GPRS is a network enhancement that was introduced in GSM networks (Global System for Mobile Communication) in 2000. Since then, many new cellular technologies and improvements have been introduced, but GPRS is still around.
General Packet Radio Service or GPRS is an enhancement added to GSM networks as part of the 2G (second-generation) mobile network evolution. GPRS introduced packet-switched nodes in GSM networks to lay the foundation for EDGE (2G enhancement) and UMTS (3G technology). 4G LTE is separate from GPRS.
What is GPRS and how does it work?
GPRS (General Packet Radio Service) is a network enhancement that allows second-generation GSM networks to enable highly efficient mobile internet services through packet-switched technology. GPRS can offer maximum download speeds of up to 171.2 kbps and average data rates of around 30 to 50 kbps.
When GSM networks were initially introduced, they only had a circuit-switched part primarily used for voice calls and short message service (SMS). GSM networks use a combination of Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA). The GSM frequency band is first divided into frequency channels (Absolute Radio Frequency Channel Numbers – ARFCN) and then split into eight timeslots per channel. These timeslots are used for facilitating voice calls, SMS and mobile data (mobile internet). The circuit-switched technology requires dedicated timeslots for each session or call, which is inefficient. Mobile data services do not require dedicated timeslots because a user is not uploading and downloading all the time during a session. This led to the introduction of GPRS, which is packet-switched technology. Before introducing GPRS, GSM networks used Circuit-Switched Data (CSD) technology that relied on dedicated timeslots for each session. CSD later evolved to High-Speed Circuit-Switched Data (HSCSD), which improved the data rates but continued using dedicated timeslots. I have written a dedicated post on the difference between circuit-switching and packet-switching, which can help you understand the key differences more clearly.
GPRS follows a bursty approach with a short access time and uses a shared pool of network resources. The GPRS enhancement also uses timeslots just like circuit-switched networks, but instead of engaging the timeslot permanently for a session, it shares the timeslot between multiple users.
GPRS can utilise 1 to 8 timeslots or channels to connect a mobile user to the public data network through a standard protocol address, i.e. IP or X.25. Network resource allocation in GPRS is dynamic depending on the demand, and it can support a maximum data rate of up to 171.2 kbps in the downlink for downloads. HSCSD, in comparison, could enable peak download speeds of up to 64 kbps. GPRS does not replace the circuit-switched part of the GSM network. Instead, it uses circuit-switched to ensure good quality of service (QoS) in voice calls and packet-switched for efficient mobile data services.
GPRS is a second-generation (2G) technology
GPRS is a second-generation (2G) network enhancement that was a step-change in the evolution of GSM networks. GPRS introduced two new mobile core network nodes, GGSN and SGSN, in 2G GSM networks that also exist in the third-generation (3G) UMTS networks.
GPRS is a second-generation (2G) network enhancement introduced in the most widely deployed 2G cellular technology standard, GSM. GPRS was released in the year 2000 and was followed by another 2G enhancement, EDGE or Enhanced Data rates for Global Evolution. As the name suggests, the whole point of EDGE was to improve the data rates that could be achieved with GPRS. EDGE is more of an umbrella term that represents two network enhancements, one for the packet-switched GPRS technology and the other for the circuit-switched HSCSD. The GPRS enhancement in EDGE is called Enhanced GPRS or E-GPRS, which improves the peak download data rates to 384 kbps. GPRS introduced two new core network nodes, SGSN (Serving GPRS Support Node) and GGSN (Gateway GPRS Support Node), as part of the second-generation upgrade. These core network nodes continue to exist in EDGE as well as the third-generation UMTS networks. UMTS networks (Universal Mobile Telecommunication System) use WCDMA for the radio network but use the same mobile core network that was enhanced when GPRS was launched.
For completeness, GPRS has nothing to do with the CDMA-based mobile networks Interim Standard-95 (IS-95 or cdmaOne) and CDMA2000. GPRS was part of GSM evolution, whereas IS-95 and CDMA2000 were part of the CDMA mobile network evolution. IS-95 is the second-generation (2G) CDMA technology and consists of two variants, IS-95 A and IS-95 B. IS-95 A can provide peak download data rates of up to 14.4 kbps, whereas IS-95 B can enable peak download data rates of up to 115 kbps.
