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dsa.py @ 385

Revision 385, 10.4 KB (checked in by sriram, 15 years ago)
Cleaning up the code a little..need to test this more for bugs.

Rev	Line
[378]	1	#!/usr/bin/env python
	2	#Transmission and reception, one ata a time on the same antena
	3
	4	from gnuradio import gr, gru, modulation_utils
	5	from gnuradio import eng_notation
	6	from gnuradio.eng_option import eng_option
	7	from optparse import OptionParser
	8	from numpy import random
	9	import random, time, struct, sys, math
[384]	10	from datetime import datetime
[378]	11
	12	# from current dir
	13	from transmit_path import transmit_path
	14	from receive_path import receive_path
[385]	15
	16	global sync_status,mode,ch,traffic_flag,n_rcvd, n_right
[378]	17	sync_status = False
[385]	18	#Defining modes of operation
	19	# sync: the two nodes are trying to rendezvous on a common channel
	20	# traffic: the two node are communicating information to each other
	21	mode = "sync" #Default mode is sync
[378]	22	traffic_flag = False
	23	class my_top_block(gr.top_block):
	24
	25	def __init__(self, mod_class, demod_class,
	26	rx_callback, options_tx,options_rx):
	27
	28	gr.top_block.__init__(self)
	29	self.rxpath = receive_path(demod_class, rx_callback, options_rx)
	30	self.txpath = transmit_path(mod_class, options_tx)
	31	self.connect(self.txpath);
	32	self.connect(self.rxpath);
	33
	34
	35	def main():
[385]	36
[384]	37	global n_rcvd, n_right,sync_status,mode,ch,traffic_flag,n_attempts,return_flag
[378]	38	n_rcvd = 0
	39	n_right = 0
[382]	40	n_attempts = 5
[384]	41	return_flag = 0
[385]	42
[378]	43	def send_pkt(self, payload='', eof=False):
	44	return self.txpath.send_pkt(payload, eof)
[384]	45
	46	def get_freq(hop_freq,probe_level,absent_time):
[378]	47
[384]	48	channel = int(random.choice([1,7,8,14]))
	49	if channel < 8:
	50	hop_freq = float(1e6 * (462.5625+(channel-1)*0.025))#setting the centre freq frequency for sending packets
	51	else:
	52	hop_freq = float(1e6 * (467.5625+(channel-8)*0.025))#setting the centre freq frequency for sending packets
[378]	53
[384]	54	return channel,hop_freq #returning the channel number and hop frequency
	55
	56
[378]	57	def rx_callback(ok, payload):
[385]	58
[378]	59	global n_rcvd, n_right,sync_status,mode,ch,traffic_flag
[385]	60	########################## sync ####################################
[378]	61	if mode == "sync":
	62	if ok:
	63	(pktno,) = struct.unpack('!H', payload[0:2])
	64	(sync_signal,) = struct.unpack('!s', payload[2])
	65	(data_channel,) = struct.unpack('!H', payload[3:5])
[385]	66
[378]	67	if str(sync_signal) == 'o' and str(data_channel) == str(ch):
[385]	68
	69	sync_status = True
[378]	70	#tb.stop()
[385]	71
[378]	72	if str(sync_signal) == 's' and str(data_channel) == str(ch):
[385]	73
[378]	74	sync_status = True
[385]	75	data = 'o'
[378]	76	pktno=0
	77	ack_payload = struct.pack('!HsH', pktno & 0xffff,data,ch & 0xffff) #+ data
	78	send_pkt(tb,ack_payload) #sending back the acknowledgement
[385]	79	#else:
	80	# print "sync packet not ok\n"
	81	###################################################################
[378]	82
[385]	83	######################### traffic #################################
[378]	84	if mode == "traffic":
	85	if ok:
	86	(data_header,) = struct.unpack('!s', payload[0])
	87	if data_header == 'd':
	88	traffic_flag = True
	89	comm = struct.unpack('!14s', payload[1:15])
	90	data = 'dI am fine.....' #Sending this message
	91	payload = struct.pack('!15s', data)
	92	send_pkt(tb,payload)
[381]	93
[385]	94	#else:
	95	# print "data packet not ok\n"
