(1G) mobile radio systems. It was developed by Motorola and used in Europe and Asia. ETACS is an extension of
Total Access Communications System (TACS) in which additional radio channels are allocated. ETACS operates in the 900 MHz band with frequency modulation and supports up to 1,000 radio channels with a bandwidth of 25 kHz. ETACS uses Frequency Division Multiple Access (FDMA) as the access method. Communication is bidirectional with Frequency Division Duplex (FDD) via dowlinks and uplinks.