| 1 | #!/usr/bin/env python |
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| 2 | #Transmission and reception, one ata a time on the same antena |
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| 3 | |
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| 4 | from gnuradio import gr, gru, modulation_utils |
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| 5 | from gnuradio import eng_notation |
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| 6 | from gnuradio.eng_option import eng_option |
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| 7 | from optparse import OptionParser |
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| 8 | from numpy import random |
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| 9 | import random, time, struct, sys, math |
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| 10 | from datetime import datetime |
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| 11 | |
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| 12 | # from current dir |
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| 13 | from transmit_path import transmit_path |
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| 14 | from receive_path import receive_path |
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| 15 | |
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| 16 | global sync_status,mode,ch,traffic_flag,n_rcvd, n_right |
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| 17 | sync_status = False |
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| 18 | #Defining modes of operation |
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| 19 | # sync: the two nodes are trying to rendezvous on a common channel |
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| 20 | # traffic: the two node are communicating information to each other |
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| 21 | mode = "sync" #Default mode is sync |
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| 22 | traffic_flag = False |
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| 23 | class my_top_block(gr.top_block): |
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| 24 | |
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| 25 | def __init__(self, mod_class, demod_class, |
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| 26 | rx_callback, options_tx,options_rx): |
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| 27 | |
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| 28 | gr.top_block.__init__(self) |
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| 29 | self.rxpath = receive_path(demod_class, rx_callback, options_rx) |
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| 30 | self.txpath = transmit_path(mod_class, options_tx) |
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| 31 | self.connect(self.txpath); |
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| 32 | self.connect(self.rxpath); |
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| 33 | |
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| 34 | |
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| 35 | def main(): |
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| 36 | |
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| 37 | global n_rcvd, n_right,sync_status,mode,ch,traffic_flag,n_attempts,return_flag |
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| 38 | n_rcvd = 0 |
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| 39 | n_right = 0 |
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| 40 | n_attempts = 5 |
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| 41 | return_flag = 0 |
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| 42 | |
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| 43 | def send_pkt(self, payload='', eof=False): |
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| 44 | return self.txpath.send_pkt(payload, eof) |
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| 45 | |
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| 46 | def get_freq(hop_freq,probe_level,absent_time): |
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| 47 | |
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| 48 | channel = int(random.choice([1,7,8,14])) |
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| 49 | if channel < 8: |
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| 50 | hop_freq = float(1e6 * (462.5625+(channel-1)*0.025))#setting the centre freq frequency for sending packets |
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| 51 | else: |
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| 52 | hop_freq = float(1e6 * (467.5625+(channel-8)*0.025))#setting the centre freq frequency for sending packets |
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| 53 | |
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| 54 | return channel,hop_freq #returning the channel number and hop frequency |
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| 55 | |
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| 56 | |
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| 57 | def rx_callback(ok, payload): |
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| 58 | |
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| 59 | global n_rcvd, n_right,sync_status,mode,ch,traffic_flag |
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| 60 | ########################## sync #################################### |
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| 61 | if mode == "sync": |
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| 62 | if ok: |
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| 63 | (pktno,) = struct.unpack('!H', payload[0:2]) |
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| 64 | (sync_signal,) = struct.unpack('!s', payload[2]) |
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| 65 | (data_channel,) = struct.unpack('!H', payload[3:5]) |
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| 66 | |
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| 67 | if str(sync_signal) == 'o' and str(data_channel) == str(ch): |
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| 68 | |
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| 69 | sync_status = True |
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| 70 | #tb.stop() |
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| 71 | |
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| 72 | if str(sync_signal) == 's' and str(data_channel) == str(ch): |
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| 73 | |
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| 74 | sync_status = True |
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| 75 | data = 'o' |
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| 76 | pktno=0 |
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| 77 | ack_payload = struct.pack('!HsH', pktno & 0xffff,data,ch & 0xffff) #+ data |
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| 78 | send_pkt(tb,ack_payload) #sending back the acknowledgement |
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| 79 | #else: |
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| 80 | # print "sync packet not ok\n" |
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| 81 | ################################################################### |
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| 82 | |
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| 83 | ######################### traffic ################################# |
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| 84 | if mode == "traffic": |
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| 85 | if ok: |
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| 86 | (data_header,) = struct.unpack('!s', payload[0]) |
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| 87 | if data_header == 'd': |
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| 88 | traffic_flag = True |
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| 89 | comm = struct.unpack('!14s', payload[1:15]) |
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| 90 | data = 'dI am fine.....' #Sending this message |
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| 91 | payload = struct.pack('!15s', data) |
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| 92 | send_pkt(tb,payload) |
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| 93 | |
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| 94 | #else: |
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| 95 | # print "data packet not ok\n" |
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| 96 | ############################################################## |
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| 97 | |
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| 98 | n_rcvd += 1 |
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| 99 | if ok: |
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| 100 | n_right += 1 |
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| 101 | |
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| 102 | #print "ok = %5s pktno = %4d n_rcvd = %4d n_right = %4d" % ( |
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| 103 | # ok, pktno, n_rcvd, n_right) |
