Third-Generation Wireless Communication
The objective of the third generation of wireless communication is to provide fairly high-speed wireless communications to support multimedia, data, and video in addition to voice. The ITU's International Mobile Telecommunications for the year 2000 (IMT-2000) initiative has defined the ITU's view of third-generation capabilities as follows:
Voice quality comparable to the public switched telephone network
144 Kbps data rate available to users in high-speed motor vehicles over large areas
384 Kbps available to pedestrians standing or moving slowly over small areas
Support (to be phased in) for 2.048 Mbps for office use
Support for both packet-switched and circuit-switched data services
An adaptive interface to the Internet to reflect efficiently the common asymmetry between inbound and outbound traffic
More efficient use of the available spectrum in general
Support for a wide variety of mobile equipment
Flexibility to allow the introduction of new services and technologies
More generally, one of the driving forces of modern communication technology is the trend toward universal personal telecommunications and universal communications access. The first concept refers to the ability of a person to identify himself or herself easily and use conveniently any communication system in an entire country, over a continent, or even globally, in terms of a single account. The second refers to the capability of using one's terminal in a wide variety of environments to connect to information services (for example, to have a portable terminal that will work in the office, on the street, and on airplanes equally well). This revolution in personal computing will obviously involve wireless communication in a fundamental way. The GSM cellular telephony, with its subscriber identity module, for example, is a large step toward these goals.
Personal communications services (PCSs) and personal communication networks (PCNs) are names attached to these concepts of global wireless communications, and they also form objectives for third-generation wireless.
Generally, the technology planned is digital, using time-division multiple access or code-division multiple access to provide efficient use of the spectrum and high capacity.
PCS handsets are designed to be low-power and relatively small and light. Efforts are being made internationally to allow the same terminals to be used worldwide. Worldwide frequency allocations have been made for second-generation cordless telephones (CT-2) in the 800 MHz region and for more advanced personal communications in the 1.72.2 GHz region of the spectrum.
The 1992 World Administrative Radio Conference (WARC 92) resulted in worldwide allocations for future public land mobile telecommunications systems (FPLMTS). This concept includes both terrestrial and satellite-based services. In addition, allocations were made for low-earth-orbiting (LEO) satellite services that can be used to support personal communications.
Some proposed technologies that come under the umbrella of PCS are American Digital Cellular System, Japanese Digital Cellular System, second-generation cordless telephones (CT-2), the European Community's General Speciale Mobile (GSM) for digital cellular service, and Digital European Cordless Telephone (DECT). These technologies involve advanced wireless telephony, which may be supported by LEO satellites and geostationary satellites, as well as by terrestrial antennas. The technology is developing rapidly. One desirable third-generation capability is mobile telephone and mobile terminals that can access web services.