Các mạng UTMS và công nghệ truy cập vô tuyến P6

SERVICE COMPONENTS IN UMTSBACKGROUNDUMTS services will not only offer mobile services supported by 2nd generation systems such as GSM, but will also expand these services to higher rates and greater flexibility. The services evolving in the GSM platform through its Circuit Switched (CS) and Packet Switched (PS) services will continue in UMTS while new services are introduced.
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Các mạng UTMS và công nghệ truy cập vô tuyến P6 The UMTS Network and Radio Access Technology: Air Interface Techniques for Future Mobile Systems Jonathan P. Castro Copyright © 2001 John Wiley & Sons Ltd Print ISBN 0-471-81375-3 Online ISBN 0-470-84172-9 SERVICE COMPONENTS IN UMTS6.1 BACKGROUNDUMTS services will not only offer mobile services supported by 2nd generation systemssuch as GSM, but will also expand these services to higher rates and greater flexibility.The services evolving in the GSM platform through its Circuit Switched (CS) and PacketSwitched (PS) services will continue in UMTS while new services are introduced.Thus, future UMTS services will have user transmission rates from low bit up to 2Mbps. Although, high rates will occur primarily within indoor environments, there willbe substantial increases in rates throughout all environments when compared to thetypical 9.4 kbps. Table 6.1 (an extract from Table 2.1) illustrate this increase. Table 6.1 Range of Transmission Rates High level Maximal bit rate Maximal speed Cell coverage description (kbits/s) (km/h) Rural outdoor 144s 500 Macrocell Suburban outdoor 384 120 Microcell Macrocell Indoor/ 2048 10 Picocell Low range outdoor MicrocellThen the question of the transmission range for UTMS services, is no longer just whattransmission rates, but what type of services, when and where. It is no longer “commu-nications any where any time”, but “what I want when I want where ever I want”.Practically, the exploitation of wider transmission rates will facilitate the expansion ofdata traffic. As illustrated Table 6.2 there exists a clear trend for the convergence of IPprotocol to wireless, or to what we now call wireless IP. The latter will lead to the Wire-less Internet, where about 200 M Internet and 300 M mobile subscribers will merge into1 billion Wireless Internet users. Table 6.2 Convergence of Internet Protocol (IP) to Wireless Computer: mobility Telecommunications: mobility Media: mobility high speed services wide services personal services Internet access ISDN services Streaming audio Electronic mail Video telephony Video on demand Real time images Wideband data services Interactive video services Multimedia Location services coupled with TV/radio/data contribution application servers and distributionNon-voice services will make demands not only on manufacturers and operators butalso from supporting industries, creating a need for new service enablers. However,232 The UMTS Network and Radio Access Technologysuch demand will also introduce new challenges and the need for pragmatic integrationof services and devices, as well as new data processing and managing techniques. Thesedemands can be summarized as needs as illustrated in Table 6.3. Table 6.3 Needs for Service Providers and Technology Enablers Needs for service providers Needs for technology enablers Strategy for innovative services Well integrated CS and PS system Economic and spectrum efficiency data pipe Advanced value added platforms (e.g. WAP, IS, location services, unified messaging, etc.) Standard interface to phone display Power efficient handsets Dynamic management control points Effective yet very light device OSs New and flexible billing systems Text “ speech Perception of market needs Speech “ text Personalization Intelligent voice recognition Addressing all user segments Multi-band terminals exploiting software radio New data processing and management Synchronization techniques Cost efficient terminals and devices Pragmatic user interfaces (e.g. efficient portals)Clearly, the challenges cover all main areas of SW/HW and management technology. Inthe forthcoming sections we will see how UMTS addresses these needs and outline themain approaches and requirements to meet the challenges.6.2 THE UMTS BEARER ARCHITECTUREAs illustrated in Figure 6.1 after [1], UMTS proposes a layered bearer service architec-ture, where each bearer service on a specific layer offers its individual services based onlower layers. Thus, the UMTS bearer service architecture serves as an ideal platform forend-to-end services providing key features in preceding layers. @I9ÃUPÃ@I9ÃT@SWD8@ U@HUà y‚phy @‘‡r…hy VHUTÃ7@6S@SÃT@SWD8@ ...