| 单词 | GPRS (General Packet Radio Service) |
| 释义 | GPRS (General Packet Radio Service) The 2.5G data service enhancement for GSM host networks. GPRS is a packet-switched service that takes advantage of available GSM time slots for data communications and supports both X.25 and TCP/IP packet protocols, with quality of service (QoS) mechanisms. GPRS enables high-speed mobile datacom usage and is considered most useful for bursty data applications such as mobile Internet browsing, e-mail, and various push technologies. Through concatenating as many as eight GSM channels, GPRS yields a theoretical transmission rate as high as 171.2 kbps. GPRS maintains the same Gaussian minimum shift keying (GMSK) modulation scheme used by GSM and provides always-on access. GPRS can run in either symmetric or asymmetric mode, with the speed in either direction sensitive to which of the 12 multislot service classes is selected. The multislot service class determines the number of time slots in each direction, with each time slot supporting a theoretical data rate of 21.4 kbps. The simplest is service class 1, which supports one time slot in each direction.The most capable is service class 12, which supports four time slots in each direction. GPRS specifications were developed in 1997 by the European Telecommunications Standards Institute (ETSI), which subsequently passed that responsibility to the 3rd Generation Partnership Project (3GPP). In Enhanced Data rates for GSM Evolution (EDGE) cellular radio networks, Enhanced GPRS (EGPRS) is a packet-switched transmission mode that supports transmission rates as high as 473.6 kbps. See also 2.5G, 3GPP, always on, channel, concatenation, EDGE, EGPRS, ETSI, GMSK, GSM, modulation, packet switch, protocol, QoS, time slot, and transmission rate. |
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