WIRELESS TECHNOLOGYProtocols, Standards, and Techniques pdf phần 7 pps

P1: FNT book CRC-Wireless November 8, 2001 18:23 Char Count= 268 Part IV 3G Systems © 2002 by CRC Press LLC E:\Java for Engineers\VP Publication\Java for Engineers.vp Thursday, April 25, 2002 9:27:36 AM Color profile: Disabled Composite Default screen P1: FNT book CRC-Wireless November 8, 2001 18:23 Char Count= 268 7 IMT-2000 7.1 Introduction The conception of third-generation (3G) wireless systems is embodied by the International Mobile Telecommunications-2000 (IMT-2000). IMT-2000 stan- dards and specifications have been developed by various standards organiza- tions worldwide under the auspices of the International Telecommunications Union (ITU). 3G telecommunication services target both mobile and fixed users, with the access provided via a wireless link. A wide and ambitious range of user sectors, radio technology, radio coverage, and user equipment is covered by IMT-2000. In essence, a 3G system must provide for: r Multimedia services, in circuit-mode and packet-mode operations r User sectors such as private, public, business, residential, local loop, and others r Terrestrial-based and satellite-based networks r Personal pocket, vehicle-mounted, or any other special terminal Moreover, global roaming and virtual home environment (VHE) are sup- ported by 3G systems. Global roaming capability allows users to roam across different wireless networks, and the VHE characteristic provides roamers with the set of services and features of their home network. The key features of IMT-2000, as specified in Reference 1, include: r High degree of commonality of design worldwide r Compatibility of services within IMT-2000 and fixed networks r High quality r Small terminal for worldwide use r Capability for multimedia applications and wide range of services and terminals © 2002 by CRC Press LLC E:\Java for Engineers\VP Publication\Java for Engineers.vp Thursday, April 25, 2002 9:27:36 AM Color profile: Disabled Composite Default screen P1: FNT book CRC-Wireless November 8, 2001 18:23 Char Count= 268 IMT-2000 may be implemented as a stand-alone network or as an integral part of the fixed networks.Inthefirst case, gateways and interfacing units must be provided so that internetworking operations can be supported. Note that this has been the standard solution for the internetworking operation be- tween conventional public land mobile and fixed networks and also between conventional mobile networks of different technologies. In the second case, the fixed network must accommodate the functionality specific to the mobile networks, such as location registration, paging, handover, and others. This is feasible with the development of IN (intelligent network) capability and the use of exchanges with ISDN (Integrated Service Digital Network) and B-ISDN (Broadband-ISDN) capabilities. 3G systems provide for modularity in terms of both capacity and function- ality. A start-up network may gradually evolve from a simple and small 3G system to a large network with complex 3G applications. In this sense, the IMT-2000 functional model is developed to be flexible to accommodate a wide range of 3G applications while meeting the necessary requirements of quality of service (QoS). As opposed to the fixed QoS (defined as best effort) in the 1G and 2G wireless systems, 3G systems provide for flexible QoS. Users and their applications can be assigned a default QoS with negotiations for a suitable QoS occur- ring as desired. Resources are then allotted depending on a series of param- eters such as QoS profiles authorized by subscription, system load, propa- gation conditions, type of traffic (which is dependent on the application), and others. In summary, the key goals for 3G networks are the following: r Universal adoption of a core set of standards for the air interface r Promotion of global roaming r Efficient support of a wide range of data services including multi- media In practical terms, 3G systems are deployed with two main objectives: 1. To support packet data services with speed and quality available on fixed networks 2. To provide Internet access 7.2 Some Definitions This section lists the definitions of some terms [3] that are used in a more specific sense in the context of this chapter. © 2002 by CRC Press LLC E:\Java for Engineers\VP Publication\Java for Engineers.vp Thursday, April 25, 2002 9:27:36 AM Color profile: Disabled Composite Default screen P1: FNT book CRC-Wireless November 8, 2001 18:23 Char Count= 268 r Access Link. An access link constitutes an aggregation of logical chan- nels supporting a connection link between the mobile terminal and the core network. It comprises two segments: the access radio link and the BS approach link. r Access Radio Link. An access radio link is the radio portion of the access link. r Association between an IMT-2000 Terminal/User and the Network (Ter- minal/User Association). A terminal/user association corresponds to a logical association between the IMT-2000 terminal/user and the network. Such an association is established at the first outgoing or incoming call of the terminal/user at the idle state. It is used by the network to