Types of Mobile Network by Multiple‐Access Scheme

Mobile radio networks can be distinguished by operation modes, services and applications and multiple‐access schemes. A major influence on the development of commercial radio communication systems is the scarcity of radio spectrum available for utilization. An apparent objective is to assign the maximum number of users to an available radio frequency segment. This objective is achieved by using various multiple‐access schemes. This chapter lists the four most common technologies: frequency division multiple access (FDMA), time‐division multiple access (TDMA), code division multiple access (CDMA) and orthogonal frequency division multiple access (OFDMA). It illustrates the principles of multiple‐access schemes used in mobile communications. The chapter looks at the frequency‐time‐domain channel structure when considering the Global System Mobile (GSM) based on combined FDMA/TDMA multiple‐access technology. In CDMA, all users occupy the same frequency channel and can transmit/receive at the same time.