[Help] Update station positions from SUMO into Mininet-WiFi
ELENA VENTURA
Hi everyone,
I am working with Mininet-WiFi integrated with SUMO, and I would like to clarify how to correctly update the positions of stations.
What I need is quite simple: if my stations (e.g., sta1, sta2) move in SUMO according to the mobility defined in the .rou.xml and .net.xml files, I want their positions to be automatically updated in Mininet-WiFi
Here is what I did:
-
I configured a SUMO GUI simulation with 4 stations moving along a straight road (defined in road.sumocfg).
-
I launched Mininet-WiFi with the following script (simplified example below).
The SUMO GUI works fine and I can clearly see the stations moving but then I tried to check the stations’ positions from the Mininet CLI using sta1 position, but the position did not seem to update at all. In fact, the CLI sometimes tells me the position is not even defined.
My question is:
Am I missing some step to correctly synchronize SUMO mobility with the Mininet-WiFi stations’ positions?
Do I need to explicitly match the station IDs in Mininet with the vehicle IDs in SUMO, or use clients=2 when launching SUMO?
Any minimal working example (e.g., 2 stations moving along a road and their positions updating in Mininet CLI) would be very helpful.
Thank you very much for your support!
Elena
Ramon Fontes
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ELENA VENTURA
Good morning,
I tried running the example you suggested, and it helped me a lot to develop my solution!
My goal was to implement a specific topology with moving stations that automatically associate and disassociate from the AP depending on whether they are inside or outside the AP’s coverage range.
I replaced the default map.sumocfg file in runner.py, so that the positions of my stations (cars) are tracked based on a simpler road network (a straight 100m line) crossing the AP’s coverage area.
I ran some experiments with ping to check how the stations would associate and disassociate depending on their position. However, I found that only entering the AP’s range worked correctly (the station associates). When the station leaves the coverage area, I get an error, and the AP still allows communication even though the station has already left its range.
BEFORE CROSSING THE RANGE
64 bytes from 10.0.0.10: icmp_seq=66 ttl=64 time=0.717 ms
64 bytes from 10.0.0.10: icmp_seq=67 ttl=64 time=0.841 ms
...
64 bytes from 10.0.0.10: icmp_seq=70 ttl=64 time=0.757 ms
WHILE CROSSING THE RANGE: Here is the error I get when the station goes out of range:
Exception in thread wifiParameters:Traceback (most recent call last):
File "/usr/lib/python3.8/threading.py", line 932, in _bootstrap_inner
self.run()
File "/usr/lib/python3.8/threading.py", line 870, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/lib/python3.8/dist-packages/mn_wifi/mobility.py", line 175, in parameters
self.config_links(mob_nodes)
File "/usr/local/lib/python3.8/dist-packages/mn_wifi/mobility.py", line 197, in config_links
ack = self.associate_interference_mode(intf, ap_intf)
File "/usr/local/lib/python3.8/dist-packages/mn_wifi/mobility.py", line 184, in associate_interference_mode
return self.check_in_range(intf, ap_intf)
File "/usr/local/lib/python3.8/dist-packages/mn_wifi/mobility.py", line 143, in check_in_range
self.ap_out_of_range(intf, ap_intf)
File "/usr/local/lib/python3.8/dist-packages/mn_wifi/mobility.py", line 109, in ap_out_of_range
intf.disconnect(ap_intf)
File "/usr/local/lib/python3.8/dist-packages/mn_wifi/link.py", line 522, in disconnect
self.iwdev_cmd('{} disconnect'.format(self.name))
File "/usr/local/lib/python3.8/dist-packages/mn_wifi/link.py", line 117, in iwdev_cmd
return self.cmd('iw dev', *args)
File "/usr/local/lib/python3.8/dist-packages/mininet/node.py", line 386, in cmd
self.sendCmd( *args, **kwargs )
File "/usr/local/lib/python3.8/dist-packages/mininet/node.py", line 303, in sendCmd
assert self.shell and not self.waiting
AssertionError
64 bytes from 10.0.0.10: icmp_seq=71 ttl=64 time=0.773 ms
64 bytes from 10.0.0.10: icmp_seq=72 ttl=64 time=0.759 ms
So in short:
-
Association works fine when the station enters the AP range.
