1x Evolution-Data Optimized (1xEV-DO)
In an IP-based 1xEV-DO network, radio nodes perform radio frequency processing, baseband modulation/demodulation and packet scheduling.
Radio nodes installed at a cell site can support hundreds of subscribers. Radio network controllers (RNC) typically are located in a central office and provide hand-off assistance, mobility management and terminal-level security via a Remote Authentication Dial-In User Service server. Each RNC can support many radio nodes and connects to a service provider's core data network through a standard wireless router called a packet data serving node. Finally, an element management system lets service providers manage 1xEV-DO radio networks.
1xEV-DO takes advantage of recent advances in mobile wireless communications, such as the adaptive modulation system, which lets radio nodes optimize their transmission rates based on instantaneous channel feedback received from terminals. This, coupled with advanced turbo coding, multilevel modulation and macrodiversity via sector selection, lets 1xEV-DO achieve download speeds that are near the theoretical limits of the mobile wireless channel.
1xEV-DO also uses a new concept called multiuser diversity. This allows more efficient sharing of available resources among multiple, simultaneously active data users. Multiuser diversity combines packet scheduling with adaptive channel feedback to optimize total user throughput.
A 1xEV-DO network is distinguished from other 3G networks in that it is completely decoupled from the legacy circuit-switched wireless voice network. This has let some vendors build their 1xEV-DO networks based entirely on IP technologies.
From CDMA2000 1xEV-DO delivers 3G wireless, Network World Tech Update, 02/25/02.Additional resources
Topic: Wireless/Mobile
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