Presentation on theme: "WCDMA RAN Protocols and Procedures Chapter 5 RLC and MAC Protocols"— Presentation transcript:
1WCDMA RAN Protocols and Procedures Chapter 5 RLC and MAC Protocols In this chapter we will look at the considerations that must be taken into account when planning a CDMA network.
2Objectives of Chapter 5, RLC and MAC Protocols After this chapter the participants will be able to:Explain the RLC functions.List the different modes of RLC (transparent, unacknowledged and acknowledged mode) and explain the structure of the Protocol Data Unit (PDU) involved in these cases.Explain the MAC functions.Explain the MAC architecture, its entities and their usage for the mapping of transport channels.List the contents of the MAC Protocol Data Unit (PDU).Explain the Transport Format selection and the relation between Combinations (TFC) and Sets (TFCS).Explain Channel Type Switching.Explain the structure and mapping of physical channels.
5Uu interface protocol architecture (figure 5-1) (2) The control interfaces between the RRC and all the lower layer protocols are used by theRRC layer :* configure characteristics of the lower layer protocol entities, including parameters forthe physical, transport and logical channels.* to command the lower layers to report measurement results and errors to the RRC.
6RADIO LINK CONTROL (RLC) PROTOCOL -- INTRODUCTION--
7INTRODUCTIONThe RLC work in transparent, unacknowledged and acknowledged mode.in the control plane, the service provided by the RLC layer is called Signalling RadioBearer (SRB).In the user plane, the service provided by the RLC layer is called a Radio Bearer (RB)
8Protocol Data Unit (PDU) and Service Data Unit (SDU) (1) (figure 5-2) Uu interfacePDCPPDCP PDUPDCP PDURLC PCIRLC SDURLC SDURLCRLC PDURLC PCIpayloadRLC PDURLC PCIpayloadMACMAC SDUMAC SDUSDU : Service Data UnitPDU : Protocol Data UnitPCI: Protocol Control InformationProcessing done for the SDUs at layer N can be e.g.: -Add overhead (e.g. sequence number, ch type info)-Segmentation, etc.
9Protocol Data Unit (PDU) and Service Data Unit (SDU) (2) the Radio Link Control (RLC) layer receives a PDCP PDU.In the RLC layer, the data will be known as an RLC SDUAfter the header is added, the data is called an RLC PDUIn the Medium Access Layer (MAC) this is now a MAC SDU.The MAC layer may add a MAC header and send MAC PDUs to the physical layer.
10RADIO LINK CONTROL (RLC) PROTOCOL -- RLC FUNCTIONS --
11RLC Protocol Entity (1) RLC Services RLC Functions L2 connection establishment and releaseTransparent data transferUnacknowledged data transferAcknowledged data transferRLC FunctionsSegmentation and re-assemblyConcatenationPaddingTransfer of user data in transparent,unacknowledged and acknowledged mode.Error correction (ARQ)In-sequence deliveryDuplicate detectionFlow controlSequence number checkCiphering
12RLC Protocol Entity (2) 1. Segmentation and reassembly Performs segmentation/reassembly of variable length higher layer PDUs into/fromsmaller RLC Payload Units (PUs).2. ConcatenationIf the contents of an RLC SDU do not fill an integral number of RLC PDUs, the firstsegment of the next RLC SDU may be put into the RLC PDU in concatenation with thelast segment of the previous RLC SDU3. PaddingWhen concatenation is not applicable and the remaining data to be transmitted doesnot fill an entire RLC SDU of given size, the remainder of the data field is filled withpadding bits.4. Transfer of user dataRLC supports acknowledged, unacknowledged and transparent data transfer.Transfer of user data is controlled by QoS setting.
17RLC Layer Architecture (figure 5-3) TMUMAMTxRxTxRxTx/RxRxTxRxTxTx/RxIn Transparent and Unacknowledged Mode the RLC entities are unidirectionalIn Acknowledged Mode, it is bi-directional
18RLC Transparent Mode PDU (figure 5-4) The RLC TM PDU introduces no overheadProtocol functions may still be applied e.g. segmentationDataTM is used for voice and circuit switched data where delay should be as low as possible. It is also used for the SRB for BCCH and PCCH.
20RLC Unacknowledged Mode PDU (figure 5-6) Sequence number.E: Extension bit. Indicates whether next octet will be a length indicator and E bit.Data shall be a multiple of 8 bits.If the transmitted data does not fill an entire PDU the remainder of the data field is filled with padding bits.Oct1ELength IndicatorDataPADOct N(Optional).Sequence NumberCiphering Unitno retransmission protocol is used and data delivery is not guaranteed. Received erroneous data iseither marked or discarded depending on the configuration.