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| 104 | |
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| 105 | |
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| 106 | mods = modulation_utils.type_1_mods() |
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| 107 | demods = modulation_utils.type_1_demods() |
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| 108 | |
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| 109 | #setting up the tx options parser |
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| 110 | |
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| 111 | parser_tx = OptionParser(option_class=eng_option, conflict_handler="resolve") |
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| 112 | expert_grp_tx = parser_tx.add_option_group("Expert_tx") |
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| 113 | |
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| 114 | parser_tx.add_option("-m", "--modulation", type="choice", choices=mods.keys(), |
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| 115 | default='gmsk', |
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| 116 | help="Select modulation from: %s [default=%%default]" |
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| 117 | % (', '.join(mods.keys()),)) |
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| 118 | |
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| 119 | parser_tx.add_option("-s", "--size", type="eng_float", default=1500, |
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| 120 | help="set packet size [default=%default]") |
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| 121 | parser_tx.add_option("-M", "--megabytes", type="eng_float", default=1.0, |
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| 122 | help="set megabytes to transmit [default=%default]") |
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| 123 | parser_tx.add_option("","--discontinuous", action="store_true", default=False, |
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| 124 | help="enable discontinous transmission (bursts of 5 packets)") |
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| 125 | parser_tx.add_option("","--from-file", default=None, |
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| 126 | help="use file for packet contents") |
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| 127 | |
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| 128 | transmit_path.add_options(parser_tx, expert_grp_tx) |
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| 129 | |
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| 130 | for mod in mods.values(): |
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| 131 | mod.add_options(expert_grp_tx) |
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| 132 | |
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| 133 | (options_tx, args_tx) = parser_tx.parse_args () |
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| 134 | |
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| 135 | if len(args_tx) != 0: |
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| 136 | parser_tx.print_help() |
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| 137 | sys.exit(1) |
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| 138 | |
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| 139 | ############# Setting some default values for tx side of the block |
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| 140 | options_tx.tx_freq = 462.5625e6 |
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| 141 | options_tx.samples_per_symbol = 2 |
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| 142 | options_tx.modulation = 'dbpsk' |
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| 143 | options_tx.fusb_block_size = 4096 |
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| 144 | options_tx.fusb_nblocks = 16 |
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| 145 | options_tx.bitrate = 0.0125e6 |
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| 146 | ############# |
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| 147 | |
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| 148 | if options_tx.tx_freq is None: |
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| 149 | sys.stderr.write("You must specify -f FREQ or --freq FREQ\n") |
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| 150 | parser_tx.print_help(sys.stderr) |
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| 151 | sys.exit(1) |
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| 152 | |
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| 153 | if options_tx.from_file is not None: |
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| 154 | source_file = open(options_tx.from_file, 'r') |
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| 155 | |
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| 156 | parser_rx = OptionParser (option_class=eng_option, conflict_handler="resolve") |
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| 157 | expert_grp_rx = parser_rx.add_option_group("Expert_rx") |
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| 158 | parser_rx.add_option("-m", "--modulation", type="choice", choices=demods.keys(), |
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| 159 | default='gmsk', |
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| 160 | help="Select modulation from: %s [default=%%default]" |
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| 161 | % (', '.join(demods.keys()),)) |
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| 162 | |
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| 163 | receive_path.add_options(parser_rx, expert_grp_rx) |
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| 164 | |
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| 165 | for mod in demods.values(): |
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| 166 | mod.add_options(expert_grp_rx) |
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| 167 | |
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| 168 | (options_rx, args_rx) = parser_rx.parse_args () |
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| 169 | |
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| 170 | if len(args_rx) != 0: |
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| 171 | parser_rx.print_help(sys.stderr) |
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| 172 | sys.exit(1) |
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| 173 | ############# Setting some default values for rx side of the block |
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| 174 | options_rx.rx_freq = 462.5625e6 #setting default rx_freq value |
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| 175 | options_rx.samples_per_symbol = 2 |
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| 176 | options_rx.modulation = 'dbpsk' |
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| 177 | options_rx.fusb_block_size = 4096 |
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| 178 | options_rx.fusb_nblocks = 16 |
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| 179 | options_rx.bitrate = 0.0125e6 |
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| 180 | ############# |
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| 181 | |
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| 182 | if options_rx.rx_freq is None: |
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| 183 | sys.stderr.write("You must specify -f FREQ or --freq FREQ\n") |
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| 184 | parser_rx.print_help(sys.stderr) |
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| 185 | sys.exit(1) |
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| 186 | |
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| 187 | # build the graph |
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| 188 | |
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| 189 | tb = my_top_block(mods[options_tx.modulation], |
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| 190 | demods[options_rx.modulation], |
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| 191 | rx_callback,options_tx, |
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| 192 | options_rx) |
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| 193 | r = gr.enable_realtime_scheduling() |
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| 194 | if r != gr.RT_OK: |
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| 195 | print "Warning: failed to enable realtime scheduling" |
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| 196 | |
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| 197 | tb.start() |
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| 198 | |
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| 199 | #listening to random frequencies untill a match is found |
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| 200 | running = True |
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| 201 | ch_energy = tb.rxpath.probe.level() #setting initial value |
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| 202 | hop_freq = options_tx.tx_freq # = options_rx.rx_freq...same for tx and rx side |
