GPRS (General
Packet Radio) Service and is a second generation (2G) and third generation
(3G)--or sometimes referred to as in-between both generations, 2.5G--wireless
data service that extends GSM data capabilities for Internet access, multimedia
messaging services, and early mobile Internet applications via the wireless
application protocol (WAP), as well as other wireless data services.
GPRS
usage is typically charged based on volume of data. This contrasts with circuit
switching data, which is typically billed per minute of connection time,
regardless of whether or not the user transfers data during that period.
GPRS
is a best-effort service, implying variable throughput and latency that depend
on the number of other users sharing the service concurrently, as opposed to
circuit switching, where a certain quality of service is guaranteed during the
connection. In 2G systems, GPRS provides data rates of 56–114 kbit/second. 2G
cellular technology combined with GPRS is sometimes described as 2.5G, that is,
a technology between the second (2G) and third (3G) generations of mobile
telephony. It provides moderate-speed data transfer, by using unused time
division multiple access channels in, for example, the GSM system. GPRS is
integrated into GSM Release 97 and newer releases.
GPRS
is a method of enhancing 2G phones to enable them to send and receive data more
rapidly. With a GPRS connection, the phone is "always on" and can
transfer data immediately, and at higher speeds: typically 32 - 48 kbps. An
additional benefit is that data can be transferred at the same time as making a
voice call. GPRS is now available on most new phones.
GPRS
Class Types
The
class of a GPRS phone determines the speed at which data can be transferred.
Technically the class refers to the number of timeslots available for upload
(sending data from the phone) or download (receiving data from the network).
The timeslots used for data are in addition to the slot that is reserved for
voice calls. These timeslots are available simultaneously, so the greater the
number of slots, the faster the data transfer speed. Because GPRS transmits
data in packets, the timeslots are not in use all the time, but are shared
amongst all users of the network. That increases the overall data capacity of
the network, and it also means that you are billed for the quantity of data
transmitted, not the time that you are online. It may mean that during busy
times, data transfer rates slow down, because the network will give priority to
voice calls. Generally speaking, the higher the GPRS class, the faster the data
transfer rates.
The
most common GPRS classes in use are as follows:
Services
offered
GPRS extends the GSM
Packet circuit switched data capabilities and makes the following services
possible:
- · SMS messaging and broadcasting
- · "Always on" internet access
- · Multimedia messaging service (MMS)
- · Push to talk over cellular (PoC)
- · Instant messaging and presence—wireless village
- · Internet applications for smart devices through wireless application protocol (WAP)
- · Point-to-point (P2P) service: inter-networking with the Internet (IP)
- · Point-to-Multipoint (P2M) service: point-to-multipoint multicast and point-to-multipoint group calls
If SMS over GPRS is
used, an SMS transmission speed of about 30 SMS messages per minute may be
achieved. This is much faster than using the ordinary SMS over GSM, whose SMS
transmission speed is about 6 to 10 SMS messages per minute.
