Editing GPRS (section)

== Technical overview ==
{{See also|GPRS Core Network}}
The GPRS core network allows [[2G]], [[3G]] and [[WCDMA]] [[mobile telephony|mobile networks]] to transmit [[Internet Protocol|IP packets]] to external networks such as the [[Internet]]. The GPRS system is an integrated part of the [[GSM]] [[network switching subsystem]].<ref>{{Cite web |title=What Is GPRS (General Packet Radio Service)? Meaning, Working, Advantages, and Applications |url=https://www.spiceworks.com/tech/networking/articles/what-is-gprs/ |access-date=2023-05-01 |website=Spiceworks |language=en-US}}</ref><ref name="Bhandari">{{Cite web |author=Sandeep Bhandari |date=2021-09-17 |title=Difference Between GSM and GPRS |website=askanydifference.com |url=https://askanydifference.com/difference-between-gsm-and-gprs-with-table/ |access-date=2023-05-01 |language=en-US}}</ref><ref>{{Cite web |title=4G vs GPRS: What is the difference between 4G LTE and GPRS? |website=Commsbrief |url=https://commsbrief.com/4g-vs-gprs-what-is-the-difference-between-4g-lte-and-gprs/ |access-date=2023-05-01 |language=en-US}}</ref>

GPRS is a [[best-effort service]], implying variable [[throughput]] and [[latency (engineering)|latency]] that depend on the number of other users sharing the service concurrently, as opposed to [[circuit switching]], where a certain [[quality of service]] (QoS) is guaranteed during the connection. It uses unused [[time-division multiple access]] (TDMA) channels in the GSM system for efficiency. Unlike older circuit switching data, GPRS was sold according to the total volume of data transferred instead of time spent online,<ref>{{Cite web |title=BBC - Bristol - Digital Future - WAP gets a rocket |url=https://www.bbc.co.uk/bristol/content/digitalfuture/2002/02/06/gprs.shtml |access-date=2024-06-18 |website=www.bbc.co.uk}}</ref> which is now standard. 

=== Services offered ===
[[File:SonyEricssonK310-GPRS-Wikipedia.jpg|thumb|Sony Ericsson K310a showing [[Wikipedia]]'s [[homepage]] on the Internet transmitted using a GPRS connection]]
GPRS extends the GSM Packet circuit switched data capabilities and makes the following services possible:
* SMS messaging and broadcasting
* "Always on" internet access
* Multimedia messaging service (MMS)
* Push-to-talk over cellular (PoC)
* Instant messaging and presence—wireless village
* Internet applications for smart devices through wireless application protocol (WAP)
* Point-to-point (P2P) service: inter-networking with the Internet (IP)
* Point-to-multipoint (P2M) service: point-to-multipoint multicast and point-to-multipoint group calls

If SMS over GPRS is used, an SMS transmission speed of about 30 SMS messages per minute may be achieved. This is much faster than using the ordinary SMS over GSM, whose SMS transmission speed is about 6 to 10 SMS messages per minute.

=== Frequencies ===
As the GPRS standard is an extension of GSM capabilities, the service operates on the [[2G]] and [[3G]] [[cellular communication]] GSM frequencies.<ref name=Bhandari/><ref name=":0">{{Cite web |title=Ofcom UK Frequency Allocation (UKFAT) Page |website=static.ofcom.org.uk |url=http://static.ofcom.org.uk/static/spectrum/fat.html |access-date=2023-05-01}}</ref> GPRS devices can typically use (one or more) of the frequencies within one of the frequency bands the radio supports (850, 900, 1800, 1900&nbsp;MHz). Depending on the device, location and intended use, regulations may be imposed either restricting or explicitly specifying authorised frequency bands.<ref name=":0" /><ref>{{Cite web |date=2014-10-07 |title=What frequency does the data traffic use in GPRS? |website=Honeywell AIDC |url=https://support.honeywellaidc.com/s/article/What-frequency-does-the-data-traffic-use-in-GPRS |publisher=Honeywell |access-date=2023-05-01  |archive-date=2023-05-01  |archive-url=https://web.archive.org/web/20230501041408/https://support.honeywellaidc.com/s/article/What-frequency-does-the-data-traffic-use-in-GPRS |url-status=dead }}</ref><ref>{{Cite web |title=Mobile Spectrum Assignments by Country |website=CellMapper Wiki |url=https://docs.cellmapper.net/mw/Mobile_Spectrum_Assignments_by_Country |access-date=2023-05-01}}</ref>

