inserted into the header and footer as specified by the COMPANYNAME and PROJECTNAME keywords in the report templates

PL50 report generation

Select the Operations - PL5 reports menu to access the Reports dialog in the network display. This is used for batch printing reports. Note the following differences between this dialog and the pl50L reports dialog.

  • The network display can be included in the report.
  • The preview profile button is not available.
  • Individual report printing is not available.

Select the files to print (selection, group or all links from the drop down list) and click the blue arrow button for "Print selected links.

Report formats

In the network display or link design section select Configure - PL50L options - Report layouts. Alternately in the reports dialog click the blue arrow for "Edit report formats"

RTF template files are provided for the following reports:

Transmission summary

P5transcalc_summ.rtf

Transmission detail

P5transcalc_detl.rtf

Profile display

P5profile_disp.rtf

Default report

P5default_rept.rtf

Batch print

P5batch_print.rtf

Interference case detail

P5interf_casedetl.rtf

Interference cross reference

P5interf_crossref.rtf

Performance summary

P5perform_summ.rtf

Network display - portrait

P5network_port.rtf

Network display - landscape

P5network_ldsc.rtf


These files are located in the cstmdata folder in the Pathloss program directory. The template files contain the report formatting including the header and footers. For each report click the "Edit RTF template file" button and edit the format as stated in the text in the template files.

The network display printing is automatically set to portrait or landscape based on the drawing aspect ratio.

Select the specific report to edit its format. Start by setting the units to either inches or millimeters. The following formatting options are available:

  • Default image width and height - this is the size of the image (usually a profile display) as it will appear in the report. This can be resized in the report itself; however, in batch printing, the appropriate size should be determined on a single report before carrying out a batch print.
  • A different font can be used for each report type.
  • Color printer - a reflection analysis report uses color coded lines to display the relative receive signal level as a function of a variable. If color printer is not checked the coding will be changed from colors to a line style (dotted, dashed...).
  • The contents of the pl5 file note pad can be included in the report. This option only refers to reports in the PL50L link design section.






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