21RLC Fields (table 5-1) length indicators Length Indicators are also used to define whether Padding is included in the UMD PDU.It may be 7 bits (if the largest PDU size is ≤ 125 octets) or 15 bits long (otherwise).some length indicator sequences are predefined
23RLC Unacknowledged Mode Entities (figure 5-7) Segmentation & ConcatenationPaddingCipheringSequence number checkTransfer of user dataUE/UTRANRadio Interface (Uu)UTRAN/UEUM-SAPUM-SAPTransmissionTransmittinReceivingReassemblybuffergUM RLCUM RLCentityentityRemove RLCSegmentation &headerConcatenationReceptionAdd RLC headerbufferCipheringDecipheringDCCH/DTCH–UEDCCH/DTCH–UTRANCCCH/SHCCH/DCCH/DTCH/CTCH–UTRANCCCH/SHCCH/DCCH/DTCH/CTCH–UEExample for UM RLC: The cell broadcast service is an example of a user service thatcould utilise UM as well as the RRC Connection Setup/Reject message sent onCCCH/FACH.
24RLC Acknowledged Mode PDU (figure 5-8) D/C: Data/Control PDU indicator bitP: Poll bit. To be used to request fora Status PDU.HE: Header Extension bits. Indicates if thenext octet will be data or a length indicatorand E bit.E: Extension bit. Indicates whether next octetwill be a length indicator and E bit.Sequence NumberD/CELength IndicatorDataPADor a piggybacked STATUS PDUOct12OctNPHE.(Optional)3Example for AM RLC:* for packet-type services such as Internetbrowsing and (DTCH).* also used for signalling, when it isimportant that the signalling is receivedcorrectly but delay is not the mostimportant.Ciphering Unit
25RLC fields (table 5-3 and 5-4) D/C fieldLength: 1bit.The D/C field indicates the type of an AM PDU. It can be either data or control PDU.BitDescriptionControl PDU1Data PDUNOTE: There are some predefined sequence numbers
27RLC fields continued (table 5-7) The Status PDU : is used for retransmission. The receiver transmits status reports to thesender in order to inform the sender about which AMD PDUs have been received and notreceived.
28RLC PDU Formats- Status PDU (figure 5-9) D/CPDU typeSUFI 1Octet 1SUFI1Octet 2SUFIKOctet ND/C: Data/control PDU indicator.SUFI: Super Field. This field can be either a list, bitmap, relative bitmap, Acknowledgment field etc. Which type of field it is is indicated within the SUFI.
29Super Fields (SUFI)Acknowledgement: Gives the SN up to which all PDUs are received correctlyList: Lists the SNs of the PDUs which were not received correctlyBitmap: Indicates the erroneous PDUs in a bitmapRelative List: Optimised method of listing erroneous PDUsMove Receive Window: Moves the receiving window when SDU discard is performedNo More Data: Indicates the end of a Status ReportWindow Size: This field is for flow control purposes
30RLC Acknowledged Mode PDU (figure 5-10) UE/UTRANAM-SAPAM RLC entitySegmentation/ConcatenationRLC Control UnitAdd RLC headerPiggybacked statusOptionalRetransmissionbuffer &ReassemblymanagementReceivedRemove RLC header & ExtractMUXacknowledgementsPiggybacked informationTransmissionReception bufferAcknowledgementsbuffer& RetransmissionmanagementThis block diagram of a WCDMA UE transmitter shows clearly that the DPCCH and DPDCH are not time multiplexed but are transmitted on the I and Q branches of an I/Q modulator. In other words complex spreading is done. The reason for this is as previously stated is to reduce the peak to average power output from the UE and hence reduce the interference to equipment close to the transmitter.DecipheringSet fields in PDU Header (e.g. set pollbits) & piggybacked STATUS PDUCiphering(only for AMD PDU)Demux/RoutingTransmitting sideReceiving sideDCCH/DCCH/DCCH/DCCH/DCCH/DCCH/DTCH**DTCH*DTCH**DTCH**DTCH*DTCH**
31MEDIUM ACCESS CONTROL (MAC) PROTOCOL ---INTRODUCTION---
32The MAC layer offers services to upper layers in the form of : * data transfer on logical channels* reallocation of radio resources* MAC parameters :reconfiguration of MAC functions such as change of identity of UE, change oftransport format (combination) sets, change of transport channel type.* reporting of measurements:such as traffic volume and quality indication
33MEDIUM ACCESS CONTROL (MAC) PROTOCOL ---MAC FUNCTIONS---
34MAC Protocol Entity (1) MAC Services MAC Functions Data Transfer Reallocation of resourcesMeasurement reportingMAC FunctionsMapping between logical channels and transport channelsSelection of appropriate Transport Format for each Transport Channel depending on the instantaneous source rateUE identification on common transport channelsMultiplexing of logical channels (common and dedicated)Traffic volume measurementTransport Channel Type switchingCiphering for transparent mode RLC
35MAC Protocol Entity (2) MAC Functions Mapping between logical channels and transport channelsSelection of appropriate Transport Format for each Transport Channel depending on the instantaneous source ratePriority handling between data flows of one UEachieved by selecting “high bit rate” and “low bit rate” Transport Formatsfor different data flows.UE identification on common transport channelsthe identification of the UE (Cell Radio Network Temporary Identity (C-RNTI) or UTRAN Radio Network Temporary Identity (U-RNTI)) is included inthe MAC header.
