Third Generation (3G) Universal Mobile Telecommunication System (UMTS) is one of two competing 3G technologies utilized in cellphones. The 3G UMTS standard can allow for faster data speeds than the previous 2G systems. Additionally, UMTS contains specifications for the entire 3G voice and data network. 3G UMTS is closely related to older technologies, such as Enhanced Data rates for GSM Evolution (EDGE) and Global System for Mobile Communications (GSM). Some UMTS handsets can use one or both of these slower protocols when a 3G network is unavailable.
The UMTS standard is in use throughout the world, though the actual UMTS name is most often used in Europe. In the US, 3G UMTS is usually marketed simply as 3G. Though 3G UMTS builds on many concepts utilized in EDGE and GSM, UMTS cannot be operated concurrently in the same frequencies as these standards. UMTS also requires entirely new hardware to be installed in a carrier's cell towers. So while EDGE may be operated concurrently with GSM, UMTS can represent a comparatively expensive upgrade. Some carriers may choose to use EDGE as a stopgap measure before building a full UMTS network.
3G UMTS networks are often billed as broadband. Though actual download and upload speeds may be slower than traditional broadband connections, they can often represent a substantial improvement over 2G data systems. EDGE may also offer increased speed over the older GSM system, but UMTS can increase potential speeds into low-end broadband territory. Dedicated 3G UMTS modems are usually available for computers, providing a broadband connection while on the go. Similarly, some carriers may allow users to tether their UMTS phones to a computer. This tethering process can also provide a broadband connection where a broadband connection might otherwise not be available.
The main competing 3G protocol is known as Code Division Multiple Access (CDMA2000). This technology is used by a number of carriers in the US, though it is not as widespread in most other countries. While UMTS is part of the Third Generation Partnership Project (3GPP), CDMA2000 belongs to the competing Third Generation Partnership Project 2 (3GPP2). A direct evolution of the Interim Standard 95 (IS-95) 2G protocol, CDMA2000 can coexist within the same frequencies as this older technology. This is similar to the relationship between the 3GPP GSM and EDGE technologies, though CDMA2000 is fully 3G. Due to this interoperability, the build costs for CDMA2000 networks may be less expensive when compared to UMTS networks. Unlike UMTS, CDMA2000 does not have a natural successor. Long Term Evolution (LTE), a 3GPP standard, is the sole successor to both competing 3G technologies.
