3G Wireless Demystified
Telecom experts provide the big picture of 3rd Generation universal mobile telecommunication systems (UMTS).
TABLE OF CONTENTS 3G Wireless Demystified
General Packet Radio Service (GPRS)
General packet radio service provides high-speed packet data service on a GSM network. GPRS is part of the phase 2+ specifications for GSM, now under control of the 3rd generation partnership project (3GPP). The GPRS system dynamically assigns time slots on a GSM radio channels to allow quick and efficient transfer small packets of data. GPRS allows point-to-point and point-to-multipoint packet data transmission. GPRS provides a maximum data transmission capacity of 171.2 kbps.
System Overview
To use the radio link most effectively for bursty data transmission, the GPRS system dynamically assigns a particular time slot on a particular carrier frequency to a particular user who has packets to transmit in the appropriate direction.
When that user finishes sending packets, the GPRS system can immediately assign the channel to another packet user. This overall process is much more efficient than a circuit switched connection that wastes the channel capacity by leaving it assigned to the subscriber even when there is no data to transmit at certain times.
Figure 4.14 shows some of the key GPRS network elements that include a gateway GPRS support node (GGSN), a serving GPRS support node (SGSN) and a GPRS backbone network. The SGSN registers and maintains a list of active packet data radios in its network and coordinates the packet transfer between the mobile radios, local GPRS network, and the GPRS (may be a mobile data device).
Figure 4.14. General Packet Radio Service (GPRS) System.
The GPRS system is packet...
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