36MAC Protocol Entity (3)Multiplexing of logical channels (common and dedicated)Traffic volume measurement* Measure on the amount of data in the RLC transmission buffer* MAC compares the amount of data corresponding to a transport channel withthe threshold set by RRC. If the amount of data is too high or too low, MACsends a measurement report on traffic volume status to RRC.* use these reports for triggering reconfiguration of Radio Bearers and/orTransport Channels.Transport Channel Type switchingCiphering for transparent mode RLC
37MEDIUM ACCESS CONTROL (MAC) PROTOCOL ---ARCHITECTURE---
38Logical Channels Provided by L2/MAC sublayer to higher layers Defined by which type of information is transportedControl ChannelsBroadcast Control Channel (BCCH, DL)Paging Control Channel (PCCH, DL)Common Control Channel (CCCH, DL & UL)Dedicated Control Channel (DCCH, DL & UL)Traffic ChannelsDedicated Traffic Channel (DTCH, DL & UL)Common Traffic Channel (CTCH, DL)
39Transport ChannelsServices provided by the physical layer (layer 1) to the MAC layerDefined by “how and with what characteristics” the data is transportedCommon Transport ChannelsBroadcast Channel (BCH) (DL)Paging Channel (PCH) (DL)Random Access Channel (RACH) (UL)Forward Access Channel (FACH) (DL)Downlink Shared Channel (DSCH) (DL)Common Packet Channel (CPCH) (UL)Dedicated Transport ChannelsDedicated Channel (DCH) (UL & DL)Same channel used by several users No UE identification provided by L1, in-band signaling of UE identityFor exclusive use of one userUE inherently identified by thephysical channel
40MAC architecture (figure 5-11) BCCHMAC ControlPCCHBCCHCCCHCTCHSHCCHMAC ControlMAC ControlDCCHDTCHDTCHTDD onlyMAC-dServing RNCper UEMAC-bMAC-c/shControlling RNC, per cellTransparentRBS, per cellBCHPCHFACHFACHRACHCPCHUSCHUSCHDSCHDSCHDCHDCHIur or localFDD onlyTDD onlyTDD only
41MEDIUM ACCESS CONTROL (MAC) PROTOCOL ---MAC PDU AND FLOW---
42PDU in MACThe MAC PDU : consists of an optional MAC header and a MAC Service Data Unit (MACSDU).Transport Block: Each RLC PDU (e.g. TMD, UMD or AMD) is mapped onto one and only oneTransport Block.Transport Block Set(TBS): In the UE for the uplink, all MAC PDUs delivered to the physicallayer within one Time Transmission Interval (TTI) are defined as Transport Block Set (TBS).It consists of one or several Transport Blocks, each containing one MAC PDU.
43MAC DATA PDU (figure 5-12)RLC PDUMAC headerMAC SDUUE-IdTCTFUE-IdC/TMAC SDUtypeCiphering UnitTarget Channel Type Field (TCTF) identifies the type of logical channel (CCCH, BCCH, CTCH, DTCH/DCCH) on RACH/FACH.UE-Id provides an identifier of the UE on common transport channels.UE-Id type is needed to ensure correct coding of the UE-Id field.C/T identifies the logical channel number (in case of MAC multiplexing of several DTCH and DCCH).
44Target Channel Type Field (TCTF) (table 5-1 and 5-2) Provides identification of the logical channel class on FACH or RACHTCTFDesignation00BCCHCCCHReserved(PDUs with this coding will be discarded by this version of the protocol)CTCH11DCCH or DTCHover FACHTCTFDesignation00CCCH01DCCH or DTCHover RACH10-11Reserved(PDUs with this coding will be discarded by this version of the protocol)
45C/T Field (table 5-3)Provides identification of the logical channel instance when multiple channels are carried on the same transport channel.C/T fieldDesignation0000Logical channel 10001Logical channel 2...1110Logical channel 151111Reserved(PDUs with this coding will be discarded by this version of the protocol)
46UE Id Field (table 5-4)Provides an identifier of the UE on common transport channels.UE Id typeLength of UE Id fieldU-RNTI32 bitsC-RNTI16 bits
47UE-Id Type Field (table 5-5) Needed to ensure correct coding of the UE-Id fieldUE-Id Type field 2 bitsUE-Id Type00U-RNTI01C-RNTI10Reserved(PDUs with this coding will be discarded by this version of the protocol)11
48WCDMA RAN side MAC architecture / MAC-d details (1) DCCHDTCHDTCHMAC-ControlUETransport Channel Type SwitchingC/T MUXDeciphering/ PrioritysettingC/TMAC-dFlow ControlMUXto MAC-c/shMAC–c/sh /MAC-dDL scheduling/priority handlingCipheringDCHDCH
49WCDMA RAN side MAC architecture / MAC-d details (2) Transport Channel Type Switching : If requested by RRC, MAC switches the mappingof one designated logical channel between common and dedicated transport channels.C/T MUX : a C/T field is added indicating the logical channel instance where the dataoriginates. This is always needed for common transport channels, such as the FACH, butfor dedicated it is only needed when several logical channels are multiplexed into C/TMUX.Priority setting function : is responsible for priority setting on data received fromDCCH/DTCH.flow control function : exists between MAC-c/sh and MAC-d to limit buffering in theMAC-c/sh entity.Ciphering/deciphering : in MAC-d is only performed for transparent mode data.
