ZyXEL Communications IES-5005 manual IES-5000/5005/6000 Support Notes Upstream Power Back-Off UPBO

IES-5000/5005/6000 Support Notes

Upstream Power Back-Off (UPBO)

What is UPBO?

Upstream Power back-of (UPBO) helps to run services over loops with different length co-located in the same cable binder (“mixed length” deployments), especially in FEXT-dominated noise environment.

Strong FEXT generated by short loops can significantly degrade the performance of long loops if UPBO is not applied. On the other hand, UPBO reduces the transmit power of short loops and thus degrades their performance as well.

PSD	PSD		PSD
f		f		f

PSD

f

PSD

f

Enable UPBO to allow the system to adjust the transmit PSD of all lines based on a reference line length so that the PSD at the receiving end is the same.

PSD	PSD		PSD
f		f		f

	PSD
	f
PSD
	f

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