Why are SGSN and GGSN used in GPRS networks?
The mobile core network in the original GSM networks consists of MSC (Mobile Switching Centre) and Gateway MSC (GMSC) to connect the mobile network to external telephone networks like PSTN and ISDN. These core network components primarily facilitate voice calls and SMS but can also enable circuit-switched mobile data (internet) for CSD and HSCSD technologies. The original GSM core network did not have the packet-switched capability, and therefore enabling GPRS required a switching solution that could facilitate shared radio resources. The new switching solution was enabled by Serving GPRS Support Node (SGSN) and Gateway GPRS Support Node (GGSN). SGSN is the packet-switched equivalent of MSC, and GGSN is the packet-switched equivalent of GMSC. I have a detailed post on SGSN and GGSN with network diagrams to help you understand what these nodes mean for 2G & 3G networks and what role they play in 4G networks.
When you are on GPRS you see a “G” symbol on your phone
When you are in geographical areas with poor 3G, 4G or 5G coverage, your phone is likely to switch to the 2G GSM networks that use GPRS and EDGE to enable mobile data. GPRS is shown on your mobile phone as “G”, whereas EDGE is shown on your mobile phone as “E”.
If you have your mobile subscription from a mobile operator that uses GSM networks, then your phone may go on GPRS if you travel to areas with 2G-only coverage. On the other hand, if your mobile operator is CDMA-based (e.g. CDMA2000 or EVDO), your phone will not show GPRS, but you will instead be served by IS-95 A/B in 2G-only coverage areas.
What peak and average speeds you get with GPRS
GPRS can enable a peak or maximum download speed of up to 171.2 kbps. The average speeds are lower than the peak speeds and roughly around 30 kbps to 50 kbps. With the EDGE enhancement, E-GPRS can offer a peak download speed of up to 384 kbps, which is more than double the speed that 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, i.e. 130-200 kbps. Like GPRS, EDGE also uses the packet-switched methodology to send and receive mobile data. Below is a quick table that summarises this information. You may also check out our dedicated post that provides a detailed comparison of the data rates that can be achieved through various mobile technologies, including 2G, 3G, 4G and 5G technologies.
|Technology||Network Generation||Meaning||Maximum download speed||Average download speed|
|GPRS||2G (or 2.5 G)||General Packet Radio Service||171.2 kbps||30-50 kbps|
|EDGE||2G (or 2.75 G)||Enhanced Data for Global Evolution||384 kbps||130-200 kbps|
GPRS or General Packet Radio Service is a GSM enhancement introduced in 2000 to facilitate packet-switched mobile data. GPRS is a 2G technology for the GSM mobile network evolution track; however, the network nodes it introduced are also used in 3G UMTS networks. Recent mobile networks, including 4G LTE and 5G New Radio (NR), are fully packet-switched without any circuit-switched network components. GPRS is a step-change in GSM mobile network evolution because it started the packet-switched technology to enable highly efficient mobile data services. GPRS can offer peak data rates of up to 171.2 kbps and average data rates of around 30 to 50 kbps.
Here are some helpful downloads
Thank you for reading this post. I hope it helped you in developing a better understanding of cellular networks. Sometimes, we need extra support, especially when preparing for a new job, studying a new topic, or buying a new phone. Whatever you are trying to do, here are some downloads that can help you:
Students & fresh graduates: If you are just starting, the complexity of the cellular industry can be a bit overwhelming. But don’t worry, I have created this FREE ebook so you can familiarise yourself with the basics like 3G, 4G etc. As a next step, check out the latest edition of the same ebook with more details on 4G & 5G networks with diagrams. You can then read Mobile Networks Made Easy, which explains the network nodes, e.g., BTS, MSC, GGSN etc.
Professionals: If you are an experienced professional but new to mobile communications, it may seem hard to compete with someone who has a decade of experience in the cellular industry. But not everyone who works in this industry is always up to date on the bigger picture and the challenges considering how quickly the industry evolves. The bigger picture comes from experience, which is why I’ve carefully put together a few slides to get you started in no time. So if you work in sales, marketing, product, project or any other area of business where you need a high-level view, Introduction to Mobile Communications can give you a quick start. Also, here are some templates to help you prepare your own slides on the product overview and product roadmap.