50WCDMA RAN side MAC architecture / MAC-c/sh details (1) –ControlPCCHBCCHSHCCHCCCHCTCH(TDD only)MAC-c/shFlow Controlto MAC–dMAC-c/sh / MAC-dTCTF MUX / UE Id MUXScheduling / Priority Handling/ DemuxTFC selectionTFC selectionDL: codeallocationPCHFACHFACHDSCHDSCHUSCHUSCHRACHCPCHTDD onlyTDD only(FDD only )
51WCDMA RAN side MAC architecture / MAC-c/sh details (2) UE id MUX: After receiving the data from MAC-d, the MAC-c/sh entity first adds the UEidentification type, which is the actual UE identification (CRNTI or U-RNTI).the scheduling/priority handling function : is to decide the exact timing when the PDU ispassed to layer 1 via the FACH transport channel with an indication of what transportformat used.The Transport Format Combination (TFC) selection : is done in the downlink for FACH,PCH and DSCH.DL code allocation : is only used to indicate the code if DSCH is used.
52MAC Model/WCDMA RAN side (figure 5-13 and figure 5-14 connected) PCCHBCCHCCCHCTCHMAC-ControlDCCHDTCHDTCHMAC-c/shTransport Channel Type SwitchingFlow ControlMAC-c/sh/MAC-dC/T MUXDecipheringPrioritysettingC/T MUXMAC-dTCTF MUX / UE Id MUXScheduling / Priority Handling/ DemuxDL scheduling/priority handlingCipheringTFC selectionPCHFACHFACHRACHDCHDCH
53MEDIUM ACCESS CONTROL (MAC) PROTOCOL ---TRANSPORT FORMAT---
54The Transport Format (TF) and Transport Format Set (TFS) : describes the data transfer format offered by L1 to MAC (and vice versa) and is configured by RRC for aspecific transport channel. Each transport channel is configured with one or more TransportFormats (TF). This is referred to as the Transport Format Set (TFS)* The maximum number of TFs per transport channel is 32 (numbered 0-31).* Each TF corresponds to a certain number of equal size transport blocks, i.e. TransportBlock Set (TBS), which may be transmitted on the transport channel within the sameinterval.* The length of the interval is defined by the Transmission Time Interval (TTI), which is afixed periodicity of transport blocks and can have a length of 10, 20, 40 and 80 ms.
55Transport Format Set (TFS) (figure 5-15) Only the dynamic attributes differ between the TFs within the TFSTF1TF2TF3Increasing bit rateTFS
56Transport format (figure 5-16) Describes instantaneous characteristics of a transport channel and the data transfer format offered by L1.Semi-static partTransmission Time Interval (TTI)Channel-coding schemeReconfiguration by RRC is needed.Dynamic partNumber of transport blocks per TTINumber of bits per transport blockTransport formatThe Transport Format (TF) describes how the data is transmitted on a transport channel.For each transport channel a set of transport formats are defined, the so-called Transport Format Set (TFS). The TFS is assigned to MAC from RRC when the transport channel is set up. MAC may then choose the actual transport format within the TFS. MAC may change the transport format within the Transport Format Set once every Transmission Time Interval.The transport format consists of two parts:- Semi-static part (can be reconfigured on slow basis):- Same for all transport formats in the transport format set- TTI, coding scheme, etc.- Dynamic part:- May differ for different transport formats within the transport format set- Number of transport blocks per TTI- Number of bits per transport blockTransport BlockNTransport BlockTransport BlockTransport BlockTransport BlockTransport BlockL bitsTTI
57Transport Channel Coding (figure 5-17) CRC (Cyclic Redundancy Check)Calculated for and added to each transport blockCRC length : 0/8/12/16/24 bitsFEC (Forward Error Correction)Convolution coding (R=1/2, R=1/3)Turbo coding (R=1/3)Channel InterleavingBlock interleaving over one TTIAdd CRCChannel codingInterleavingTransport Channel CodingThe figure illustrates how channel coding and interleaving is applied to each transport channel.First a Cyclic Redundancy Check (CRC) is added to each transport block. The CRC allows for detection of errors in the transport blocks. The error detection can e.g. be used for- Uplink soft-handover combining- Threshold setting for closed-loop power-control.- General indication of erroneous transport blocks to higher layersThe CRC can be of different length depending on the error-detection requirements. The CRC length is part of the transport format.Forward Error Correction (FEC) is then applied to each transport channel.Two different coding schemes can be applied:- Convolutional coding- Turbo codingWhat channel-coding scheme to use is determined by the RRC and is part of the transport format. Typically Turbo coding is used for higher-rate services or services with high quality requirements.Finally, block interleaving with an interleaving span of one TTI is applied to each coded transport channel.Coded Transport Channel
58Examples of transport channel structures, simple variable rate speech and packet data (figure 5-18) TTI = 20 msConvolutional codingOne transport block per TTI (one speech frame)Variable-length transport blocksTTI (typically 20 ms)Rate = RRate = R/4Rate = R/2TTIOne ”packet”Packet dataTurbo codingFixed-length transport blocksVariable number of transport block per TTITransport-channel structure, examplesThis figure shows some examples of transport-channel structuresIn case of variable-rate speech, the speech codec typically delivers one block of data of variable size once every 20 ms. This can be mapped to a transport channel with TTI = 20 ms and one transport block of variable length per TTI. Convolutional coding is typically used for speech.In case of packet data, higher layers typically deliver a variable number of blocks of fixed length. This can be mapped to a transport channel with fixed length transport blocks. The fixed block size is useful in conjunction with ARQ protocols typically used for packet data, since new blocks to transmit and retransmitted blocks then have the same size.
