High-Speed Circuit-Switched Data (HSCSD)
High-Speed Circuit-Switched Data (HSCSD) is circuit-switched wireless data transmission for mobile users at data rates up to 38.4 Kbps, four times faster than the standard data rates of the Global System for Mobile (GSM) communication standard in 1999. HSCSD is comparable to the speed of many computer modems that communicate with today's fixed telephone networks.
HSCSD is an evolutionary technology on the way to Universal Mobile Telecommunications Service (UMTS).