DOCSIS 3.1 PHY Layer Measurements
应用文章
DOCSIS 3.1 enables a new generation of cable-based broadband services by increasing data throughput to an unprecedented 10 Gbit/s downstream and 1-2 Gbit/s upstream. This is accomplished by means of a highly bandwidth-efficient new PHY layer, based on orthogonal frequency division multiplex (OFDM) modulation. This new PHY layer is compatible with existing DOCSIS 1.0-3.0 single-carrier QAM (SC-QAM) channels, allowing operators to deploy both within the same system.
As might be expected, the high spectral efficiency of OFDM comes at a cost in complexity. Even engineers with broad experience in the SC-QAM PHY will find the signals challenging to test and verify, with new parameters to be measured, new setups and procedures for doing so, and even new troubleshooting methods needed to diagnose problems.