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My laptop has capabilities for 802.11n connections.

With my previous router, I could transer data faster than 54Mb/s. Now I have D-Link router and for some reason the maximum connection speed is 54Mb/s, which implies that the connection was established with 802.11g.

How can I check which standard (g or n) has been established? Is there any command to get that information? (nm-applet does not give any information about that in the connection information window).

5 Answers 5

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The utility iw shows the used bitrate and indicates the used IEEE 802.11 standard by its listed capabilities.

Read your interface name from the iw dev output, and use it within <name>.

iw dev <name> link

Example output when associated with a legacy (non-802.11n) AP:

    tx bitrate: 36.0 MBit/s

"MCS index", indicating a 802.11n AP:

    tx bitrate: 300.0 MBit/s MCS 15 40Mhz short GI

"VHT", indicating support for 802.11ac:

    tx bitrate: 86.7 MBit/s VHT-MCS 8 short GI VHT-NSS 1

Compare this with the Linux driver 802.11n table. You'll see how the example "MCS 15 40Mhz short GI" 300 MBit/s corresponds to a row within the "HT40 rates" for the "short 400ns GI" column.

To see what your Wi-Fi adapter is generally capable of, independent of the AP link, run iw phy0 info (synonymous to iw list) and look for keywords like HT (802.11n) / VHT (802.11ac, (Very) High Throughput), MCS (Modulation and Coding Schemes) index number and long/short GI (Guard Interval).

For more explanations, continue with this Super User answer.

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  • Nice answer! How would I recognize an 802.11e connection? Does the output contain "QoS"? Jul 31, 2020 at 17:02
  • WMM is a subset of 802.11e. iw dev <name> station dump will list if WMM is in use for the established link
    – wbob
    Aug 1, 2020 at 22:07
  • What about for WiFi 6 (802.11ax) and WiFi 6E? How would you tell if your connection is one of those?
    – Garrett
    Feb 10 at 17:33
  • look for the HE (High Efficiency) letters and its MCS index to correlate. See this spreadsheet link for theoretical max bitrate per index. For example "HE MCS index 8, 2 spatial streams (depends on your device support), short (0.4µs) Guard Interval and 40Mhz channel width" is a theoretical 360 Mbit/s max
    – wbob
    Feb 10 at 19:14
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  1. try lshw -C network
  2. try iwconfig and search for Bit Rate
  3. try lspci | grep -i wireless
  4. wavemon is the ultimate tool for wireless
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  • 1
    first, wavemon is awesome! unfortunately, none of those tools supply which standard the connection using (g or n). 54Mbit can be g and n... does anybody knows what can be the reason that the interface is not lock down the n standard? at my mom's laptop, it is connected at 65Mbit, and my computer has n capabilites (again, with other routers working with n)
    – idgar
    Sep 22, 2012 at 12:10
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With sudo lshw -C network you should be able to see which modes you wifi adapter supports. But since your problem seems to be the router find out your wifi adapters name using iwconfig (should be something like wlan0 or eth0). Then try a iwlist wlan0 scan (replace wlan0 with your adapters name). It will list the supported bit rates. If the highest is is 54Mbit/s your router doesn't seem to support the n standard.

This way you can find out if you should be able to connect with the n standard. Sadly I know no way to find out what standard the present connection uses.

0

this question was already answered: https://unix.stackexchange.com/questions/62265/linux-find-wifi-networks-protocola-b-g-n-version-of-all-available-access-point

in short issue: iw dev wlan0 scan and the output should indicate which access point has what capabilities around you.

More details are in the mentioned link.

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    I'm pretty sure these are two different questions: The question you linked to is about which standards the AP supports, while this question wants to know the standard that the AP and the connected host are actually using. Aug 2, 2020 at 8:34
  • if you're very strict about it - then yes these are two different questions. however your equipment can detect only standard it can use - so there's no real practical difference when detecting what can you and the AP negotiate upon - this is de-facto the standard you're going to use when connection to this particular AP. (Or maybe I'm wrong?) Aug 2, 2020 at 14:58
  • Here's an example: iw dev wlan0 scan tells me (indirectly) that the AP supports up to IEEE 802.11ac. Now I'd have to find out which standards the wireless chip in my host supports. How to do that (iw phy) is not part of your answer and the answer you linked to. Assuming that I know now that my host supports up to IEEE 802.11n, I'm probably right in thinking that the AP and the host will use IEEE 802.11n. But I want to be sure what the actual connection uses. That's the question. Addendum: To my knowledge, the output of iw dev wlan0 scan is independent of the host's capabilities. Aug 3, 2020 at 11:51
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You can install WiFi Radar which is a utility for managing, scanning, and auto-connecting to WiFi profiles.

https://wifi-radar.tuxfamily.org/

It appears to be in the Ubuntu repository

https://packages.ubuntu.com/search?keywords=wifi-radar

sudo apt install wifi-radar
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  • WiFi Radar's last release was over five years ago. It seems abandoned. Jul 31, 2020 at 7:33
  • @MatthiasBraun thanks I wasn't aware. I installed it on my machine running 18.04 and it runs fine and does give some useful information. I don't know if there is any way to remove my post to avoid negative reputation.
    – Raffles
    Jul 31, 2020 at 10:58
  • If you really want to delete your question (I didn't downvote by the way), there are a couple of actions below your question: share edit delete flag Jul 31, 2020 at 12:40

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