# 4.7 Uniform distribution of ILT vs VLR

<span>You may define a uniform deployment density of terminals/transmitters per km</span><span> (see ANNEX 13:</span>**).**<span> This can either be done by using the “</span>**Uniform Density” mode**<span> combined with the calculation of a simulation radius as described in section 4.7.1 and A13.2 or by using the “</span>**none” mode**<span> combined with the choice of uniform path polar distance as described in section 4.7.2. </span>

# 4.7.1 Uniform density mode - simulation radius calculation

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/YL3nDQffwX4mxQjq-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/YL3nDQffwX4mxQjq-image.png)

The number of active transmitters that will be uniformly located within the simulation radius is given by:

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/fxk5lJJMVsi3fXBU-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/fxk5lJJMVsi3fXBU-image.png) (Eq. 28)

Figure 120 presents the GUI with the input value.

<table border="1" id="bkmrk-settings-in-the-syst" style="border-collapse: collapse; width: 100%;"><colgroup><col style="width: 50%;"></col><col style="width: 50%;"></col></colgroup><tbody><tr><td>**Settings in the System tab**</td><td>**Settings in the Scenario tab**</td></tr><tr><td>[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/QQsGwc78HTIcPgZs-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/QQsGwc78HTIcPgZs-image.png)

</td><td>[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/hK5xBs1NucCNErqS-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/hK5xBs1NucCNErqS-image.png)

</td></tr></tbody></table>

**Figure 120: Setting up the simulation radius in SEAMCAT** (Note that the results of the simulation radius is displayed only after running simulation)

The simulation radius is calculated by using the following formula:

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/QzbhPAAHF1adgLWw-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/QzbhPAAHF1adgLWw-image.png) (Eq. 29)

In the example of Figure 120, this gives:

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/vTJB5YDQbnyRfe5h-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/vTJB5YDQbnyRfe5h-image.png)

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/mn4agbt2u2dcCM2G-image.png)

<div class="rich-media-item mediaSingleView-content-wrap image-align-start css-1fcvn4m" data-layout="align-start" data-media-vc-wrapper="true" data-node-type="mediaSingle" data-renderer-start-pos="772" data-vc="media-single" data-width="463" data-width-type="pixel" id="bkmrk-figure-121%3A-irss-usi"><div class="css-lxubws"><div data-alt="" data-collection="contentId-494239" data-context-id="494239" data-file-mime-type="image/png" data-file-name="121.png" data-file-size="65128" data-height="475" data-id="c3838e44-86df-44a3-97cf-a0804b182d6d" data-node-type="media" data-renderer-start-pos="773" data-type="file" data-width="880"><div class="_2rko18qm _vchhusvi _kqswh2mm _ect4ttxp _p12f1osq _c71l1osq _1bsb1qmm _4t3ine4n _1hlmd0i9 _1rquusvi _eg541i5c _mts3kb7n _1ntskb7n _yfmhtlke _5sb1v00u new-file-experience-wrapper" data-media-vc-wrapper="true" data-testid="media-card-view" id="bkmrk-figure-121%3A-irss-usi-1"><div class="_1reo15vq _18m915vq _2rko18qm _1e0c1txw _kqswh2mm _p12f1osq _1bsb1osq _4t3i1osq _c71l1osq media-file-card-view" data-cursor="pointer" data-test-media-name="121.png" data-test-progress="1" data-test-source="remote" data-test-status="complete" data-testid="media-file-card-view"><div class="_kqswstnw _1bsb1osq _4t3i1osq _1e0c1txw _2lx21bp4 _1bah1h6o _4cvr1h6o align-center" data-testid="ImageRendererWrapper">![](blob:https://ecowiki.atlassian.net/6c49db2f-75de-418f-a485-3075525a4274#media-blob-url=true&id=c3838e44-86df-44a3-97cf-a0804b182d6d&collection=contentId-494239&contextId=494239&mimeType=image%2Fpng&name=121.png&size=65128&width=880&height=475&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 121: iRSS using the simulation radius for 1 active transmitter (R=0.178)**</div></div></div></div></div></div>[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/J00mjnYWTj1GFptH-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/J00mjnYWTj1GFptH-image.png)

