Transmitter/Base/Hub/Router Site Details

To access the Transmitter/Base/Hub/Router Site Details dialog box (also referred to as Transmitter Site Details), click the Edit Site or Create Site button from within the Edit Transmitter Group dialog box. You can also right-click on a transmitter site in the main map window to open a contextual menu and select Site Properties to access the Transmitter Site Details dialog box. To create a new transmitter from the main map window, click the New site buttonin the toolbar. The mouse cursor will change to a sectorized circle, then left click anywhere on the main map window to place the new site. 

For each transmitter site, you may specify up to 48 operating transmitters. These transmitters are usually sectors used in cellular, WiMAX or LTE systems, but they need not be related or even part of same system. For each of these transmitters/sectors, you need to specify all the detailed data required to predict its contribution to system coverage. As described below, these parameters include antenna center of radiation, height above ground, transmitter power, antenna type, and the sector’s reception characteristics when it is used in a two-way system. The operation of the dialog boxes where this information is entered is explained below.

On the details screen you can enter or change any of these values to suit your study requirements. When you finish making changes for this transmitter site, select OK to save the changes and, if you started at the Edit Transmitter Group dialog box, you will be returned to that dialog box. You can then highlight another transmitter site, select it, and enter or change the technical details for that selected transmitter site.

Site Properties

The Site Name field is where you name your site and this name is used as the site label on your map. The Site Elevation field is normally grayed out, as this value is read from the currently active terrain database. If you select Manual from the radio buttons just to the right, this field will become active and you can manually enter the site elevation. This is not recommended, unless you are modeling a transmitter, such as aircraft or satellite. The two Terrain elevation radio button options control what happens to the site base elevation if a building database is present. The first option (Terrain elevation only) ignores the building height, so your site base will be at ground level, which could place the antenna height inside the building. The second option adds the building height to the site base elevation, like an antenna mounted on a roof.

Coordinates

Enter the coordinates of the transmit site here. The coordinate data entry positions will be adjusted depending on which coordinate system you've selected in the Map>Coordinate System and Map>Units dialog boxes. For example, for latitude-longitude, there will be entry positions for degrees, minutes, and seconds for both latitude and longitude. You can also use the radio buttons to change from North to South, or from East to West. In the case of the UK National Grid coordinate system, for example, there are only three entries: a 2-letter grid block reference along with x and y values in meters. If you switch from one coordinate system to another, it is helpful to remember that the data entry positions will also change.

For latitude-longitude entry, you may enter seconds to the hundredths of a second, resulting in an average site location resolution of about 0.2 meters. This hundredth of a second resolution is used for latitude-longitude coordinate entry throughout the EDX software. With such fine site resolution, EDX software is suitable for doing even indoor wireless system studies.

Since it is possible for transmitters to be collocated with other RF systems, the user has the option to use the Locate button, which opens a dialog box that shows all transmitters, link ends and CPE’s that exist in the project. Selecting one of these will populate the latitude and longitude values of the transmitter with those of the selected RF object.

Other Transmitter Site Information

To help keep track of radio sites in large systems, the Other Information dialog box is available where you can enter supplemental information about a transmitter site, including its address, ownership, a contact telephone number, and notes field where any text may be included. You can also associate other files, site photographs, or other images as an additional way of keeping track of the information for the site. The photo or image files designated in the photos section must be in Windows “.bmp” format. Simply enter the name of the file in the location indicated, click in the image space, and the photo will be shown. This information, including the name of the photo file, is saved for each transmitter site in your map file; however, it is not used in the signal studies.

Transmitters/Sectors

Below the basic site properties section, there is a section where summary information for each transmitter/sector at this site is listed. The information shown in the scrolling box will change as the parameters for that site are changed. You can use the Add transmitter/sector and Delete transmitter/sector buttons to add and delete transmitters/sectors from this list. 

Transmitter/Sector Properties

The Transmitter/Sector properties section has number of data entry fields, selection buttons and checkboxes. These entries and controls apply to the highlighted transmitter/sector in the list. To change basic information such as frequency for a transmitter/sector, click on that transmitter/sector to highlight it, and then make your changes. The changes you make will be reflected in the information shown for that transmitter/sector.

ID

This ID is an important character string the software uses in a number of ways. It can be used to label the site on your map and is also used in creating the working files generated by the EDX software during study runs. This field is limited to a maximum of 8 characters.

