5 GHz Mesh Support in Mininet-WiFi (mesh_11ac.py)

[Kavin Kumar T]

Hi everyone,

I wanted to share a modified example of the default mesh.py in Mininet-WiFi that attempts to enable mesh communication in the 5 GHz band (802.11ac / channel 36). This setup is intended for anyone experimenting with higher-throughput mesh networks using 802.11ac.

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🔧 Changes Made:

• Switched from channel=5 (2.4 GHz) to channel=36 (5 GHz)

• Changed ht_cap to 'HT40+'

• Set wmediumd_mode=False to bypass RF propagation limitations during testing

• Assigned IPs manually to mesh interfaces (staX-mp0) when needed

• Optional: Tried patching format_freq() to avoid NoneType errors when using 5 GHz channels

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✅ Current Result:

Although the mesh interfaces are created and IPs are assigned, the 5 GHz mesh nodes are not forming links, and ping between them fails unless fallback to 2.4 GHz is used. If anyone has managed to get 802.11s mesh working over 5 GHz in Mininet-WiFi, I’d really appreciate your input or suggestions.

I've attached the modified mesh_11ac.py file for reference.

Thanks and Regards,
Kavin

[Ramon Fontes]

Hello,

It works If you add the link as follows:
net.addLink(sta1, cls=mesh, ssid='meshNet', intf='sta1-wlan0',
channel=36, ht_cap='HT40+', mode="ac")

As you can see, I just added the ac mode and set the channel.

Since wmediumd doesn't support 5GHZ with HT40+ you also have to
disable it. I think I have to take one of my students to add support
to HT40+. At first it doesn't seem to be an hard task if we consider
https://mcsindex.com/.

[Kavin Kumar T]

“Tested and confirmed — adding mode='ac' inside addLink() with wmediumd disabled works!”

Thank the maintainers for confirming and highlighting the HT40+ changes in future.

[Kavin Kumar T]

Hi everyone,

Following up on my previous discussion where I shared the modified mesh_11ac.py to simulate Wi-Fi mesh over 5 GHz using mode='ac', I’m now working on simulating a new profile which is based on 802.11ah (HaLow) for sub-GHz mesh networking for my research work:

---

✅ Progress So Far:

• My system supports sub-GHz frequencies (902–928 MHz), confirmed via iw list:

  Frequencies: * 902.5 MHz * ... * 927.5 MHz

• mac80211_hwsim also exposes these frequencies under Band 5 also confirmed in iw reg get.

• Mesh interface mode (mesh point) is supported.

---

❓ Questions:

1. How do we correctly assign a mesh interface to a channel in the 902–928 MHz range in addLink()?

   • For example, should I use:

     net.addLink(sta1, cls=mesh, intf='sta1-wlan1', mesh_id='halowNet', freq=915, ht_cap='HT20', mode='11ah')

     or is channel=<custom> preferred?

2. Is mode='11ah' officially supported or just a label?

   • I don’t see 11ah listed in Mininet-WiFi’s docs, but I’d like to simulate the MCS0–7 behavior and long preamble/guard interval as closely as possible.

3. How should I configure bandwidth (1/2/4 MHz) in the absence of native 802.11ah support?

   • Should I shape traffic externally using tc qdisc, or is there a Mininet-WiFi method?

Thanks & Regards,

Kavin

[Ramon Fontes]

802.11ah is not supported yet because I haven't had the chance to try it out yet. I am aware about some support of s1g by mac80211_hwsim but I still have to investigate it.

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[Kavin Kumar T]

Hi Prof. Ramon Fontes,

Thank you for your reply.

I’m currently working on a multi-radio mesh setup as part of my research, and I’ve encountered a blocker related to HT40+ support in the 5 GHz band using wmediumd.

As you mentioned:

"Since wmediumd doesn't support 5GHZ with HT40+, you also have to disable it. I think I have to take one of my students to add support to HT40+. At first it doesn't seem to be a hard task if we consider https://mcsindex.com/."