<div class="rich-media-item mediaSingleView-content-wrap image-align-start css-kdxquf" data-layout="align-start" data-media-vc-wrapper="true" data-node-type="mediaSingle" data-renderer-start-pos="859" data-vc="media-single" data-width="550" data-width-type="pixel" id="bkmrk-figure-122%3A-calculat"><div class="css-cxbalt"><div data-alt="" data-collection="contentId-494239" data-context-id="494239" data-file-mime-type="image/png" data-file-name="122.png" data-file-size="5094" data-height="114" data-id="f9c29404-1f24-4042-bfb6-71857e1fa7df" data-node-type="media" data-renderer-start-pos="860" data-type="file" data-width="550"><div class="_2rko18qm _vchhusvi _kqswh2mm _ect4ttxp _p12f1osq _c71l1osq _1bsb1qmm _4t3ine4n _1hlmd0i9 _1rquusvi _eg541i5c _mts3kb7n _1ntskb7n _yfmhtlke _5sb1v00u new-file-experience-wrapper" data-media-vc-wrapper="true" data-testid="media-card-view" id="bkmrk-figure-122%3A-calculat-1"><div class="_1reo15vq _18m915vq _2rko18qm _1e0c1txw _kqswh2mm _p12f1osq _1bsb1osq _4t3i1osq _c71l1osq media-file-card-view" data-cursor="pointer" data-test-media-name="122.png" data-test-progress="1" data-test-source="remote" data-test-status="complete" data-testid="media-file-card-view"><div class="_kqswstnw _1bsb1osq _4t3i1osq _1e0c1txw _2lx21bp4 _1bah1h6o _4cvr1h6o align-center" data-testid="ImageRendererWrapper">![](blob:https://ecowiki.atlassian.net/1a0ddaed-afd7-4be6-a9b2-2d674508034e#media-blob-url=true&id=f9c29404-1f24-4042-bfb6-71857e1fa7df&collection=contentId-494239&contextId=494239&mimeType=image%2Fpng&name=122.png&size=5094&width=550&height=114&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 122: Calculated simulation radius with 1 active transmitter**</div></div></div></div></div></div>Then for a ***<u data-renderer-mark="true">single</u>*** interefering link transmitter located at the edge of the simulation radius (R = 0.178 km), the iRSS<sub data-renderer-mark="true">unwanted</sub> may be calculated:

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/lYJua3z4vr5NzZrA-image.png)

When increasing the number of active transmitters to 10 (see Figure 123), the simulation radius becomes:

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/a8iQUUE2iY7pRBz9-image.png)

Then, for a ***<u data-renderer-mark="true">single</u>*** interefering link transmitter located at the edge of that simulation radius (R = 0.564 km), the iRSS<sub data-renderer-mark="true">unwanted</sub> resulting from this terminal may be calculated as:

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/n7ZJZzL2LTqOnhXd-image.png)

If 10 active terminals are located at the edge of the simulation radius, the iRSS<sub data-renderer-mark="true">unwanted</sub> may be calculated in the following way:

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/yX5nALsb99tBubiS-image.png)

<div class="fabric-editor-block-mark fabric-editor-alignment" data-align="center" id="bkmrk-then-the-irssunwante"><div class="inline-extension-renderer css-e2q2ep"><div class="_kqswh2mm" data-testid="ForgeExtensionContainer"><div class="_19itglyw _vchhusvi _r06hglyw _kqswh2mm" data-testid="hosted-resources-iframe-container"><div class="_19itglyw _vchhusvi _r06hglyw _kqswh2mm">  
</div></div></div></div>Then the iRSS<sub data-renderer-mark="true">unwanted</sub> should be above -24.5 dBm as shown on Figure 124.</div>![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/ph1gUEqzI3So0V1Q-image.png)

<div class="rich-media-item mediaSingleView-content-wrap image-align-start css-njvpmj" data-layout="align-start" data-media-vc-wrapper="true" data-node-type="mediaSingle" data-renderer-start-pos="1689" data-vc="media-single" data-width="318" data-width-type="pixel" id="bkmrk-figure-123%3A-setting-"><div class="css-1u2phmy"><div data-alt="" data-collection="contentId-494239" data-context-id="494239" data-file-mime-type="image/png" data-file-name="123.png" data-file-size="20321" data-height="357" data-id="a287a47a-a3fe-414e-abb5-278d98369256" data-node-type="media" data-renderer-start-pos="1690" data-type="file" data-width="455"><div class="_2rko18qm _vchhusvi _kqswh2mm _ect4ttxp _p12f1osq _c71l1osq _1bsb1qmm _4t3ine4n _1hlmd0i9 _1rquusvi _eg541i5c _mts3kb7n _1ntskb7n _yfmhtlke _5sb1v00u new-file-experience-wrapper" data-media-vc-wrapper="true" data-testid="media-card-view" id="bkmrk-figure-123%3A-setting--1"><div class="_1reo15vq _18m915vq _2rko18qm _1e0c1txw _kqswh2mm _p12f1osq _1bsb1osq _4t3i1osq _c71l1osq media-file-card-view" data-cursor="pointer" data-test-media-name="123.png" data-test-progress="1" data-test-source="remote" data-test-status="complete" data-testid="media-file-card-view"><div class="_kqswstnw _1bsb1osq _4t3i1osq _1e0c1txw _2lx21bp4 _1bah1h6o _4cvr1h6o align-center" data-testid="ImageRendererWrapper">![](blob:https://ecowiki.atlassian.net/3e50e67d-3053-40ca-93ad-e01c232ac665#media-blob-url=true&id=a287a47a-a3fe-414e-abb5-278d98369256&collection=contentId-494239&contextId=494239&mimeType=image%2Fpng&name=123.png&size=20321&width=455&height=357&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 123: Setting up the simulation radius in SEAMCAT with a different**   
 **number of active transmitters**</div></div></div></div></div></div>![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/PyLDqczjkG10Anx5-image.png)

