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The communication setup between SORA and commercial 11b card

    Question

  • I have met some problems and need experts' suggestion. The communication setup between SORA and commercial 11b card is always fail.

    1. the SDR viutual Ethernet driver is OK

    "Microsoft SDR Ethernet Adatper" is installed correctly, and it can be found in the list of network connection. The LEDs on SORA board work well, when the SDR ethernet adapter is enabled. (D3 blinks and D4 glows sometime)

    2. configuration of commercial 11b card

    Here NETGEAR WG511 V2 (802.11b/g, atheros chip inside) is used.

    Its mode is set to "ad hoc".

    The SSID name is set to "sdr".

     IP address and subnet mask is: 192.168.1.111, 255.255.255.0

     3. configuration of SORA

    IP address and subnet mask is: 192.168.1.222, 255.255.255.0

    set some parameters:

    dot11config -r 1000 //1Mbps

    dot11config -c 2412 //channel 1

    dot11config -R 0x000 //rxgain

    dot11config --rxpa 0x000 //rx PA

    Then I tried to set up the communication as follows. Unfortunately, none of them succeeded.

    (1)Method #1

    Scan the availble wireless network using 11b. No network named "sdr" can be found.

    (2)Method #2

    use the 11b commercial card to ping SORA "ping 192.168.1.222 -t"

    use SORA to ping the 11b card "ping 192.168.1.111.-t"

    No packets can be transmitted successfully in the both directions.

    (3)Method #3

    Let the 11b card broadcast in subnet using "iperf".

    No route can be found.

    (4)Method #4

    Try to adjust other parameters using "dot11config", such as --rxgain_preset0 0x000, --rxgain_preset1 0x000, -r 5500. It didn't work, either.

    What should I do then?

    Here are some other questions.

    (1)Except for "Readme11b.txt", are there any other more detailed user guide? It seems not easy for me to set up the communicaion just according to this document.:)

    (2)"dot11config" is important, but the meaning of some parameters is not clear, such as rxgain_preset0, rxgain_preset1, etc. Are there any other document which decribes them more detailedly? What are their default value? What are their typical value?

    (3)After SDR ethernet adapter installation is completed, and its IP address and subnet mask are set correctly, if "ipconfig" is run, nothing can be got. What's worse, cmd can not work well any more unless the SDR ethernet adapter is stopped.

    Thank you very much.

    PS: I have found a website which introduce how to start to use SORA platform. http://sites.google.com/site/mhfirooz/home/research/sora

    Tuesday, November 09, 2010 3:07 PM

Answers

  • We didn't suffer from this problem because we modified the driver of our wifi card and hard-coded the BSSID. If you can modify the driver of your commercial wifi card, you can also use our solution.

    Thanks

    -Jiansong

    • Marked as answer by Kun TanOwner Monday, December 13, 2010 6:02 PM
    Thursday, November 18, 2010 6:50 AM
    Moderator
  • You may play with the gain value a bit to see if it improves. You may properly set the gain too low or too high.

    Thx,

    - Kun

     

    • Marked as answer by Kun TanOwner Monday, December 13, 2010 6:02 PM
    Wednesday, December 01, 2010 9:37 AM
    Owner

All replies

  • Hi all,
    I have done some other experiments using "iperf". SORA still can not receive the packet sent by 11b commercial card.

    There are one PC installed with SORA, and two laptops (called LT1 and LT2). NETGEAR WG511 V2 (PCMCIA) is insterted into LT1. The in-built wifi card is used in LT2.

