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When 54 Mbps isn't 54 Mbps: 802.11g's Real Speed

Posted by michael on from the compatibility-more-important-than-speed dept.

eggboard writes "Matthew Gast, author of 802.11 Wireless Networks, filed this article for O'Reilly Networks explaining exactly how fast 802.11g really is: that is, what's the actual data payload and real throughput, not the rated maximum speed. His conclusion? In mixed 802.11b/g networks, which will be common for years to come, g is only 1.6 to 2.4 times faster than b, not 5 times faster as it is in its g-only mode. This article has real math based on the specs, rather than armchair speculation."

2 of 127 comments (clear)

  1. Maybe I just can't summon the righteous anger by chriso11 · · Score: 5, Insightful

    Oh, so I only get a 60% faster connection? Given that soon enough the price differential between B & G will be gone, I still think G is the superior choice. When the wireless cards are only $15 to $20, I think that pure G networks will be much more common. And then you will get much higher throughputs.

    Maybe they should go after Dannon yogurt for decreasing the size of their container to 6oz from 8oz, but keeping the price constant. Then at least they would be reporting on something I could care about.

    --
    No, I don't trust in god. He'll have to pay up front, like everybody else.
  2. TCP model oversimplified by kuknalim · · Score: 5, Insightful
    I stopped reading the article when i got to this:

    "Furthermore, the model ignores the sophistication in the TCP acknowledgement model. To avoid constraining throughput, TCP uses "sliding windows" and allows multiple outstanding frames to be transmitted before acknowledgement. In practice, TCP acknowledgements can apply to multiple segments, so this model overstates the impact of higher-layer protocol acknowledgements."

    This reduces the "TCP" he uses to a stop-and-wait protocol.