60Multiple transport channels (figure 5-19) A connection typically consists of multiple transport channels in each directionOne set of transport formats per transport channelTransport Format Combination (TFC):The instantaneous combination of transport formats for all transport channels to (from) one UESignaled over L1 as Transport Format Combination Indicator (TFCI)DL TrCh #1DL TrCh #MUL TrCh #1UL TrCh #NUTRANUEMultiple transport channelsAn uplink or downlink connection typically (almost always) consists of more than one transport channel.The combination of transport formats of all transport channels is known as the (instantaneous) Transport Format Combination (TFC). This is signaled over the air to the receiver by means of the so-called Transport Format Combination Indicator (TFCI). The TFCI is a physical-layer signal.
61Transport Format Set (TFC) (figure 5-20) A combination of currently valid Transport Formats at a given point of time containing one Transport Format for each transport channel.Transport channel 1Transport channel 2Transport channel 3TF1TF2TF3TF1TF2TF3TF1TF2TF3TFC1
62Transport Format Set (TFCS) (figure 5-21) TFCS is the set of TFCs that has been configured (by RRC)MAC selects a TFC out of the TFCSCurrent TFC is indicated by the Transport Format Combination Indicator (TFCI) in each physical frame every 10 msTF1TF2TF3Transport channel 1Transport channel 2Transport channel 3TFC1TFC2TFC3TFC4TFCS
63Summary of Data Exchange through transport channels Transport block: the basic unit exchanged between L1 and MACTransport block set: a set of transport blocks which are exchanged between L1 and MAC at the same time instance on the same TrCHThe Transmission Time Interval (TTI) and the error protection scheme to apply are semi-static parameters for the TrCH while the number of transport blocks and their size are dynamic onesTransport format: a defined format offered by L1 for the delivery of a Transport Block Set during a TTITransport format set: a set of Transport Formats associated to a Transport ChannelTransport Format Combination: a combination of transport formats submitted simultaneously to L1, containing one Transport Format for each transport channel.Transport Format Combination Set: a set of transport format combinationsThe Transport Format Combination Indicator (TFCI): on L1 indicates the currently valid TFC.
64MEDIUM ACCESS CONTROL (MAC) PROTOCOL ---CHANNEL SWITCHING---
65The purpose of Channel Switching : is to optimize the use of the radio resources, by dynamically changing the resources allocated to the best-effort users. Whenthere are plenty of resources available, the best-effort user receives high bit rates but whenthe system is heavily loaded and there are not many resources left,
671. Switch from Cell_FACH to Cell_DCH state based on the buffer load.Downlink buffer load measurements in the S-RNC , uplink buffer loadmeasurement by the UE in the MAC layer.in the Idle State or Cell_FACH the UE will read the System Information andconfigure its measurements.For the DCH state, measurements are configured by a “MeasurementControl” message.In the UL case the UE sends a “Measurement Report” to the RNC when thebuffer size is reached. In the DL case, the RNC handles the switch internally.
682. switch from Cell_DCH to Cell_FACH Throughput basedtriggers the MAC layer to report to RRC and send a “Measurement Report” to theRNC for low throughput in UE.If both the throughput in the UL and the DL is below the set values, a switch fromCell_DCH to Cell_FACH will be performed via Radio Bearer Reconfigurationprocedure.3. Up Switch between the Radio Bearers for the Cell_DCH statebased on bandwidth need.The supported bit rates are 64/64, 64/128 and 64/384 kbps.When the throughput becomes close to the maximum user bandwidth (64 or 128kbps) the procedure is triggered.In the UL case, the UE sends a “Measurement Report” and in the DL case it ishandled in the RNC internally.
