Example #1
0
    def run(self):
        pkt = self.socket.recv(1000)
        arrived_packet = pickle.loads(pkt)
        '''
        MAC layer checks whether there is a packet to transmit
        '''
        if ("no_packet" == arrived_packet["HEADER"]
            ):  # check whether the queue is empty
            print "Receive a query from MAC to check the buffer......"
            if self.cs.isEmpty() == True:
                print "The buffer is empty"
                x = plcp.create_packet("NO", "")
                plcp.send_to_mac(self.socket, x)
                #print "Send NO to MAC!!!!"
            else:
                self.cs.elements.reverse()
                if self.cs.read(0) == "[beacon packet]":
                    x = plcp.create_packet("BEACON", "")
                    print "Buffer has BEACON to send....."
                else:
                    x = plcp.create_packet("YES", self.cs.read(0))
                    print "Buffer has a DATA to send......"
                self.cs.elements.reverse()
                plcp.send_to_mac(self.socket, x)
                print "Buffer sends DATA to MAC......"

        if ("remove" == arrived_packet["HEADER"]
            ):  # Remove a packet from the buffer
            print "Upper buffer is set to remove a packet......"
            self.cs.elements.reverse()
            self.cs.pop()
            self.cs.elements.reverse()
        if ("copy" == arrived_packet["HEADER"]
            ):  # A packet arrives from MAC layer
            self.cs2.push(arrived_packet["DATA"])
        '''
        Upper layer has a packet to send and stores it in the buffer
        '''
        if (arrived_packet["HEADER"] == "PAYLOAD"
            ):  # Payload received from Upper Layer Traffic generator
            self.cs.push(arrived_packet["DATA"])
            #self.socket.close()
        elif (arrived_packet["HEADER"] == "BEACON"):  # Beacon request arrival
            print "Buffer receives a BEACON from upper layer......"
            self.cs.push(arrived_packet["DATA"])
            #self.socket.close()

        # Show the buffer state
        print "========== PACKETS TO TRANSMIT ============"
        print self.cs.elements
        print "==========================================="
        print "\n\n"
        print "======== RECEIVED PACKETS FROM MAC ========"
        print self.cs2.elements
        print "==========================================="
    def run(self):
        pkt = self.socket.recv(1000)
        arrived_packet = pickle.loads(pkt)
        """
        MAC layer checks whether there is a packet to transmit
        """
        if "no_packet" == arrived_packet["HEADER"]:  # check whether the queue is empty
            if self.cs.isEmpty() == True:
                x = plcp.create_packet("NO", "")
                plcp.send_to_mac(self.socket, x)
            else:
                self.cs.elements.reverse()
                if self.cs.read(0) == "[beacon packet]":
                    x = plcp.create_packet("BEACON", "")
                else:
                    x = plcp.create_packet("YES", self.cs.read(0))
                self.cs.elements.reverse()
                plcp.send_to_mac(self.socket, x)

        if "remove" == arrived_packet["HEADER"]:  # Remove a packet from the buffer
            self.cs.elements.reverse()
            self.cs.pop()
            self.cs.elements.reverse()
        if "copy" == arrived_packet["HEADER"]:  # A packet arrives from MAC layer
            self.cs2.push(arrived_packet["DATA"])
        """
        Upper layer has a packet to send and stores it in the buffer
        """
        if arrived_packet["HEADER"] == "PAYLOAD":  # Payload received from Upper Layer Traffic generator
            self.cs.push(arrived_packet["DATA"])
            self.socket.close()
        elif arrived_packet["HEADER"] == "BEACON":  # Beacon request arrival
            self.cs.push(arrived_packet["DATA"])
            self.socket.close()

        # Show the buffer state
        print "========== PACKETS TO TRANSMIT ============"
        print self.cs.elements
        print "==========================================="
        print "\n\n"
        print "======== RECEIVED PACKETS FROM MAC ========"
        print self.cs2.elements
        print "==========================================="
Example #3
0
def main():
    def send_pkt(puerto, main_regime, sub_regime, eof=False):
        return tb.txpath.send_pkt(puerto, main_regime, sub_regime, eof)


