802.11ac: Better Coverage, But Won't Hit Advertised Speeds

New submitter jcenters writes "Apple's new AirPort routers feature the new 802.11ac protocol, promising Wi-Fi speeds in excess of 1 Gbps, but Glenn Fleishman of TidBITS explains why we are unlikely to see such speeds any time soon. Quoting: 'When Apple says that its implementation of 802.11ac can achieve up to 1.3 Gbps — and other manufacturers with beefier radio systems already say up to 1.7 Gbps — the reality is that a lot of conditions have to be met to achieve that raw data rate. And, as you well know from decades of network-technology advertising, dear reader, a “raw” data rate (often incorrectly called “theoretical”) is the maximum number of bits that can pass over a network. That includes all the network overhead as well as actual data carried in packets and frames. The net throughput is often 30 to 60 percent lower.'"

Comments

Re:wasteful on spectrum

[phizi0n]

5GHz doesn't penetrate well so you won't get much interference from neighbors except maybe in very small apartments, the real problem is other devices within your home that use 5GHz such as cordless phones.

The problem is that you see different ones spec'd

[Sycraft-fu]

Wire based Ethernet is spec'd at MAC layer throughput. It is talking about the data rate of Ethernet frames, the 8b/10b encoding overhead is already accounted for and all that. So you discover that, particularly with Jumbo Frames, you get real near that speed in actual throughput.

Wireless Ethernet, not so much. You find that effective throughput, even under basically ideal conditions, are way less than the listed speed.

So it leads to confusion for people. Basically wireless is over advertising the speed.