High Speed Packet Access (HSPA) is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA), that extends and improves the performance of existing 3G mobile telecommunication networks utilizing the WCDMA protocols.
GSM
Global System for Mobile Communication.
GSM is the dominant 2G digital mobile phone standard for most of the world. It determines the way in which mobile phones communicate with the land-based network of towers.
GSM is one of two major mobile phone technologies in the U.S. The other is CDMA. Cingular and T-Mobile use GSM. Sprint and Verizon use CDMA. GSM is more prevalent in most other parts of the world, and especially in Europe.
Although GSM and CDMA provide similar basic features and services to end-users, (such as voice calling, text messaging, and data services,) they operate very differently at many technical levels. This makes GSM phones completely incompatible with CDMA networks, and vice-versa.
The most visible feature of GSM are SIM cards. SIM cards are removable, thumbnail-sized smart cards which identify the user on the network, and can also store information such as phone book entries. SIM cards allows users to switch phones by simply moving their SIM card from one phone to the other.
GPRS
General Packet Radio Service.
A packet-switched technology that enables data communications.
GPRS is used for various data applications on phones, including wireless Internet (WAP), MMS, and software that connects to the Internet. Basically, any network connection that is not voice or text messaging uses a data connection like GPRS.
GPRS offers a tenfold increase in data speed over previous (circuit-switched) technologies, up to 115kbit/s (in theory). Typical real-world speeds are around 30-40 Kbps.
Newer technologies like EDGE and 3G are much faster.
See: EDGE
Using a packet switching, subscribers are always connected and always on-line, so services will be easy and quick to access.
GPRS is considered a "2.5G" technology, meaning it is more advanced than standard 2G digital technology, but does not meet the requirements of a full-feldged 3G technology.
EDGE
Enhanced Data for Global Evolution.
An upgrade for GSM/GPRS networks that triples data rates (speed) over standard GPRS.
EDGE is used automatically when both the phone and network support it. EDGE phones will automatically revert to the slower GPRS standard when EDGE service is not available.
Although many EDGE phones and devices are theoretically capable of up to 236 Kbps, most EDGE networks are only configured to allow up to 135 Kbps, to conserve spectrum resources. Real-world data rates are usually lower than the maximum.
Because it is based on existing GSM technology, EDGE is a smooth upgrade for GSM network operators. It also works within existing spectrum, making it ideal for countries without dedicated 3G spectrum, such as the US.
Although EDGE works at a low level within the GSM standard that includes voice, the main benefit is to increase GPRS data rates. GPRS operating over EDGE is called EGPRS.
Quad-Band
Designates a GSM phone that supports all four major GSM frequency bands, making it compatible with all major GSM networks worldwide.
The four bands include the 850 and 1900 MHz bands - used in the Americas - and 900 / 1800, used in most other parts of the world.
Compared to a tri-band phone supporting the 900 / 1800 / 1900 bands, a quad-band phone adds support for GSM 850 for full coverage in the Americas.
Compared to a tri-band phone supporting the 850 / 1800 / 1900 bands, a quad-band phone adds support for GSM 900 for full coverage in Europe and Asia.
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