identify the IMT-2000 terminal/user among all the IMT- 2000 terminals/users having control relationships with it. It is kept active until all the calls and connections on the terminal are released. r Authentication Data. Authentication data encompass authentication parameters and authentication information asused for authentication purposes. r Authentication Information. The authentication information constitutes the information used for user authentication (e.g., the triplet chal- lenge, response, and ciphering key). r Authentication Parameter. An authentication parameter constitutes se- cret data utilized for individual user authentication (e.g., authentica- tion key, shared secret data). r Bearer. A bearer is a communication path between adjacent nodes associated with a given connection. r Bearer Control. The bearer control supports the node-to-node control of network resources providing for an end-to-end carriage of infor- mation. r BS Approach Link. A BS approach link is the segment of the access link which, together with the access radio link, composes the access link. r Call. A call is defined as an end-to-end logical association between two or more parties. It is associated with a service request. r Call Control. A call control constitutes a set of functions (service ne- gotiation, setup, modification, and release) performed to process a call as a result of a service request. One call may trigger connections ranging from none to several connections. r Camp on a Cell. A mobile terminal is said to “camp on a cell” when it lodges temporarily within a cell after the cell selection/reselection process is completed. r Connection. A connection consists of an end-to-end association of network resources or entities to provide means for a transfer of © 2002 by CRC Press LLC E:\Java for Engineers\VP Publication\Java for Engineers.vp Thursday, April 25, 2002 9:27:36 AM Color profile: Disabled Composite Default screen P1: FNT book CRC-Wireless November 8, 2001 18:23 Char Count= 268 information between points within the network. A connection is es- tablished by the union of connection links. r Connection Control. A connection control constitutes a set of functions performed to set up, maintain, and release a communication path between users or between a user and a network entity. r Connection Link. A connection link constitutes a part of a connection between two connection control functions. r Diversity Convergence Point. A diversity converging point is the point into which physical bit streams merge to form one logical information stream. r Diversity Branch. A diversity branch corresponds to a path diverging from the diversity point. r Diversity Handover. Diversity handover is a handover that uses macro- diversity techniques. r Diversity Link. A diversity link is a set of diversity paths. r Diversity Path. A diversity path is a branch of a diversity link. r Handover Branch. A handover branch constitutes an access radio link branch that takes part in a handover. r Handover Path. A handover path constitutes a sequence of link ele- ments that take part in a handover. r Link Element. A link element is a logical channel connecting two ad- jacent functional nodes. r Macrodiversity. Macrodiversity is a kind of diversity in which theradio paths of redundant information are separated by large distances as compared to the propagated radio wavelength. In the uplink, the communication is characterized by a point-to-multipoint connection with the mobile terminal signal captured by several base stations. In the downlink, the communication is characterized by a multipoint-to- point connection with the signals from several base stations captured by a single mobile terminal. The macrodiversity techniques include base station diversity, diversity handover, simulcast, and others. r Radio Resource. The radio resource is the portion of the radio spectrum available within the cell. 7.3 Frequency Allocation The World Administrative Radio Conference 1992 (WARC 1992), Torremo- linos, Spain, identified two frequency bands, a total of 230 MHz, to be used for IMT-2000 applications. The identified frequency bands spanned from 1885 © 2002 by CRC Press LLC E:\Java for Engineers\VP Publication\Java for Engineers.vp Thursday, April 25, 2002 9:27:36 AM Color profile: Disabled Composite Default screen P1: FNT book CRC-Wireless November 8, 2001 18:23 Char Count= 268 to 2025 MHz and from 2110 to 2200 MHz. Later on, the World Radio Con- ference 2000 (WRC 2000), Istanbul, Turkey, identified three other frequency bands, an additional 519 MHz for IMT-2000 applications. These new bands spanned from 806 to 960 MHz, from 1710 to 1885 MHz, and from 2500 to 2690 MHz. These bands are intended to be available on a global basis for countries wishing to implement IMT-2000 systems. Note that, by allowing these bands to overlap with those bands already used for other wireless serv- ices, the 2G cellular systems included, a high degree of flexibility is provided with the operators able to migrate toward IMT-2000 according to the market and other national considerations. 