What are the two most-used PCS coding techniques used to separate different calls?

The two most-used PCS coding techniques to separate different calls are CDMA and GSM. CDMA, which stands for Code Division Multiple Access, is a technology that allows multiple signals to occupy the same transmission channel by assigning unique codes to each communication. This enables simultaneous support of multiple calls without interference, making it highly efficient in optimizing bandwidth.

On the other hand, GSM, or Global System for Mobile Communications, uses time division multiple access (TDMA) principles where users are assigned specific time slots during which they can transmit. GSM is widely used in many mobile networks around the world, particularly in Europe and other regions.

The other choices, while they involve pertinent technologies in telecommunications, do not pertain specifically to the most-used PCS coding techniques. UMTS (Universal Mobile Telecommunications System) and LTE (Long-Term Evolution) are more advanced standards and not typically categorized specifically under PCS coding techniques. TETRA (Terrestrial Trunked Radio) and DMR (Digital Mobile Radio) are communication standards primarily used in specific professional and emergency service scenarios, not for general PCS operations. Lastly, TDMA and FDMA (Frequency Division Multiple Access) are important concepts, but they do not each represent distinct coding techniques used in the modern context of PCS as