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Cooper Bussmann 945U-E Wireless Ethernet Modem & Device Server User Manual
79
Rev Version 2.14
Example 2
In Figure 79, notice that chart one shows the amount of data being received from Wi-Fi devices, and chart two
shows the amount of other noise that is being received. From this you can see that in the last 60-second period
there was a 20-second interval with around 60-80% channel utilization, in this case from another 900-MHz device.
Figure 79 Custom Survey 2
With this type of outside interference, it is recommended to perform the same test over a longer period in order to
get a clearer indication of channel utilization.
Figure 80 Channel Utilization
4.4 Throughput Test
The performance of a wireless link is best measured in terms of the maximum throughput that can be achieved. The
recommended method of measuring throughput is with the “Iperf” utility. Iperf has client and server functionality,
where the server waits for a client connection. For wireless links, it is recommended that Iperf throughput testing is
performed on point-to-point links, while the remainder of the wireless network is inactive (not sending any data).
The Iperf utility is built into the modems for convenience, and allows measurement of TCP throughput with default
Iperf parameters. The internal Iperf utility always gives a lower result than running Iperf externally because of the
additional load placed on the internal microprocessor. Even so, the throughput results still gives an excellent
indication of link performance as long as you compare the measured result against the expected result in the table.
See “3.9 Advanced Radio Configuration” for details on running this application externally.