CLEARPath™ CPM-2 Module

Ingress Detection
Electroline's CPM-2 is a second-generation return path switch that locates the source of ingress in a hybrid fiber/coax (HFC) network. To determine the source of ingress, the CPM-2 selectively switches a 6 dB pad into the return path. In locations where ingress is severe, the CPM-2 can switch off the entire 5-42 MHz band until the ingress source is repaired.

The CPM-2 utilizes a smooth switching transition that will not disrupt high-speed data services. The effect of the return path switching is monitored and displayed on a spectrum analyzer at the headend. If the monitored ingress is reduced by 6 dB (or disappears when switched off), then the source of the ingress must be further downstream from that location. It is then a matter of switching the CPM-2 units located deeper in the cable plant (the distribution leg) in order to identify the point of origin of the ingress. Once the ingress source is located within a specific distribution area, technicians are dispatched to that site.