For cable TV, the "last mile" to the connection at the home is the bottleneck that prevents higher data rates. The last mile is made up of optical fiber and coaxial cables, amplifiers and electrical/optical converters. This mix of optical fiber and coaxial cables is known as a hybrid fiber coax (HFC) network. One option for cable network providers to maximize both the downstream (DS) and upstream (US) data throughput using the existing cable TV network, but without making expensive changes to the HFC network infrastructure, is to employ the data over cable service interface specification (DOCSIS) 3.1.

This Application Note discusses the fundamental technological advances of DOCSIS 3.1 and presents measurement solutions from Rohde & Schwarz.