def cond_collision(self, frag_size):
"""Calculates if there is a collision"""
frag_ToA = get_toa(frag_size, Statsct.SF)
#check if there is a collision at the start of the packet
dprint("current time: {}, position: {}, ToA fragment: {}".format(self.current_time,self.position,frag_ToA['t_packet']))
dprint("background_traffic: {}".format(self.background_traffic[self.position]))
while self.position < len(self.background_traffic) and self.current_time > self.background_traffic[self.position][0]:
self.position += 1
dprint("position: {}, ".format(self.position))
if self.position != len(self.background_traffic):
if self.current_time == self.background_traffic[self.position][0]:
#special case when both packet start time is the same
dprint("Collision! -> packet start at same time as the next")
self.current_time += frag_ToA['t_packet'] + Statsct.dc_time_off(frag_ToA['t_packet'],Statsct.dc)
return True
elif self.position != 0 and self.current_time < self.background_traffic[self.position-1][1]:
dprint("Collision! -> packet start before the end of previous packet")
self.current_time += frag_ToA['t_packet'] + Statsct.dc_time_off(frag_ToA['t_packet'],Statsct.dc)
return True
else:
if self.current_time + frag_ToA['t_packet'] > self.background_traffic[self.position][0]:
dprint("Collision!-> packet ends after next has start")
self.current_time += frag_ToA['t_packet'] + Statsct.dc_time_off(frag_ToA['t_packet'],Statsct.dc)
return True
self.current_time += frag_ToA['t_packet'] + Statsct.dc_time_off(frag_ToA['t_packet'],Statsct.dc)
input('')
return False
def generate_background_traffic(self, G, background_frag_size):
self.background_traffic
T = get_toa(background_frag_size, Statsct.SF)
g = G / T['t_packet']
print("g: {}, G:{}, T:{}".format(g, G, T['t_packet']))
for i in range(1000):
#aleatoire = machine.rng()
#aleatoire2 = aleatoire/(2**24-1)
aleatoire = urandom.getrandbits(8) / 256
aleatoire2 = aleatoire / (2**24 - 1)
#print(aleatoire2)
if aleatoire2 != 0:
test = -1 * math.log(aleatoire2) / 1 / g
self.background_traffic.append((test, test + T['t_packet']))
if enable_statsct:
Statsct.set_background_traffic(self.background_traffic)