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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?"
Enterprise hardware does not use general-purpose CPUs, it uses special-purpose ASICs. These are lower power than general purpose hardware. They are fab'd using a newer process than the older ones, and so use less power per transistor than the old chips. Less power per transistor means more transistors (which means more processing power) per watt. If you rolled out 802.11g infrastructure four years ago, you can now fit around three to four times as many transistors on the same area of silicon as was possible when you deployed your current infrastructure.
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Maybe skimming TFA wasn't the best basis for comment. The article mentions no power issue at the client. It's basically saying that:
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?
First of all, this has little to do with what is usually considered power infrastructure. This has to do with power-over-ethernet. It appears some dual band 802.11n radios require more power than one particular specification (802.3af) allows. Solution? Don't use 802.3af, or, don't use the radios which require too much power. Not really a big deal. I expect that manufacturers will bring the power requirements down to allowable levels over time.
Essentially just because vendor A has devices which consume "up to 18 watts" it doesn't mean that nobody can build devices which take less than 13 Watts.
That's just 5 watts difference. You could probably achieve this by switching to higher efficiency components. Or you could store some energy for the short bursts of transmission, getting a steady power of 13 watts.
Keep in mind that most vendors probably still have the very first itteration of hardware. It will significantly improve over the next years anyhow.
Enterprise hardware does not use general-purpose CPUs, it uses special-purpose ASICs
Actually they don't - take a look in a high-end AP some time. "Enterprise" wireless systems use the same, or often older generation, of wireless technology that is in consumer access points. Competition in the consumer AP market is what drives all the incredible price/performance in wireless technology, and I assure you nobody is going to spend the tens of millions to do a custom spin of one of those chipsets for the relatively small high-end market. Those products sell on branding, special software features, and support contracts, not silicon performance. And as far as the CPU/memory etc, these are going to be much LESS specialized in a high-end system than in a consumer AP. Low-cost APs use highly integrated ARM or MIPs-based SOCs that are designed for sub $20 BOM cost. A higher-end system, however, is not bound by BOM costs and might have four times the memory and a more general purpose processor capable of running more software.
Routers and switches are a different story, and those DO use ASICs and FPGAs. The high-end models of these have to deliver a totally different hardware feature set than consumer equipment, and unlike wireless technology, the bleeding edge tends to be developed for the highest priced products before trickling down.