Что (кто) такое Switched Multimegabit Data Service - определение
DATA TRANSMISSION STANDARD FOR MOBILE PHONES
High-Speed Circuit-Switched Data; HSCSD; High Speed Circuit Switched Data; High-speed circuit-switched data; Cellular Switched Data; Circuit-Switched-Data; Circuit-Switched Data; GSM CSD; CDMA Circuit Switched Data
![Few devices support HSCSD – the Nokia CardPhone 2.0 [[PC Card]] is one of them.](https://commons.wikimedia.org/wiki/Special:FilePath/Nokia CardPhone 2.0.jpg?width=200 "Few devices support HSCSD – the Nokia CardPhone 2.0 [[PC Card]] is one of them.")
Switched Multimegabit Data Service
<networking> (SMDS) An emerging high-speed datagram-based
public data network service developed by Bellcore and
expected to be widely used by telephone companies as the basis
for their data networks.
See also Metropolitan Area Network.
(1997-01-31)
HSCSD
High Speed Circuit Switched Data (Reference: GSM, mobile-systems)
Википедия
Circuit Switched Data
In communications, Circuit Switched Data (CSD) is the original form of data transmission developed for the time-division multiple access (TDMA)-based mobile phone systems like Global System for Mobile Communications (GSM). After 2010 many telecommunication carriers dropped support for CSD, and CSD has been superseded by GPRS and EDGE (E-GPRS).
