GPRS stands for General Packet Radio Service and it is a technology enhancement that belongs to the second generation of mobile networks on the GSM path. GSM networks were originally circuit-switched, GPRS added the packet-switched part for efficient mobile data services.
The introduction of GPRS allowed mobile operators to offer efficient mobile data services to their customers. The word ‘efficient’ is important here because GSM networks already had the capability to offer very limited data services by using the circuit-switched part of the mobile network before GPRS. We have a dedicated post on circuit-switched vs packet-switched which you can check out for details, but generally speaking, the circuit-switched technique is not the most efficient way of transferring data. So, a different solution was required and that gap was filled by GPRS which used the packet-switched technique for mobile data.
What speeds do you get with GPRS?
GPRS can enable peak download speeds of up to 171.2 kbps which in today’s world (2020) is very low. However, GPRS was a big achievement as it paved the way for the evolution of mobile data based on the packet-switched technique. GPRS was followed by another enhancement called EDGE or Enhanced Data for Global Evolution which improved the speeds a bit further. GPRS and EDGE are often referred to as 2.5G and 2.75G respectively. EDGE can offer peak downlink speeds of up to 384 kbps for downloads, which is more than double of what GPRS can offer. Even though 384 kbps can theoretically support basic mobile internet tasks, we don’t get peak speeds in real life. Generally, depending on how many people are on the network and how far you are from the base station, you may only get to enjoy a small portion of this 384 kbps. EDGE also uses the packet-switched methodology to send and receive mobile data just like GPRS. If you are looking for a comparison of the data rates that can be achieved through various mobile technologies, have a look at this post.
What is Packet-Switched?
GSM networks use the circuit-switched technique for voice calls which requires a dedicated circuit to be made available for the entire duration of a call even if the users are not speaking. Now as you can imagine, that doesn’t sound like an efficient way of doing business. The mobile data sessions are very different from voice calls because in data sessions users don’t necessarily send and receive at the same time.
Therefore, GPRS networks employed the packet-switched technique which was more efficient. With the packet-switched method, the data is sent and received in the form of packets of data bursts at different time intervals by sharing the available capacity with multiple users. So rather than dedicating the entire capacity to one session, the capacity is shared to facilitate multiple sessions. In this way, when a certain user in a certain session isn’t sending/receiving any data-bursts, other users in other sessions can utilise the same capacity.
Just for completeness, this whole efficiency thing doesn’t mean that GPRS replaces the circuit-switched part of the GSM network. It just means that the voice calls continue to use circuit-switched to ensure the right quality of service, but the data sessions use the packet-switched part of the mobile network to offer efficient mobile data services.