In this three-part series, we will be discussing points one through four. Older digital services like Sega and DMX were only about 1 to 3 MHz wide and resembled a haystack because of their rounded appearance. Most of today's digital signals that are generally flat across the channel bandwidth. This allows it to be multiplexed with other MPEG-2 digital streams and send filler packets when needed. Upstream data signals from the subscribers' equipment are bursty as in Figure 2 .
Measurements are easier to make on a continuous data carrier than on upstream, bursty signals.
Making accurate measurements Measurements should be made with the proper test equipment, such as a thermocouple power meter or test equipment made for an average power measurement. This is critical for set-up to prohibit laser clipping or extreme intermodulation noise. One approach to average power measurements takes small slices of the integrated RF-energy, summing them together to one total power reading as displayed in Figure 3 . Technically, it doesn't matter what the modulation scheme is as long as it is always on. It wouldn't matter.