# 1.4.5 Unwanted emissions

The level of ***unwanted emissions*** ( i.e. consisting of the out-of-band emissions and the spurious emissions [\[8\]](https://ecowiki.atlassian.net/wiki/spaces/SH/pages/494676/A26+List+of+references#A26Listofreferences-R08 "https://ecowiki.atlassian.net/wiki/spaces/SH/pages/494676/A26+List+of+references#A26Listofreferences-R08") of the <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>) falling within the <span data-highlighted="true" data-vc="highlighted-text"><span class="_kqswh2mm"><span class="_5pioz8co _189e1dm9 _1il9buyh _19lc184f _d0altlke" data-testid="definition-highlighter">VLR</span></span></span> receiver bandwidth (Figure 11) is determined using the interferer’s transmit mask, the receiver bandwidth of the <span data-highlighted="true" data-vc="highlighted-text">VLR</span>, the interferer-to-victim frequency separation, the gains of the antennas and the propagation loss. The receiver experiences the unwanted power directly as additional noise in terms of I+N. There is no possibility in terms of filtering with which the receiver could reduce this impact by itself.

Note that the receiver bandwidth is taken into account in the unwanted calculation.

Further details on the unwanted emission mask are provided in[ ANNEX 6](https://ecowiki.atlassian.net/wiki/spaces/SH/pages/494667/A6+sRSS+calculation#A6sRSScalculation-A6 "https://ecowiki.atlassian.net/wiki/spaces/SH/pages/494667/A6+sRSS+calculation#A6sRSScalculation-A6"):. Details on the iRSS<sub data-renderer-mark="true">unwanted</sub> calculation are given in [ANNEX 5](https://ecowiki.atlassian.net/wiki/spaces/SH/pages/494649/A5+iRSS+calculation#A5iRSScalculation-A5 "https://ecowiki.atlassian.net/wiki/spaces/SH/pages/494649/A5+iRSS+calculation#A5iRSScalculation-A5"):. The unwanted emission is also sometimes quantified using the term Adjacent Channel Leakage Ratio (ACLR) (see Annex [A15.7](https://ecowiki.atlassian.net/wiki/spaces/SH/pages/491958/A15.7+ACS+ACLR+AND+ACIR+APPROACH+IN+SEAMCAT#A15.7ACS,ACLRANDACIRAPPROACHINSEAMCAT-A15.7 "https://ecowiki.atlassian.net/wiki/spaces/SH/pages/491958/A15.7+ACS+ACLR+AND+ACIR+APPROACH+IN+SEAMCAT#A15.7ACS,ACLRANDACIRAPPROACHINSEAMCAT-A15.7")).

[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/R0RQDNpy0w73iU8h-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/R0RQDNpy0w73iU8h-image.png)

**Figure 11: Illustration of the interference due to the unwanted emissions (i.e. the unwanted emissions of <span data-highlighted="true" data-vc="highlighted-text">ILT</span> falling in the receiver bandwidth of <span data-highlighted="true" data-vc="highlighted-text">VLR</span>)**