Focus

This checkbox controls how/if the highlighted transmitter/sector will be used in certain studies. For Point Studies, the only transmitter/sector used is the Focus transmitter/sector. In fact, you can’t do a Point Study unless you have one transmitter/sector designated as the Focus transmitter/sector. Shadow studies and Profile to Pint /Live Profile to Point studies also use the focus checkbox to know which transmitter you’re interested in seeing those specific results for.

Set Chan Plan Nominal Freq

This feature allows you to assign a nominal frequency from a channel plan for the highlighted transmitter/sector operating frequency by choosing frequencies from a System Channel Plan file/template. In order to use this feature, a channel plan file must be assigned for use by EDX SignalPro. You can assign a basic channel plan file by using the Generic System Setup dialog box discussed in the Generic System Channel Plan. If you have any of the advanced design modules, another option is to assign a channel plan file template from within the Network Design/Analysis menu. For LTE and WiMAX modules, use the dialog box opened from the Systems details/Service area selection. For the Mobile and Cellular Networks module, use the dialog box opened from the System Type/Service Area selection. These dialog boxes are discussed in later chapters specific to those modules. 

Once the channel plan file has been assigned, click the Channels/Traffic button at the bottom of the Transmitter Site Details dialog box, which opens the Generic Systems Channels dialog box. Select the desired channels from the file (minimum of one) by clicking each entry, which changes the entry from black to red, then click OK to save the selection(s). Clicking the Set Chan Plan Nominal Freq button will assign a representative channel frequency to the highlighted Transmitter/Sector from those channel entries selected in the channel plan file. The Frequency field will be updated with that new value.

Frequency

This field is used to store the operating frequency of the highlighted transmitter/sector. You can assign the exact frequency,which is useful if you’re going to do interference studies, or you can input the generic frequency, say 900mHz for LMR. Entries from 30 MHz to 100,000 MHz are allowed depending on the EDX software are using and the propagation models which are available in it. See the first table in Appendix A for a complete listing of the propagation models and their allowable frequencies. The frequency you enter here is always used for the signal level prediction and for calculating co-channel and adjacent interference, along with transmitter Power Spectral Density (PSD) definitions and receiver filter shape definitions. However, this frequency is not used for C/(I+N) calculations for cellular/PCS, 4G LTE/WiMAX or point-to-multipoint systems studies. Instead, the channel assignment matrices for each sector are used for interference calculations.

Simulcast delay offset

This entry is only relevant to simulcast systems where multiple transmitters use the same frequency. Many modern digital Land Mobile and paging systems use this technique to increase throughput. To mitigate interference between transmitters, it is sometimes useful to artificially delay the signal transmitted from a given site. By carefully assigning offsets to different sites, it is possible to exercise some control on where interference occurs in a simulcast system. Refer to Appendix F for more information on how simulcast delay spread studies are performed.

Neighbor List

Neighbor lists are a collection of cell sites or sectors maintained at each cell site which indicate the other cells or sectors to which a mobile unit will likely be handed off. Neighbor lists can initially be developed using predictions of signal levels (or pilot powers) at cell boundaries, but in non- homogeneous, non-contiguous service areas, the cell boundary concept may not be very useful. 

EDX software can calculate neighbor lists using signal levels, regardless of the service area type. This function is available in all the advanced design modules. Please refer to the appropriate design module chapters in this manual for further information. If you have calculated a neighbor list, you can view its contents by clicking on the Neighbor List button.

The neighbor list will show the predicted neighbors based on the study you have created in one of the design modules as mentioned above. A sector ID that is appended with an “ * ” indicates that this neighbor sector does not list the current sector as a neighbor. It also provides a place to create a manually entered list that can be based on predicted neighbors and neighbors that have been determined from operational experience or from drive test data. You may enter or maintain lists of up to 16 neighbors for a given cell site sector.

System name/type

This selection drop-down list is used to associate transmitters/sectors with system setups in the additional add-on modules. For example, selecting LTE from the drop-down list assumes you have the LTE module installed, set up, and will be using the settings from the LTE module. NOTE: do not select anything other than Generic transmit/receive unless you have that specific module installed in EDX SignalPro. Doing so will cause numerous errors when you try and run your studies. The optional advanced design modules include Mobile and Cellular, WiMAX and LTE, which can be accessed and set up from the Network Design/Analysis menu. The mesh module is accessed through the Mesh Design/Analysis menu.

