Changes between Version 39 and Version 40 of 802.11/wlan_exp/app_notes/dcf_with_multiple_flows


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Timestamp:
Apr 21, 2014, 9:15:36 PM (10 years ago)
Author:
murphpo
Comment:

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  • 802.11/wlan_exp/app_notes/dcf_with_multiple_flows

    v39 v40  
    11= Investigating Physical Carrier Sensing in the DCF with Multiple Traffic Flows =
    22
    3 The purpose of the 802.11 Distributed Coordination Function (DCF) is to allow multiple flows of traffic to contend for a shared wireless medium. In this application note, we investigate how the 802.11 Reference Design behaves when subjected to multiple traffic flows. This note provides a case study on how the WLAN Experiment Framework can be used to control and analyze the performance of the 802.11 Reference Design.
     3The purpose of the 802.11 Distributed Coordination Function (DCF) is to allow multiple traffic flows to contend for a shared wireless medium. In this application note we investigate how the Mango 802.11 Reference Design behaves when subjected to multiple traffic flows. This note provides a case study on how the design's experiments framework can be used to control and analyze the performance of 802.11 Reference Design nodes.
    44
    5 == Requirements ==
    6 
    7 To run the code provided in this note, the following requirements must be met:
    8 
    9  * 3 WARP v3 kits
    10  * [wiki:../../../Changelog#a0.91BetaRelease 802.11 Reference Design v.91 Beta]
    115
    126=== Experimental Setup ===
    137
     8The experiments described below used 3 Mango WARP v3 kits, each running the [wiki:../../../Changelog#a0.91BetaRelease 802.11 Reference Design (version v0.91)].
     9
     10Each node's RF interface was connected to an antenna with a toroidal pattern with 5dBi gain in all horizontal directions ([http://www.l-com.com/wireless-antenna-24-ghz-7-dbi-desktop-omni-antenna-4ft-sma-male-connector L-Com RE07U-SM]).
     11
     12The nodes were indoors in a small office environment with limited mobility.
    1413
    1514||  [[Image(wiki:802.11/wlan_exp/app_notes/dcf_with_multiple_flows/figs:experimental_setup_photo.jpg, width=600)]]  ||
    … …  
    1716
    1817We use 4 traffic flows in our experiments:
    19  * '''Flow 1:''' Backlogged constant bit-rate (CBR) traffic from AP to STA_1
    20  * '''Flow 2:''' Backlogged CBR traffic from AP to STA_2
    21  * '''Flow 3:''' Backlogged CBR traffic from STA_1 to AP
    22  * '''Flow 4:''' Backlogged CBR traffic from STA_2 to AP
     18 * '''Flow 1:''' Backlogged traffic from AP to STA_1
     19 * '''Flow 2:''' Backlogged traffic from AP to STA_2
     20 * '''Flow 3:''' Backlogged traffic from STA_1 to AP
     21 * '''Flow 4:''' Backlogged traffic from STA_2 to AP
    2322
    2423 [[Image(wiki:802.11/wlan_exp/app_notes/dcf_with_multiple_flows/figs:experimental_flows.png, width=600)]]
    2524
    26 The colors in the figure above correspond to the colors used in per-flow plots below.
     25The colors in the figure above are used throughout this app note to denote each flow.
    2726
    28 == Experiment 1: Enabled Physical Carrier Sensing ==
     27== Experiment 1: Physical Carrier Sensing Enabled ==
     28
     29The first experiment enables physical carrier sensing at all 3 nodes. This experiment highlights the expected behavior of the DCF in an environment with heavy contention for the medium.
    2930
    3031=== Experiment Details ===
    3132 * Packet Length: 1400 byte payloads (1428 bytes OTA with MAC header and FCS)
    32  * PHY Rate: 18 Mbps
     33 * PHY Rate: 18 Mbps (QPSK, code rate 3/4)
    3334 * Tx Power: -5 dBm
    3435 * Trial Duration: 300 seconds
    35  * Channel 1
    36  * Physical Carrier Sensing Threshold: 250/1023
    37 
     36 * 2.4GHz channel 1
     37 * Physical Carrier Sensing Threshold: 250/1023 (approximately -70 dBm)
    3838
    3939=== Results ===