sta1 does not ping sta2 if I change the association of sta1 from ap2 to ap1

memran2 commented 4 years ago

I have created the python code for mininet-wifi in which I have simple two aps, two stations sta1 and sta2 and I have added the code in it for mobility to take step by step the position of the sta1 during its mobility as i have to note down sta1 positions, its distance from ap1 and ap2 and its received RSSI from both the ap1 and ap2. Every thing works perfect mobility, handover and ping between sta1 and sta2. But when I change the association of sta1 back to ap1 the ping stops. To change the association manually I used the command: py sta1.setPosition('20,40,0') But when I enable the controller then in SDN case it works fine. Actually I want to compare the none SDN scenario with SDN scenario that is why I disabled the controller in this code.

The code is attached please guide I will be thankful to you. Regards,

#!/usr/bin/python

'Example for Handover'

import sys
from time import sleep # Additionally added than Simplehandover1.py
from mininet.log import setLogLevel, info
from mn_wifi.cli import CLI
from mn_wifi.net import Mininet_wifi
from mn_wifi.node import UserAP
from mn_wifi.link import wmediumd
from mn_wifi.wmediumdConnector import interference

def topology(args):
    global net, sta1, sta2, ap1, ap2 # Globally declared variables 
    global sta1_loc_x, sta1_loc_y, sta2_loc_x, sta2_loc_y
    global list_dist_s1_ap1, list_dist_s1_ap2, list_dist_s2_ap1, list_dist_s2_ap2
    global rssi_s1_ap1, rssi_s1_ap2, rssi_s2_ap1, rssi_s2_ap2
    global sta1_associated, sta2_associated

    sta1_loc_x = [] # all variables are initialized as empty list to contain number of multiple values in this list ex 10 
    sta1_loc_y = []
    sta2_loc_x = []
    sta2_loc_y = []
    list_dist_s1_ap1 = []
    list_dist_s1_ap2 = []
    list_dist_s2_ap1 = []
    list_dist_s2_ap2 = []
    rssi_s1_ap1 = []
    rssi_s1_ap2 = []
    rssi_s2_ap1 = []
    rssi_s2_ap2 = []
    sta1_associated = []
    sta2_associated = []

    "Create a network."
    net = Mininet_wifi(accessPoint=UserAP, link=wmediumd, wmediumd_mode=interference)

    info("*** Creating nodes\n")
    sta1_args, sta2_args = dict(), dict()
    if '-s' in args:
        sta1_args['position'], sta2_args['position'] = '0,30,0', '60,30,0'

    sta1 = net.addStation('sta1', mac='00:00:00:00:00:01', **sta1_args)
    sta2 = net.addStation('sta2', mac='00:00:00:00:00:02', **sta2_args)
    ap1 = net.addAccessPoint('ap1', ssid='ssid-ap1', failMode="standalone", channel='1', position='15,30,0')
    ap2 = net.addAccessPoint('ap2', ssid='ssid-ap2', failMode="standalone",  channel='6', position='80,30,0')
#    c1 = net.addController('c1')

    net.setPropagationModel(model="logDistance", exp=4.6)

    info("*** Configuring wifi nodes\n")
    net.configureWifiNodes()

    info("*** Creating links\n")
    net.addLink(ap1, ap2)

    if '-p' not in args:
       net.plotGraph(max_x=110, max_y=110)

    if '-s' not in args: # this mobility code is not used , used our own written code below, by passed with -s
        net.startMobility(time=0)

        net.mobility(sta1, 'start', time=1, position='10,30,0')

        net.mobility(sta2, 'start', time=2, position='10,40,0')

        net.mobility(sta1, 'stop', time=10, position='60,30,0')
        net.mobility(sta2, 'stop', time=10, position='30,40,0')
        net.stopMobility(time=11)

    info("*** Starting network\n")
    net.build()
 #   c1.start()
    ap1.start([])
    ap2.start([])

    if '-s' in args: # Additional other than Simplehandover1.py
        for x in range(20):
            collect_info()
            print_info()
            move_station(5,0,0)
            sleep(0.5) # Additional other than Simplehandover1.py
        output_csv()

    info("*** Running CLI\n")
    CLI(net)

    info("*** Stopping network\n")
    net.stop()

