Kitz Forum

Broadband Related => Router Monitoring Software => Topic started by: pdes on December 15, 2015, 08:42:12 AM

Title: Does low power affect speed?
Post by: pdes on December 15, 2015, 08:42:12 AM: I have just looked at the stats summary in Mydslwebstats (pdes) and noticed that my power down is 7.4db. This seems to be far lower than anyone else's. I am on a long line (33.5db) but so are others with a much higher down power. What dictates the power level? If the power level was higher, would I attain a higer sync speed?

Thanks
Title: Re: Does low power affect speed?
Post by: ejs on December 15, 2015, 06:27:06 PM: I think it's more likely that the low speed resulted in the power being lower. After the initial analysis when the connection is established, the tones that are determined to be unusable, will have nothing or only a very low nominal power level transmitted on those tones. If you have lots of unusable tones, then the aggregated power level totalled over all the tones, might be lower than that of a line that is able to make use of more tones.

The maximum permitted power level for a particular tone would be determined by the band plan. If, when transmitting at that maximum power level, the SNR on that tone isn't enough for it to have any bits allocated (because line is too long and the attenuation of the signal at that frequency is too high, and/or there's too much noise), then there isn't really much point in continuing to transmit on that tone.
Title: Re: Does low power affect speed?
Post by: Dray on December 15, 2015, 06:30:49 PM: I've always thought that low power indicates some sort of line problem - poor conductivity or a fault.
Title: Re: Does low power affect speed?
Post by: NewtronStar on December 15, 2015, 06:57:10 PM: I thought the power mask was to stop a VDSL circuit from interfering with other ADSL circuits so pdes lower power should help ADSL user from crosstalk from his line.
Title: Re: Does low power affect speed?
Post by: ejs on December 15, 2015, 08:11:11 PM: Yes, and there are different configurations depending on the distance between the cabinet and the exchange.