[378]	96	##############################################################
	97
	98	n_rcvd += 1
	99	if ok:
[379]	100	n_right += 1
[378]	101
	102	#print "ok = %5s pktno = %4d n_rcvd = %4d n_right = %4d" % (
	103	# ok, pktno, n_rcvd, n_right)
[385]	104
[378]	105
	106	mods = modulation_utils.type_1_mods()
	107	demods = modulation_utils.type_1_demods()
	108
	109	#setting up the tx options parser
[385]	110
[378]	111	parser_tx = OptionParser(option_class=eng_option, conflict_handler="resolve")
	112	expert_grp_tx = parser_tx.add_option_group("Expert_tx")
[385]	113
	114	parser_tx.add_option("-m", "--modulation", type="choice", choices=mods.keys(),
[378]	115	default='gmsk',
	116	help="Select modulation from: %s [default=%%default]"
	117	% (', '.join(mods.keys()),))
	118
	119	parser_tx.add_option("-s", "--size", type="eng_float", default=1500,
	120	help="set packet size [default=%default]")
	121	parser_tx.add_option("-M", "--megabytes", type="eng_float", default=1.0,
	122	help="set megabytes to transmit [default=%default]")
	123	parser_tx.add_option("","--discontinuous", action="store_true", default=False,
	124	help="enable discontinous transmission (bursts of 5 packets)")
	125	parser_tx.add_option("","--from-file", default=None,
	126	help="use file for packet contents")
[385]	127
[378]	128	transmit_path.add_options(parser_tx, expert_grp_tx)
	129
	130	for mod in mods.values():
	131	mod.add_options(expert_grp_tx)
	132
	133	(options_tx, args_tx) = parser_tx.parse_args ()
	134
	135	if len(args_tx) != 0:
	136	parser_tx.print_help()
	137	sys.exit(1)
	138
	139	############# Setting some default values for tx side of the block
[384]	140	options_tx.tx_freq = 462.5625e6
[378]	141	options_tx.samples_per_symbol = 2
	142	options_tx.modulation = 'dbpsk'
	143	options_tx.fusb_block_size = 4096
	144	options_tx.fusb_nblocks = 16
	145	options_tx.bitrate = 0.0125e6
	146	#############
	147
	148	if options_tx.tx_freq is None:
	149	sys.stderr.write("You must specify -f FREQ or --freq FREQ\n")
	150	parser_tx.print_help(sys.stderr)
	151	sys.exit(1)
	152
	153	if options_tx.from_file is not None:
	154	source_file = open(options_tx.from_file, 'r')
[385]	155
[378]	156	parser_rx = OptionParser (option_class=eng_option, conflict_handler="resolve")
	157	expert_grp_rx = parser_rx.add_option_group("Expert_rx")
	158	parser_rx.add_option("-m", "--modulation", type="choice", choices=demods.keys(),
	159	default='gmsk',
	160	help="Select modulation from: %s [default=%%default]"
	161	% (', '.join(demods.keys()),))
[385]	162
[378]	163	receive_path.add_options(parser_rx, expert_grp_rx)
	164
	165	for mod in demods.values():
	166	mod.add_options(expert_grp_rx)
	167
	168	(options_rx, args_rx) = parser_rx.parse_args ()
	169
	170	if len(args_rx) != 0:
	171	parser_rx.print_help(sys.stderr)
	172	sys.exit(1)
	173	############# Setting some default values for rx side of the block
[384]	174	options_rx.rx_freq = 462.5625e6 #setting default rx_freq value
[378]	175	options_rx.samples_per_symbol = 2
	176	options_rx.modulation = 'dbpsk'
	177	options_rx.fusb_block_size = 4096
	178	options_rx.fusb_nblocks = 16
	179	options_rx.bitrate = 0.0125e6
	180	#############
	181
	182	if options_rx.rx_freq is None:
	183	sys.stderr.write("You must specify -f FREQ or --freq FREQ\n")
	184	parser_rx.print_help(sys.stderr)
	185	sys.exit(1)
[385]	186
[378]	187	# build the graph
	188
	189	tb = my_top_block(mods[options_tx.modulation],
	190	demods[options_rx.modulation],
	191	rx_callback,options_tx,
	192	options_rx)
	193	r = gr.enable_realtime_scheduling()
	194	if r != gr.RT_OK:
	195	print "Warning: failed to enable realtime scheduling"
	196
	197	tb.start()
[385]	198
[378]	199	#listening to random frequencies untill a match is found
	200	running = True
[384]	201	ch_energy = tb.rxpath.probe.level() #setting initial value
	202	hop_freq = options_tx.tx_freq # = options_rx.rx_freq...same for tx and rx side
[379]	203	while running:
[378]	204
[379]	205	################################################sync mode####################################
	206	if mode == "sync":
	207	if sync_status != True:
[384]	208
	209	if return_flag == 0:
	210	ch,hop_freq = get_freq(hop_freq,ch_energy,0)
	211	else:
	212	ch,hop_freq = get_freq(hop_freq,ch_energy,elapsed_time)
	213	return_flag = 0
	214
	215	tb.txpath.set_freq(hop_freq)
[379]	216	tb.rxpath.set_freq(hop_freq)
[384]	217
	218	ch_energy = tb.rxpath.probe.level() #check if primary user is present
	219
	220	if int(ch_energy) > 1.5e8: #if primary user is there then dont transmit on this channel
[379]	221	continue
[384]	222
	223	nbytes = 5 #int(1e6 * .0003)
[379]	224	pkt_size = 5
	225	n = 0
	226	pktno = 0
	227	while n < nbytes:
	228	if options_tx.from_file is None:
[385]	229	data = 's'
[379]	230	else:
	231	data = source_file.read(pkt_size - 2)
	232	if data == '':
	233	break;
[378]	234
[379]	235	payload = struct.pack('!HsH', pktno & 0xffff,data,ch & 0xffff) #+ data
[385]	236
[379]	237	send_pkt(tb,payload)
[385]	238	n += len(payload)
[379]	239	sys.stderr.write('.')
	240	if options_tx.discontinuous and pktno % 5 == 4:
	241	time.sleep(1)
	242	pktno += 1
	243	time.sleep(0.1)
[385]	244
[379]	245	else:
	246	print "sync channel found..channel ",ch,"\n"
[382]	247	n_attempts_counter = 0
[379]	248	mode = "traffic"
[380]	249	traffic_flag = False
	250	sync_status="False"
[384]	251	start_time = datetime.now() #measuring the time for which the primary user is away
[380]	252
	253	################################################end of sync mode####################################
[378]	254
[380]	255	################################################Communications mode#################################
	256	if mode == "traffic":
[385]	257
[381]	258	nbytes = 15
	259	pkt_size = 15
	260	data_pktno = 0
	261	n = 0
	262	while n < nbytes:
[385]	263
[381]	264	if options_tx.from_file is None:
[385]	265	data = 'dHi how are you' #Sending this message
	266
[381]	267	else:
	268	data = source_file.read(pkt_size - 2)
	269	if data == '':
	270	break;
[380]	271
	272
[381]	273	payload = struct.pack('!15s', data)
[385]	274
[381]	275	send_pkt(tb,payload)
[385]	276	#print "printing payload",data,"**\n"
[381]	277	n += len(payload)
	278	sys.stderr.write('.')
	279	if options_tx.discontinuous and data_pktno % 5 == 4:
	280	time.sleep(1)
	281	data_pktno += 1
[385]	282	time.sleep(0.2 + 0.05*int(random.choice([0,1,2,3])))
[382]	283
	284	if traffic_flag != True:
	285	n_attempts_counter += 1
[383]	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
[382]	287	mode = "sync"
	288	continue
	289
[381]	290	ch_energy = tb.rxpath.probe.level() #check if primary user is present
[385]	291
[384]	292	if int(ch_energy) > 1.5e8: #if primary user is there then dont transmit on this channel
	293	stop_time = datetime.now()
	294	_elapsed_time = start_time - stop_time
	295	elapsed_time = _elapsed_time.seconds
[385]	296	print "primary user detected..moving out of this channel\n"
[381]	297	mode = "sync"
[384]	298	return_flag = 1
[381]	299
[378]	300
[379]	301	if __name__ == '__main__':
	302	try:
	303	main()
	304	except KeyboardInterrupt:
	305	pass
[378]	306
	307
	308
	309
[379]	310

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