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Re: [Discuss-gnuradio] [USRP2] - BBN 802.11b project - transmitter and r
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From: |
Juan Ramon Gutierrez Agullo |
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Subject: |
Re: [Discuss-gnuradio] [USRP2] - BBN 802.11b project - transmitter and receiver issue |
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Date: |
Mon, 21 Dec 2009 13:52:11 +0100 |
I tried TX and RX at 2.437G and doesn't work. I've tested on another
802.11 channels but I obtain the same result. Also I've tried transmit
at 2 Mbps but it's worthless (RX still receives a bad header).
I'm using the cgran BBN code (usrp2_version), is the correct one?
I'll continue testing the code, thank you for your help.
--
Juan Ramon Gutierrez Agullo <address@hidden>
El vie, 18-12-2009 a las 12:54 -0500, George Nychis escribió:
> Try both your TX and RX at 2.437G and see if you just get something
> before you try a frequency to avoid 802.11
>
> - George
>
>
> On Fri, Dec 18, 2009 at 6:30 AM, Juan Ramon Gutierrez Agullo
> <address@hidden> wrote:
> When I run the command ./bbn_80211b_rx.py -d 4 --barker -f
> 2.437G, I get
> good packets. I'm testing on a lab where are wifi (802.11b)
> transmissions and the bbn_80211b_rx.py works fine.
>
> ===========================
> Execution example (only rx)
> ===========================
> Recieved header!
> signal: 0x0A
> service: 0x04
> length: 0x06E0
> crc: 0xCFBE
> Calculated crc: 0xCFBE
> Packet Length: 220 bytes.
> 128 0 0 0 255 255 255 255 255 255 0 28 240 95 201 7 0 28 240
> 95 201 7 96 183 128 1 239 194 221 1 0 0 100 0 49 4 0 6 108 97
> 98 116 115 99 1 4 130 132 139 150 3 1 1 5 4 0 1 0 0 42 1 2 50
> 8 12 18 24 36 48 72 96 108 221 7 0 80 242 2 0 1 0 221 30 0 144
> 76 51 76 16 31 255 255 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
> 0 221 26 0 144 76 52 1 0 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
> 0 45 26 108 16 31 255 255 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0
> 0 0 0 61 22 1 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 221 5
> 0 80 242 5 2 221 14 0 80 242 4 16 74 0 1 16 16 68 0 1 2 177 25
> 13 65
> PKT: len=216, rssi=-96, src=00:1c:f0:5f:C9:07, time=93808,
> rate=1 Mbps
> Payload:
> �###������##�_�###�_�#`��#���###d#1###labtsc##����#########*##2#
>
> Recieved (short) header!
> signal: 0x6E
> service: 0x84
> length: 0x000B
> crc: 0x405D
> Calculated crc: 0x405D
> Unsupported Short Pramble Rate = 11.0 Mbps
>
> Recieved header!
> signal: 0x0A
> service: 0x04
> length: 0x0070
> crc: 0xB3D5
> Calculated crc: 0xB3D5
> Packet Length: 14 bytes.
> 212 0 0 0 0 28 191 144 4 221 151 176 108 52
> PKT: len=10, rssi=-96, src=UNKNOWN, time=1328152, rate=1 Mbps
> Payload: �#####��#�
>
> (...)
>
> After this, I try the rx with the tx in a frequency without
> other 802.11b frames (from wifi-lab) and the output is:
>
> ===========================
> Execution example (tx & rx)
> ===========================
>
> Recieved (short) header!
> signal: 0xE6
> service: 0xDA
> length: 0xC560
> crc: 0x92B7
> Calculated crc: 0x0B4F
> *** BAD CRC ***
>
> Recieved (short) header!
>
> signal: 0xE5
> service: 0xF1
> length: 0x2795
> crc: 0x368B
> Calculated crc: 0xC2B3
> *** BAD CRC ***
>
> Recieved (short) header!
>
> signal: 0x6B
> service: 0x0A
> length: 0x97D5
> crc: 0xED62
> Calculated crc: 0x17E0
> *** BAD CRC ***
>
> Recieved (short) header!
