The upstream triggered spectrum analysis measurement provides a wideband spectrum analyzer function in the CMTS which can be triggered to examine desired upstream transmissions as well as underlying noise/interference during a quiet period. The CMTS provides wideband upstream spectrum analysis capability covering the full upstream spectrum of the cable plant. The CMTS can be made to use 100 kHz or better resolution (bin spacing) in the wideband upstream spectrum measurement. Depending on the particular CMTS implementation, variable upstream spectrum analysis span is possible. It is also possible that the CMTS will provide the collection of time-domain input samples as an alternative to the frequency-domain upstream spectrum results. In pre-DOCSIS-3.1 mode, the CMTS provides the ability to trigger the spectrum sample capture and perform spectrum analysis using the following modes: - Free running - Trigger on minislot count - Trigger on SID (service identifier) - Trigger during quiet period (idle SID) In DOCSIS 3.1 mode, the CMTS provides the ability to trigger spectrum sample capture and perform spectrum analysis using the following modes: - Free running - A specified timestamp value - Minislot Number - A specified MAC address defining a SID, triggering at the beginning of the first minislot granted to that SID - The idle SID, triggering at the beginning of the first minislot granted to that SID - A specified active or quiet probe symbol, triggering at the beginning of the probe symbol