105 lines
5.2 KiB
Python
Executable File
105 lines
5.2 KiB
Python
Executable File
#!/usr/bin/env python
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from lorawan_toa_cal import get_toa
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import argparse
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def parse_args():
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p = argparse.ArgumentParser(
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description="LoRa Time on Air calculator.")
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p.add_argument("n_sf", metavar="SF", type=int,
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help="Spreading Factor. It should be from 7 to 12.")
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p.add_argument("n_size", metavar="SIZE", type=int,
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help="""PHY payload size in byte.
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Remember that PHY payload (i.e. MAC frame) consists of
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MHDR(1) + MAC payload + MIC(4), or
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MHDR(1) + FHDR(7) + FPort(1) + APP + MIC(4).
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For example, SIZE for Join Request is going to be 23.
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If the size of an application message (APP) is
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12, SIZE is going to be 25. """)
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p.add_argument("--band-width", action="store", dest="n_bw", type=int,
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default=125, metavar="NUMBER",
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help="bandwidth in kHz. default is 125 kHz.")
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p.add_argument("--disable-auto-ldro", action="store_false",
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dest="enable_auto_ldro",
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help="disable the auto LDRO and disable LDRO.")
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p.add_argument("--enable-ldro", action="store_true", dest="enable_ldro",
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help="This option is available when the auto LDRO is disabled.")
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p.add_argument("--disable-eh", action="store_false", dest="enable_eh",
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help="disable the explicit header.")
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p.add_argument("--downlink", action="store_false", dest="enable_crc",
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help="disable the CRC field, which is for the LoRaWAN downlink stream.")
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p.add_argument("--disable-crc", action="store_false", dest="enable_crc",
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help="same effect as the --downlink option.")
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p.add_argument("--cr", action="store", dest="n_cr",
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type=int, default=1, metavar="NUMBER",
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help="specify the CR value. default is 1 as LoRaWAN does.")
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p.add_argument("--preamble", action="store", dest="n_preamble",
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type=int, default=8, metavar="NUMBER",
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help="specify the preamble. default is 8 for AS923.")
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p.add_argument("--duty-cycle", action="store", dest="n_duty_cycle",
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type=int, default=1, metavar="NUMBER",
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help="specify the duty cycle in percentage. default is 1 %%.")
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p.add_argument("-v", action="store_true", dest="f_verbose",
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default=False,
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help="enable verbose mode.")
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p.add_argument("-d", action="append_const", dest="_f_debug", default=[],
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const=1, help="increase debug mode.")
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args = p.parse_args()
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args.v_de = False
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args.debug_level = len(args._f_debug)
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return args
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if __name__ == "__main__" :
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opt = parse_args()
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ret = get_toa(opt.n_size, opt.n_sf, n_bw=opt.n_bw,
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enable_auto_ldro=opt.enable_auto_ldro,
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enable_ldro=opt.enable_ldro,
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enable_eh=opt.enable_eh, enable_crc=opt.enable_crc,
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n_cr=opt.n_cr, n_preamble=opt.n_preamble)
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ret["phy_pl_size"] = opt.n_size
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ret["mac_pl_size"] = opt.n_size - 5
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ret["sf"] = opt.n_sf
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ret["bw"] = opt.n_bw
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ret["ldro"] = "enable" if ret["v_DE"] else "disable"
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ret["eh"] = "enable" if opt.enable_eh else "disable"
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ret["cr"] = opt.n_cr
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ret["preamble"] = opt.n_preamble
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ret["duty_cycle"] = opt.n_duty_cycle
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ret["t_cycle"] = (ret["t_packet"]/1000.)*(100./ret["duty_cycle"])
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ret["max_packets_day"] = 86400./ret["t_cycle"]
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if opt.f_verbose:
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print("PHY payload size : %d Bytes" % ret["phy_pl_size"])
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print("MAC payload size : %d Bytes" % ret["mac_pl_size"])
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print("Spreading Factor : %d" % ret["sf"])
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print("Band width : %d kHz" % ret["bw"])
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print("Low data rate opt. : %s" % ret["ldro"])
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print("Explicit header : %s" % ret["eh"])
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print("CR (coding rate) : %d (4/%d)" % (ret["cr"], 4+ret["cr"]))
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print("Symbol Rate : %.3f symbol/s" % ret["r_sym"])
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print("Symbol Time : %.3f msec/symbol" % ret["t_sym"])
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print("Preamble size : %d symbols" % ret["preamble"])
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print("Packet symbol size : %d symbols" % ret["n_sym_payload"])
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print("Preamble ToA : %.3f msec" % ret["t_preamble"])
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print("Payload ToA : %.3f msec" % ret["t_payload"])
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print("Time on Air : %.3f msec" % ret["t_packet"])
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print("Duty Cycle : %d %%" % ret["duty_cycle"])
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print("Min span of a cycle : %.3f sec" % ret["t_cycle"])
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print("Max Frames per day : %d frames" % ret["max_packets_day"])
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if opt.debug_level:
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ret0 = get_toa(0, opt.n_sf, n_bw=opt.n_bw,
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enable_auto_ldro=opt.enable_auto_ldro,
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enable_ldro=opt.enable_ldro,
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enable_eh=opt.enable_eh, enable_crc=opt.enable_crc,
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n_cr=opt.n_cr, n_preamble=opt.n_preamble)
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print("PHY PL=0 ToA : %.3f msec" % (ret0["t_packet"]))
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# preamble=8 cr=1? payload-len=7? crc=16 (payload) payload-crc=16
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# =? 48 ==> 6 bytes ?
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t0 = (ret["t_packet"]-ret0["t_packet"])/1000.
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print("PHY fr.dr.(48b) 7:15: %.3f bps" % ((8.*opt.n_size+48)/t0))
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print("MAC frame DR : %.3f bps" % ((8.*(opt.n_size))/t0))
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print("before ceil(x) : %.3f" % ret["v_ceil"])
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else:
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print("%.3f" % ret["t_packet"])
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