I have an access point that supports both 802.11b / 802.11g clients.

From what I understand, preventing 802.11b clients from connecting causes one or more 802.11g rates to be listed as mandatory. Does this simultaneously remove 802.11b speeds from the list of optional rates? And if it does, will the area covered by the access point be reduced because 802.11g clients can no longer use the lower 802.11b rates as their signal weakens as they move further away?

  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide and accept your own answer.
    – Ron Maupin
    Feb 19, 2018 at 19:54

1 Answer 1


Generally, no. Listing one of the 11g rates as mandatory prevents 11b clients from associating, but other, lower rates can be listed as optional.

However, the lowest rate for 11g (ODFM) is 6 MHz, and that is higher than the minimum 11b rate (1 MHz), so a 11b client could, in theory, connect farther away than a 11g client.

The goal of all this is to reduce channel utilization by removing low rates (and the channel inefficiencies of 11b clients). By forcing clients to use higher data rates, they spend less time transmitting and receiving, and therefore free up the channel for other clients.

The downside, of course, is reduced AP cell size. You will have to determine if the tradeoff is worth it.

  • Thanks Ron. If we listed the 6 Mbps rate as mandatory and therefore prevented 802.11b clients from associating but still included all 802.11b rates as optional, could that type of setup keep the same AP cell size?
    – slantalpha
    Oct 25, 2017 at 15:10
  • That kind of defeats the purpose. To work at the low rates, 11g clients have to switch to 11b mode. You might as well use 11b clients. The point of switching to 11g exclusively is to gain channel efficiency. If you allow 11b rates, that won't happen.
    – Ron Trunk
    Oct 25, 2017 at 15:15
  • Makes sense. I just switched my router from supporting 802.11b/g/n clients to just 802.11g/n clients and did a Wireshark on the 802.11 beacon frames. It looks like all that happened is that the 6, 12, and 24 rates switched from non-basic to basic. Looks like the 1, 2, 5.5, and 11 rates stayed basic for some reason. I would have thought that the 1, 2, 5.5, and 11 rates would have been removed all together when I switched from 802.11b/g/n to 802.11g/n?
    – slantalpha
    Oct 25, 2017 at 17:04
  • 1
    I suppose every AP manufacturer does it differently. I'm unaware of any "standards."
    – Ron Trunk
    Oct 25, 2017 at 17:28

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