MIMO/Adaptive

This drop-down list contains possible selections for MIMO (Multiple-Input Multiple-Output) or SDMA (Space-Division Multiple Access) configurations to describe the antenna system used for the sector. Most base stations don’t use MIMO or SDMA/Adaptive antenna systems (the MIMO/Adaptive default is “none”), but these antenna systems have significant performance advantages, especially for 4G WiMAX and LTE systems. The EDX software allows specifying the MIMO-A (Space-Time Coding), MIMO-B (Spatial Multiplexing) or SDMA/Adaptive configuration for each sector and apply performance enhancements to studies that include these sectors. The performance enhancements can be specified or modified from within the dialog box at RF Systems>MIMO/Adaptive Antennas, which is covered later in this chapter.

Adaptive Modulation

When the Use Table checkbox is selected, the Adaptive Modulation drop-down list allows choosing which adaptive modulation table to use for calculating modulation type, date-rate, and reliability. See the Adaptive Modulation for more information.

Repeater

This checkbox allows you to identify the selected sector as a repeater for another specific sector or for any sectors within range. Normal transmitters should have this option turned off, which is the default condition for newly created sectors. However, if the specified sector is a repeater, the Repeater checkbox should be selected (turned on).

Most likely server color and symbol

The Override checkbox in the Transmitter/Base/Hub/Router Site Details dialog box lets you select a custom color and symbol for this transmitter when drawing most–likely server (MLS) area study maps. Normally the EDX software will automatically assign colors for these maps by attempting to achieve sufficient color differences among adjacent or closely spaced coverage areas so that they can be easily distinguished. However, sometimes this may result in adjacent coverage areas being assigned the same color. If this happens, you can click the check box to override the study assigned color and symbol, then enter your own custom MLS color and symbol for the selected transmit site so that it can be easily distinguished.

Backhaul selection

The Backhaul selection section is used for some mesh system analyses and describes which sectors are gateway points (traffic injection points, collectors, etc…). The Type drop-down list (with default value “none”) allows selecting the type of backhaul sector. The mesh algorithms attempt to route non-backhauled sectors to these backhauled sectors. This feature is only functional in EDX SignalPro with the installation of the Mesh design modules.

Transmit Parameters

To set the transmitter power, system losses, and specify a directional antenna, click on the Transmit Parameters button and the Sector Parameters dialog box will be displayed where you can enter this formation.

More information can be found in the Sector Parameters article.

Receive Parameters

Each transmitter or sector at a site is normally assumed to consist of both a transmitter and receiver. For 2G/3G/4G cellular/PCS, WiMAX/BWA, LTE, and most mobile radio systems, this is the standard approach. For some systems, such as broadcasting and some types of paging systems, there is only a transmitter and no corresponding receiver. For such systems, the receiver portion of the sector can be ignored so only the transmitter parameters described above are relevant to predicting system operation. Having the receiver parameters separate from the transmitter parameters allows for the receive operation at a site to be set completely independent of the transmit operation, including the antenna type and pointing angle, and whether a diversity antenna is in use. For Area Studies only, the antenna height above ground value for the transmitter antenna is used for the receiver antenna. In most situations, this will give sufficiently correct results. If a leaky coax antenna system is chosen for the sector transmitter, that antenna system will also be used for uplink analyses even though the leaky coax option is not provided for the receiver antenna choice.

Click the Receive Parameters button to open the Sector Receive Parameters dialog box. More information can be found in the Sector Receive Parameters article.

Propagation Model

Returning to the Transmitter Site Details dialog box, you have the option of selecting any one of the propagation models that have been created in the main Studies<Propagation model dialog by clicking the Propagation Model button. Normally, the propagation model defaults to Global Model 1. This field is primarily used when a propagation model has been tuned for a specific sector. It can also be used in situations where you use one model for design and planning, then have to switch to an FCC model for licensing.

Channels/Traffic

Clicking the Channels/Traffic button opens the Generic System Channels dialog box. This dialog box is only accessible and relevant, if you have one of the optional Mobile/Cellular, LTE or WiMAX advanced design modules installed. It is also available if you have created a Generic System Channel Plan which is discussed later in this chapter. The use of the Generic System Channel dialog box is also described in the manual sections dealing with the advanced design modules.

Study Sector/Sector Range

To specify the area or sector where you want the signal levels calculated for this transmitter, click on the Study sector/Sector range button to open the Study Sector dialog box. 