#    def test_attribute(puerto, eof=False):
#        return tb.txpath.test_attribute(puerto, eof)

    parser = OptionParser(option_class=eng_option, usage="%prog: [options]")
    parser.add_option("-a",
                      "--args",
                      type="string",
                      default="",
                      help="UHD device address args [default=%default]")
    parser.add_option("",
                      "--spec",
                      type="string",
                      default=None,
                      help="Subdevice of UHD device where appropriate")
    parser.add_option("-A",
                      "--antenna",
                      type="string",
                      default=None,
                      help="select Rx Antenna where appropriate")
    parser.add_option("-f",
                      "--freq",
                      type="eng_float",
                      default=5.87e9,
                      help="set USRP2 carrier frequency, [default=%default]",
                      metavar="FREQ")
    parser.add_option("-w",
                      "--window-size",
                      type="int",
                      default=48,
                      help="set fir filter tap size [default=%default]")
    parser.add_option("-s",
                      "--sync-length",
                      type="int",
                      default=256,
                      help="sync length [default=%default]")
    parser.add_option("-W",
                      "--bandwidth",
                      type="eng_float",
                      default=20e6,
                      help="set symbol bandwidth [default=%default]\
                20 MHz  -> 802.11a/g, OFDM-symbol duration=4us, 10 MHz -> 802.11p, OFDM-symbolduration=8us"
                      )
    parser.add_option("-g",
                      "--gain",
                      type="int",
                      default=20,
                      help="set USRP2 Rx GAIN in [dB] [default=%default]")

    parser.add_option("",
                      "--regime",
                      type="string",
                      default="5",
                      help="set OFDM coderegime,    [default=%default]\
                        1 -> 6 (3) Mbit/s (BPSK r=0.5), \
                        2 -> 9 (4.5) Mbit/s (BPSK r=0.75), \
                        3 -> 12 (6) Mbit/s (QPSK r=0.5), \
                        4 -> 18 (9) Mbit/s (QPSK r=0.75), \
                        5 -> 24 (12) Mbit/s (QAM16 r=0.5), \
                        6 -> 36 (18) Mbit/s (QAM16 r=0.75), \
                        7 -> 48 (24) Mbit/s (QAM64 r=0.66), \
                        8 -> 54 (27) Mbit/s (QAM64 r=0.75)")

    parser.add_option("-G",
                      "--txgain",
                      type="int",
                      default=20,
                      help="set USRP2 Tx GAIN in [dB] [default=%default]")

    parser.add_option(
        "-n",
        "--norm",
        type="eng_float",
        default=0.4,
        help="set gain factor for complex baseband floats [default=%default]")
    parser.add_option("-N",
                      "--Node",
                      type="intx",
                      default=1,
                      help="USRP2 node    [default=%default]")

    parser.add_option(
        "-r",
        "--repetition",
        type="int",
        default=1,
        help=
        "set number of frame-copies to send, 0=infinite [default=%default] ")

    parser.add_option("-l",
                      "--log",
                      action="store_true",
                      default=True,
                      help="write debug-output of individual blocks to disk")

    parser.add_option("",
                      "--PHYRXport",
                      type="int",
                      default=8513,
                      help="Port used for PHY RX [default=%default] ")
    parser.add_option(
        "",
        "--PHYport",
        type="int",
        default=8013,
        help="Port used for MAC-->PHY communication [default=%default] ")

    parser.add_option("",
                      "--real-time",
                      action="store_true",
                      default=True,
                      help="Attempt to enable real-time scheduling")

    parser.add_option('-v',
                      "--verbose",
                      action="store_true",
                      default=False,
                      help="Print timing information, [default=%default]")

    parser.add_option("", "--nsym", type="int", default=1)
    parser.add_option("", "--modulation", type="string", default="bpsk")
    (options, args) = parser.parse_args()

    # Stream sockets to ensure no packet loss during PHY<-->MAC communication

    server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    #server.bind((socket.gethostname(), options.PHYport))
    server.bind((socket.gethostname(), options.PHYport))

    server.listen(1)  # PHY is ready to attend MAC requests

    phy_rx_server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    phy_rx_server.bind((socket.gethostname(), options.PHYRXport))
    phy_rx_server.listen(1)

    print '\n', "-------------------------"
    print " PHY (TX) layer running ..."
    print " (Ctrl + C) to exit"
    print "-------------------------", '\n'

    my_mac = mac.usrp2_node(options.Node)  # Assign the MAC address of the node
    rxclient = threading.Thread(target=RX_Client,
                                args=(options, my_mac, phy_rx_server))
    rxclient.start()
    # Initial values of variables used in time measurement

