Changes between Version 35 and Version 36 of 802.11/wlan_exp/app_notes/dcf_with_multiple_flows


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Timestamp:
Apr 21, 2014, 5:24:38 PM (10 years ago)
Author:
chunter
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  • 802.11/wlan_exp/app_notes/dcf_with_multiple_flows

    v35 v36  
    1212=== Experimental Setup ===
    1313
    14 In order to isolate inherent DCF behaviors (our measurement target) from fading and interference (variables we can't control), we run the first set of experiments using wired connections between the RF interfaces of the WARP v3 nodes.
    1514
    16 ||  [[Image(wiki:802.11/wlan_exp/app_notes/dcf_with_multiple_flows/figs:experimental_setup_photo.jpg, width=400)]]  ||
     15||  [[Image(wiki:802.11/wlan_exp/app_notes/dcf_with_multiple_flows/figs:experimental_setup_photo.jpg, width=600)]]  ||
    1716 ||  '''Experimental Setup'''  ||
    18 
    19 The above figure shows the experimental setup. We use an [http://www.minicircuits.com/pdfs/ZAPD-2-272+.pdf Mini-Circuits Power Splitter/Combiner] and discrete attenuators to establish a "shared" medium among the three RF interfaces. The path loss between each pair of nodes is controlled by varying the attenuation values. The inherent path loss through the power splitter/combiner is ~3dB for paths S-1 and S-2 and ~28dB for path 1-2.
    2017
    2118We use 4 traffic flows in our experiments:
    … …  
    2522 * '''Flow 4:''' Backlogged CBR traffic from STA_2 to AP
    2623
    27  [[Image(wiki:802.11/wlan_exp/app_notes/dcf_with_multiple_flows/figs:experimental_flows.png, width=400)]]
     24 [[Image(wiki:802.11/wlan_exp/app_notes/dcf_with_multiple_flows/figs:experimental_flows.png, width=600)]]
    2825
    2926The colors in the figure above correspond to the colors used in per-flow plots below.
    3027
    31 == Experiment 1: Equilateral ==
    32 
    33 In this first experiment, we aim to see how the 802.11 Reference Design behaves when all nodes are "fully connected" with nearly-matched path losses between every node. This mimics topology of three nodes at the vertices of an equilateral triangle.
     28== Experiment 1: Enable Physical Carrier Sensing ==
    3429
    3530=== Experiment Details ===
    36  * Attenuation 1: 35dB
    37  * Attenuation 2: 15dB
    38  * Attenuation 3: 15dB
    3931 * Packet Length: 1400 byte payloads (1428 bytes OTA with MAC header and FCS)
    4032 * PHY Rate: 18 Mbps
    41  * Tx Power: 10 dBm
     33 * Tx Power: -5 dBm
    4234 * Trial Duration: 300 seconds
    4335 * Channel 1
     36 * Physical Carrier Sensing Threshold: 250/1023
    4437
    4538
    46 === Experiment Results ===
     39=== Results ===
    4740
     41
     42||  [[Image(wiki:802.11/wlan_exp/app_notes/dcf_with_multiple_flows/figs:no_cs_xput_vs_time.png, width=400)]]  || [[Image(wiki:802.11/wlan_exp/app_notes/dcf_with_multiple_flows/figs:no_cs_xput_hist.png, width=400)]]  ||
     43 ||  '''Throughput vs. Time'''  || '''Throughput Histogram'''  ||
    4844
    4945