    (1) PC
    192.168.1.222, 255,255,255.0
    dot11config -r 1000
    dot11config --rxpa 0x0
    dot11config --rxgain 0x0

    (2) LT1
    192.168.1.111, 255.255.255.0
    SSID "sdr 3 b"
    ad hoc mode
    802.11b
    channel 3

    (3) LT2
    192.168.1.125, 255.255.255.0
    ad hoc mode

    Test #1
    SORA: power off
    LT1: power on
    LT2: power on
      On LT2, select "sdr 3 b" and connect it. It can be found that an ad hoc connection is set up successfully between LT1 and LT2.

    run "iperf -s -u" on LT2
    run "iperf -c 192.168.1.255 -i 1 -t 1000 -u" on LT1

      Then "[1928] local 192.168.1.125 port 5001 connected with 192.168.1.111 port 1566" can be seen on LT2.

      When the transmission of LT1 is stopped, the detailed statistical informantion such as jitter, lost/total datagrams, etc. can be found on LT2.

    Test #2
    SORA: power on
    LT1: power on
    LT2: power off
      Since NETGEAR WG511 V2 can not find SORA, no ad hoc connection can be set up between them.
    run "iperf -s -u" on SORA
    run "iperf -c 192.168.1.255 -i 1 -t 1000 -u" on LT1
      "connect failed: No route to host" can be seen on LT1. Nothing can be found on SORA. Adjusting the data rate using "dot11config -r 5500", "dot11config 11000", and moving SORA's antenna, it didn't work, either.

    Test #3
    SORA: power on
    LT1: power on
    LT2: power on
      As mentioned above, an ad hoc connection is set up between LT1 and LT2.
    run "iperf -s -u" on SORA
    run "iperf -s -u" on LT2
    run "iperf -c 192.168.1.255 -i 1 -t 1000 -u" on LT1
      Then "[1928] local 192.168.1.125 port 5001 connected with 192.168.1.111 port 1514" can be seen on LT2. But nothing can be found on SORA.

    Since this is broadcast, something shoud also be received by SORA.

    Are there any suggestions?

    Thanks.

    Thursday, November 11, 2010 4:35 PM
  • Hi Milapipi,

    You cannot set both rxgain and rxpa to zero, meaning you turn off the Rx channel completely.

    I suggest you set rxgain to something like 0x1200 and remain rxpa to zero. It should work. You can play a little around with your antenna.

    Thanks,

    - Kun

    Monday, November 15, 2010 2:13 PM
    Owner
  • Could you find a way to check your commerical card's BSSID? If the BSSID is different from Sora's, they will not be able to talk with each other.

    Sora's BSSID is hard coded and can be modified in a similar way as MAC address.

    It is possible because the BSSID is random even SSID is determined, and we didn't implement association in the 802.11b sample.

    Tuesday, November 16, 2010 4:28 AM
    Moderator
  • Hi Kun Tan,

       Thank you very for your reply. I will try it again according to your suggestion.

    Milapipi

    Tuesday, November 16, 2010 2:11 PM
  • Hi Jiansong,

      Thank you very much for your reply.

      Unfortunately, only the SSID of my commercial wifi card can be modified. Should the BSSID be set using some dos command?

      What is SORA's BSSID? sdr or "sdr" or sdr 3 b or some others?

    Thanks.

    • Proposed as answer by Tan Zhang Wednesday, March 16, 2011 9:20 PM
    Tuesday, November 16, 2010 2:31 PM
  • BSSID is a 6-byte number, which is in the same format of MAC address. Usually in commercial wifi card, the BSSID is randomly generated from the SSID. You should not be able to modify commercial wifi card's BSSID.

    Since Sora hard-coded the BSSID in the 802.11b sample (You can find the setting in sdr.inf). It can not talk to your commercial wifi card if their BSSID is different.

    The solution for this problem could be:

    1. Find out the BSSID (using some wifi sniffer tool or using Sora) of you commercial wifi card, and modify Sora's BSSID.

    2. Modify Sora's 11b sample code to adaptively change Sora's BSSID.

    Thanks

    -Jiansong

    Thursday, November 18, 2010 6:35 AM
    Moderator
  • We didn't suffer from this problem because we modified the driver of our wifi card and hard-coded the BSSID. If you can modify the driver of your commercial wifi card, you can also use our solution.

