# 4.9 Power Control

**Note:** The power control is used only in this section. When considering other sections, the power control feature should be deactivated.

A power control feature is implemented within SEAMCAT. When this feature is activated it introduces a variation of the interefering link transmitter power. More details on the implementation of the power control in SEAMCAT is presented in ANNEX 14:.

When using the scenario provided in section 3 (Victim Link and Interfering Link operate at the same frequency 1000 MHz but with a interfering link receiver antenna gain should be equal to 11 dBi), it becomes possible to define the distance between the Victim link receiver and the Interefering link transmitter.

For simplification, we consider that the Victim link receiver and the Interefering link transmitter are defined using the following assumptions (1 km distance between the Victim and the Interefering link transmitter). This is illustrated in Figure 134.

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/3eM4rgLenmG8JvB8-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/3eM4rgLenmG8JvB8-image.png)

<div class="rich-media-item mediaSingleView-content-wrap image-align-start css-1lr4ohf align-center" data-layout="align-start" data-media-vc-wrapper="true" data-node-type="mediaSingle" data-renderer-start-pos="957" data-vc="media-single" data-width="451" data-width-type="pixel" id="bkmrk-figure-134%3A-setting-"><div class="css-1y4eb78"><div data-alt="" data-collection="contentId-494267" data-context-id="494267" data-file-mime-type="" data-file-name="file" data-file-size="1" data-height="212" data-id="d41ab08f-1dd5-46f2-b637-031b56dbc4cc" data-node-type="media" data-renderer-start-pos="958" data-type="file" data-width="451"><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-134%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="134.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" data-testid="ImageRendererWrapper">![](blob:https://ecowiki.atlassian.net/f081027e-dac3-4273-aef7-a8086411adb0#media-blob-url=true&id=d41ab08f-1dd5-46f2-b637-031b56dbc4cc&collection=contentId-494267&contextId=494267&width=451&height=212&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 134: Setting up the distance between the Interfering and the Victim pair of transmitter and receiver**</div></div></div></div></div></div>If the power control is not activated then the iRSS<sub data-renderer-mark="true">unwanted</sub> is (see Figure 135):

 [![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/DPI21oN67HJzB8Di-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/DPI21oN67HJzB8Di-image.png)

<div class="fabric-editor-block-mark fabric-editor-alignment" data-align="center" id="bkmrk-%C2%A0-%C2%A0%C2%A0-%C2%A0-%C2%A0-%C2%A0-%C2%A0-%C2%A0-%C2%A0-%C2%A0%C2%A0"><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></div></div>  </div>![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/H32Z6LTnrgJNm29d-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="1179" data-vc="media-single" data-width="463" data-width-type="pixel" id="bkmrk-figure-135%3A-irssunwa"><div class="css-lxubws"><div data-alt="" data-collection="contentId-494267" data-context-id="494267" data-file-mime-type="" data-file-name="file" data-file-size="1" data-height="475" data-id="6a935a32-7f82-4aa4-9b89-d901e99c6fec" data-node-type="media" data-renderer-start-pos="1180" 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-135%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="35.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/31d441da-a5f4-499f-ae2b-b2587c811af8#media-blob-url=true&id=6a935a32-7f82-4aa4-9b89-d901e99c6fec&collection=contentId-494267&contextId=494267&width=880&height=475&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 135: iRSS<sub data-renderer-mark="true">unwanted</sub> without power control**</div></div></div></div></div></div>The same assumption is used for the distance between <span data-highlighted="true" data-vc="highlighted-text"><span class="_kqswh2mm"><span class="_5pioz8co _189e1dm9 _1il9buyh _19lc184f _d0altlke" data-testid="definition-highlighter">ILT</span></span></span> and the <span data-highlighted="true" data-vc="highlighted-text"><span class="_kqswh2mm"><span class="_5pioz8co _189e1dm9 _1il9buyh _19lc184f _d0altlke" data-testid="definition-highlighter">ILR</span></span></span> (i.e. x = 0 km and y = 1 km) where the <span data-highlighted="true" data-vc="highlighted-text">ILT</span> is the (0,0) origin as shown in Figure 136.

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/D5dg01HyuRqlY5Kx-image.png)

<div class="rich-media-item mediaSingleView-content-wrap image-align-start css-ht0p29" data-layout="align-start" data-media-vc-wrapper="true" data-node-type="mediaSingle" data-renderer-start-pos="1390" data-vc="media-single" data-width="413" data-width-type="pixel" id="bkmrk-figure-136%3A-setting-"><div class="css-bjprsf"><div data-alt="" data-collection="contentId-494267" data-context-id="494267" data-file-mime-type="" data-file-name="file" data-file-size="1" data-height="158" data-id="a095ce8d-772b-42a6-8487-15c0617cbe28" data-node-type="media" data-renderer-start-pos="1391" data-type="file" data-width="413"><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-136%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="36.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/29a1db24-0f55-4952-973d-f79a4326a070#media-blob-url=true&id=a095ce8d-772b-42a6-8487-15c0617cbe28&collection=contentId-494267&contextId=494267&width=413&height=158&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 136: Setting up the distance between the Interfering link transmitter and the Interfering link receiver to evaluate the dRSS<sub data-renderer-mark="true">Interfering link receiver</sub>.**</div></div></div></div></div></div>The power received by the Interfering link receiver (dRSS<sub data-renderer-mark="true">Interfering link receiver</sub>) is then:

