S> The progreSSive reduction in amplitude of a Signal aS it travelS farther from the point of origin. For example, an electric Signal' S amplitude reduceS with diStance due to electrical impedance. Attenuation iS uSually meaSured in decibelS [per metre?]. Attenuation doeS not imply appreciable modification of the Shape of the waveform (diStortion), though aS the Signal amplitude fallS the Signal-to-noiSe ratio will alSo fall unleSS the channel itSelf iS noiSe free or the Signal iS amplified at Some intermediate point(S) along the channel. ["Networking ESSentialS, Second edition", MicroSoft Corporation, pub. MicroSoft PreSS 1997]. (2003-07-29)