7.4 Features and Services The features and services provided by IMT-2000 systems are defined as service capabilities in the ITU-T Recommendations. An extensive list of features and services of IMT-2000 networks, divided in several categories, are listed in Reference 1 under the item Capability Set 1. This section presents the primary capabilities. In the descriptions that follow, the terms system and family member are used interchangeably; these concepts are better defined in the next section. The capability categories and the respective capabilities are described next. r Existing Capability. This category recommends that the 2G core fixed and mobile services and capabilities be kept or possibly enhanced. r Long-Term Objectives. This category traces the long-term objectives of IMT-2000 and establishes that distinct improvement over 2G systems in the areas of voice, data messaging, image, and multimedia be sup- ported. In particular, enhanced roaming, increased data rates, and multimedia and Internet wireless services are targeted. r Bearer Capability. The following constitute some of the bearer capabil- ities: Terrestrial access with BER ≤10 −6 for transmission rates of at least: 1. 144 kbit/s in vehicular radio environment. 2. 384 kbit/sin outdoor to indoor and pedestrian radio environment. 3. 2048 kbit/s in indoor office environment, for both circuit and packet services. Data rates for satellite access varying with the operating environment and with the type of terminal and ranging from 9.6 to 144 kbit/s. QoS negotiated real time/non-real time basis and according to the delay characteristics, maximum acceptable bit error rate, and bit rate/throughput. © 2002 by CRC Press LLC E:\Java for Engineers\VP Publication\Java for Engineers.vp Thursday, April 25, 2002 9:27:36 AM Color profile: Disabled Composite Default screen P1: FNT book CRC-Wireless November 8, 2001 18:23 Char Count= 268 Packet services on radio as well as on fixed interfaces. Communication configurations for bidirectional point-to-point and point-to-multipoint services, the latter comprising broadcast and multicast capabilities. Types of communication including connectionless-oriented network service and connection-oriented network service. Access links of the symmetric and asymmetric type. Fixed and variable bit rate traffic. r Access Network Capability. The following constitute some of the access network capabilities: Packet services with negotiable parameters such as bit rate, delay tolerance, and reliability classes (probability of data loss, out of sequence delivery, etc.). Constant bit rate with timing and variable bit rate with timing for connection-oriented network, constant bit rate without timing and variable bit rate without timing for connectionless-oriented net- work, and efficient link layer recovery. Radio resource control capabilities including radio channel quality monitoring, macrodiversity monitoring, channel allocation, and power control. Fixed wireless access. r Core Network Capability. The following constitute some of the core network capabilities: Constant bit rate with timing and variable bit rate with timing for connection-oriented network, constant bit rate without timing and variable bit rate without timing for connectionless-oriented net- work, and efficient link layer recovery. Handling of voice, data,andvideoby means of bothcircuit and packet communication. Internetworking with ISDN, B-ISDN, X.25 PDN (Packet Data Net- work), IP (Internet protocol) networks, and PSTN (PublicSwitched Telephone Network). Terminal mobility, personal mobility, and service mobility. Internetworking with IP networks and provision of Internet-type services. Global roaming and serviceinteroperability betweenIMT-2000 family members. Support of packet-switched and circuit-switched operations. Support of evolved family member network architecture. © 2002 by CRC Press LLC E:\Java for Engineers\VP Publication\Java for Engineers.vp Thursday, April 25, 2002 9:27:36 AM Color profile: Disabled Composite Default screen P1: FNT book CRC-Wireless November 8, 2001 18:23 Char Count= 268 Support of open interfaces with intelligent network servers, and others. r Network Capabilities—Call Control. The following constitute some of the network capabilities concerning call control: Multiple simultaneous calls per terminal or directory number, mul- timedia calls, call internetworking procedures, emergency calls, and priority calls. Geographic positioning of a terminal or user. Multiconnection calls independent of connection characteristics. r Network Capabilities—Security Procedures. The following constitute some of the network capabilities concerning security procedures: User authentication and ciphering, service-dependent authentication and ciphering meconiums, and user–network mutual authentica- tion. Terminal identification. Prevention of fraudulent (unauthorized) use. Privacy of data and user message. r Network Capabilities—Resource Allocation. The following constitute some of the network capabilities concerning resource allocation: Allocation based on QoS, overload control, mixed services configu- rations, and route optimization. r Network Capabilities—Numbering and Addressing. The following con- stitute some of the network capabilities concerning numbering and addressing: Support