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/rkltmy8znVTkHQsc-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/rkltmy8znVTkHQsc-image.png)

Note: ***You should not confuse the dRSS<sub data-renderer-mark="true">Interfering link receiver</sub> and the dRSS<sub data-renderer-mark="true">Victim link receiver</sub>. Figure 111 illustrates their differences.***

The power control can be input as shown in Figure 137.

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/y66kLBEox0BWs4h3-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="1849" data-vc="media-single" data-width="463" data-width-type="pixel" id="bkmrk-figure-137%3A-setting-"><div class="css-1q7pgp8"><div data-alt="" data-collection="contentId-494267" data-context-id="494267" data-file-mime-type="" data-file-name="file" data-file-size="1" data-height="270" data-id="483b6327-5d8e-484b-9677-bc5cc9975ad0" data-node-type="media" data-renderer-start-pos="1850" data-type="file" data-width="501"><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-137%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="37.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/f516e01f-2c2a-46df-8d6f-55deb2eb173d#media-blob-url=true&id=483b6327-5d8e-484b-9677-bc5cc9975ad0&collection=contentId-494267&contextId=494267&width=501&height=270&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 137: Setting up the power control for the interfering link**</div></div></div></div></div></div>Using these assumptions, the results of the simulation are the same as previously since the threshold (-35 dBm) is above the dRSS<sub data-renderer-mark="true">Interfering link receiver </sub>(-37.5 dB). This corresponds to the Case 1 described in ANNEX 14:.

Now, if the threshold is decreased from –35 dBm to –50 dBm (see Figure 138)

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/swXgwgzhQk9tY9wv-image.png)

<div class="rich-media-item mediaSingleView-content-wrap image-align-start css-1cjzudg" data-layout="align-start" data-media-vc-wrapper="true" data-node-type="mediaSingle" data-renderer-start-pos="2220" data-vc="media-single" data-width="464" data-width-type="pixel" id="bkmrk-figure-138%3A-reductio"><div class="css-1l353jc"><div data-alt="" data-collection="contentId-494267" data-context-id="494267" data-file-mime-type="" data-file-name="file" data-file-size="1" data-height="269" data-id="c1872589-b08b-4437-ab12-7935be41bce2" data-node-type="media" data-renderer-start-pos="2221" data-type="file" data-width="500"><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-138%3A-reductio-1"><div class="_1reo15vq _18m915vq _2rko18qm _1e0c1txw _kqswh2mm _p12f1osq _1bsb1osq _4t3i1osq _c71l1osq media-file-card-view" data-cursor="pointer" data-test-media-name="38.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/0f7e702f-6b86-466a-995d-90012c4fd5b0#media-blob-url=true&id=c1872589-b08b-4437-ab12-7935be41bce2&collection=contentId-494267&contextId=494267&width=500&height=269&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 138: Reduction of the minimum threshold in the PC**</div></div></div></div></div></div>Since, the power control feature is activated the gain of the power control is determined according to the guidance given in ANNEX 14: on page 344. Since the dRSS<sub data-renderer-mark="true">Interfering link receiver</sub> is –37.5 dBm and:

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/oZyfxI5gcVHNn2C5-image.png)

<div class="fabric-editor-block-mark fabric-editor-alignment" data-align="center" id="bkmrk-%C2%A0-%C2%A0-%C2%A0-%C2%A0-%C2%A0-%C2%A0-%C2%A0-%C2%A0-%C2%A0-%C2%A0"><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></div></div> </div>The gain of the power control (*g<sub data-renderer-mark="true">it PC</sub>*) is 10 dB (Case (i+1) in ANNEX 14:). This means that the iRSS<sub data-renderer-mark="true">unwanted</sub> will be decreased by 10 dB, i.e. :

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/7wMkWe3j49ScQG8J-image.png)

Finally, if the threshold is decreased from –50 dBm to –70 dBm, the power control feature is activated. Since the dRSS<sub data-renderer-mark="true">Interfering link receiver</sub> is –37.5 dBm, this results in:

![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/RpxiHl7Bc4xbZM18-image.png)

The gain of the power control is 20 dB (Case (*n\_step* + 2) in ANNEX 14:). This means that the iRSS<sub data-renderer-mark="true">unwanted</sub> will be decreased by 20 dB, i.e. :

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/VjjtboR6gjSqrE32-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/VjjtboR6gjSqrE32-image.png)