General Packet Radio Service /
Enhanced Data rates for Global Evolution
GSM™ is a circuit-switched network; ideal for the delivery of voice but with limitations for sending data. The standard for GSM was designed to evolve. In 2000 the introduction of General Packet Radio Service (GPRS) added packet-switched functionality and ‘kick started’ the delivery of the Internet on mobile handsets.
GPRS adds packet-switched functionality to GSM networks
Based on specifications in Release 97, GPRS typically reached speeds of 40Kbps in the downlink and 14Kbps in the uplink by aggregating GSM time slots into one bearer. Enhancements in Releases R’98 and R’99 meant that GPRS could theoretically reach downlink speeds of up to 171Kbps.
The next advance in GSM radio access technology was EDGE (Enhanced Data rates for Global Evolution) or Enhanced GRPS.
With a new modulation technique yielding a three-fold increase in bit rate (8PSK replacing GMSK) and new channel coding for spectral efficiency, EDGE was successfully introduced without disrupting the frequency re-use plans of existing GSM deployments.
EDGE… almost 3G
The increase in data speeds to 384Kbps placed EDGE as an early pre-taste of 3G, although it was labeled 2.75G by industry watchers.
Ongoing standards work in 3GPP has delivered EDGE Evolution as part of Release 7, designed to complement high-speed packet access (HSPA).
EDGE Evolution, resulting from the HUGE and RED HOT work items, hasImproved spectral efficiency with reduced latencies down to 100msIncreased throughput speeds to 1.3Mbps in the downlink and 653Kbps in the uplink
GPRS (Release 97) and EDGE (Release 98) are largely specified in the GSM EDGE Radio Access Network (GERAN)group of 3GPP;
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