GPRS stand for General Packet Radio System is a packet-switching technology that enables data transfers through cellular networks. It is used for mobile internet, MMS and other data communications. In theory the speed limit of GPRS is 115 kbps, but in most networks it is around 35 kbps. Informally, GPRS is also called 2.5G. GPRS became the first stepping-stone on the path between the second-generation GSM cellular technology and the 3G W-CDMA / UMTS system.
- The key element of GPRS technology is that it uses packet switched data rather than circuit switched data, and this technique makes much more efficient use of the available capacity.
- The data is split into packets and tags inserted into the packet to provide the destination address.
- Packets from several sources can then be transmitted over the link..
The main parameters for the GPRS, General Packet Radio System are shown in Figure 8.13
Figure 8.13 key parameters GPRS
- Advantages of GPRS: GPRS technology offered some significant benefits
- Speed: GPRS technology offers up to 172 kbps, although the maximum data rates realistically achievable under most conditions will be in the range 15 - 40 kbps.
- Packet switched operation: GPRS technology uses packet switching in line with the Internet. This makes far more efficient use of the available capacity, and it allows greater commonality with Internet techniques.
- Always on connectivity: GPRS offers an "Always On" capability. For packet switched technology charges are for the amount of data carried as this is what uses the services provider's capacity. Accordingly, always on connectivity is possible.
- More applications: GPRS was the Blackberry form of mobile or PDA. This provided for remote email applications along with web browsing, etc.
- The Capital expenditure and operational expenditure: The capital expenditure for introducing GPRS technology was not as high as deploying a complete new network. Additionally opex was not greatly affected as the basic base station infrastructure remained basically the same
- Disadvantages of GPRS:
- Voice calls have a higher priority than data packet transmissions, essentially giving you fluctuations in your connection speed.
- the actual rate lower than the theoretical value, GPRS data transfer rate to achieve the theoretical maximum 172.2kbps, must be only one user occupy all eight time slots, and no protection against mistakes.