GSM-850 and GSM-1900 are used in the United States, Canada, and many other countries in the Americas. GSM-900 and GSM-1800 are used in: Europe, Middle East, Africa and most of Asia. In South Americas these bands are used in Costa Rica (GSM-1800), Brazil (GSM-850, 900 and 1800), Guatemala (GSM-850, GSM-900 and 1900), El Salvador (GSM-850, GSM-900 and 1900). There is a more comprehensive record of [https://docs.cellmapper.net/mw/Mobile_Spectrum_Assignments_by_Country international cellular service frequency assignments]

=== Protocols supported ===
GPRS supports the following protocols:
* [[Internet Protocol]] (IP). In practice, built-in [[mobile browser]]s use [[IPv4]] before [[IPv6]] is widespread.
* [[Point-to-Point Protocol]] (PPP) is typically not supported by [[mobile phone operator]]s but if a cellular phone is used as a [[modem]] for a connected computer, PPP may be used to tunnel IP to the phone. This allows an IP address to be dynamically assigned (using [[Internet Protocol Control Protocol|IPCP]] rather than [[Dynamic Host Configuration Protocol|DHCP]]) to the mobile equipment.
* [[X.25]] connections are typically used for applications like wireless payment terminals, although it has been removed from the standard. X.25 can still be supported over PPP, or even over  IP, but this requires either a network-based [[Router (computing)|router]] to perform encapsulation or software built into the end-device/terminal; e.g., user equipment (UE).

When [[Internet protocol suite|TCP/IP]] is used, each phone can have one or more [[IP address]]es allocated. GPRS will store and forward the IP packets to the phone even during [[handover]]. The TCP restores any packets lost (e.g. due to a radio noise induced pause).

=== Hardware ===
Devices supporting GPRS are grouped into three classes:
;Class A: Can be connected to GPRS service and GSM service (voice, SMS) simultaneously. Such devices are now available{{as of?|date=June 2018}}.
;Class B: Can be connected to GPRS service and GSM service (voice, SMS), but using only one at a time. During GSM service (voice call or SMS), GPRS service is suspended and resumed automatically after the GSM service (voice call or SMS) has concluded. Most GPRS mobile devices are Class B.
;Class C: Are connected to either GPRS service or GSM service (voice, SMS) and must be switched manually between one service and the other.

Because a Class A device must service GPRS and GSM networks together, it effectively needs two radios. To avoid this hardware requirement, a GPRS mobile device may implement the [[Dual Transfer Mode|dual transfer mode (DTM)]] feature. A DTM-capable mobile can handle both GSM packets and GPRS packets with network coordination to ensure both types are not transmitted at the same time. Such devices are considered pseudo-Class A, sometimes referred to as "simple class A". Some networks have supported DTM since 2007{{citation needed|date=June 2018}}.

[[Image:Huawei E220 (Three).jpg|right|thumb|[[Huawei E220]] 3G/GPRS Modem]]
[[File:Wireless GPRS Modem.jpg|thumb|A [[PC Card]] GPRS modem for use with a notebook computer]]
USB 3G/GPRS modems have a [[terminal software|terminal]]-like interface over [[USB]] with [[V.42bis]], and {{IETF RFC|1144}} data formats. Some models include an external [[antenna (radio)|antenna]] connector. Modem cards for laptop PCs, or external USB modems are available, similar in shape and size to a [[computer mouse]], or a [[pendrive]].

=== Addressing ===
A GPRS connection is established by reference to its [[Access Point Name|access point name]] (APN). The APN defines the services such as [[Wireless Application Protocol|wireless application protocol]] (WAP)
access, [[Short Message Service|short message service]] (SMS), [[Multimedia Messaging Service|multimedia messaging service]] (MMS), and for [[Internet]] communication services such as [[email]] and [[World Wide Web]] access.

In order to set up a GPRS connection for a [[Mobile broadband modem|wireless modem]], a user must specify an APN, optionally a user name and password, and very rarely an [[IP address]], provided by the network operator.

=== GPRS modems and modules ===
GSM module or GPRS modules are similar to modems, but there's one difference: the modem is an external piece of equipment, whereas the GSM module or GPRS module can be integrated within an electrical or electronic equipment. It is an embedded piece of hardware. A GSM mobile, on the other hand, is a complete embedded system in itself. It comes with embedded processors dedicated to provide a functional interface between the user and the mobile network.