International Telecommunications Unit (ITU): IMT-2000 consists of six radio interfaces
* W-CDMA
* CDMA2000
* CDMA2001
* TD-CDMA / TD-SCDMA
* UWC-136 (often implemented with EDGE)
* DECT
3G Standards
The dream of 3G is to unify the world's mobile computing devices through a single, worldwide radio transmission standard. Imagine being able to go anywhere in the world secure in the knowledge that your mobile phone is compatible with the local system, a scenario known as "global roaming". Unfortunately, the process of unifying the numerous international standards has proved to be extremely difficult. After difficult negotiation, a 3G "standard" called IMT-2000 emerged as a rather unsatisfactory compromise. IMT-2000, in fact, represents several incompatible standards lumped together under one banner. The hope of IMT-2000 is that phones using these different standards will be able to move seamlessly between all networks, thus providing global roaming.
The rather fragmented nature of IMT-2000 has resulted in a proliferation of confusion acronyms (e.g., TDMA, UMTS, EDGE) often referred to as "alphabet soup". Possibly the most important acronym to remember is "UMTS": this is the 3G standard for Europe and Japan.
UMTS is the successor to the current ultra-successful GSM mobile phone standard in Europe. UMTS is being very heavily sold as the 3G standard (some sources use the terms "3G" and "UMTS" synonymously, though this is really not correct and just adds to the confusion).
The main global competitor to UMTS is CDMA2000, the 3G standard developed in the U.S. by Qualcomm. UMTS and CDMA2000 look set to battle it out for global supremacy. However, other less-publicised standards will not let those two have it all their own way. It is hoped that the following guide will act as a roadmap through the confusing subject of 3G standards.
3G Standards
The 3G standard was created by the International Telecommunication Union (ITU) and is called IMT-2000. The aim of IMT-2000 is to harmonize worldwide 3G systems to provide global roaming. However, as was explained in the introduction to this section, harmonizing so many different standards proved extremely difficult. As a result, what we have been left with is five different standards grouped together under the IMT-2000 label:
* W-CDMA
* CDMA2000
* TD-CDMA/TD-SCDMA
* DECT
* UWC-136
At this point, the definition of what is and what isn't "3G" becomes somewhat murky. Of these five standards, only three allow full network coverage over macro cells, micro cells and pico cells and can thus be considered as full 3G solutions: W-CDMA, CDMA2000, and TD-SCDMA. Of the remainder, DECT is used for those cordless phones you have in the house, and could be used for 3G short-range "hot-spots" (hence, it could be considered as being "part of a 3G network"), but it does not allow full network coverage so is not considered further here. And UWC-136 is another name for EDGE which is generally considered to be a 2.5G solution and was considered in the previous section.
W-CDMA
The 3G standard that has been agreed for Europe and Japan (very important markets) is known as UMTS. UMTS is an upgrade from GSM via GPRS or EDGE. UMTS is the European vision of 3G, and has been sold as the successor to the ultra-successful GSM.
The Applications
The 3G combination of high bandwidth, packet switching, IP, and always-on connections will make many new applications and devices feasible. For one thing, 3G will support very usable mobile voice, image, data, and video communications. As the technology matures, 3G connections will be used for video and audio streaming, including videoconferencing. You'll see cameras and color displays incorporated into 3G-enabled handsets and PDAs; 3G wireless connections added to digital cameras, camcorders, and MP3 players; and a number of hybrid and new devices. Insurance and real estate users, for instance, will be able to shoot photos in the field with their digital cameras and immediately upload the images to a secure Web site-no intervening device like a PC required.
Two other technologies that are evolving in parallel with 3G will add other powerful capabilities. Location-based services, based on the FCC's E-911 initiative, will be able to pinpoint your whereabouts using either the Global Positioning System (GPS) or triangulation techniques involving nearby base stations. These services will be able to tell you which hotels and restaurants are near your current location, or give you directions to your chosen destinations.
Devices that incorporate Bluetooth wireless connections in addition to 3G will make it easy to transmit files from your PDA or handset directly to your PC, or vice versa. You'll also see ticketing applications that, for example, will let you purchase and download an airline ticket over the Internet, then have it validated via a local wireless connection to your device at the gate, along with a download of your boarding pass.