ExtremeWireless (Identifi)

  • 1.  WDS Link Expected TX/RX rate

    Posted 08-11-2017 06:27
    Hello,

    I have a WDS Wireless Link with 2 AP 3965i-ROW between to building with a distance of 30 Meters.

    Setup: Last Firmware V10.31.04.0009

    Using 802.3at PoE

    Agregation Lan1 and Lan2

    Channel 104 : (5500 , [5520], 5540, 5560)

    Output: Rx Rss -58

    What is the Expected TX/RX rate in this case ?

    https://cloud.kapostcontent.net/pub/7dc1aa5b-da46-4460-a96b-f52e3a7dd0a0/ap-3965-data-sheet.pdf?kui=...



  • 2.  RE: WDS Link Expected TX/RX rate

    Posted 08-11-2017 06:34
    On the field without refections and without dedicated antennas (YAGI or sector) you will get not more than 80-100 MBit/s because of using only one stream. I have connections with sector antenna 60° horizontal/vertical 2 streams with 150-200MBit/s on 50m distance.

    br
    Volker


  • 3.  RE: WDS Link Expected TX/RX rate

    Posted 08-11-2017 06:41
    Could you please post the screenshot from the GUI > Reports > AP > Mesh Statistics.

    And what is the problem ?


  • 4.  RE: WDS Link Expected TX/RX rate

    Posted 08-11-2017 07:11
    Hello,

    This is a 3965i, the antenas are integrated 4x4:4, I think is using 4 Stream .....

    Volker, the real TX/RX is higher.





  • 5.  RE: WDS Link Expected TX/RX rate

    Posted 08-11-2017 07:11
    what's the value in rx/tx rate ?


  • 6.  RE: WDS Link Expected TX/RX rate

    Posted 08-11-2017 07:11
    780/780


  • 7.  RE: WDS Link Expected TX/RX rate

    Posted 08-11-2017 07:15
    So what is the real bandwidth you have ? What do you expect ? do you have a problem ? More info is required !
    If you use a 4x4 AP with integrated antennas without reflections or dedicated antennas you will not have 4 streams p2p active.

    br
    Volker


  • 8.  RE: WDS Link Expected TX/RX rate

    Posted 08-15-2017 13:03
    Why Not 4 streams in WDS Link?

    In the datasheet you have, Data Rates MCS0 to MSC9 with Data Streams 1 to 4 and Channel HT20, HT40, HT80.

    In the Data Sheet, Maximum Throughput 5GHz Radio 1.732 Gbps and Number of spatial streams 4.

    Then you have the Receiver Sensibility.

    The picture I send, you have the Rx Rss of -58.

    What should be the teorical value of RX/TX ?

    In the controller, were can I see the MCS negociated?





    VVeiga



  • 9.  RE: WDS Link Expected TX/RX rate

    Posted 08-15-2017 17:02
    I have run a Lab with this with 2 AP 3965i-ROW , with 5 meters distance.

    The RX TX 1560/780 see new upload file.
    1560 Means that I has using the PoE 802.3at with 4 Data Streams, and the 780 I was using the PoE 802.3af with 2 Data Streams. Look at Page DataSheet page 7, in normal GI. The Rx Rss was -28



  • 10.  RE: WDS Link Expected TX/RX rate

    Posted 08-16-2017 05:46
    OK, I understand.
    You mean the rate the radios negotiate during establishing a connection.
    This static parameter does not describe the real bandwidth on the connection.
    The internal antennas on 3965i are 360 degrees and prepared for site coverage. If you need 2/4 streams in one direction, you need a directed antenna for that.

    Example:
    http://www.mars-antennas.com/ma-wa57-qp4mimo19
    (19°, 4 Streams 45° MIMO)

    So check the real bandwidth wir iperf.

    br
    Volker


  • 11.  RE: WDS Link Expected TX/RX rate

    Posted 08-16-2017 06:21
    Valter

    The rx/tx rate is a moving average of packets rx/tx over the link. MCS is constantly changing depending on what is calculated by a rate selection algorithm, it must choose the best rate based upon the medium quality which, due to the nature of wifi, is not a fixed entity.

    As Volker suggested, using iperf over a clean link (without other user traffic) will allow you to get a better baseline.

    -Gareth



  • 12.  RE: WDS Link Expected TX/RX rate

    Posted 08-16-2017 13:28
    I understand,

    I'm not looking for real values, I mean the rate the radios negotiate during establishing a connection.

    Volker, in your opinion, the AP3965i can work as I see with 4 streams in close distance 5 Meters, but when setup for 30 Meters , only 2 or 3 of the 4 streams can be received by the remote AP ? This is because the internal antena designe location ?

    The system mesh report with:
    Rx Rss -28 with Rx/Tx 1560 / 780 power 12 dB 5 Meters
    Rx Rss -48 with Rx/Tx 877 / 780 power 19 dB 30 Meters
    Rx Rss -58 with Rx/Tx 780 / 780 power 12 dB 30 Meters

    I was changing the power, from 12 to 19 and the Rx Rss has move from -58 to -48 but the Rx/Tx was not significant.

    What is the impact of Rx Rss in the calculated by a rate selection algorithm ?

    VVeiga