    N_sym_prev = 4  # OFDM symbols of the previous packet sent
    N_sensings = 0  # Number of power measurements
    N_packets = 0  # Number of packets sent
    time_socket = 0  # Instant time of socket communication
    t_socket_TOTAL = 0  # Total time of socket communication
    T_sense_USRP2 = 0  # Time of the USRP2 measuring the power
    T_sense_PHY = 0  # Time elapsed in PHY layer due to a carrier sensing request
    T_transmit_USRP2 = 0  # USRP2 TX time
    T_configure_USRP2 = 0  # Time due to USRP2 graph management
    T_transmit_PHY = 0  # Time elapsed in PHY layer due to a packet tx request

    main_regime = int(options.regime)
    sub_regime = 0

    msgq = gr.msg_queue(1)
    first_time = True  # Is the first time to transmit?
    #fg_cca = sense_block(options)   # Set up the carrier sensing block for the first time.

    tb = wifi_rx(options, socket.gethostname(), msgq)
    tb.Start(True)

    while 1:
        socket_client, conn_addr = server.accept(
        )  # Waiting a request from the MAC layer
        arrived_packet = plcp.receive_from_mac(
            socket_client)  # Packet received from MAC
        print "Receive a packet from MAC......"
        print "Arrived packet header: %s......" % arrived_packet["HEADER"]
        print "Arrived DATA: %s......" % arrived_packet["DATA"]
        if (arrived_packet["HEADER"] == "PKT"):
            print "PHY receives a DATA frame from MAC......"
            t_socket = time.time(
            ) - arrived_packet["DATA"]["INFO"]["timestamp"]
            t_socket_TOTAL = t_socket_TOTAL + t_socket  #Update the time used in the socket communication.

            t_sendA = time.time()
            item = arrived_packet[
                "DATA"]  # Copy the packet to send from the MAC message
            info = item["INFO"]
            N_sym = info["N_sym"]  # Read N_sym and add N_sym to options
            mod = info["modulation"]

            options.nsym = N_sym
            options.modulation = mod

            print "Re-setting USRP2 graph!"
            tb = transmitter_block(
                options
            )  # If necessary, update the transmit flow-graph depending to the new OFDM parameters
            r = gr.enable_realtime_scheduling()
            if r != gr.RT_OK:
                print "Warning: failed to enable realtime scheduling"
            t_2 = time.time()
            tb.start()  # Send packet procedure starts
            #test_attribute(item,eof=False)
            t_sendB = time.time()
            send_pkt(
                item, main_regime, sub_regime, eof=False
            )  # 'item' is a dictionary which contents the packet to transmit and other information
            print "Complete send_pkt(item,eof=False)"
            send_pkt("", main_regime, sub_regime, eof=True)
            print "Complete send_pkt(" ",eof=True)"
            t_sendC = time.time()
            print "t_sendC"
            tb.wait()  # Wait until USRP2 finishes the TX-graph
            print "PHY successfully transmit one frame!!!!!!!"
            t_sendD = time.time()
            if options.verbose:
                print "Time elapsed on graph configuration (TX Packet) = \t", (
                    t_sendB - t_2)
            T_transmit_USRP2 = T_transmit_USRP2 + t_sendC - t_sendB
            T_configure_USRP2 = T_configure_USRP2 + t_sendD - t_sendA - (
                t_sendC - t_sendB)
            T_transmit_PHY = T_transmit_PHY + t_sendD - t_sendA

            # set values for the next packet tx request
            first_time = False
            N_sym_prev = N_sym  # Keep a record of the OFDM symbols' Number
            N_packets += 1

        # Carrier sensing request
        if (arrived_packet["HEADER"] == "CCA"):
            #print "PHY receives a CCA from MAC......"
            t_senseA = time.time()
            #print "Breakpoint 1......"
            msgq.flush()
            #print "Breakpoint 2......"
            t_reconfig = time.time() - t_senseA
            #print "Breakpoint 3......"
            m = msgq.delete_head()
            #print "Breakpoint 4......"
            t = m.to_string()
            #print "The head deleted is %s......" %t
            #print "Breakpoint 5......"
            msgdata = struct.unpack('%df' % (int(m.arg2()), ), t)
            #print "Breakpoint 6......"
            sensed_power = msgdata[0]
            #print "Breakpoint 7......"
            t_senseB = time.time()