-
Disassociation when leaving the range fails with the above AssertionError.
-
After that, the AP still lets the station communicate, even though it should no longer be in range.
My question is: has anyone faced this issue before, and how can I properly fix it? Should I modify the ap_out_of_range function in mobility.py to handle the disconnection differently?
If so, what would be the correct approach?
Thank you for helping me,
Elena
Ramon Fontes
I wasn’t able to reproduce this behavior. Are you running it in a VM?
If so, could you try increasing the number of allocated cores?
Em qua., 1 de out. de 2025 às 09:11, ELENA VENTURA
<eleve...@gmail.com> escreveu:
ELENA VENTURA
Maybe I didn’t explain myself clearly the first time, so I’ll try to show you step by step what I did.
I created a very simple topology where cars move along a 100m straight road in SUMO and associate/disassociate with one AP depending on coverage.
Here is the code I’m using:
#!/usr/bin/env python3
import sys
sys.path.insert(0, "/home/<my-username>/Progetti/mininet-wifi/mininet-wifi/mn_wifi/sumo")
from mininet.log import setLogLevel, info
from mn_wifi.cli import CLI
from mn_wifi.net import Mininet_wifi
from mn_wifi.node import OVSKernelAP
from mininet.node import RemoteController
from runner import sumo
from mn_wifi.link import wmediumd, ITSLink
from mn_wifi.wmediumdConnector import interference
from mn_wifi.wmediumdConnector import error_prob
def topology():
"Create a network with Ryu + SUMO cars"
net = Mininet_wifi(controller=RemoteController,
accessPoint=OVSKernelAP,link=wmediumd, wmediumd_mode=interference)
info("*** Adding Ryu controller\n")
c0 = net.addController('c0', controller=RemoteController,
ip='127.0.0.1', port=6633)
info("*** Creating nodes\n")
# Access Point connesso al controller
ap1 = net.addAccessPoint('ap1', ssid='new-ssid', mode='ac', channel='36',
position='50,20,0', range=40)
# Host
h1 = net.addHost('h1', ip='10.0.0.10/8')
# 4 cars controlled by sumo
for id in range(0, 4):
net.addCar('car%s' % (id+1), wlans=1, mode='ac') # wlans=1 basta
info("*** Configuring Propagation Model\n")
net.setPropagationModel(model="logDistance", exp=2.8)
net.configureNodes()
info("*** Creating links\n")
net.addLink(ap1, h1)
"""
for car in net.cars:
net.addLink(car, intf=car.wintfs[0].name,
cls=ITSLink, band=20, channel=181)
"""
info("*** Starting SUMO\n")
net.useExternalProgram(program=sumo, port=8813,
extra_params=["--start --delay 1000"],
clients=1, exec_order=0)
info("*** Starting network\n")
net.build()
c0.start()
ap1.start([c0])
# dinamic IP for cars
for id, car in enumerate(net.cars):
car.setIP('10.0.0.{}/8'.format(id+1),
intf=car.wintfs[0].name)
net.telemetry(nodes=net.cars + [ap1], data_type='position',
min_x=0, min_y=0, max_x=100, max_y=40)
info("*** Running CLI\n")
CLI(net)
info("*** Stopping network\n")
net.stop()
if __name__ == '__main__':
setLogLevel('info')
topology()
then i create a simple sumo map with a 100m street. I have attached some pictures that describe exactly how my test network works: one AP with a certain coverage range, and cars (stations) moving across it.
I ran two experiments:
Test 1 – Entering the AP range
I checked that a station which is still outside the AP range cannot communicate through it.
As soon as the station moves inside the AP coverage, it successfully associates and can reach the host via the AP.