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| 203 | while running: |
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| 204 | |
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| 205 | ################################################sync mode#################################### |
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| 206 | if mode == "sync": |
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| 207 | if sync_status != True: |
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| 208 | |
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| 209 | if return_flag == 0: |
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| 210 | ch,hop_freq = get_freq(hop_freq,ch_energy,0) |
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| 211 | else: |
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| 212 | ch,hop_freq = get_freq(hop_freq,ch_energy,elapsed_time) |
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| 213 | return_flag = 0 |
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| 214 | |
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| 215 | tb.txpath.set_freq(hop_freq) |
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| 216 | tb.rxpath.set_freq(hop_freq) |
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| 217 | |
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| 218 | ch_energy = tb.rxpath.probe.level() #check if primary user is present |
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| 219 | |
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| 220 | if int(ch_energy) > 1.5e8: #if primary user is there then dont transmit on this channel |
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| 221 | continue |
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| 222 | |
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| 223 | nbytes = 5 #int(1e6 * .0003) |
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| 224 | pkt_size = 5 |
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| 225 | n = 0 |
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| 226 | pktno = 0 |
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| 227 | while n < nbytes: |
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| 228 | if options_tx.from_file is None: |
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| 229 | data = 's' |
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| 230 | else: |
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| 231 | data = source_file.read(pkt_size - 2) |
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| 232 | if data == '': |
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| 233 | break; |
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| 234 | |
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| 235 | payload = struct.pack('!HsH', pktno & 0xffff,data,ch & 0xffff) #+ data |
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| 236 | |
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| 237 | send_pkt(tb,payload) |
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| 238 | n += len(payload) |
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| 239 | sys.stderr.write('.') |
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| 240 | if options_tx.discontinuous and pktno % 5 == 4: |
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| 241 | time.sleep(1) |
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| 242 | pktno += 1 |
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| 243 | time.sleep(0.1) |
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| 244 | |
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| 245 | else: |
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| 246 | print "sync channel found..channel ",ch,"\n" |
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| 247 | n_attempts_counter = 0 |
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| 248 | mode = "traffic" |
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| 249 | traffic_flag = False |
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| 250 | sync_status="False" |
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| 251 | start_time = datetime.now() #measuring the time for which the primary user is away |
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| 252 | |
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| 253 | ################################################end of sync mode#################################### |
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| 254 | |
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| 255 | ################################################Communications mode################################# |
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| 256 | if mode == "traffic": |
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| 257 | |
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| 258 | nbytes = 15 |
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| 259 | pkt_size = 15 |
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| 260 | data_pktno = 0 |
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| 261 | n = 0 |
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| 262 | while n < nbytes: |
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| 263 | |
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| 264 | if options_tx.from_file is None: |
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| 265 | data = 'dHi how are you' #Sending this message |
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| 266 | |
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| 267 | else: |
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| 268 | data = source_file.read(pkt_size - 2) |
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| 269 | if data == '': |
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| 270 | break; |
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| 271 | |
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| 272 | |
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| 273 | payload = struct.pack('!15s', data) |
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| 274 | |
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| 275 | send_pkt(tb,payload) |
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| 276 | #print "printing payload",data,"**\n" |
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| 277 | n += len(payload) |
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| 278 | sys.stderr.write('.') |
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| 279 | if options_tx.discontinuous and data_pktno % 5 == 4: |
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| 280 | time.sleep(1) |
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| 281 | data_pktno += 1 |
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| 282 | time.sleep(0.2 + 0.05*int(random.choice([0,1,2,3]))) |
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| 283 | |
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| 284 | if traffic_flag != True: |
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| 285 | n_attempts_counter += 1 |
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| 286 | if n_attempts_counter > n_attempts: #get out of the data channel as it seems that the other node is still trying to rendezvous |
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| 287 | mode = "sync" |
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| 288 | continue |
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| 289 | |
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| 290 | ch_energy = tb.rxpath.probe.level() #check if primary user is present |
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| 291 | |
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| 292 | if int(ch_energy) > 1.5e8: #if primary user is there then dont transmit on this channel |
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| 293 | stop_time = datetime.now() |
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| 294 | _elapsed_time = start_time - stop_time |
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| 295 | elapsed_time = _elapsed_time.seconds |
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| 296 | print "primary user detected..moving out of this channel\n" |
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| 297 | mode = "sync" |
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| 298 | return_flag = 1 |
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| 299 | |
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| 300 | |
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| 301 | if __name__ == '__main__': |
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| 302 | try: |
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| 303 | main() |
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| 304 | except KeyboardInterrupt: |
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| 305 | pass |
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| 306 | |
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| 307 | |
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| 308 | |
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| 309 | |
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| 310 | |
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