            # PHY responds with the power measured to the MAC
            #print "PHY creates CCA......"
            packet = plcp.create_packet("CCA", sensed_power)
            #print "PHY sends CCA to MAC......"
            plcp.send_to_mac(socket_client, packet)
            #print "MAC finishes sending CCA to MAC......"
            t_senseC = time.time()
            T_sense_USRP2 = T_sense_USRP2 + (t_senseB - t_senseA)
            T_sense_PHY = T_sense_PHY + (t_senseC - t_senseA)
            N_sensings += 1
            if options.verbose:
                print "Time elapsed on graph configuration (Carrier Sensing) = \t", t_reconfig

        if (arrived_packet["HEADER"] == "RATE"):
            header_pkt = arrived_packet["DATA"]
            print "The header of the pkt is %s......................" % header_pkt
            main_regime, sub_regime = v2r(int(header_pkt))
            options.regime = str(main_regime)
            print "Now the rate is %s..............................." % options.regime

        # MAC requests an incoming packet to the PHY
        if (arrived_packet["HEADER"] == "TAIL"):
            header_pkt = arrived_packet["DATA"]

            len_data = data.length()
            len_ack = ack.length()
            len_rts = rts.length()
            len_cts = cts.length()

            if (header_pkt
                    == "DATA") and len_data > 0:  # There are Data packets?
                #print "Header is DATA......"
                data.elements.reverse()
                x = data.read(0)
                phy_pkt = plcp.create_packet("YES", x)
                data.pop()
                data.elements.reverse()

            elif header_pkt == "ACK" and len_ack > 0:  # There are ACK packets?
                ack.elements.reverse()
                x = ack.read(0)
                phy_pkt = plcp.create_packet("YES", x)
                ack.pop()
                ack.elements.reverse()

            elif header_pkt == "RTS" and len_rts > 0:  # There are RTS packets?
                rts.elements.reverse()
                x = rts.read(0)
                phy_pkt = plcp.create_packet("YES", x)
                rts.pop()
                rts.elements.reverse()
            elif header_pkt == "CTS" and len_cts > 0:  # There are CTS packets?
                cts.elements.reverse()
                x = cts.read(0)
                phy_pkt = plcp.create_packet("YES", x)
                cts.pop()
                cts.elements.reverse()
            else:  # There are not packets
                #print "There are no packets in PHY......"
                phy_pkt = plcp.create_packet("NO", [])
            #print "PHY sends notifications to MAC......"
            plcp.send_to_mac(
                socket_client,
                phy_pkt)  # Send the result (PHY packet) to MAC layer
        #socket_client.close()

        if options.verbose:
            print "===================== Average statistics ===================="
            print "Number of Carrier Sensing Requests = ", N_sensings
            if N_sensings > 0:
                print "Time spent by USRP2 on sensing channel = \t", T_sense_USRP2 / N_sensings
                print "Time spent by PHY layer on sensing channel = \t", T_sense_PHY / N_sensings
            print "============================================================="
            print "Number of packets transmitted = ", N_packets
            if N_packets > 1:
                print "Time spent by USRP2 on sending a packet = \t", T_transmit_USRP2 / N_packets
                print "Time spent by USRP2 on configuring the graphs\t", T_configure_USRP2 / N_packets
                print "Time spent by PHY on sending a packet = \t", T_transmit_PHY / N_packets
                print "Time spent on Socket Communication = \t", t_socket_TOTAL / N_packets
            print "============================================================="

    tb.Wait()
Example #4
0
def main():
    def send_pkt(puerto, eof=False):
        return tb.txpath.send_pkt(puerto, eof)
    parser = OptionParser(option_class=eng_option, usage="%prog: [options]")
    parser.add_option("-a", "--args", type="string", default="",
                          help="UHD device address args [default=%default]")
    parser.add_option("", "--spec", type="string", default=None,
                          help="Subdevice of UHD device where appropriate")
    parser.add_option("-A", "--antenna", type="string", default=None,
                          help="select Rx Antenna where appropriate")
    parser.add_option("-f", "--freq", type="eng_float",
                          default = 5.825e9, help="set USRP2 carrier frequency, [default=%default]",
                          metavar="FREQ")
    parser.add_option("-w", "--window-size", type="int", default=48 , help = "set fir filter tap size [default=%default]")
    parser.add_option("-s", "--sync-length", type="int", default=256 , help = "sync length [default=%default]")
    parser.add_option("-W", "--bandwidth", type="eng_float", default=1e7, help="set symbol bandwidth [default=%default]\
                20 MHz  -> 802.11a/g, OFDM-symbol duration=4us, 10 MHz -> 802.11p, OFDM-symbolduration=8us")
    parser.add_option("-g", "--gain", type="int", default=0 , help = "set USRP2 Rx GAIN in [dB] [default=%default]")

