CPRI协议标准

CRPI协议的标准，小众，但是对需要的人来说非常实用，希望能有帮助！CPRI Specification V1.0(2003-09-30)4. 4.1. Layer 2 Framing374.4.2. Media Access Control/Data Mapping3843. Flow Control444. Control data protection/ retransmission mechanism404.5Start-up SequenceB.n404.5.1. General404.5.2. Layer 1 Start-up Timer404.5.3. State Description414.5.4. Transition Description465Interoperability495,1Forward and backward compatibility5.1.1. Fixing Minimum Control Information Position in CPRi FrameStructure5.1.2. Reserved Bandwidth within CPR5.1.3.∨ ersion numb495.1. 4. Specification Release Version mapping into CPRi frame495.2. Compliance,,,,,,,,,,,…,,…,…,"…,…,50Annex……516.1Delay Calibration Example( Informative)…………517.List of abbreviations528References,……154CPRICPRI Specification V1.0(2003-09-30)1 IntroductionThe Common Public Radio Interface(CPRI)is an industry cooperation aimed at defining a publicly availablespecification for the key internal interface of radio base stations between the Radio Equipment Control(RECand the Radio Equipment (RE. The parties cooperating to define the specification are Ericsson AB, HuaweTechnologies Co Ltd, NEC Corporation, Nortel NetworkS SA and Siemens AGMotivation for cpriThe CPRI specification enables flexible and efficient product differentiation for radio base stations andindependent technology evolution for Radio Equipment(RE)and Radio equipment Control (REC)Scope of specificationThe necessary items for transport, connectivity and control are included in the specification. This includesUser Plane data, Control and Management Plane transport mechanisms, and means for synchronizationa focus has been put on hardware dependent layers (layer 1 and layer 2 ) This ensures independenttechnology evolution(on both sides of the interface), with a limited need for hardware adaptation. In additionproduct differentiation in terms of functionality, management, and characteristics is not limitedThe specification will have the following scopea digitized and serial internal radio base station interface between Radio Equipment Control(RECand Radio Equipment(RE)will be specified2. Three different information flows(User Plane data, Control and Management, Synchronization will bemultiplexed over the interface3. The specification will cover Layers 1 and 23a. The physical layer (layer 1) will support both an electrical interface (e.g, what is used intraditional radio base stations), and an optical interface(e.g. for radio base stations with remoteradio equipment3b. Layer 2 will support flexibility and scalabilityThe specification shall comply with 3GPP UTRA FDD release 5Radio equipment Control (rec)Radio Equipment (re)lubControl Sync User PlaneControl Sync User PlaneMgmtMgmtLayer 2Layer 2Layer 1Laver 1Digitized Radio Base Stationinternalinterface specificationFigure 1: System and Interface DefinitionCPRICPRI Specification V1.0(2003-09-30)2. System DescriptionThis chapter describes the CPri related parts of the basic radio base station system architecture and definesthe mapping of the functions onto the different subsystems. Furthermore, the reference configurations andthe basic nomenclature used in the following chapters will be definedThe following description will be based on the UMTS (Universal Mobile Telecommunication Systemnomenclature, because this is the first mobile radio standard the Common Public Radio Interface(CPRI)specification supports. However, the interface may also be used for other radio standards2.1. Definitions/nomenclatureThis section provides the basic nomenclature that will be used in the following chaptersSubsystemsThe radio equipment control and the radio equipment are described in the following chapterProtocol layersThis specification defines the protocols for the physical layer(layer 1) and the data link layer(layer 2)Layer 1 definesElectrical characteristicsOptical characteristicsTime division multiplexing of the different data flows· Low level signallingLayer 2 defines● Media access controlFlow controlData protection of the control and management information flowProtocol data planesThe following data flows can be discernedControl planeControl data flow used for call processingManagement Plane: Management information for the operation, administration and maintenance of theCPRi link and the reUser planeData that has to be transferred from the radio base station to the mobile station andvice versa. These data are transferred in the form of lq dataSynchronizationData flow which transfers synchronization and timing information between rec andREThe control