Chapter 24:

General Packet Radio Service (GPRS)

Overview

With the simultaneous gate−opening effects of technological innovation and industry deregulation,

The demand for communications and available solutions is exploding. This demand is being fueled by the needs of people and businesses. The most visible evidence of the boom is within Internet traffic and e−commerce or m−commerce. However, it is less appreciated that an unprecedented Demand exists from worldwide telephone subscribers. It took a century to get 700 million phones lines installed. Another 700 million will be deployed in the next 15 to 20 years and that could prove to be a conservative estimate. Although the majority of the new deployments will be wireless phones 700 million of them over the next 10 years demand for wireline communications is also exploding, driven in part by the need to access the Internet.

GPRS is expected to profoundly change the mobile data services that GSM, CDMA and TDMA (ANSI-I36) network operation can offer. GPRS will increase opportunities for higher revenues and enable new, differentiated services and tariff dimensions to be offered (such as a charge for the number of kilobytes of data transferred). GPRS combines mobile access with internet protocol (IP) based services, using packet data transmission that makes highly efficient use of radio spectrum and enables high data speeds. It gives users increased bandwidth, making it possible and cost effective to remain constantly connected, as well as to send and receive data as text, graphics and video.

WHAT IS GPRS?

GPRS (general radio service) is a packet based data bearer service for wireless communication services that is delivered as a network overlay for GSM, CDMA and TDMA (ANSI-I36) networks. GPRS applies a packet radio principle to transfer user data packets in efficient way between GSM mobile stations and external packet data networks. Packet switching is where data is split into packets that are transmitted separately and then reassembled at receiving end. GPRS supports the world’s leading packet based internet communication protocols, internet protocol (IP) and X.25. GPRS enables any existing IP or X.25 application to operate over a GSM cellular connection. Cellular networks with GPRS capabilities are wireless extensions of internet and X.25 networks.

GPRS gives almost instantaneous connection set-up and continuous connection to the internet. GPRS users will be able to log on to an APN (access point name) and have access to many services or an office network (without the need to dial-up) and remain continuously connected until they log off, only paying when data is actually transmitted. A physical end to end connection is not required because network resources and bandwidth are only used when data is actually transferred. This makes extremely efficient use of available radio bandwidth. Therefore, GPRS packet based services should cost users less than circuit switched services since communication channels are being shared and are on as packets are needed basis rather than dedicated to only one user at a time. It should also be easier to make applications available to mobile users because the faster data rate means that middleware currently needed to adapt applications from fixed lines rates to the slower speed of wireless systems will no longer be needed.

The first data service for GSM cellular carriers. GPRS added a packet capability to GSM, which uses dedicated, circuit-switched channels for voice conversations.

Ø  GPRS speeds range from 14.4 kbit/s(using radio timeslot) to 115kbit/s (by amalgamating timeslots).

Ø  Offer connection to internet for mobile phone and computer users.

Ø  GPRS data speeds are likely to average at about 56 kbit/s,with between 28 and 40 kbit/s initially.

Ø  The higher data rates will allow users to take part in video conferences and interact with multimedia web sites and similar applications using mobile handheld devices as well as notebook computers.

The key drivers for operators to evolve to GPRS networks are to:

Ø  Increase revenues by moving into the mobile data market, especially since the voice market has had profit margins squeezed with the commodization of voice services.

Ø  Gain new subscribers who require mobile data services or do not want to invest in a PC to gain internet  access.

Ø  Retain current subscribers by offering new services.

Ø  Reduce cost due to the efficient use of network resources.

Ø  Ease of adapting applications fro mobile users because high data speeds mean that middleware is no longer required to convert fixed applications for mobile use.

How is GPRS different to GSM?

• Higher  and therefore data, speeds.

• Seamless, immediate and continuous connection to the internet always online.

• Packet switching rather than circuit switching, which means that there is no higher radio spectrum efficiency because network resources and bandwidth are only used when data is actually transmitted even though it is always connected.

• Different mediation, rating and billing requirements such as collecting records from GPRS and Ip networks, charging for volumes of data transferred rather than connection time and new and multiple  members of the billing value chain.

• First important step on the path to 3G.

GPRS works on GPRS cellphones as well as laptops and portable devices that have GPRS modems. Users have typically experienced downstream data rates up to 80 Kbps. GPRS is not the same as GSM's short messaging service (GSM-SMS), which is limited to messages of 160 bytes in length. GPRS was superseded by EDGE, which changed the modulation method to increase speed.

Advantages of GPRS

GPRS brought mobile phone users out from the world of WAP, and into a world where Internet was finally available on mobiles. This in itself was a monumental feat, and hence GPRS took off with quite a bang. With GPRS, large amounts of data can be transferred to and from the mobile device over the Internet.

References:

http://en.wikipedia.org/wiki/GPRS_Core_Network

Broadband Telecommunications Handbook