    parser.add_option("", "--regime", type="string", default="1",
                          help="set OFDM coderegime,    [default=%default]\
                        1 -> 6 (3) Mbit/s (BPSK r=0.5), \
                        2 -> 9 (4.5) Mbit/s (BPSK r=0.75), \
                        3 -> 12 (6) Mbit/s (QPSK r=0.5), \
                        4 -> 18 (9) Mbit/s (QPSK r=0.75), \
                        5 -> 24 (12) Mbit/s (QAM16 r=0.5), \
                        6 -> 36 (18) Mbit/s (QAM16 r=0.75), \
                        7 -> 48 (24) Mbit/s (QAM64 r=0.66), \
                        8 -> 54 (27) Mbit/s (QAM64 r=0.75)")

    parser.add_option("-G", "--txgain", type="int", default=10 , help = "set USRP2 Tx GAIN in [dB] [default=%default]")

    parser.add_option("-n", "--norm", type="eng_float", default=0.3 , help="set gain factor for complex baseband floats [default=%default]")
    parser.add_option("-N", "--Node", type="intx", default=1, help="USRP2 node    [default=%default]")

    parser.add_option("-r", "--repetition", type="int", default=1 , help="set number of frame-copies to send, 0=infinite [default=%default] ")

    parser.add_option("-l", "--log", action="store_true", default=False, help="write debug-output of individual blocks to disk")

    parser.add_option("", "--PHYRXport", type="int", default=8513 , help="Port used for PHY RX [default=%default] ")
    parser.add_option("", "--PHYport", type="int", default=8013 , help="Port used for MAC-->PHY communication [default=%default] ")

    parser.add_option("", "--real-time", action="store_true", default=False,
                      help="Attempt to enable real-time scheduling")

    parser.add_option('-v', "--verbose", action="store_true", default=False,
                        help="Print timing information, [default=%default]")
    
    parser.add_option("", "--nsym", type="int", default=1)
    parser.add_option("", "--modulation", type="string", default="bpsk")
    (options, args) = parser.parse_args()

    # Stream sockets to ensure no packet loss during PHY<-->MAC communication

    server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server.bind((socket.gethostname(), options.PHYport))
    server.listen(1)    # PHY is ready to attend MAC requests

    phy_rx_server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    phy_rx_server.bind((socket.gethostname(), options.PHYRXport))
    phy_rx_server.listen(1)

    
    print '\n',"-------------------------"
    print " PHY (TX) layer running ..."
    print " (Ctrl + C) to exit"
    print "-------------------------",'\n'

    my_mac = mac.usrp2_node(options.Node)   # Assign the MAC address of the node
    rxclient = threading.Thread(target=RX_Client, args=(options,my_mac,phy_rx_server))
    rxclient.start()
    # Initial values of variables used in time measurement

    N_sym_prev=4             # OFDM symbols of the previous packet sent
    N_sensings = 0          # Number of power measurements
    N_packets = 0          # Number of packets sent
    time_socket = 0       # Instant time of socket communication
    t_socket_TOTAL = 0      # Total time of socket communication
    T_sense_USRP2 = 0     # Time of the USRP2 measuring the power
    T_sense_PHY = 0       # Time elapsed in PHY layer due to a carrier sensing request 
    T_transmit_USRP2 = 0  # USRP2 TX time 
    T_configure_USRP2 = 0  # Time due to USRP2 graph management
    T_transmit_PHY = 0    # Time elapsed in PHY layer due to a packet tx request
    
    msgq = gr.msg_queue(1)


    first_time = True               # Is the first time to transmit?
    #fg_cca = sense_block(options)   # Set up the carrier sensing block for the first time.
    rb = receiver_block(options,socket.gethostname(),msgq)
    rb.start()

    while 1:

        socket_client, conn_addr = server.accept()     # Waiting a request from the MAC layer
        arrived_packet=plcp.receive_from_mac(socket_client) # Packet received from MAC
        if (arrived_packet["HEADER"]=="PKT"): 
            t_socket = time.time()-arrived_packet["DATA"]["INFO"]["timestamp"]
            t_socket_TOTAL =t_socket_TOTAL + t_socket   #Update the time used in the socket communication.