I wanted to kindly check if there have been any updates or progress on this front, or if you could share any guidance or suggestions for implementing this support myself. I’d be happy to develop the necessary changes and contribute them back to the community.

Looking forward to your advice.

Code Snippet:

net = Mininet_wifi(link=wmediumd, wmediumd_mode=interference)

info("*** Creating nodes (Wi-Fi `mp0`, HaLow simulate `mp1`)\n")

sta1 = net.addStation('sta1', wlans=2, position='10,10,0', txAntennas=[2, 1],rxAntennas=[2, 1],ht_capab=['[HT40+]', '[HT20]'])

sta2 = net.addStation('sta2', wlans=2, position='50,10,0', txAntennas=[2, 1],rxAntennas=[2, 1],ht_capab=['[HT40+]', '[HT20]'])

sta3 = net.addStation('sta3', wlans=2, position='90,10,0', txAntennas=[2, 1],rxAntennas=[2, 1],ht_capab=['[HT40+]', '[HT20]'])

info("*** Configuring Propagation Model\n")

net.setPropagationModel(model="logDistance", exp=4)

info("*** Configuring nodes\n")

net.configureNodes()

# Wi-Fi mesh on `wlan0`

sta1.params['range'][0] = 100

sta2.params['range'][0] = 100

sta3.params['range'][0] = 100

net.addLink(sta1, cls=mesh, ssid='wifi-mesh', intf='sta1-wlan0', channel=149, ht_cap='HT40+', mode="ac", txpower=24)

net.addLink(sta2, cls=mesh, ssid='wifi-mesh', intf='sta2-wlan0', channel=149, ht_cap='HT40+', mode="ac", txpower=24)

net.addLink(sta3, cls=mesh, ssid='wifi-mesh', intf='sta3-wlan0', channel=149, ht_cap='HT40+', mode="ac", txpower=24)

# HaLow simulate mesh on `wlan1`

sta1.params['range'][1] = 200

sta2.params['range'][1] = 200

sta3.params['range'][1] = 200

net.addLink(sta1, cls=mesh, ssid='halow-mesh', intf='sta1-wlan1', channel=11, mode='g', txpower=30)

net.addLink(sta2, cls=mesh, ssid='halow-mesh', intf='sta2-wlan1', channel=11, mode='g', txpower=30)

net.addLink(sta3, cls=mesh, ssid='halow-mesh', intf='sta3-wlan1', channel=11, mode='g', txpower=30)

# Call the regulatory domain utility here

set_regulatory_domain_to_us(net)

info("*** Starting Network\n")

net.start()

Thanks & Regards,

Kavin

[Ramon Fontes]

Dear Kumar,

Unfortunately, I haven't made any progress on this yet. We're currently managing multiple ongoing tasks that need to be completed before we can focus on HT40+ support. As for contributions, both the community and I would greatly appreciate them—they are more than welcome! I recommend tracking the packets around this line in the code: https://github.com/ramonfontes/wmediumd/blob/mininet-wifi/wmediumd/wmediumd.c#L338.

To view this discussion visit https://groups.google.com/d/msgid/mininet-wifi-discuss/b1c073b4-5bb4-4af1-9853-6fa23feb8c5fn%40googlegroups.com.

[Kavin Kumar T]

Dear Prof. Ramon Fontes,

Thanks for your quick response and i will explore wmediumd code.

Meanwhile, as i have showed in the previous code snippet, since 11ah is not supported, simply considered as 11g and channel 11. This seems reasonable for mesh link comparisons for now.

# HaLow simulate mesh on `wlan1`

sta1.params['range'][1] = 200

sta2.params['range'][1] = 200

sta3.params['range'][1] = 200

net.addLink(sta1, cls=mesh, ssid='halow-mesh', intf='sta1-wlan1', channel=11, mode='g', txpower=30)

net.addLink(sta2, cls=mesh, ssid='halow-mesh', intf='sta2-wlan1', channel=11, mode='g', txpower=30)

net.addLink(sta3, cls=mesh, ssid='halow-mesh', intf='sta3-wlan1', channel=11, mode='g', txpower=30)

However, for Wi-Fi mesh simulation, i am wondering without this HT40+ limitation with wmediumd any other way quick way to simulate for now.

