| 20 | | To provide a concrete example of where this function can be useful, consider the [wiki:802.11/wlan_exp/app_notes/dcf_with_multiple_flows DCF with Multiple Flows Application Note]. This experiment was to show the interaction of DCF behaviors on a few nodes in a very small tabletop topology. In this experiment, the Tx power was intentionally lowered to a minimum value (-10dBm), resulting in received powers between [https://warpproject.org/trac/raw-attachment/wiki/802.11/wlan_exp/app_notes/dcf_with_multiple_flows/figs/v1_0_cs_pow_vs_time.png -75 dBm and -70 dBm] for the duration of the experiment. At the same time, in the active scan figure above, we can see that there are other Wi-Fi channels near the scanner that packets as low as -90 dBm. If we set the minimum detection power to, say, -80dBm, we can keep the PHY from being "distracted" by the low-level interference yet still detect our -75 dBm to -70 dBm traffic with high probability. If we hadn't lowered the Tx power so much, we could potentially raise this threshold much more. |
| | 20 | To provide a concrete example of where this function can be useful, consider the [wiki:802.11/wlan_exp/app_notes/dcf_with_multiple_flows DCF with Multiple Flows Application Note]. This experiment was to show the interaction of DCF behaviors on a few nodes in a very small tabletop topology. In this experiment, the Tx power was intentionally lowered to a minimum value (-10dBm), resulting in received powers between [https://warpproject.org/trac/raw-attachment/wiki/802.11/wlan_exp/app_notes/dcf_with_multiple_flows/figs/v1_0_cs_pow_vs_time.png -75 dBm and -70 dBm] for the duration of the experiment. At the same time, in the active scan figure above, we can see that there are other Wi-Fi channels near the scanner that packets as low as -90 dBm. If we set the minimum detection power to, say, -80dBm, we can keep the PHY from being "distracted" by the low-level interference and yet still be able to detect our -75 dBm to -70 dBm traffic with high probability. If we hadn't lowered the Tx power so much, we could potentially raise this threshold much more. |