694. Down Switch between the Radio Bearers for the Cell_DCH state performed due to coverage, i.e. due to DL power.In this case the congestion control triggers it based on measurements via NBAP(from RBS to RNC).5. Other channel switching type is not indicated here !!!!
71Channel Switching from dedicated to common (DCCH and DTCH) before switching (figure 5-24) MAC-dDTCHTFC SelectionDCHPhysical layer L1CipheringC/T MUXDCCHsNo MAC header is needed for the DTCH.Multiplexing of logical channels (DCCHs used for SRBs, C/T MUX)Mapped on DCH transport channelsDCCHsDTCHMAC SDUC/TMAC headerCiphering UnitRLC PDURLC PDUMAC SDUMAC SDUCiphering Unit
72Channel Switching from dedicated to common (DCCH and DTCH) after switching (figure 5-25) Switching is transparent for the logical channelsDTCH and DCCH mapped to RACH/FACHMAC header fields to distinguish logical channels and UEsDCCHDTCHChannel switchingC/T MUXUE IDTCTF MUXCCCHCTCHBCCHRACHFACHMAC-dMAC-cPhysical layer, L1MAC SDUC/TUE-IdMAC headerTCTFtypeCiphering UnitRLC PDU
74>> If ciphering is used it is between S-RNC and UE << The protection of the user data and some of the signaling information is done by bothintegrity protection, executed by RRC layer and ciphering, performed either in RLC or inthe MAC layer according to the following rules:* If a radio bearer is using a non-transparent RLC mode (AM or UM), ciphering isperformed in the RLC sub layer.* If a radio bearer is using the transparent RLC mode, ciphering is performed in theMAC sub layer (MAC-d entity).>> If ciphering is used it is between S-RNC and UE <<
75Ciphering of user and signaling data transmitted over the radio access link (figure 5-26) (1) SRNCf8CKCOUNT-CBEARERDIRECTIONLENGTHPLAIN TEXTBLOCKCIPHERTEXT/SenderUE or SRNCReceiverSRNC or UEKEYSTREAMKEYSTREAM
76Ciphering of user and signaling data transmitted over the radio access link (figure 5-26) (2) Procedure for ciphering:* The input parameters to the algorithm : the ciphering key, CK, a time-dependent input,COUNT-C, the bearer identity, BEARER, the direction of transmission, DIRECTION,and the length of the key stream required, LENGTH.* Based on these input parameters the algorithm generates the output keystream block,KEYSTREAM, that is used to encrypt the input plaintext block, PLAINTEXT, toproduce the output ciphertext block, CIPHERTEXT.
77Input Parameters to the Cipher Algorithm (1) COUNT-C : ciphering sequence numberCK, Ciphering Key: The CK is established during the Authentication procedureusing cipher key derivation function f3 available in the USIM and in the HLR/AUCBEARER : There is one BEARER parameter per radio bearer associated with the sameuser . The radiobearer identifier is input to avoid that for different keystream an identicalset of input parameter value is used.DIRECTION : The value of the DIRECTION is 0 for UL messages and 1 for DL.
78Input Parameters to the Cipher Algorithm(2) LENGTH : The parameter determines the length of the required keystream block .Ciphering key selection: There is one CK for CS radio bearer, CKCS, connectionsand one CK for PS radio bearer, CKPS, connections.
80Physical channelsThe final Layer 1 bit stream to be carried over the airMultiple multiplexed coded transport channels (CCTrCH)Layer 1 control informationPilot bitsTransmit Power Control (TPC) commands and other Feedback Information (FBI)Transport Format Combination Indicator (TFCI)Mapped to combination ofCarrier frequencyCode (channelization/scrambling code pair)Relative phase (UL only): On either the I branch or the Q branch of a QPSKsignal (uplink only).Physical channelA physical channel is the final bit stream that is to be carried over the air.It consists of different parts:- Higher-layer data, i.e. the coded and multiplexed transport channels- Data generated within the physical layer- Pilot bits for channel estimation- Transmit power control commands (TPC)- Other feedback information (FBI), e.g. for closed loop transmit diversity- Transport Format Combination Indicator (TFCI)The physical channel is transmitted over the air:- on a specific carrier frequency- spread by a specific spreading code or more exactly a specific channelization/ scrambling code pair (see below)- on either the I branch or the Q branch of a QPSK signal (uplink only)