This works correctly ( in the second image you can see that from "Destination Host Unreachable" it start sending package as the station enters in the range )
Test 2 – Leaving the AP range
I checked that a station which leaves the AP range should automatically disconnect and lose connectivity to the host.
However, this does not happen: instead, I get the previous error with that strange behaviour
I was wondering if maybe I could modify it or adapt it in some way to properly handle the disconnection when a station leaves the AP range
Ramon Fontes
xterm and run a ping from there?
ELENA VENTURA
ELENA VENTURA
Hi,
I tried your suggestion with xterm and it worked!
So the issue was exactly what you suspected: when I was running the ping directly from the Mininet CLI, the node’s shell was already busy. Since the disconnect function is not asynchronous, Mininet couldn’t send the command and raised the AssertionError.
Running the ping inside an xterm kept the Mininet shell free, and now the disconnect works correctly when the station leaves the AP range.
Thanks a lot for the advice, it really clarified what was going on!
daniel crown
ELENA VENTURA
Dear Daniel,
thank you for your message and for your interest in my setup.
Unfortunately I did not directly experiment with IEEE 802.11p in my work. I mainly used 802.11ac, since my focus was on network slicing and delay behavior rather than on VANET-specific PHY/MAC features.
One thing I noticed while working with Mininet-WiFi is that support for some wireless modes can be quite limited depending on the version and the model used. For instance, I initially tried to work with 802.11ax but had to switch to 802.11ac because ax did not behave as expected in my setup.
Because of this, it might be worth checking the Mininet-WiFi GitHub issues and documentation to verify whether the 802.11p / ITSLink support is fully functional in the version you are using.
Hope this helps, and good luck with your experiments.
Best regards,
Elena
daniel crown
import sys
from mininet.log import setLogLevel, info
from mn_wifi.cli import CLI
from mn_wifi.net import Mininet_wifi
from mn_wifi.node import OVSKernelAP
from mininet.node import RemoteController
from mn_wifi.link import wmediumd, ITSLink
from mn_wifi.wmediumdConnector import interference
from mn_wifi.wmediumdConnector import error_prob
def topology():
"Create a network with Ryu + SUMO cars"
net = Mininet_wifi(controller=RemoteController,
accessPoint=OVSKernelAP,link=wmediumd, wmediumd_mode=interference)
info("*** Adding Ryu controller\n")
c0 = net.addController('c0', controller=RemoteController,
ip='127.0.0.1', port=6633)
info("*** Creating nodes\n")
# Access Point connesso al controller
ap1 = net.addAccessPoint('ap1', ssid='new-ssid', mode='ac', channel='36',
info("*** Running CLI\n")
CLI(net)
info("*** Stopping network\n")
net.stop()
if __name__ == '__main__':
setLogLevel('info')
topology()
ELENA VENTURA
Hi David,
" Do you think ac mode can be mapped as p mode?"
Even if 802.11p and 802.11ac are different, 802.11ac i think is a reasonable choice when the focus is on mobility and connectivity.
I used it throughout my bachelor’s thesis to build an urban simulation environment where vehicles shared and differentiated the network in a city scenario, so in my opinion for learning and urban simulations I think it works well.
"In terms of your setup I updated script like following, I receive Destination Host Unreachable when I do sta1 ping h1 (script used from your first script of this page) which I always get same issue with other examples, this is either range issue or do I miss something. car1 look in range of ap1 (I add image file as well). Do I need to check something else"
I was checking your code.
From what I understand, this is a remake of examples/vanet_sumo.py, right?
I’m trying to figure out whether the issue comes from the code itself or from the Mininet-WiFi configuration. For example, does examples/vanet_sumo.py, work correctly on your setup (e.g. can the nodes ping each other)?
I’m asking because if ping doesn’t work even in the official examples, then it might be an installation or configuration issue rather than a problem with your code. This actually happened to me as well at the beginning. Let me know, so we can try to solve this problem together.
Best regards,
Elena