<div class="rich-media-item mediaSingleView-content-wrap image-align-start css-1fcvn4m" data-layout="align-start" data-media-vc-wrapper="true" data-node-type="mediaSingle" data-renderer-start-pos="1801" data-vc="media-single" data-width="463" data-width-type="pixel" id="bkmrk-figure-124%3A-irss-usi"><div class="css-lxubws"><div data-alt="" data-collection="contentId-494239" data-context-id="494239" data-file-mime-type="image/png" data-file-name="124.png" data-file-size="70633" data-height="475" data-id="8afc5787-44db-498f-8c38-b6d36f6acdf3" data-node-type="media" data-renderer-start-pos="1802" data-type="file" data-width="880"><div class="_2rko18qm _vchhusvi _kqswh2mm _ect4ttxp _p12f1osq _c71l1osq _1bsb1qmm _4t3ine4n _1hlmd0i9 _1rquusvi _eg541i5c _mts3kb7n _1ntskb7n _yfmhtlke _5sb1v00u new-file-experience-wrapper" data-media-vc-wrapper="true" data-testid="media-card-view" id="bkmrk-figure-124%3A-irss-usi-1"><div class="_1reo15vq _18m915vq _2rko18qm _1e0c1txw _kqswh2mm _p12f1osq _1bsb1osq _4t3i1osq _c71l1osq media-file-card-view" data-cursor="pointer" data-test-media-name="124.png" data-test-progress="1" data-test-source="remote" data-test-status="complete" data-testid="media-file-card-view"><div class="_kqswstnw _1bsb1osq _4t3i1osq _1e0c1txw _2lx21bp4 _1bah1h6o _4cvr1h6o align-center" data-testid="ImageRendererWrapper">![](blob:https://ecowiki.atlassian.net/58258340-2b3b-4141-83ab-06262fb77526#media-blob-url=true&id=8afc5787-44db-498f-8c38-b6d36f6acdf3&collection=contentId-494239&contextId=494239&mimeType=image%2Fpng&name=124.png&size=70633&width=880&height=475&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 124: iRSS using the simulation radius calculated for 10 active interferers (R=0.564 km)**</div></div></div></div></div></div>[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/nvWwpk7aBs0QgxNH-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/nvWwpk7aBs0QgxNH-image.png)![](blob:https://ecowiki.atlassian.net/1d4a788f-459b-448f-8cb1-75fb50d7af28#media-blob-url=true&id=15de77d0-d290-42c1-aaab-8bd52b51da07&collection=contentId-494239&contextId=494239&mimeType=image%2Fpng&name=125.png&size=5261&width=555&height=106&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 125: Calculated simulation radius with 10 active transmitters**

# 4.7.2 "None" mode

When you select the “**None” mode** (see ANNEX 13:**)**, he can also define a Uniform density of terminal/transmitter by using the Uniform polar distance defined within the path distance factor and a uniform distributed path azimuth (0 to 360 deg).**Uniform polar distance** leads to uniformly distributed terminals in the **circular area** (area) and the **Uniform distance** leads to uniformly distributed terminals along the **radius** (line).

Then using a user-defined radius of 0.178 km and 1 interefering link transmitter (see Figure 126), it is possible to reproduce the results of section 4.7.1. Therefore, the same results as those given in Figure 121 are found as shown in Figure 127.