    Thanks

    -Jiansong

    • Marked as answer by Kun TanOwner Monday, December 13, 2010 6:02 PM
    Thursday, November 18, 2010 6:50 AM
    Moderator
  • Hi Jiansong,

      Thank you very much for your reply.

      It is good news that the connection finally can be set up by using the first method you suggested.

       But the PER of UDP is as high as 98%. And the connection is not stable, sometimes although the connection is set up, no packet can not be transmitted successfully. And sometimes the connection can not be set up successfully. Would you please give some further suggestion?

      Thanks again. :)

    Monday, November 22, 2010 2:49 PM
  • You may play with the gain value a bit to see if it improves. You may properly set the gain too low or too high.

    Thx,

    - Kun

     

    • Marked as answer by Kun TanOwner Monday, December 13, 2010 6:02 PM
    Wednesday, December 01, 2010 9:37 AM
    Owner
  • Milapipi - great to see you have it working - can you let us know which type of computer / motherboard / chipset you are using?  Thanks.
    Thursday, December 09, 2010 5:07 PM
  • Tan Kun,

        Thank you very much for your suggestion.

        Now the test results are good. The rxgain was not changed. I just used unicast instead of broadcast. That is using "iperf -c 192.168.1.222 -i 1 -t 100 -u" instead of "iperf -c 192.168.1.255 -i 1 -t 100 -u". The detailed test results(packet loss ratio) are as follows. At each rate, the test is repeated three times. The antenna of SORA is very close to the commercial card.

    (1)1Mbps (dot11config -r 1000), dot11config --rxpa 0x00, dot11config --rxgain 0x1200

    0%,  0%,  0%

    (2)5.5Mbps (dot11config -r 5500), dot11config --rxpa 0x00, dot11config --rxgain 0x1200

    0%,  0%,  0.22%

    (3)11Mbps (dot11config -r 11000), dot11config --rxpa 0x00, dot11config --rxgain 0x1200

    0%,  0.85%,  0.086%

      Sora used as transmitter is also tested.  No transmitted parameters of SORA are modified. And the test results are pretty good. PER is always zero.

     Another test was also taken.  One commercial card (LT1) transmits packets  and the other one (LT2) receives them.  They are located very clo se to each other. The test is repeated five times. And the PER is always zero, too.

      According to the test results, sometimes SORA's performance is not as good as commercial card when SORA is used as receiver. What is the possible reason?

      Thanks.

    Sunday, December 12, 2010 2:29 PM
  • Hi Milapipi,

    Sounds your test went well.

    To your last question, I don't have exactly answer. I'd say Sora sample for 802.11 can only be treated as an example implementation. We haven't implemented all features that a commerical nic should have, for example the automatic gain control. The RF front-end may not be as good as a commerical one, though, adding additional noise. And of course, the demodulation algorithms can be further tuned for the best performance.

    Nevertheless, our goal is to provide a good enough platform for wireless research.

    Thanks,

    - Kun

    Monday, December 13, 2010 12:45 AM
    Owner
  • Hi xwy78,

       The PC I am using is LENOVO M8200t. But the OS is XP, not Windows 7. :)

     http://appserver.lenovo.com.cn/Lenovo_Product_Detail.aspx?gdsid=A0200011195

    Monday, December 13, 2010 12:59 PM
  • Hi Tan Kun,

       Thank you much for your reply. 

     

    Hi Tan Kun and Jiansong,

       I think my problems about the connetion setup between SORA and wifi commercial card have been resolved successfully. Thanks again for your good suggestions.

    Monday, December 13, 2010 1:09 PM
  • Hi,

    We have been trying to get the communication between laptop with inbuilt wi-fi card  and SORA kit. We have followed all the steps mentioned above but still unable to get the communication successful.

     

    We did the following steps:

    1. We created a adhoc network with ssid "sdr".

    2. We set the card to be used in 802.11b mode (as it is a b/g card) from device manager.

    3. Since we can't change the BSSID of the wif-fi card we used "netsh wlan show networks MODE=BSSID" to know the BSSID of the ad-hoc network created.

