ABSTRACT
With the widespread deployment of Internet services, it is expected that people will demand to access Internet service “anytime and anywhere.” Third generation (3G) cellular mobile communication systems, which can provide very wide coverage, are contributing to the realization of this goal. However, the 384 kbps data transmission rate provided by current 3G systems is not sufficient to support many emerging multimedia services. Moreover, due to the use of licensed spectrum, the data services provided by 3G systems are very expensive. Contrarily, some other wireless access technologies such as wireless local area networks (WLAN) can provide high-speed Internet access in
Services, Technologies,
small areas like cafes or airports at a much lower cost because they operate on unlicensed spectrum. These access technologies can be a good complement to 3G mobile communication systems. Due to advances in signal processing technologies and microelectronics, a contemporary mobile device can be equipped with multiple radio interfaces that enable it to be connected to multiple networks. As a result, it is anticipated that the next generation (NG) wireless communication systems will integrate different wireless access technologies together and provide user “Always Best Connected” (ABC) services [1] via the heterogeneous wireless access networks.