of numbering and addressing portability. Support of conventional and advanced addressing and numbering plans. Identity management for terminal, international mobile user, sub- scriber ISDN, multicast group. r Network Capabilities—Charging and Accounting. The following consti- tute some of the network capabilities concerning charging and ac- counting: Standardized billing and charging user profiles and new charging mechanisms based, for example, on the traffic volume, QoS, time, etc. Real-time charging, third-party charging, prepaid billing, location- dependent billing and charging, and real-time access to billing information. © 2002 by CRC Press LLC E:\Java for Engineers\VP Publication\Java for Engineers.vp Thursday, April 25, 2002 9:27:36 AM Color profile: Disabled Composite Default screen P1: FNT book CRC-Wireless November 8, 2001 18:23 Char Count= 268 Charging information generation for circuit-switched calls, packet data transmission, and signaling traffic. r Network Capabilities—Roaming. The following constitute some of the network capabilities concerning roaming: Mobility and global roaming including location management, user registration and cancellation, security and authentication database management and control, and others. Ability to supplement mobility management and authentication con- trol with intelligent network–type service logic. r Network Capabilities—Service Portability. The following constitute some of the network capabilities concerning service portability: The capabilities under service portability basically concern the VHE feature. VHE, as previously defined, provides roamers with the set of services and features of their home network. r Network Services/Features—Handover. The following constitute some of the network services/features concerning handover: Support of hierarchical cell structure with call transfer and handover across cell layers and location management within multiple cell layers. r Network Services/Features—Service Provisioning. The following consti- tute some of the network services/features concerning service provi- sioning: Provision for over-the-air service such as support for voice and data, and security and authentication. r Network Services/Features—Quality of Service. The following constitute some of the network services/features concerning QoS: Support of QoS based on subscription, or on negotiation during a service invocation, or on renegotiation during a service session. Provision for QoS equivalent to that of the wired access. Fulfillment of minimum delay requirements. r Network Services/Features—Supplemental Support. The following con- stitute some of the network services/features concerning supplemen- tal support: Support of cordless telephone access, virtual private networks, IP- based services, satellite access, media transparency, and operator services. r Network Services/Features—Terminals and User Interface Modules. The following constitute some of the network services/features concern- ing terminals and user interface modules: © 2002 by CRC Press LLC E:\Java for Engineers\VP Publication\Java for Engineers.vp Thursday, April 25, 2002 9:27:36 AM Color profile: Disabled Composite Default screen P1: FNT book CRC-Wireless November 8, 2001 18:23 Char Count= 268 Provision for a network model to support uploading and download- ing of user profiles, data information capabilities, software config- urable terminals, future enhancements in software-defined radios. Support of mobiles and user interface modules with downloading capabilities over the air for data and applications. Support of multiple calls on a single terminal and multiple registra- tion of one user on several terminals for different services. r Network Services/Features—Packet Transfer Control. The following con- stitute someof the network services/features concerningpacket trans- fer control. Support of registration/authentication, static and dynamic address assignment, sleep mode for battery power conservation, optimal packet routing, multiprotocol, data compression, internetworking, location identification, load balancingacross RF channels, multiple simultaneous address registrations on a single terminal, priority access, and multimedia sessions. As mentioned before, the set of capabilities listed above corresponds to what is called Capability Set 1 in the ITU-T Recommendations. Future capa- bility sets with enhanced and new capabilities shall be built upon the pre- vious capability sets and shall support backward and forward compatibility between capability sets. 7.5 Traffic Classes Four classes of trafficaredefined to be supported by 3G systems: conversa- tional, streaming, interactive, and background. r Conversational Class. The conversational class is the most familiar class of traffic. It preserves the time relation between information entities of the stream and demands a constant and short end-to-end delay. An example application is voice. r Streaming Class. The streaming class preserves the time relation be- tween information entities of the stream. This class of traffic works within a small rangeof delays and throughput rates.It is characterized by applications for which the processing of the traffic can be started for presentation to the user before the whole file is transmitted to the subscriber. An example application is streaming video. r Interactive Class. The interactive class requests response pattern and preserves payload content. This class of traffic works with an © 2002 by CRC Press LLC E:\Java for Engineers\VP Publication\Java for Engineers.vp Thursday, April 25, 2002 9:27:36 AM Color profile: Disabled Composite Default screen [...]