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Support for MIMO AP's

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  • Support for MIMO AP's

    WirelessMon v2 build 1002 does not show proper states for MIMO AP's .. it would be appropriate for WirelessMon to capture stats generated by MIMO AP's and NIC's.

    I and many of my clients happen to use gear that incorporates Airgo Networks True MIMO technology [802.11n] ... I am also aware that currently 5 million + units [Linksys, Netgear, Belkin, Buffalo] incorporating Airgo True MIMO chips sets are out there worldwide.

  • #2
    ...does not show proper states
    Do you mean states or stats? I'm assuming you mean stats.

    Different wireless cards report different collections of statistical information. So not all statistical information is reported for all card types.

    This doesn't (or shouldn't) really effect the core functions of the software. You should still be able to list available access points (from any manufacturer), connect to access points, and get the basic information for the AP. This assumes the manufacturer has released decent device drivers for their hardware.

    Which particular piece of statistical information are you referring to? If you are referring to specific 802.11n information, the according to the IEEE 802.11 Working Group Project Timelines, the 802.11n standard is not due for final approval until July 2007. About a year from now.

    ----
    David

    Comment


    • #3
      Originally posted by passmark View Post
      Do you mean states or stats? I'm assuming you mean stats.

      Which particular piece of statistical information are you referring to? If you are referring to specific 802.11n information, the according to the IEEE 802.11 Working Group Project Timelines, the 802.11n standard is not due for final approval until July 2007. About a year from now.
      Yes I mean stats.

      RSSI fluctuates wildly;
      using a Belkin F5D8010 the RSSI fluctuates between 45 and 100
      using a Linksys WPC54GX4 the RSSI fluctuates between 35 and 47 [RSSI should be much better than the F5D8010]

      Link speed are wrong for both.

      Yes I am aware that the 802.11n standard is not fully baked --- however there is a lot [5+ million] of True MIMO gear out there.

      Comment


      • #4
        My understanding is the MIMO and 802.11n are unrelated technologies and MIMO could be and is used with 802.11b/g.

        MIMO just seems to be the old trick of using more than one antenna to overcome the effects of fading due to physical phenomena such as multipath reception. And thus isn't really related to 802.11n (even if 802.11n does use MIMO in its final standard). The same concept has been in use for many years on other radio systems (like GSM telephone base stations).

        WirelessMon only reports the information is gets from your wireless gear. So if you see fluctuating RSSI levels, then this is probably what is really happening (or the card or it's driver is at fault).

        If you are seeing the wrong speeds reported by WirelessMon for the non standard 802.11n gear, then this might be our fault, or it might be that the manufacturers aren't following the standards from reporting this speed information (the standards being the ones that don't really exist that is ).

        So we will do a new patch release of WirelessMon to dump out the raw data concerning supported data rates from the card. We can then pull apart the raw data to see what the manufacturers report and if we interpret it correctly. We'll put up another post when it is available.

        -----
        David

        Comment


        • #5
          Originally posted by passmark View Post
          My understanding is the MIMO and 802.11n are unrelated technologies and MIMO could be and is used with 802.11b/g.
          Perhaps some education may be of help;

          http://www.airgonetworks.com/mimo/history/

          http://www.airgonetworks.com/mimo/faqs/

          http://80211n.wifinetnews.com/

          Comment


          • #6
            All that is just company hype and a new buzz word for something very old. Multiple antennas for diversity are nothing new. It has been in use since the 1920's. See,
            http://www.radioblvd.com/DiversityDD1.html

            ----
            David

            Comment


            • #7
              Over the past 2 years I have installed 400+ wireless networks all of which are based on True MIMO tech [primarily True MIMO gear from Belkin, Linksys, Netgear and Buffalo]. This stuff works exceptionally well, providing dramatically superior range, throughput at a distance and interference avoidance. I've been working with wireless networks for close to 5 years and I can make the claim that the Airgo Tech is head over heals better than anything anyone else produces bar none. My client satisfaction rating now is 1000% better than it was when I was supporting gear that incorporated tech from Atheros, Broadcom, Marvel etc.

              I do understand your hype comment, but my real world experience with Airgo tech is no BS. Perhaps you should look more closely at what they are doing and the influence they actually have on the emerging 802.11n standards.

              My primary interest, having purchase your product is to have it properly reflect the stats based on the technology in use.

              Comment


              • #8
                Over the past 2 years I have installed 400+ wireless networks all of which are based on True MIMO...
                You're lucky. Draft 802.11n gear has only been available here (in Sydney) for about 2 weeks now.

                We obviously want our software to report the right information, even for non standard gear where possible.

                I suspect the available speeds reporting problem is something we can do something about, but the RSSI level fluctuation is not really in our control.

                We post a new version of the software tomorrow with some additional logging to debug the problem.

                ---
                David

                Comment


                • #9
                  Originally posted by passmark View Post
                  Draft 802.11n gear has only been available here (in Sydney) for about 2 weeks now.
                  True MIMO gear should not be confused with MIMO gear because there IS a world of difference between the 2 ... True MIMO has been available in the USA and Canada as well as the EU for just over 2 years. Airgo has had the market unto itself for 18 months via SOHOWare, Belkin then Linksys followed by Netgear then followed by Buffalo. The competition then entered the market because they were very surprised by Airgo’s True MIMO adoption rates subsequently Draft N followed prematurely.

                  http://wifinetnews.com/archives/006382.html

                  All the Draft N gear produced today - from my field trials and subsequent client rejection - dose not compare to the True MIMO Gen3 gear ... and I suspect that the next draft N v2.0 which does have Airgo's somewhat reserved support will probably compete more favorably with the True MIMO performance capabilities.

                  Based on some of your commentary I surmise that you have not been following industry developments nor are you aware of the MIMO differentiators.

                  Comment


                  • #10
                    There is a new release of WirelessMon available from http://www.passmark.com/ftp/wirelessmon.exe that has some extra debugging information.

                    Could you please run this with the "DEBUGMODE" command line parameter and send us the "WirelessMonTestLog.txt" file that is created. See the "Debug" section of the help file for instructions on how to add a command line parameter.
                    Last edited by Tim (PassMark); 09-01-2006, 01:12 AM.

                    Comment


                    • #11
                      OK Thanks -- I've sent the debug info to help@passmark.com -- FYI, when I run the debug version of WirelessMon you’ve produced for me it causes my WPC54GX4 NIC to lose its Power led and Link led in effect it appears to shutdown the card.

                      Comment


                      • #12
                        It seems that currently for 802.11n there is little support from the Microsoft Windows XP API functions. The debug logs showed no speeds were returned higher than 54 MB/s.

                        This can be seen in dump information returned by the device driver,
                        82848B962430486C00000000000000

                        82 represents the lowest speed available, 1Mbit/sec
                        6C represents the highest speed available, 54Mbit/sec

                        The maximum reportable speed, due to the way the values returned from the device driver are encoded, would be 63.5 MB/s. So it seems XP itself can never report the correct speeds for 802.11n.


                        If the connection is using any sort of non standard speed, it's possible that the current/max speed will reported as a 802.11g standard value, eg 54 MB/s, while the actual data throughput of the connection could be much higher.

                        We don't know why your card wants to power down. Again probably the device drivers are at fault. I would suggest increasing the sample period in WirelessMon to 5 or more seconds. This will put less load on the device driver.

                        With the release of Vista it seems Microsoft are updating the Network Driver Interface Specification (to version 6) to allow for support of 802.11n and future standards.

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