            t_sendA = time.time()
            item=arrived_packet["DATA"]  # Copy the packet to send from the MAC message 
            info = item["INFO"]
            N_sym=info["N_sym"] # Read N_sym and add N_sym to options
            mod = info["modulation"]    

            options.nsym = N_sym
            options.modulation=mod


            print "Re-setting USRP2 graph!"
            tb = transmitter_block(options) # If necessary, update the transmit flow-graph depending to the new OFDM parameters
            r = gr.enable_realtime_scheduling()    
            if r != gr.RT_OK:
                print "Warning: failed to enable realtime scheduling" 
            t_2 = time.time()
            tb.start()                  # Send packet procedure starts
            t_sendB= time.time()
            send_pkt(item,eof=False)   # 'item' is a dictionary which contents the packet to transmit and other information 
            send_pkt("",eof=True)
            t_sendC = time.time()     
            tb.wait()                   # Wait until USRP2 finishes the TX-graph 
            t_sendD= time.time()
            if options.verbose: print "Time elapsed on graph configuration (TX Packet) = \t", (t_sendB - t_2)
            T_transmit_USRP2 = T_transmit_USRP2 + t_sendC-t_sendB
            T_configure_USRP2 = T_configure_USRP2 + t_sendD-t_sendA - (t_sendC-t_sendB)
            T_transmit_PHY = T_transmit_PHY + t_sendD-t_sendA 

            # set values for the next packet tx request
            first_time=False
            N_sym_prev = N_sym       # Keep a record of the OFDM symbols' Number
            N_packets += 1


        # Carrier sensing request
        if (arrived_packet["HEADER"]=="CCA"):
            t_senseA = time.time()
            msgq.flush()
            t_reconfig = time.time()-t_senseA
            m=msgq.delete_head()
            t = m.to_string()
            msgdata = struct.unpack('%df' % (int(m.arg2()),), t)
            sensed_power=msgdata[0]
            t_senseB = time.time()

            # PHY responds with the power measured to the MAC
            packet=plcp.create_packet("CCA",sensed_power)
            plcp.send_to_mac(socket_client,packet)
            t_senseC = time.time()
            T_sense_USRP2 = T_sense_USRP2 + (t_senseB - t_senseA)
            T_sense_PHY = T_sense_PHY + (t_senseC - t_senseA)
            N_sensings +=1 
            if options.verbose: print "Time elapsed on graph configuration (Carrier Sensing) = \t", t_reconfig

            
        # MAC requests an incoming packet to the PHY
        if (arrived_packet["HEADER"]=="TAIL"): 
            header_pkt = arrived_packet["DATA"]
            
            len_data = data.length()
            len_ack = ack.length()
            len_rts = rts.length()
            len_cts = cts.length()
            
            if (header_pkt == "DATA") and len_data>0: # There are Data packets?
                data.elements.reverse()
                x=data.read(0)
                phy_pkt = plcp.create_packet("YES",x)
                data.pop()
                data.elements.reverse()
                           
            elif header_pkt == "ACK" and len_ack>0:   # There are ACK packets?
                ack.elements.reverse()
                x=ack.read(0)
                phy_pkt = plcp.create_packet("YES",x)
                ack.pop()
                ack.elements.reverse()
                       
            elif header_pkt == "RTS" and len_rts>0:   # There are RTS packets?
                rts.elements.reverse()
                x=rts.read(0)
                phy_pkt = plcp.create_packet("YES",x)
                rts.pop()
                rts.elements.reverse()           
            elif header_pkt == "CTS" and len_cts>0:   # There are CTS packets?
                cts.elements.reverse()
                x=cts.read(0)
                phy_pkt = plcp.create_packet("YES",x)
                cts.pop()
                cts.elements.reverse()
            else:                                   # There are not packets
                phy_pkt = plcp.create_packet("NO",[])
            plcp.send_to_mac(socket_client,phy_pkt)  # Send the result (PHY packet) to MAC layer
        socket_client.close()

        
        if options.verbose:
            print "===================== Average statistics ===================="
            print "Number of Carrier Sensing Requests = ",N_sensings
            if N_sensings>0:
                print "Time spent by USRP2 on sensing channel = \t",T_sense_USRP2/N_sensings
                print "Time spent by PHY layer on sensing channel = \t",T_sense_PHY/N_sensings
            print "============================================================="
            print "Number of packets transmitted = ",N_packets
            if N_packets>1:
                print "Time spent by USRP2 on sending a packet = \t",T_transmit_USRP2/N_packets 
                print "Time spent by USRP2 on configuring the graphs\t",T_configure_USRP2/N_packets
                print "Time spent by PHY on sending a packet = \t",T_transmit_PHY/N_packets
                print "Time spent on Socket Communication = \t", t_socket_TOTAL/N_packets
            print "============================================================="
            
    rb.wait()