# Wi-Fi mesh on `wlan0`

sta1.params['range'][0] = 100

sta2.params['range'][0] = 100

sta3.params['range'][0] = 100

net.addLink(sta1, cls=mesh, ssid='wifi-mesh', intf='sta1-wlan0', channel=149, ht_cap='HT40+', mode="ac", txpower=24)

net.addLink(sta2, cls=mesh, ssid='wifi-mesh', intf='sta2-wlan0', channel=149, ht_cap='HT40+', mode="ac", txpower=24)

net.addLink(sta3, cls=mesh, ssid='wifi-mesh', intf='sta3-wlan0', channel=149, ht_cap='HT40+', mode="ac", txpower=24)

I have tried multiple options, but none of those working and finally end up similar to HaLow simulate (11g) one that will not be helpful for my multi-radio/link research work. Kindly help if any better option for the same

#channel=149, ht_cap='HT40+', mode="ac", txpower=24 => Ping and iPerf traffic fails

#channel=149, ht_cap='HT20', mode="n", txpower=24 => same as 11ac (Ping, iPerf fails)

#channel=149, ht_cap='HT20', mode="ac", txpower=24 => same as 11ac (Ping, iPerf fails)

#channel=149, ht_cap='HT40+', mode="n", txpower=24 => same as 11ac (Ping, iPerf fails)

#channel=1, mode='g', txpower=24 => Works, but same as HaLow simulate

#channel=1, mode='n', txpower=24 => Error as follow

#channel=1, ht_cap='HT40+', mode="n", txpower=24 => Error as follow

#channel=1, ht_cap='HT20', mode="n", txpower=24 => Error as follow

'''net.addLink(sta1, cls=mesh, ssid='wifi-mesh', intf='sta1-wlan0', channel=1, ht_cap='HT40+', mode="n", txpower=24)

File "/usr/local/lib/python3.10/dist-packages/mininet_wifi-2.6-py3.10.egg/mn_wifi/net.py", line 651, in addLink

link = cls(node=node1, **params)

File "/usr/local/lib/python3.10/dist-packages/mininet_wifi-2.6-py3.10.egg/mn_wifi/link.py", line 1911, in __init__

self.configureMesh()

File "/usr/local/lib/python3.10/dist-packages/mininet_wifi-2.6-py3.10.egg/mn_wifi/link.py", line 1940, in configureMesh

self.mesh_join(self.ssid, self.format_freq(), self.ht_cap)

File "/usr/local/lib/python3.10/dist-packages/mininet_wifi-2.6-py3.10.egg/mn_wifi/link.py", line 231, in format_freq

return int(format(self.freq, '.3f').replace('.', ''))

TypeError: unsupported format string passed to NoneType.__format__'''

#channel=1, freq=2.4, band=20, mode="g", txpower=24 => Works, but same as HaLow simulate

#channel=1, freq=2.4, band=20, mode="n", txpower=24 => Error as above

#channel=1, freq=2.4, band=40, mode="n", txpower=24 => Error as above

#channel=36, ht_cap='HT40+', mode="ac", txpower=24 => same as channel 149

PS: Attached my working code for reference. 

Thanks & Regards,

Kavin

[Ramon Fontes]

Hi Kumar,

I just noticed that hwsim has some support for MLO (https://github.com/torvalds/linux/blob/cbe2691bee4e54024b9985ef78e740d9655d92f3/drivers/net/wireless/virtual/mac80211_hwsim.c#L70). However, as you know, I haven't had the chance to test it yet.

hwsim supports many features, just as hostap (hostapd + wpa_supplicant) does, but I can't cover everything. That’s why contributions from the community are always welcome!

Till now I was submitting patches to the Linux Kernel towards a wmediumd support for IEEE 802154 - https://patchwork.kernel.org/project/linux-wpan/patch/20250331103924.1490...@gmail.com/ :/.

Looking forward to any insights you might have!

--

Ramon

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