>
> signal: 0xE9
> service: 0x03
> length: 0xD191
> crc: 0xEBB5
> Calculated crc: 0x99D2
> *** BAD CRC ***
>
> I'm trying to understand (line-by-line) the transmitter
> behaviour, and I
> think that the mistake is when TX "creates" the 802.11b
> packet, because
> RX is unable to read successfully the header fields and
> obtains a bad
> CRC.
> Maybe I'm using wrong the TX. Is it normal?
>
> Thank you for your help
>
>
> --
> Juan Ramon Gutierrez Agullo <address@hidden>
>
>
>
> El jue, 17-12-2009 a las 12:23 -0500, George Nychis escribió:
>
> > Run your receiver like this, only, and don't turn your
> transmitter on:
> > ./bbn_80211b_rx.py -d 4 --barker -f 2.437G
> >
> > Do you get any good packets?
> >
> > On Thu, Dec 17, 2009 at 10:37 AM, Juan Ramon Gutierrez
> Agullo
> > <address@hidden> wrote:
> > Hello everyone,
> >
> > I was running the examples proposed
> ( bbn_80211b_tx.py &
> > bbn_80211b_rx.py ) and I noticed that something was
> wrong.
> > First of all, I've installed succesfully GNU Radio
> toolkit and
> > BBN project.
> > The issue is:
> > I run bbn_80211b_tx.py (transmitter) with an USRP2
> in a
> > computer with random arguments (f=2.4GHz, ...) and
> at the same
> > time I run bbn_80211b_rx.py (receiver) with another
> USRP2 in
> > another computer with random arguments too. And the
> result
> > is....
> >
> > =========
> > TRANSMITTER
> > =========
> >
> > $ ./bbn_80211b_tx.py
> > >>> gr_fir_ccf: using SSE
> >
> > Network interface: eth0
> > USRP2 address: xx:xx:xx:xx:xx:xx (MAC hidden)
> > Using TX d'board id 0x0060
> > Tx baseband frequency: 2.4G
> > Tx DUC frequency: 0
> > Tx residual frequency: 0
> > Tx interpolation rate: 4
> > Samples per data bit: 25
> >
> >
> > DATA:
> >
> > Hello world
> >
> > Four score ...
> > [11 textlines]
> > ... shall not perish from the earth.
> >
> >
> > Sending pkt 0
> > Sending pkt 1
> > Sending pkt 2
> > Sending pkt 3
> > Sending pkt 4
> > Sending pkt 5
> > Sending pkt 6
> > Sending pkt 7
> > Sending pkt 8
> > Sending pkt 9
> >
> > ======
> > RECEIVER
> > ======
> > ./bbn_80211b_rx.py
> > >>> gr_fir_ccf: using SSE
> > Recieved (short) header!
> > signal: 0x50
> > service: 0xCD
> > length: 0x3ADD
> > crc: 0x7B3B
> > Calculated crc: 0xADB7
> > *** BAD CRC ***
> >
> > Recieved header!
> > signal: 0x1B
> > service: 0x26
> > length: 0xCB69
> > crc: 0xD9EA
> > Calculated crc: 0xE01A
> > *** BAD CRC ***
> >
> > Recieved (short) header!
> > signal: 0x00
> > service: 0xA5
> > length: 0x111D
> > crc: 0xCA9E
> > Calculated crc: 0xEE55
> > *** BAD CRC ***
> >
> > (... and more) still receiving frames when the
> transmitter
> > isn't running.
> >
> > I've been reading the code of the tx and don't see
> where I
> > could test the value of the fields (signal, service,
> length,
> > crc) have each packet.
> > Am I running propertly the examples? I don't have
> too much
> > experience with this code.
> > Why rx calculates always a bad CRC?
> >
> > Thank you very much for your help,
> >
> >
> > --
> > Juan Ramon Gutierrez Agullo <address@hidden>
> >
> > _______________________________________________
> > Discuss-gnuradio mailing list
> > address@hidden
> >
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> >
> >
>
>
>