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This story was printed from CNET Asia.
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A CNET tutorial: What is GPRS?

By Ernest Khoo
02/07/2002
URL: http://asia.cnet.com/digitalliving/tips/0,3800004921,39060160,00.htm

GPRS, not to be confused with GPS (Global Positioning System), stands for General Packet Radio Service. Why should you care? For one thing, this could perhaps be the technology that allows us to really start using the mobile Internet. Often touted as 2.5G, GPRS is considered one step ahead of HSCSD (High Speed Circuit Switched Data), and a step towards third-generation (3G) networks.

Instant, always-on connection
GPRS is a packet-switching technology for GSM networks. Information sent on a GPRS network is split into separate "packets" before it is transmitted and reassembled at the receiving end. Simply put, packet switching is like a jigsaw puzzle. A complete image is divided into several pieces and placed in the box. When you buy the puzzle, you reassemble the puzzle to form the original image.

One of the advantages of GPRS is its ability to provide instant connection where information can be sent and received immediately. Unlike the current GSM network where you have to "dial up" and wait for a connection to be established, GPRS allows users to be "always connected" to the network.

According to the specifications provided by the European Telecommunications Standards Institute (ETSI), the highest speed for a single user session (or time slot) is the coding scheme CS4, which allows 21.4Kbps per time slot. Thus, theoretically, a GPRS connection can provide a data transmission speed of up to 171.2Kbps (approximately three times that of a fixed-line 56K dial-up) if all eight slots are used. GPRS's rival, HSCSD, can achieve up to 57.6Kbps.

However, it is unlikely that network operators will let a single user use up all the time slots. Even Nokia admitted that realistically GPRS can achieve only about 43Kbps while Ericsson thinks 56Kbps is achievable.

A comparison of data transfer speed (in Kbps)
56K dial-up GSM HSCSD (max. speed) GPRS (max. speed) GPRS (realistic speed)
56 9.6 57.6 171.2 43 to 56

What is GPRS?
 |  Why GPRS?

What GPRS can do for you?
As mentioned, GPRS allows you to have an "always on" connection to the network. This means you can access WAP sites without having to wait up to 30 seconds for a connection to be established. This can be important for e-commerce applications where it would be unacceptable for customers to constantly wait to access the site.

With a high-speed data connection, tons of consumer and corporate applications can be made available to the user. This means anyone who needs wireless mobile data access will benefit from GPRS.

With GPRS, you can access your email, browse the Internet, tranfer/share documents, and remotely access your office's Local Area Network (LAN). Even home automation is possible when household appliances are equipped with Internet Protocol (IP)!

What is GPRS?
 |  Why GPRS?