Basically, the study sector is defined as a circular arc that extends from the Start azimuth clockwise around to the Stop azimuth. The size of the arc is determined by these azimuths and by the Study radius (radials). The resolution of the coverage across this arc depends on the Azimuth increment, or spacing, and the point spacing along the study radials (Study point spacing on radials).

In most cases, you will want a study to be done in all directions from your transmitter site. In this case your Start azimuth should be 0 degrees, your Stop azimuth 360 degrees, and your Azimuth increment 

1. 0 degrees. The distance or length of the 

Study radius should be chosen for the particular service type. For wireless broadband or PCS/cellular telephone base stations, a Study radius of 30 km (about 20 miles) is often used. For high power Land Mobile, FM, or TV broadcast, a 100 or 150 km radius might be appropriate. Remember that if you are plotting FCC contours, the minimum distance is 16 km so make sure that all the required terrain information is available to construct the average.

For some special cases, you may want to confine the study area across a limited arc and decrease the azimuth spacing. For example, you could set the Start azimuth at 45 degrees, the Stop azimuth at 90 degrees, and use an Azimuth increment of 0.5 degrees. For a very fine resolution study across a limited arc, you could set the total arc span at 36 degrees and use an Azimuth increment of 0.1 degrees. You can also specify a limited azimuth arc across North for example, by entering -90 degrees for the Start azimuth and 90 degrees for the Stop azimuth. The only limitation to defining the study azimuth arc is that the maximum number of azimuths you can use in a single study is 720. 

The study point spacing on the study azimuth (or radials) also affects the study resolution. Typical values range from 0.01 to 0.5 km. For long distance studies of high power broadcast stations, you may want to increase the Study point spacing on radials to 0.5 km. The only important limit on the study point spacing is a maximum of 10,000 points per radial. If you had specified study radius 100 km long (a study distance of 100 km), the smallest point spacing you could use would be 0.01 km (10 meters) for a radial line study.

When selecting the azimuth and study point spacing to set study resolution, it is sensible to take into account the final form in which the study results will be displayed. Because the number of study points directly affects how long it will take to complete a study, it is wasteful to select a very small azimuth or point spacing when the resolution of the final study grid plot cannot show this resolution. This is an important consideration when using laser printers for study plots where the paper size is only A4 or letter-size.

For certain propagation models in the Advanced Propagation Module, the propagation study is not done along radial lines but to points defined by the Study Grid (see Appendix F). In that case, the Study Sector parameters entered in this dialog box are irrelevant. The model types where this restriction applies are: 2D and 3D outdoor ray-tracing models, the COST-231 Walfisch-Ikegami model, the EDX simplified indoor model, and the 3D indoor ray-tracing model. 

The study radials are also irrelevant if you select the Direct-to-Grid Calculation Method in the Area Study dialog box.

The Approximate sector range field is used to set the style of the transmitter sector icon as viewed on the Map. The value in this field is used in conjunction with the Show size based on range option in the Map Layers “Style” dialog box for the “Transmitter base/hub sites” layer. It also can be used to control the maximum range when this particular transmitter will be chosen as a serving sector (Most Likely Sector). See Studies Menu for the use of this value in setting up an Area Study.

Quick Contours

Quick contours are intended to be a fast and convenient way to get the height above average terrain (HAAT) and distances-to-contours information for your currently highlighted transmitter/sector. This information is most often used for FCC application engineering exhibits.

After highlighting the transmitter/sector, click on the Quick contours button and a dialog box will appear where you can select the propagation model, the time and location percentages, and field strength contour signal levels in dBµV/m (up to five). The propagation models available in the list are restricted to simple, empirically based models, where the signal level decreases monotonically with distance. Usually these models are based on published propagation curves like those found in the FCC Rules. This allows a unique, single distance value to be found for a contour location. Depending on the model type, the time and location percentages may be restricted. Typical values for service contours are 50% location, 50% time, or F(50,50) in FCC parlance. Interference contours are usually F(50,10). For DTV stations, F(50,90) contours are used.

Once you have made your selections, click on the Calculate button and the contour distances and HAAT values will be verified and saved in a contour file called “quikcntr.ctr”. The contents of this file are then displayed in the scroll box. You can also print or save this file, or have the calculated contour drawn on your map by clicking on the Display contours button, which also adds the “quikcntr.ctr” file to the Map Layer list so it will appear when you return to the map display.