and management plane will be mapped to a single information flow over the CPRI linkUser plane dataThe user plane data are transported in the form of iQ data. Several lQ data flows will be sent via onephysical CPRI link Each IQ data flow reflects the data of one antenna for one carrier, the so-called antennacarrier(AXC)Antenna-carrier(AXC)One antenna-carrier is the amount of digital baseband(IQ)U-plane data necessary for either reception ortransmission of one UtRa-Fdd carrier at one independent antenna elementAxC ContainerIt contains the lQ samples of one Axc for one UMTs chip durationCPRICPRI Specification V1.0(2003-09-30)Service Access PointsFor all protocol data planes layer 2 services access points are defined that will be used as reference pointsfor performance measurements. These service access points will be denoted as saPcm, saPs and saPio asustrated in Figure 2DownlinkDirection from rec to reUplinkDirection from re to REC2.2. System ArchitectureFuture radio base stations should provide deployment flexibility for the mobile network operators, i.e., inaddition to a concentrated radio base station, more flexible radio base station system architectures involvingremote radio equipment shall be supported. This can be achieved by a decomposition of the radio basestation into two basic building blocks, the so-called radio equipment control (REC) and the radio equipment(RE) itself. Both parts may be physically separated (i.e, the RE may be close to the antenna, whereas theREC is located in a conveniently accessible site )or both may be co-located as in a conventional radio basestation designThe radio equipment control provides access to the Radio Network Controller via the lub interface(for theUMTS radio access network), whereas the radio equipment serves as the air interface to the user equipmen(in an UMTS network this is called the Uu interface ) The REc comprises the radio functions of the digitabaseband domain, whereas the RE contains the analogue radio frequency functions. The functional splitbetween both parts is done in such a way that a generic interface based on In-Phase and Quadrature(IQdata can be defined. A more detailed description of the functional split between both parts of an UMTSsystem is provided in Section 2. 4In addition to the user plane data(iQ data), control and management as well as synchronization signals haveto be exchanged between the Rec and the re. all information streams will be multiplexed onto a digitalserial communication line using appropriate layer 1 and layer 2 protocols. The different information flows willhave access to the layer 2 via appropriate service access points(SAPs).This defines the common publicradio interface illustrated in Figure 2Radio Btation SysterRadio Equipment Con trol (REC)Radio Equipment (RE)Control Sync User PlaneControl Sync User PlanelubMgmt(APCM(SAPS)(SAP,SAPCM(SAPS)(SAPIoLayer 2Laver 2Layer 1CPRILayerCommon public radio inte rfaceFigure 2: Basic System Architecture and common Public Radio Interface definitionCPRICPRI Specification V1.0(2003-09-30)2.3. Reference ConfigurationsThis section provides the reference configurations that have to be supported by the CPRi specification. Thebasic configuration, shown in Figure 3, is composed of one REC and one RE connected by a single CPRIphysical link. The basic configuration can be extended in several waysFirst, several CPRI physical links can be used to enhance the system capacity as required for largesystem configurations involving many antennas and carriers(see Figure 4 ). This extension of thespecification is straightforward if it is assumed that an iQ data flow of a certain antenna and a certainantenna-carrier(see Section 2. 1)is carried by one CPRi link and is not distributed over several CPRIlinks. Therefore, the number of physical links is not restricted by this specificationSecond, several radio equipment entities may be served by one rec as illustrated in Figure 5RECCPRIlinkREFigure 3: Single point-to-point link between one REC and one RECPRI linkRECRECPRI linkFigure 4: Multiple point-to-point links between one Rec and one reRECPRI link(s)REC冷sREFigure 5: Multiple point-to-point links between one REC and several RESCPRICPRI Specification V1.0(2003-09-30)2.4. Functional Descriptionstandard, which provides the basis for the requirement definition in the next chapter and RE for the UMTSThis section provides a more detailed view on the functional split between RECBasically, the REC is concerned with the lub transport, the radio base station control and