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Concerns Over Increased 802.11n Power Usage
alphadogg writes "Next-generation 802.11n systems promise to considerably improve WLAN performance. But the processing required for the boost sucks up more power than the older 802.11a/b/g networks. Still, many enterprise-class Wi-Fi vendors claim to deliver full 802.11n capabilities without enterprise customers having to touch their power infrastructures. So what gives?"
It's like 8 watts instead of 3 watts (not exact numbers). It's not a significant amount of power. That's why you don't need to upgrade your infrastructure.
I'm not sure how a silly article like this gets published. If it was tons of power, how could they make 802.11n adapters for laptops?
A laptop, 802.11n
Suckin 18 watts, instead of 15,
It's way less than a lightbulb, on a dull day
But the article author thinks there's no way
And isn't it ironic, don't you think?
No, sorry, can't see the irony there. And ffs for the 3 extra watts per base station/machine, it amounts to switching on a couple of extra lights at the company. I know it's still better to save power where you can, but needing a new power infrastructure to support it? You have to lol. *sigh*
which is totally what she said
This could end up being good for the ratification of 802.11n. The spec that gets its power usage down to meet the 802.3af power first, wins.
Just because a given access point will use "up to 18watts" does not mean it will always use 18watts. As long as the average power consumption is under what the supply can deliver, all can be well. Several possibilities exist.
Best case is that the supply can deliver short term bursts of power sufficient to meet the demand. This is realistic in most scenarios today, as supplies are typically rated by long-term average power. For example, the 20amp breaker on your typical home circuit will easily supply a few seconds at 30amps. My irrigation pump is rated at 28amps, the breaker at 50amps, and the pump draws over 100amps every time it starts. No problems.
Worst case is the access point requires some local power storage to meet the demand. This might take the form of a supercap or rechargeable battery. Average power usage keeps the battery charged, and peak demands are met from the battery. Only if the battery becomes depleted does the access point have to limit power usage -- perhaps by limiting transmit power or by limiting speed.
sdb
There is several ways vendors are getting around the power issue with .11n, by only having one antenna or by doing some software trickery where instead of getting 15.4 watts over every interface you lower the power to a couple and redistribute that power to get it to 18watts , (I know Cisco is doing this on their 3750-E switches and have been told they plan on it on their 4500E switches). Since most companies don't put 30 access points on one switch anyway (would be bad if that switch went out!) that probably will not be an issue, unless you run IP phones that eat a lot of juice also.
What I see as the large issue is that a significant amount of people have only 10/100 to the copper port and to run 802.11n you must have 1Gb copper to provide full bandwidth. (then power the device by how ever you want PoE, injector, wall plug)