81Physical-layer overview (figure 5-27) Transport channelsChannel codingChannel codingMultiplexingPhysical-layerproceduresand measurementsTransport-channelprocessingMapping to physical channelsPhysical channelsSpreadingSpreadingPhysical layer overviewThe figure illustrates the different processing steps carried out by the physical layer.Transport channels are basically processed according to the following steps:- Channel coding (per transport channel)- Transport-channel multiplexing (in case of multiple transport channelsto/from one UE)- Mapping to physical channels- Spreading of the physical channels to the chip rate by means of user-specific spreading codes. For WCDMA, the chip rate is 3.84 Mcps.- Modulation of the chip-rate sequence to a radio carrier. For WCDMA, the bandwidth is approximately 5 MHz.In parallel to the transport-channel processing, the physical layer also carries out some other tasks such as searching for new cells for handover and collection of other measurement data to be delivered to the higher layers.3.84 McpsModulationModulation5 MHz
87Uplink DPDCH/DPCCH (figure 5-33) Dedicated Physical Data Channel (DPDCH) Slot (0.666 mSec)ICoded Data, 10 x 2k bits, k=0…6 (10 to 640 bits)Dedicated Physical Control Channel (DPCCH) Slot (0.666 mSec)QPilotTFCIFBITPC1234567891011121314151 Frame = 15 slots = 10 mSecDPCCH: 15 kb/sec data rate, 10 total bits per DPCCH slotPILOT: Fixed patterns (3, 4, 5, 6, 7, or 8 bits per DPCCH slot)TFCI: Transmit Format Combination Indicator (0, 2, 3, or 4 bits)FBI: Feedback Information (0, 1, or 2 bits)TPC: Transmit Power Control bits (1 or 2 bits); power adjustment in steps of 1, 2, or 3 dBNo animations
88Uplink Signaling Radio Bearer on DPDCH/DPCCH (figure 5-34) RRC UMRRC AM or NAS DT normal or high priority1361281368 bit RLC12816 bit RLC1444 bit MAC1444 bit MACMAC Layer136 bits in 10 msec => 13.6 kbps128bits in 10 msec => 12.8 kbps148CRC 161648 tail bits172516Rate 1/3 CC1st Interleaving600Rate Matching2nd InterleavingNo animation40Slot segmentation40I branch QDPDCH 60ksps => SF = 64PILOTTFCITPCDPCCH 15ksps622
89Downlink DPDCH/DPCCH (figure 5-35) 1 Slot = mSec = 2560 chips = 10 x 2k bits, k = [0...7] SF = 512/2k = [512, 256, 128, 64, 32, 16, 8, 4]Data 2TFCIData 1TPC1 Frame = 15 slots = 10 mSecDPDCHPilotDPCCH1234567891011121314The diagram above shows how in the downlink the dedicated physical data channel (DPDCH) the and dedicated physical control channel (DPDCH) are multiplexed onto one WCDMA timeslot.The DPDCH carries user traffic, layer 2 overhead bits and layer 3 signaling data. The DPCCH carries layer 1 control bits that is, the pilot bits which are used by the receiver to measure the channel quality, the transmission power control (TPC) bits used to adjust the power of the UE in conjunction with the quality levels measured using the pilot bits. This channel also contains transport format combination indicator (TFCI) bits used to tell the receiver what type of transport channels are contained in the CCTrCH.The SF can vary in steps from (512/20) 512 to (512/27) 4 to allow it to carry variable data rates. It should be remembered that the data carried by the DPDCH includes L3 signaling, for example handover messages etc.The DPDCH carries user traffic, layer 2 overhead bits, and layer 3 signaling data. The DPCCH carries layer 1 control bits: Pilot, TPC, and TFCIDownlink Closed-Loop Power Control steps of 1 dB dB
90Downlink Signaling Radio Bearer on DPDCH/DPCCH (figure 5-36) RRC UMRRC AM or NAS DT normal or high priority1361281368 bit RLC12816 bit RLC1444 bit MAC1444 bit MACMAC Layer148CRC 16136 bits in 10 msec => 13.6 kbps128bits in 10 msec => 12.8 kbps1648 tail bits172516Rate 1/3 CC1st Interleaving510Rate MatchingNo animations2nd Interleaving34Slot segmentation34422 TPC & 4 PILOT24DPDCH/DPCCH = 30ksps => SF = 128
91Uplink Speech RAB mapping (figure 5-37) RRC UMRRC AM or NAS DT normal priority20 msec of each subflow40 msec81103601361281368 bit RLC12816 bit RLC81CRC 121444 bit MAC1444 bit MACMAC Layer93103608 tail bits148CRC 161/31/31/2Convolutional coding1648 tail bits303+1333+1136Radio frame equalization516 Rate 1/3 CC1st interleaving3043341361st Interleaving1291291291291521521671676868Frame segmentation1401401401401521676815216768Rate matching2nd speech blockRate match 360140Rate match 36014015216768#1 11015216768#2 110No animations2nd interleaving2nd interleaving6006004040404040404040I Branch QDPDCH 60kbps => SF=64DPDCH 60kbps => SF=64600 bits (600 symbols)600 bits (600 symbols)QPILOTTFCITPCDPCCH 15kbps622
92Uplink Speech RAB mapping (during SID frame) (figure 5-38) No animationsAfter every eight frames the UE sends a Silence Descriptor (SID) frame, which is usedduring the discontinuous speech periods.
