VDSL's Power, Part II

12:25 PM -- In yesterday's post, I reminded readers that, while today's broadband access technologies are touted as green, they are also big fat power pigs compared to the oldest of the older technologies they are replacing (i.e., Ye Olde Phone Network).

We have to take the claim that FTTH is a greener technology for telcos in the proper context. It is greener for telcos because they install loads of active electronics on the subscriber's house, and thus offload the power burden of tomorrow's technology to today's unsuspecting consumer. That's the price we pay for progress.

Bottom line: FTTH is greener for telcos, not for you. But, depending on how much more often FTTH allows you to work from home, even that point could be debated.

Finally, there's also some debate as to whether VDSL2 does actually use less power than ADSL2. A presentation used by BroadLight Inc. at the most recent FTTH Conference noted that VDSL actually consumes more power, but the point of the comparison was to show that GPON was the best bet (for telcos) overall.

Broadlight's findings (and assumptions) are below:

Table 1: GPON's Green Tint
GPON vs. Power Savings Power Cost Savings CO2 Savings
ADSL2 ~11 MWh $1.2M ~4.8M lbs CO2 or 250K gallons of gas
VDSL ~29 MWh $2.9M ~13.6M lbs CO2 or 700K gallons of gas
� $0.10 kWh ( kWh = kiloWatt hour, MWh = MegaWatt hour)
� http://www.pge.com/about_us/environment/calculator/index.html

Source: Broadlight, Inc.

— Phil Harvey, Editor, Light Reading

paolo.franzoi 12/5/2012 | 3:24:54 PM
re: VDSL's Power, Part II
Its pretty simple. VDSL2 is about 1 and 1/2 watts a port. A modern ADSL2+ implementation is less than a watt per port. Those are rough numbers and games can be played with very specific VDSL2 implementations at very specific reaches.

You don't get more spectrum for less energy.

drewcwsj 12/5/2012 | 3:24:54 PM
re: VDSL's Power, Part II I can't find Broadlight's presentation and would be interested in seeing it. In general there are a lot of games being played with power and I suspect they tweaked the numbers.

I did attend LR's green telecom conference in Dallas and think ATIS/Verizon are heading down the right road with TEER (Telecom Energy Efficiency Ratio). Verzion has some good info on objectively measuring power here http://www.verizonnebs.com/

Basically TEER is the ratio of network throughput versus node power consumption. But it also takes into account the utilization of the network.

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