management aswell as the digital baseband processing. The radio equipment provides the analogue and radio frequencyfunctions such as filtering, modulation, frequency conversion and amplification. An overview on the functionalseparation between REC and RE is given in Table 1Table 1: Functional decomposition between REC and RE (valid for the UMTS FDD standard)Functions of recFunctions of reDownlinkUplinkDownlinkUplinkRadio base station control managementlub transportRRC Channel Filteringlub frame protocolsD/A conversionA/D convers ionChannel CodingChannel De-codingUp ConversionDown conversionInterleavingDe-InterleavingON/OFF control of each Automatic Gain ControlcarrierSpreadingDe-spreadingCarrier MultiplexingCarrier De-multiplexingScramblingDe-scramblingPower amplification and Low Noise AmplificationirmitinAdding of physical Signal distribution to Antenna supervisionchannelssignal processing unitsTransmit Power Control Transmit Power Control &RF filteringRF filteringof each physical channel Feedback InformationdetectionFrame and slot signalgeneration(includingclock stabilization)MeasurementsMeasurementsCPRICPRI Specification V1.0(2003-09-30)3. Interface BaselineThis chapter provides an overview on the basic input requirements for the CPRI specification. Theserequirements will also provide the basis for future enhancements of CPri3.1. Supported Radio standardsThe interface shall support transmission of all necessary data between REC and re in both directions for aradio base station consisting of one REC and one or more REs compliant to the following radio standardsRequirement NoRequirement Definition Requirement ValueRadio Standard and 3GPP UTRA FDDReleaseRelease 5, June 2003The support of other standards is not required in this release of the CPRI specification, but the future use ofthe interface for other standards shall not be precluded3.2. Operating RangeThe interface shall support a continuous range of distances (i.e, cable lengths)between REC and RE. Theminimum required range is defined by the cable length in the following tableRequirement NoRequirement Definition Requirement valueR-2Cable length(lower limit)0 mR-3Cable length(upper limit)>10 kmThe interface shall support one cable for uplink and downlink with separate transmission media(e.g. opticafibres) for uplink and downlink. Simplex operation shall be supported per transmission medium(e. g, opticalfibres3.3. Topology/Switching/MultiplexingThe following topologies shall be supported by the CPRI specificationRequirement NoRequirement Definition Requirement ValueTopologyStar topologe. oneREC With one or severaRESThe support of other topologies is not required in this release of the specification but the use of the interfacein other topologies shall not be precludedThe connection of one re to more than one rec is not consideredCPRI10CPRI Specification V1.0(2003-09-30)3. 4. Bandwidth/Capacity/Scalability3.4.1. Capacity in terms of Antenna-CarriersThe capacity of one interface link shall be expressed in terms of UTRA-FDD-antenna-carriers(abbreviationantenna-carrier"or AXC"). One UTRA-FDD-antenna-carrier is the amount of digital baseband (IQ)U-planedata necessary for either reception or transmission of one UTRA-FDD carrier at one independent antennaelement. One antenna element is typically characterized by having exactly one antenna connector to the rECPRI shall be defined in such a way that the following typical Node b configurations can be supported1 RE supports one sectoro Up to 4 carriers x 1 antenna per RE(e.g. 6 REs for 3 sectorsc Up to 4 carriers x 2 antennas per RE(e.g 3 REs for 3 sectors)·1 RE supports3 sectorsc from 1 to 4 carriers x2 antennas x 3 sectors per reTherefore, the following number of Axc shall be supported by the cPri specificationRequirement NRequirement Definition Requirement ValueR-5Number of antenna 4carriers per physical lineR-6Number of antenna 6carriers per physical lineR-7Number of antenna 8carriers per physical lineR-8Nof antenna 12riers per physical lineR-9Number of antenna 18arriers per physical lineR-10Number of antenna 24carriers per physical line3.4.2. Required U-plane IQ Sample WidthsThe uplink IQ sample widths supported by the CPRI specification shall be between 4 and 10 bits and thedownlink IQ sample widths supported by the CPRI specification shall be between 8 and 20 bitsRequirement noRequirement Definition Requirement ValueR-11Minimum uplink iQ sample 4widthR-12Maximum uplink iQ sample 10idthR-13Minimum downlink IQ 8sample widthR-14Maximum downlink IQ 20aple widthCPRI