A device for optimizing coexistence between communication signals sent over communication lines (101, 102); wherein a first set of said communication lines is configured to interoperate according to a first communication standard in a first frequency range; and wherein a second set of said communication lines is configured to interoperate according to a second communication standard operating in a second frequency range overlapping with said first frequency range; said device being configured to perform the following steps: - measuring coupling information indicative for an influence of second communication signals sent over said second set on first communication signals sent over said first set; and - estimating from said coupling information an adapted Power Spectral Density or PSD for said second communication signals in said overlapping frequency range such that said influence from said second communication signals is within a predetermined tolerance level; and - applying said adapted PSD to communication signals sent over said second set; characterized in that - said first communication signals correspond to first symbols (920, 921, 922, 910, 911, 912) of a predetermined fixed length; and wherein said second communication signals correspond to frames of a fixed length further comprising second symbols of a fixed length; and wherein a frame is divided over time in an upload portion of said second symbols and a download portion of said second symbols; and wherein a length of said frame corresponds to a length of an integer amount of said first symbols (920, 921, 922, 910, 911, 912); and wherein a beginning of said frames is synchronized with a beginning of said first symbols; and wherein said measuring further comprises measuring total noise from a synchronization symbol (920, 912) in said first symbols when said synchronization symbol falls completely within said upload or within said download portion thereby obtaining a separate total noise measure for said upload and download portion respectively; or - said second communication signals correspond to second symbols (1120, 1121, 1122) of a predetermined fixed length; and wherein said first communication signals correspond to frames of a fixed length further comprising first symbols of a fixed length; and wherein a frame is divided over time in an upload portion of said first symbols and a download portion of said first symbols; and wherein a length of said frame corresponds to a length of an integer amount of said second symbols (1120, 1121, 1122); and wherein a beginning of said frames is synchronized with a beginning of said second symbols; and wherein said measuring further comprises measuring total noise from a synchronization symbol (1130, 1132) in said first symbols thereby obtaining a total noise measure indicative for background noise together with interference noise from said second set. - measuring coupling information indicative for an influence of second communication signals sent over said second set on first communication signals sent over said first set; and - estimating from said coupling information an adapted Power Spectral Density or PSD for said second communication signals in said overlapping frequency range such that said influence from said second communication signals is within a predetermined tolerance level; and - applying said adapted PSD to communication signals sent over said second set; - said first communication signals correspond to first symbols (920, 921, 922, 910, 911, 912) of a predetermined fixed length; and wherein said second communication signals correspond to frames of a fixed length further comprising second symbols of a fixed length; and wherein a frame is divided over time in an upload portion of said second symbols and a download portion of said second symbols; and wherein a length of said frame corresponds to a length of an integer amount of said first symbols (920, 921, 922, 910, 911, 912); and wherein a beginning of said frames is synchronized with a beginning of said first symbols; and wherein said measuring further comprises measuring total noise from a synchronization symbol (920, 912) in said first symbols when said synchronization symbol falls completely within said upload or within said download portion thereby obtaining a separate total noise measure for said upload and download portion respectively; or - said second communication signals correspond to second symbols (1120, 1121, 1122) of a predetermined fixed length; and wherein said first communication signals correspond to frames of a fixed length further comprising first symbols of a fixed length; and wherein a frame is divided over time in an upload portion of said first symbols and a download portion of said first symbols; and wherein a length of said frame corresponds to a length of an integer amount of said second symbols (1120, 1121, 1122); and wherein a beginning of said frames is synchronized with a beginning of said second symbols; and wherein said measuring further comprises measuring total noise from a synchronization symbol (1130, 1132) in said first symbols thereby obtaining a total noise measure indicative for background noise together with interference noise from said second set.