When engaging in voice communications via an INMARSAT-B terminal, what techniques are used?

The use of CODECs to digitize the voice signal is essential when engaging in voice communications via an INMARSAT-B terminal. INMARSAT-B systems are designed to handle voice communications over satellite links, which necessitates the conversion of analog voice signals into digital format. This conversion is accomplished through the use of CODECs (coder-decoders), which perform the necessary digitization and compression to efficiently transmit the audio data over the satellite network.

The digitalization of the voice signal offers several advantages, such as improved quality, reduced bandwidth usage, and the ability to transmit multiple calls over the same channel. By employing digital encoding techniques, INMARSAT-B can optimize the use of satellite resources and maintain effective communication, especially in remote or challenging environments where analog methods might not be suitable.

In contrast, other techniques like direct current modulation, analog transmission methods, and waveform modulation techniques do not align with the operational principles of an INMARSAT-B terminal, as they either pertain to older telecommunication technologies or do not effectively handle the requirements of modern voice communication over satellites.