Dell W-7030 AOS 6.4.x User Guide - Page 807

Parameter Channel Range Center Frequency Span Show Description If you selected Channel in the X-Axis parameter, you must also specify a channel range to determine which channels appear in the x-axis of this chart. Click the first drop-down list to select the lowest channel in the range, then click the second drop-down list to select the highest channel to appear in the chart. NOTE: This parameter is not configurable for graphs created by hybrid APs. If you selected Frequency in the X-Axis parameter, enter the frequency, in MHz, that you want to appear in the center of the x-axis of this chart. If you selected Frequency in the X-Axis parameter, specify the size of the range of frequencies around the selected center frequency. If you set a frequency span of 100 MHz, for example, the chart shows the FFT duty cycle for a range of frequencies from 50MHz lower to 50 MHz higher than the selected center. Select a checkbox to display that information on the FFT Duty Cycle chart. l Duty Cycle: The percentage of duty cycle the channel or frequency was actively used. l Max Hold: The maximum recorded percentage of active duty cycles for the channel frequency since the chart was last reset. To clear this setting, click the down arrow at the end of the title bar for this graph and select Reset MaxHold. l Max of last sweeps: This chart shows the maximum percentage of active duty cycles for the channel of frequency recorded during the last 10 sweeps, by default. To change the number of sweeps used to determine this value, enter a number from 2 to 20, inclusive. To clear this setting, click the down arrow at the end of the title bar for this graph and select Reset MaxNSweep. Interference Power The Interference Power chart displays various power levels of interest, including the Wi-Fi AP with maximum signal strength, noise, and interferer types with maximum signal strength. The ACI displayed in the Interference Power Chart is the ACI power level based on the signal strength(s) of the Wi-Fi APs on adjacent channels. A higher ACI value in Interference Power Chart does not necessarily mean higher interference, because the AP that is contributing to the maximum ACI may or may not be very actively transmitting data to other clients at all times. The ACI power levels are derived from the signal strength of the beacons. This chart displays the noise floor of each selected channel in dBm. The noise floor of a channel depends on the noise figure of the RF components used in the radio, temperature, presence of certain types of interferers or noise, and the width of the channel. For example, in a clean RF environment, a 20 MHz channel has a noise floor around -95 dBm and a 40 MHz channel has a noise floor around -92 dBm. Certain types of fixedfrequency continuous transmitters such as video bridges, fixed-frequency phones, and wireless cameras typically elevate the noise floor seen by the spectrum monitor. Other interferers such as frequency-hopping phones, Bluetooth, and Xbox may not affect the noise floor of the radio. A Wi-Fi radio can only reliably decode Wi-Fi signals that are a certain dB above the noise floor. Therefore estimating and understanding the actual noise floor of the radio is critical to understanding the reliability of the RF environment. The chart also includes information about the AP on each channel with the highest power level. You can hover your mouse over an AP on the chart to view the AP's name, SSID, and current power level. The example below shows that the AP with the maximum power on channel 157 has the SSID qa-ss, and a power level of -55dBm. 807 | Spectrum Analysis Dell Networking W-Series ArubaOS 6.4.x | User Guide