By Ted Hartson, Capital Cities Cable
The implications of signal leakage from a cable television system have changed as dramatically as the cable industry. In the earliest days a cable operator was concerned with radiation simply as it provided a mechanism for unauthorized reception. Today we have regulations which prescribe the conditions by which we may use certain frequencies and require affirmative actions to control system leakage and ongoing record keeping, yet we still tend to refer to our systems by subjectively saying "a good tight system", "a lotta leakage" or so forth.
The Average Leakage Index (ALI) was developed to rank system leakage and access repair effectiveness. ALI serves as a repeatable, objective method which yields an 'executive summary' of leakage within a system.