GPRS - General Packet Radio Service

GPRS

The General Packet Radio Service (GPRS) network is an "always on", private network for data. It uses the existing GSM network to transmit and receive TCP/IP based data to and from GPRS mobile devices.

Private IP addresses are typically dynamically assigned within the network to mobile devices. However, Access Point Names (APN's) provide a gateway route to other networks such as the Internet, WAP services or private corporate networks. Firewalls typically reside at the APN to isolate the public and private networks. IP addresses allocated to mobile GPRS devices are therefore not addressable from outside the GPRS network (e.g. from the Internet) without specialised services or infrastructure.

GPRS benefits :

• Efficient - GPRS mobile devices only use the GSM network when data is transferred. The GSM connection is not dedicated to each user, therefore it can be shared with many users resulting in efficient use of the network.


• Speed - GPRS gives speeds of upto 5 time faster than GSM. GPRS offers maximum data rates of 56Kbps (down) and 14.4kbps (up), however this is shared bandwidth therefore actual data rates are potentially lower.
  
• Always on connectivity- GPRS is an always-on service. There is no need to dial up like you have to on a home PC for instance. This feature is not unique to GPRS but is an important standard that will no doubt be a key feature for migration to 3G. It makes services instantaneously available to a device.


• New and Better applications - Due to its high-speed connection and always-on connectivity GPRS enables full Internet applications and services such as video conferencing straight to your desktop or mobile device. Users are able to explore the Internet or their own corporate networks more efficiently than they could when using GSM. There is often no need to redevelop existing applications.


• GSM operator Costs- GSM network providers do not have to start from scratch to deploy GPRS. GPRS is an upgrade to the existing network that sits along side the GSM network. This makes it easier to deploy.


• Payment based on data usage - Billing is not based on time, but on the amount of data actually transferred.

To know more on GPRS:

• Working of GPRS
• GPRS Tutorial
• GPRS Info
• GPRS Applications

GSM - Global System for Mobile Communications

What is GSM:

Short for Global System for Mobile Communications, GSM is a digital cellular communications system. It was developed in order to create a common European mobile telephone standard but it has been rapidly accepted worldwide.

GSM is designed to provide a comprehensive range of services and features to the users not available on analogue cellular networks and in many cases very much in advance of the old public switched telephone network (PSTN). In addition to digital transmission, GSM incorporates many advanced services and features like worldwide roaming in other GSM networks.

GSM provides recommendations, not requirements. The GSM specifications define the functions and interface requirements in detail but do not address the hardware. The reason for this is to limit the designers as little as possible but still to make it possible for the operators to buy equipment from different suppliers. The GSM network is divided into three major systems: the switching system (SS), the base station system (BSS), and the operation and support system (OSS).


Architecture of the GSM Network:

(Click on the Image for a bigger picture)

Base Transceiver Station (BTS)
Base Station Controller (BSC)
Home Location Register (HLR)
Mobile Services switching Center (MSC)
Gateway Mobile Services switching Center (GMSC)
Visitor Location Register (VLR)
Authentication Center (AUC)
Equipment Identity Register (EIR)


Mobile Station:
The Mobile Station (MS) represents the only equipment the GSM user ever sees from the whole system. It actually consists of two distinct entities. The actual hardware is the Mobile Equipment (ME), which is anonymous and consists of the physical equipment, such as the radio transceiver, display and digital signal processors.

Base Station Subsystem:
The Base Station Subsystem is composed of two parts, the Base Transceiver Station (BTS) and the Base Station Controller (BSC). The BTS houses the radio transceivers that define a cell and transmits and receives signals on the cells' allocated frequencies with the mobile station.

Network Subsystem:
The central component of the Network Subsystem is the Mobile services Switching Center (MSC). It acts like a normal switching node of the normal telephones of the land lines and in addition provides all the functionality needed to handle a mobile subscriber, including registration, authentication, location updating and inter-MSC handovers.

To Know more on the topic:

• GSM Specifications
• GSM Overview
• GSM World
• GSM in Wikipedia
• GSM Specifications