WIFI Advisor TrueMargin versus Broadband Service Margin

On the Wifi Advisor througput results, what is the difference between the TrueMargin and the Broadband Service Margin?

The WIFI Advisor TrueMargin result is the Actual Throughput minus the througput threshold in Mbps. A positive value not only indicates a pass (versus the throughtput threshold), but also indicates resilency of the wireless link. The larger the TrueMargin value (positive), the more readily the wireless link can withstand changes in the RF environment which impact wireless performance. The throughput threshold is part of the test profile that was selected.  A negative result would indicate that througput was less than the threshold value. The Broadband Service margin is the Actual Throughput minus the Broadband Service Level in Mbps. A positive result  indicates that the wireless link will not be the limiting factor when delivering service to to the wireless endpoint under test. The Broadband Service Level is configured by the tester on the site assessment configuration page. The Broadbad Service level/rate is referring to the Mbps being delivered by the carrier to the facility (i.e. via the DSL line, the fiber feed, etc..)