# 6.5.3 Some of the channels are blocked and some are available

This is a typical example. In such a scenario, the detection threshold is taken to a value of -80 dB (flat over the frequency range). This mean that when considering the sRSS of Figure 168, for some of the events, the sRSS will be above that threshold and therefore some WSDs will be considered as off (which explains the -1000 dBm value in Figure 169 (b)) and the <span data-highlighted="true" data-vc="highlighted-text"><span class="_kqswh2mm"><span class="_5pioz8co _189e1dm9 _1il9buyh _19lc184f _d0altlke" data-testid="definition-highlighter">WSD</span></span></span> frequencies are randomly distributed.

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/hMc9gIN0JRYu0wRS-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/hMc9gIN0JRYu0wRS-image.png)

<div class="rich-media-item mediaSingleView-content-wrap image-align-start css-i5keov" data-layout="align-start" data-media-vc-wrapper="true" data-node-type="mediaSingle" data-renderer-start-pos="410" data-vc="media-single" data-width="442" data-width-type="pixel" id="bkmrk-figure-168%3A-srss-for"><div class="css-1mfrdyg"><div data-alt="" data-collection="contentId-494491" data-context-id="494491" data-file-mime-type="image/png" data-file-name="68.png" data-file-size="283314" data-height="552" data-id="c807dd06-ceaf-4644-941e-2d53cfcfd818" data-node-type="media" data-renderer-start-pos="411" data-type="file" data-width="977"><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-168%3A-srss-for-1"><div class="_1reo15vq _18m915vq _2rko18qm _1e0c1txw _kqswh2mm _p12f1osq _1bsb1osq _4t3i1osq _c71l1osq media-file-card-view" data-cursor="pointer" data-test-media-name="68.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/7e6ed786-3199-4b32-a3f2-160c6e634003#media-blob-url=true&id=c807dd06-ceaf-4644-941e-2d53cfcfd818&collection=contentId-494491&contextId=494491&width=977&height=552&alt=&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18)**Figure 168: sRSS for 5 WSDs per event**</div><div class="_kqswstnw _1bsb1osq _4t3i1osq _1e0c1txw _2lx21bp4 _1bah1h6o _4cvr1h6o align-center" data-testid="ImageRendererWrapper"></div><div class="_kqswstnw _1bsb1osq _4t3i1osq _1e0c1txw _2lx21bp4 _1bah1h6o _4cvr1h6o align-center" data-testid="ImageRendererWrapper"></div></div><div class="_kqswstnw _1bsb1osq _4t3i1osq _1e0c1txw _2lx21bp4 _1bah1h6o _4cvr1h6o align-center" data-testid="ImageRendererWrapper"></div></div></div></div></div><div class="_kqswstnw _1bsb1osq _4t3i1osq _1e0c1txw _2lx21bp4 _1bah1h6o _4cvr1h6o align-center" data-testid="ImageRendererWrapper" id="bkmrk--1"></div><table border="1" id="bkmrk-%28a%29-wsd-frequency-%28b" style="border-collapse: collapse; width: 100%; height: 29.6px;"><colgroup><col style="width: 50.0477%;"></col><col style="width: 50.0477%;"></col></colgroup><tbody><tr style="height: 29.6px;"><td style="height: 29.6px;">[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/eoWBw1VczAacfQXx-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/eoWBw1VczAacfQXx-image.png)

</td><td style="height: 29.6px;">[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/0cw7Dr7SuQQAFmnz-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/0cw7Dr7SuQQAFmnz-image.png)

</td></tr><tr><td>**(a) <span data-highlighted="true" data-vc="highlighted-text">WSD</span> frequency**

</td><td>**(b) <span data-highlighted="true" data-vc="highlighted-text">WSD</span> e.i.r.p.**

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

**Figure 169: Output results of the <span data-highlighted="true" data-vc="highlighted-text">WSD</span> in (a) frequency and (b) e.i.r.p.**

In this case, one can see that all the channels were occupied in Figure 170. The WSDs were allowed to transmit with an e.i.r.p. of 33 dBm in the 3 middle channels (1000.3 MHz to 1000.7 MHz) while for the side channels less power was allowed (i.e. 24 dBm for 1000.1 MHz and 16.89 dBm for 1000.9 MHz).

Figure 170 (b) also indicates that not all the simulated WSDs were active (those having an e.i.r.p. of -1000 dBm), and that per event about only 1 <span data-highlighted="true" data-vc="highlighted-text">WSD</span> was active.

<table border="1" id="bkmrk-%28a%29-average-e.i.r.p." style="border-collapse: collapse; width: 100%; height: 296.312px;"><colgroup><col style="width: 50%;"></col><col style="width: 50%;"></col></colgroup><tbody><tr style="height: 266.712px;"><td style="height: 266.712px;">[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/MY0UAVVeYzGuJbHR-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/MY0UAVVeYzGuJbHR-image.png)

</td><td style="height: 266.712px;">[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/L311iPSAU3O6TW8E-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/L311iPSAU3O6TW8E-image.png)

</td></tr><tr style="height: 29.6px;"><td style="height: 29.6px;">**(a) average e.i.r.p.**

</td><td style="height: 29.6px;">**(b) average number of active WSDs**

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

**Figure 170: output results of the <span data-highlighted="true" data-vc="highlighted-text">WSD</span> in (a) frequency and (b) e.i.r.p.**