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Comment by maxmouchet | Hacker News Reader

Also 2.5G is interesting for 802.11ac Wi-Fi APs that provides bandwidth >1G. No need for port aggregation.

Net bandwidth on 802.11ac is nowhere near real 1Gbps though. Most i got out of a good 802.11ac AP that claimed 1,3Gbps was ~500-600Mbps in the real world on very close distance and it falls off pretty fast. Even the ones claiming nearly 2Gbps can't reach real 1Gbps afaik. Still very nice, but Wifi has a lot of overhead.

The problem is that a lot of access points advertise n Gbps but that refers to full system bandwidth on multiple channels and such so you got somewhere close to what they were really expecting you to get. Heck, my Ubiquiti Unifi AC Pro can get me a bit over 800 Mbps without a problem in bursts (and it advertises well over 2 Gbps) but the nature of wifi networks is that I won't get that sustained for very long. For home server uses that most people don't have, I absolutely won't be able to work off a pure wireless network for many reasons.

This is consistent with the other 802.11 speed ratings, back to 802.11b. You can generally divide the bitrate by 2 to get the maximum practical goodput.

Enterprise wireless has some way to go before you'll actually need even 1Gbps. Any sane wireless engineer is using 20mhz channels. That yields a PHY of 217Mbps on a 3x3:3 client/AP. My iperf results are usually about the 170Mbps range using said client.

>Any sane wireless engineer is using 20mhz channels.

Any reason not to use larger channels on 5GHz at home? I can generally only see 1 or 2 other 5GHz networks indoors, compared to dozens of 2.4GHz networks, so SNR should be no issue on a larger channels.

But maybe you were referring to high density enterprise deployments?

Correct, Enterprise networks generally need the higher number of channels available that is provided with 20mhz width. For example, I have five story buildings with 20-30 APs per floor. There would be too much overlap if I were to use 40/80Mhz channels.

Larger channels can be fine at home. But only if you ensure there are no neighbors that overlap with your range. Keep in mind that as you grow in channel width, you'll need a better SNR to maintain those top data rates.

The one other issue I can think of is auto-channel on a neighbor's 802.11n router. An 802.11n router might not recognize the 80mhz channel used in your network, and thus pick a channel that overlaps.

That being said, I use 40Mhz channels at home with no noticeable issues.

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