# This function is collecting information on Sta1 positio,Sta1 (X,y) position, Sta1 Distance from AP, RSSI and association
def collect_info():
    global pos_sta1 
    global pos_sta2
    global dist_s1_ap1, dist_s1_ap2, dist_s2_ap1, dist_s2_ap2
    #create empty lists

    pos_sta1 = sta1.position # finding position of station 1 and storing in variable pos_sta1
    pos_sta2 = sta2.position
    sta1_loc_x.append(pos_sta1[0])
    sta1_loc_y.append(pos_sta1[1])
    sta2_loc_x.append(pos_sta2[0])
    sta2_loc_y.append(pos_sta2[1])
    dist_s1_ap1 = sta1.get_distance_to(ap1)
    dist_s1_ap2 = sta1.get_distance_to(ap2)
    dist_s2_ap1 = sta2.get_distance_to(ap1)
    dist_s2_ap2 = sta2.get_distance_to(ap2)

    list_dist_s1_ap1.append(dist_s1_ap1)
    list_dist_s1_ap2.append(dist_s1_ap2)
    list_dist_s2_ap1.append(dist_s2_ap1)
    list_dist_s2_ap2.append(dist_s2_ap2)
    rssi_s1_ap1.append(sta1.wintfs[0].get_rssi(ap1.wintfs[0], dist_s1_ap1))
    rssi_s1_ap2.append(sta1.wintfs[0].get_rssi(ap2.wintfs[0], dist_s1_ap2))
    rssi_s2_ap1.append(sta2.wintfs[0].get_rssi(ap1.wintfs[0], dist_s2_ap1))
    rssi_s2_ap2.append(sta2.wintfs[0].get_rssi(ap2.wintfs[0], dist_s2_ap2))
    sta1_associated.append(sta1.wintfs[0].associatedTo)
    sta2_associated.append(sta2.wintfs[0].associatedTo)

# Mobility function 
def move_station(x,y,z):
    new_x = pos_sta1[0] + x # in x Position of Sta1, X is added and new_x is calculated 
    new_y = pos_sta1[1] + y
    new_z = pos_sta1[2] + z
    new_loc = str(new_x) + "," + str(new_y) + "," + str(new_z) # str function converts numeric value to string in Python
    sta1.setPosition(new_loc) # Sta1 new position is setup or Sta1 is moved to new position

# This function prints the Stations and AP positions values and their associations
def print_info(): 
    info("sta1 position is: " + str(pos_sta1) + "\n")
    info("sta2 position is: " + str(pos_sta2) + "\n")
    info("sta1 to ap1 distance = " + str(dist_s1_ap1) + "\n")
    info("sta1 to ap2 distance = " + str(dist_s1_ap2) + "\n")
    info("sta2 to ap1 distance = " + str(dist_s2_ap1) + "\n")
    info("sta2 to ap2 distance = " + str(dist_s2_ap2) + "\n")
    info("sta1 to ap1 rssi = " + str(rssi_s1_ap1) + "\n")
    info("sta1 to ap2 rssi = " + str(rssi_s1_ap2) + "\n")
    info("sta2 to ap1 rssi = " + str(rssi_s2_ap1) + "\n")
    info("sta2 to ap2 rssi = " + str(rssi_s2_ap2) + "\n")
    info("sta1 associatedTo = " + str(sta1_associated) + "\n")
    info("sta2 associatedTo = " + str(sta2_associated) + "\n")

def output_csv():
    fhandle = open("dataSimple.csv", "w")
    header = "sta1_x,sta1_y,sta2_x,sta2_y,dist_s1_ap1,dist_s1_ap2,dist_s2_ap1,dist_s2_ap2,rssi_s1_ap1,rssi_s1_ap2,rssi_s2_ap1,rssi_s2_ap2,sta1_associateion,sta2_association\n"
    fhandle.write(header)
    for i in range(len(sta1_loc_x)):
        row = str(sta1_loc_x[i])+","+str(sta1_loc_y[i])+","
        row = row + str(sta2_loc_x[i])+","+str(sta2_loc_y[i])+","
        row = row + str(list_dist_s1_ap1[i])+","+str(list_dist_s1_ap2[i])+","
        row = row + str(list_dist_s2_ap1[i])+","+str(list_dist_s2_ap2[i])+","
        row = row + str(rssi_s1_ap1[i])+","+str(rssi_s1_ap2[i])+","
        row = row + str(rssi_s2_ap1[i])+","+str(rssi_s2_ap2[i])+","
        row = row + str(sta1_associated[i])+","+str(sta2_associated[i])+"\n"
        print(row)
        fhandle.write(row)
    fhandle.close()

if __name__ == '__main__':
    setLogLevel('info')
    topology(sys.argv)