Spawn

Hi all, sorry if I'll have English mistakes..... I have a little problem. I want to measure the output power of Cable Modem TDMA burst. Can anyone advise me how to perform this test? My solution so far is quite dubious - The Cable Model output is connected to Spectrum Analayzer input, the Spectrum Analayzer's video out is connected to scope for Trigger. A Vector Analyzer uses's this trigger to measure the burst.... Is there any other way for this test?