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lorawan_toa
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enabled to show the detail in calculation with the -v option.

master
Shoichi Sakane 2017-09-28 07:02:36 +09:00
parent 6c89e6d0a0
commit 93213cb784
1 changed files with 25 additions and 8 deletions
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33
lorawan_toa.py
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@ -18,6 +18,7 @@ def mpsrange(a, b):
def get_toa(n_size, n_sf, n_bw=125, enable_dro=1, disable_h=0, n_cr=1,
n_preamble=8):
'''
return the time on air in milisecond.
n_size:
PL in the fomula. PHY Payload size in byte (= MAC Payload + 5)
n_sf: SF (12 to 7)
@ -44,11 +45,20 @@ def get_toa(n_size, n_sf, n_bw=125, enable_dro=1, disable_h=0, n_cr=1,
t_preamble = (n_preamble + 4.25) * t_sym
a = 8.*n_size - 4.*n_sf + 28 + 16 - 20.*disable_h
b = 4.*(n_sf-2.*enable_dro)
v_ceil = a/b
nb_sym_payload = 8 + max(math.ceil(a/b)*(n_cr+4), 0)
t_payload = nb_sym_payload * t_sym
t_frame = t_preamble+ t_payload
return round(t_frame, 3)
ret = {}
ret["t_sym"] = t_sym
ret["t_preamble"] = t_preamble
ret["v_ceil"] = v_ceil
ret["nb_sym_payload"] = nb_sym_payload
ret["t_payload"] = t_payload
ret["t_frame"] = round(t_frame, 3)
return ret
if __name__ == "__main__" :
import sys
@ -90,10 +100,10 @@ if __name__ == "__main__" :
# main
#
opt = parse_args()
t_frame = get_toa(opt.n_size, opt.n_sf,
n_bw=opt.n_bw, enable_dro=opt.v_de,
disable_h=opt.v_h, n_cr=opt.n_cr,
n_preamble=opt.n_preamble)
ret = get_toa(opt.n_size, opt.n_sf, n_bw=opt.n_bw, enable_dro=opt.v_de,
disable_h=opt.v_h, n_cr=opt.n_cr, n_preamble=opt.n_preamble)
ret0 = get_toa(0, opt.n_sf, n_bw=opt.n_bw, enable_dro=opt.v_de,
disable_h=opt.v_h, n_cr=opt.n_cr, n_preamble=opt.n_preamble)
if opt.f_verbose:
print "PHY payload size : %d Bytes" % opt.n_size
print "MAC payload size : %d Bytes" % (opt.n_size-5)
@ -103,7 +113,14 @@ if __name__ == "__main__" :
print "Explicit header : %s" % ("disable" if opt.v_h else "enable")
print "CR (coding rate) : %d (4/%d)" % (opt.n_cr, 4+opt.n_cr)
print "Preamble size : %d symbols" % opt.n_preamble
print "Time on Air : %.3f msec" % t_frame
print "MAC frame data rate : %.3f bps" % (opt.n_size-5 / t_frame)
print "Other symbol size : %d symbols" % ret["nb_sym_payload"]
print "Symbol Time : %.3f msec" % ret["t_sym"]
print "Preamble ToA : %.3f msec" % ret["t_preamble"]
print "Payload ToA : %.3f msec" % ret["t_payload"]
print "Time on Air : %.3f msec" % ret["t_frame"]
if opt.debug_level:
print "MAC frame data rate : %.3f bps" % ((8.*(opt.n_size-5)) /
((ret["t_frame"]-ret0["t_frame"])/1000.))
print "Ceil(x) : %.3f" % ret["v_ceil"]
else:
print "%.3f" % t_frame
print "%.3f" % ret["t_frame"]