    4. We then modified the BSSID to the same BSSID as the commercial card and updated the drivers. But still SORA is not able to connect to the adhoc network created on the laptop.

    Do we have to anything else also to get the connection. Is the connection made automatically or we have to manually do something to make it connect to the adhoc network created on laptop.

     

     

    PS: What changes do we have to make in sdr.inf file to run the 802.11 b code. We just made the following changes:

    [SDRMiniport.Reg]

    HKR,    ,                         NetworkAddress,      0, "02-50-F2-00-00-01"

    HKR,     ,                         BSSID,               0, "02 26 C7 05 55 10" (This is the BSSID of the adhoc network created on laptop)

    HKR,     ,                         ModMode,             0, "802.11b"

    ;HKR,     ,                         11ADataRate,         0, "6" (commented out)

     

    Can you give any insights where are we doing something wrong?

     

    Thursday, December 16, 2010 11:39 PM
  • Jitin, you only need change "802.11a" to "802.11b", and BSSID. don't need to comment other key out.

    You might need try to adjust the rxgain to make it work.

    Friday, December 17, 2010 9:09 AM
    Moderator
  • I have tried adjusting rxgain with a large range of values, but still no success. I am unable to figure out what is the problem.

    I have few more doubts;

    1. If we don't use any antennas with the USRP radio board with the SORA kit, then what is the communication range we can get with the board. (I am asking this because we didn't get any antennas with the kit so we are testing without antennas and some other antennas we already have) So, I was doubting if the problem is because of this.

    2. I also want to try out hardcoding BSSID on my laptop wireless drivers. Can you give me any idea if we need to change lot of changes in wireless network driver code to hardcode BSSID? Any pointers to how can it be done? I am using atheros card in linux with ath5k drivers.I guess you also have done it on same drivers.

     

    Thanks,

    Jitin

    Sunday, December 19, 2010 5:11 AM
  • hi, Sen Xiang

          Does it mean to what we should do is only changing the BSSID in the "sdr.inf" file and adjusting the rxgain to make it work?

         thx,

        -dimly

    Thursday, December 30, 2010 3:41 AM
  • Hi Jitin Bajaj,

     

       Sorry, I haven't visited the forum for a long time.

     

       Basing on my test, there is one point that needs attention. SORA must be in association state before it begin to communicate with the target station. Only the association is set up successfully, the BSSID can be fixed. And the BSSID can be seen in the associated wifi card's configuration window. That is why two laptops and one desktop computer are used in my test.

     

       Assuming Laptop1 is my target station. Laptop 2 is just used to set up the association.

     

       (1) Laptop 2 is associated with SORA. And the BSSID can be got on Laptop 2. BSSID will be changed if the association is set up again. If you can not find the BSSID, you may try some kind of wifi sniffer tool.

       (2) Changing SORA's BSSID according to the one got in step 1.

       (3) Using "dot11config" to config Sora's RX parameter. For example,  dot11config -r 1000, dot11config --rxpa 0x00, dot11config --rxgain 0x1200

       (4) You should download the "iperf.exe". Running "iperf -s -u" on Laptop 1, and running "iperf -c 192.168.1.222 -i 1 -t 100 -u" on SORA. If it works, some information can be seen in the iperf window.

        Hope you can finally succeed. Good luck.:)

    Tuesday, January 18, 2011 2:29 PM
  • Hello,Milapipi,

    I am testing the communication between the SORA kit and the commercial wifi card. Now I have some question:

    1)You mentioned that we need Laptop2 associated with SORA. But as I know, the SORA didn't provide the association function.

    So I want to ask how to associate the SORA with laptop.

    2)Whether we use the specific commercial card, eg. Atheros ? Could you give me some advice about the commercial card's configuration?

    Thanks a lot.

    Wednesday, April 06, 2011 8:02 AM