... Functions related to random access are grouped under this item The following functions are identified: r Random-Access Initiation This function initiates the specified randomaccess procedure when the mobile terminal accesses the network r Random-Access Detection and Handling This function detects the random-access initiation attempt carried out by the mobile terminal It handles the random access by responding... such as reservation/ activation of the new radio and wireline resources required for handover and final switching from the old to the new resources r Handover Completion This function releases the resources that are no longer needed r Handover Trigger This function recognizes cells to be added to or deleted from the access link 7. 7 .7 Location Management and Geographic Position–Finding Functions Functions... the association and access link between an MT and the network Tasks performed by the RACF include interaction with other FEs to allocate and reallocate physical channels for a branch of an access radio link and to set up, maintain, modify, and release a branch of a BS approach link and associated access radio link; execution of handover decision; execution of handover; completion of handover; RF power... ability to provide bearers with flexible QoS, parallel calls, and point-tomultipoint calls r Management of Circuit-Switched and Packet-Switched Communications This function supports circuit-switched and packet-switched communication paths simultaneously 7. 7.9 Data Coding and Compression Functions Functions related to data coding, signaling compression, and data compression are grouped under this item The following... monitoring, acquisition and selection of surrounding cells, and others r Cell Selection in Packet Data Transfer Mode This function enables the mobile terminal to select the best cell when engaged in a packet data transaction This process involves tasks such as signal quality monitoring, detection of traffic condition within the candidate cells, and others 7. 7.2 Radio Resource Management and Control Functions... 2002 9: 27: 36 AM Color profile: Disabled Default screen Composite P1: FNT book CRC -Wireless November 8, 2001 18:23 Char Count= 268 Some of these functions are listed in Reference 3, where they are grouped according to their relations with the overall service and network capabilities This section summarizes these functions 7. 7.1 Overall System Access Control Functions The access to services and facilities... throughput rates and is very tolerant of delays but relatively intolerant of errors Example applications include background download of e-mails, short messaging services, and file downloads 7. 6 IMT-2000 System and IMT-2000 Family Two important concepts are formally defined within the IMT-2000 philosophy: IMT-2000 System and IMT-2000 Family An IMT-2000 System comprises a set of subsystems, entities, and interfaces... detection and correction, flow control procedures, and load balancing across RF channels r RF Power Control This function controls the levels of transmitted power of both the mobile terminal and the base station upon assessing the radio channel quality r RF Power Setting This function constitutes an intrinsic part of any power control scheme It is used to adjust the output power of the transmitter 7. 7.3 Random-Access... UIM and with the RAN In addition, it supports user mobility and user services r Radio Access Network The RAN subsystem performs functions to support communication with the MT and with the CN It provides means for exchanging information between MT and CN, acting as a bridge, router, and gateway as required r Core Network The CN subsystem performs functions to support com- munication with the RAN and. .. service request 7. 7.5 Channel Coding Function This item contains only one function as follows: r Radio Channel Source and Error Protection Coding and Decoding This function is related to the procedures used to protect the data transmission against errors This is achieved by the use of convolutional codes for error detection and correction, of cyclic redundancy check codes for error detection, and of interleaving . detection of traffic condition within the candidate cells, and others. 7. 7.2 Radio Resource Management and Control Functions Functions related to allocation and maintenance of physical channels are grouped. error detection and correction, of cyclic redundancy check codes for error detection, and of interleaving for error protection. 7. 7.6 Handover Function Functions related to handover are grouped. other frequency bands, an additional 519 MHz for IMT-2000 applications. These new bands spanned from 806 to 960 MHz, from 171 0 to 1885 MHz, and from 2500 to 2690 MHz. These bands are intended