What characterizes a constant bit rate (CBR) telephone system?

A constant bit rate (CBR) telephone system is characterized by its ability to transmit data at a consistent rate regardless of the variability of the content being sent. The defining aspect of such a system is that it maintains a steady bandwidth and fixed transmission speed, making it well-suited for applications requiring a continuous stream of data, such as voice communications.

In the context of this question, converting analog audio signals into Digital Signal (DSO) circuits for switching is central to how traditional telephony operates. This conversion allows for the digitization of voice signals, which can then be efficiently managed by enabling constant transmission rates. By utilizing DSO circuits, the system ensures that voice data is encoded in a way that adheres to CBR principles, maintaining the integrity and timing of voice calls.

The other options do not reflect the central aspect of CBR telephone systems. While packet-switching technology is influential in modern communication systems, CBR specifically emphasizes a constant stream of data rather than packets that can vary in size and timing. Sole reliance on digital signal processing is not characteristic of all CBR systems, as many also utilize analog components, especially in traditional telephone networks. Additionally, stating that a CBR system only operates under high network load does not accurately capture