Understanding the Concept:
GSM stands for Global System for Mobile Communications. It is a second-generation (2G) cellular network standard developed to replace first-generation (1G) analog networks.
The key features of the GSM standard include:
• It is a fully digital system providing circuit-switched data and voice optimization.
• It employs a combined access mechanism combining both Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA).
• The total system bandwidth is divided into discrete carrier frequency channels (FDMA), and each individual carrier frequency is further subdivided into 8 distinct time slots (TDMA) to support multiple users concurrently.
Step-by-step Option Elimination:
• Option A details: Analog frequency modulation (FM) was the core access scheme utilized by 1G networks like AMPS, whereas GSM uses digital Gaussian Minimum Shift Keying (GMSK).
• Option B details: Multi-carrier transmission (such as OFDM) is characteristic of 4G (LTE) and 5G systems, not 2G GSM networks.
• Option C details: GSM splits bands via FDMA and allocates time intervals via TDMA. This matches the established specification perfectly.
• Option D details: Digitization and multiple access slots provide a massive increase in overall system capacity compared to old analog structures.