First of all welcome to the firewall.cx forums. In a few words tha difference is that attenuation is the loss of a signal as it travels and crosstalk is the interference between two cables (for example).
If you need more information on specific subjects please post back.
Hope I helped,
Re: Abt the cross talk and attenuation
12 years 11 months ago #13566
well both attenuation and crosstalk are used extensively in communications especially in data communications.
the difference between the two is how they both affect signal or intelligence run across a media from a point of origin to a destination.
attenuation is the degradation of the signal due to various reasons such as noise introduction, lossy media, distance, and the like.
crosstalk however is the interference of signal to an adjacent one whereby affecting the signal's essence. usually cause by radiation of electromagnetic induction run through a media usually copper.
usually a high frequency transmitted over a wired media causes crosstalks to adjacent ones if proper shielding is neglected, however attenuation may also occur if the signal is projected towards a lossy media over a long distance and with the presence of noise.
both are always introduce in a communication environment but have their differences where one degrades while the other affects signal.
Attenuation and Crosstalk
12 years 11 months ago #13617
A UTP network cable consists of four 'pairs' of wires. The two wires in each pair are twisted around eachother to help provide immunity to interference. If we consider a signal being sent down one pair in isolation, then the attenuation of the cable is the degree to which the signal gets reduced in magnitude as it travels down the cable and comes out the other end. As mentioned, this causes degradation of the signal because as you get less and less signal then the noise, interference etc also present on the cable becomes more significant and can corrupt the data.
Crosstalk is the extent to which a signal sent down one pair of the cable also appears on another pair. The cross-coupling occurs by electromagnetic induction, and the 'unwanted' signal due to the crosstalk also contributes to the noise on the pair that competes with the wanted signal. The twisting of the pairs aims to reduce the induction, lowering both the crosstalk between the pairs within the cable and interference induced from outside. What determines the attenuation is a little more complex, but basically it's to do with how the construction of the cable matches the frequency being used. The higher the data rate (anf hence frequency of the signal) the 'better' the cable has to be and the tigher the manufacturing tolerances