In a DOCSIS 3.1 CMTS, what is true?

In a DOCSIS 3.1 Cable Modem Termination System (CMTS), the use of Orthogonal Frequency Division Multiplexing (OFDM) and Quadrature Amplitude Modulation (QAM) carriers for downstream transmission is a significant enhancement over previous DOCSIS standards. These technologies allow for much higher data rates and improved spectral efficiency, which are essential for meeting the growing demand for broadband services.

OFDM enables the CMTS to transmit data across multiple carrier frequencies simultaneously, providing a more robust signal that is less susceptible to interference and allows for better use of the available bandwidth. QAM, on the other hand, modulates the data onto the carrier waves, and in DOCSIS 3.1, higher-order QAM (such as 1024 QAM) can be utilized, resulting in greater throughput compared to earlier standards.

This combination of OFDM and QAM is a key feature of DOCSIS 3.1, enabling cable operators to deliver faster internet speeds and serve more users effectively. Other statements in the choices either overstate or mischaracterize the capabilities of the CMTS within the DOCSIS framework, making the first choice the accurate one.