Signal ingress is a problem which has always plagued cable systems. While there has always been potential for problems from VHF television stations, with the modern cable system encountering the UHF television band, the susceptibility of cable systems to ingress interference is increasing. Immunity from ingress problems can only be achieved by maintaining system integrity at levels better than those required by specification.
Interfering signals leak into a cable system not only thru flaws in the cable system but also by way of consumer equipment, cable ready televisions and VCRs. The increase in the number of these devices as well as other factors lead to a need to be able to efficiently diagnose and cure signal ingress problems.