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/FgDVJXDdtN0Axq5W-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/FgDVJXDdtN0Axq5W-image.png)

<div class="rich-media-item mediaSingleView-content-wrap image-align-start css-13moijr" data-layout="align-start" data-media-vc-wrapper="true" data-node-type="mediaSingle" data-renderer-start-pos="677" data-vc="media-single" data-width="400" data-width-type="pixel" id="bkmrk-figure-126%3A-uniform-"><div class="css-1cwoque"><div data-alt="" data-collection="contentId-494284" data-context-id="494284" data-file-mime-type="image/png" data-file-name="126.png" data-file-size="25911" data-height="358" data-id="cf294ff3-74bd-4564-a36e-2c0b13216ab7" data-node-type="media" data-renderer-start-pos="678" data-type="file" data-width="573"><div class="_2rko18qm _vchhusvi _kqswh2mm _ect4ttxp _p12f1osq _c71l1osq _1bsb1qmm _4t3ine4n _1hlmd0i9 _1rquusvi _eg541i5c _mts3kb7n _1ntskb7n _yfmhtlke _5sb1v00u new-file-experience-wrapper" data-media-vc-wrapper="true" data-testid="media-card-view" id="bkmrk-figure-126%3A-uniform--1"><div class="_1reo15vq _18m915vq _2rko18qm _1e0c1txw _kqswh2mm _p12f1osq _1bsb1osq _4t3i1osq _c71l1osq media-file-card-view" data-cursor="pointer" data-test-media-name="126.png" data-test-progress="1" data-test-source="remote" data-test-status="complete" data-testid="media-file-card-view"><div class="_kqswstnw _1bsb1osq _4t3i1osq _1e0c1txw _2lx21bp4 _1bah1h6o _4cvr1h6o align-center" data-testid="ImageRendererWrapper">![](blob:https://ecowiki.atlassian.net/cc27631f-e002-480b-9bda-1c8a72061280#media-blob-url=true&id=cf294ff3-74bd-4564-a36e-2c0b13216ab7&collection=contentId-494284&contextId=494284&width=573&height=358&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 126: Uniform density using “None” mode**</div></div></div></div></div></div>[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/fGqs2Po67vV5PHG3-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/fGqs2Po67vV5PHG3-image.png)![](blob:https://ecowiki.atlassian.net/2679b233-ff48-47ce-9c6b-05fe4ff50f94#media-blob-url=true&id=718dd3f0-ad23-4f7d-8ada-a701cd258379&collection=contentId-494284&contextId=494284&width=880&height=475&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 127: iRSS<sub data-renderer-mark="true">unwanted</sub> / Uniform polar feature / 1 interfering link transmitter and simulation radius of 0.178 km (same results as in Figure 121)**

Using a user-defined radius of 0.564 km and 10 interefering link transmitters, the same results as those given in Figure 124 are reached as shown in Figure 128.

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/K2MeRcMFiI8jwZkK-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/K2MeRcMFiI8jwZkK-image.png)

<div class="rich-media-item mediaSingleView-content-wrap image-align-start css-1fcvn4m" data-layout="align-start" data-media-vc-wrapper="true" data-node-type="mediaSingle" data-renderer-start-pos="1045" data-vc="media-single" data-width="463" data-width-type="pixel" id="bkmrk-figure-128%3A-irssunwa"><div class="css-1f3qnes"><div data-alt="" data-collection="contentId-494284" data-context-id="494284" data-file-mime-type="image/png" data-file-name="image2016-8-8 11:16:52.png" data-file-size="133536" data-height="347" data-id="33a799ba-ee87-4d6c-908d-255e30963e18" data-node-type="media" data-renderer-start-pos="1046" data-type="file" data-width="643"><div class="_2rko18qm _vchhusvi _kqswh2mm _ect4ttxp _p12f1osq _c71l1osq _1bsb1qmm _4t3ine4n _1hlmd0i9 _1rquusvi _eg541i5c _mts3kb7n _1ntskb7n _yfmhtlke _5sb1v00u new-file-experience-wrapper" data-media-vc-wrapper="true" data-testid="media-card-view" id="bkmrk-figure-128%3A-irssunwa-1"><div class="_1reo15vq _18m915vq _2rko18qm _1e0c1txw _kqswh2mm _p12f1osq _1bsb1osq _4t3i1osq _c71l1osq media-file-card-view" data-cursor="pointer" data-test-media-name="image2016-8-8 11:16:52.png" data-test-progress="1" data-test-source="remote" data-test-status="complete" data-testid="media-file-card-view"><div class="_kqswstnw _1bsb1osq _4t3i1osq _1e0c1txw _2lx21bp4 _1bah1h6o _4cvr1h6o align-center" data-testid="ImageRendererWrapper">![](blob:https://ecowiki.atlassian.net/6185e6fe-b3f2-425a-b2ef-02db0ed46181#media-blob-url=true&id=33a799ba-ee87-4d6c-908d-255e30963e18&collection=contentId-494284&contextId=494284&mimeType=image%2Fpng&name=image2016-8-8%2011%3A16%3A52.png&size=133536&width=643&height=347&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 128: iRSS<sub data-renderer-mark="true">unwanted</sub> / Uniform polar feature / 10 interfering link transmitter**   
 **(same results as in Figure 121)**</div></div></div></div></div></div>