GPRS

GPRS

GPRS stands for General Packet Radio Service.
GPRS is a mobile data service that provides e-mail and Internet access for 2G and 3G mobiles.
It is also called as 2.5G technology, that is, a technology between 2G and 3G.
GPRS is usually charged based on amount of data transferred whereas circuit-switched data is billed per min of connection time.
GPRS is a best service that has variable throughput and latency that depends on number of users sharing the service at the same time.

CHARACTERISTICS:

Data rate - 115kbps
Speed - 40 to 50kbps
Latency is very high.
Roundtrip time - 600 to 700ms and often 1s is achieved.

SERVICES OFFERED:

GPRS offers services like SMS, MMS, P2P service, P2M service, Push to Talk, Instant Messaging, etc..
In GPRS, an SMS transmission speed of about 30 SMS per minute can be achieved and it is fast enough technology for MMS and browsing.

PROTOCOLS SUPPORTED:

Internet Protocol (IP) - It is built in mobile browsers and it uses IPv4.
Point to point protocol (PPP) – It is not supported by mobile phones but it is used to provide IP to the phone when it is used as modem to the computer.

HARDWARE SUPPORTED:

CLASS A – It can be connected to GPRS and GSM service using both at a time.
CLASS B – It can be connected to GPRS and GSM service using only one at a time. Most of the GPRS mobile services are Class B.
CLASS C – It can be connected to either GPRS or GSM service.

ACCESSING METHOD:

Multiple Access method used in GSM with GPRS is based on Frequency Division Duplex(FDD) and Time Division Multiple Access(TDMA).
Hence it is possible that the several users can share the same frequency channel.