93Downlink Speech RAB mapping (figure 5-39) RRC UMRRC AM or NAS DT normal priority13640 msec12820 msec of each subflow1368 bit RLC12816 bit RLC81103601444 bit MAC1444 bit MACMAC Layer81CRC 12148CRC 1693103608 tail bits1648 tail bits303 (1/3)333 (1/3)136 (1/2)Convolutional coding516 Rate 1/3 CC294316172Rate matching4762943161721st interleaving1st interleaving1471471581588686Frame segmentation1191191191192nd speech block147158861191471588611915216768#1 11015216768#2 110No animations2nd interleaving2nd interleaving60060034343434404040402 TPC 4 Pilot2 TPC 4 PilotDPDCH 60ksps => SF=128DPDCH 60kbps => SF=128600600
94Uplink CS 64 RAB mapping (figure 5-40) RRC UMRRC AM or NAS DT normal priority64 kbps = 1280 in 20 msec =>2X640 bit Transport Blocks13640 msec1281368 bit RLC12816 bit RLC6406401444 bit MAC1444 bit MAC640640CRC 16MAC Layer148CRC 16Turbo Coding 393612 Trellis termination bits1648 tail bits1st Interleaving516 Rate 1/3 CC1st interleaving19741974Frame segmentation12912912912922432243Rate matching1571571571572nd speech block22431572243157152#2 110152#2 110No animations2nd interleaving2nd interleaving60060016016016016040404040I Branch QDPDCH 240kbps => SF=16DPDCH 240kbps => SF=16600 bits (600 symbols)600 bits (600 symbols)QPILOTTFCITPCDPCCH 15kbps622
95Downlink CS 64 RAB mapping (figure 5-41) RRC UMRRC AM or NAS DT normal priority64 kbps = 1280 in 20 msec =>2X640 bit Transport Blocks13640 msec1281368 bit RLC12816 bit RLC1444 bit MAC1444 bit MAC640640MAC Layer148CRC 16640640CRC 161648 tail bitsTurbo Coding 393612 Trellis termination bits516 Rate 1/3 CC3926Rate matching54839261st interleaving1st interleaving19631963Frame segmentation1371371371372nd speech block19631371963137No animations2nd interleaving2nd interleaving1401401401404 / 8 / 8TPC/TFCI/PILOTDPDCH 120ksps => SF=32DPDCH 120ksps => SF=32600600
96Uplink Streaming 57.6 kbps RAB mapping (figure 5-42) Up to 4X576 TBs in 40 msec => max data rate = 57.6 kbpsRRC UMRRC AM or NAS DT normal priority123413640 msec1281368 bit RLC12816 bit RLC1444 bit MAC1444 bit MAC57616576165761657616CRC 16MAC Layer148CRC 16Turbo Coding 710412 Trellis termination bits1648 tail bits1st Interleaving 7116516 Rate 1/3 CC1st interleaving1779177917791779Frame segmentation1291291291292218221822182218Rate matching1821821821822nd speech block2218182221818215216768#1 11015216768#2 110No animations2nd interleaving2nd interleaving60060016016016016040404040I Branch QDPDCH 240kbps => SF=16DPDCH 240kbps => SF=16600 bits (600 symbols)600 bits (600 symbols)QPILOTTFCITPCDPCCH 15kbps622
97Downlink Streaming 57.6 kbps RAB mapping (figure 5-43) RRC UMRRC AM or NAS DT normal priorityUp to 4X576 TBs in 40 msec => max data rate = 57.6 kbps13640 msec1281368 bit RLC12816 bit RLC12341444 bit MAC1444 bit MACMAC LayerCRC 1657616576165761657616CRC 161481648 tail bitsTurbo Coding 710412 Trellis termination bits516 Rate 1/3 CC7764Rate matching63677641st interleaving1st interleaving1941194119411941Frame segmentation1591591591592nd speech block19411591941159No animations2nd interleaving2nd interleaving1401401401404 / 8 / 8TPC/TFCI/PILOTDPDCH 120ksps => SF=32DPDCH 120kbss => SF=32600600
98Uplink PS DATA CELL_FACH (DCCH on RACH) (figure 5-44) RRC UMRRC AM, NAS DT normal or low priority1361281368 bit RLC12816 bit RLC14424 bit MAC14424 bit MACMAC layer136 bits in 10 msec => 13.6 kbps128 bits in 10 msec => 12.8 kbps16816 CRC 168 tail bits184Rate 1/2 Convolutional Coding 3841st InterleavingRate Matching 300No animations2nd Interleaving20Slot segmentation20I Branch QRACH message part 30ksps => SF = 128PILOTTFCI82
99Uplink PS DATA CELL_FACH (DTCH on RACH) (figure 5-45) Frame segmentation 3842nd InterleavingRate Matching 30020RACH message 30ksps => SF = 128PILOTTFCI16 CRC 16376360MAC layer8 tail bitsRate 1/2 Convolutional Coding 7681st InterleavingAM => 16 bit RLC32033624 bit MACMax user plane 320 bits in 20 msec => 16 kbps82No animations
100Downlink PS DATA CELL_FACH (DCCH on FACH) (figure 5-46) RRC UMRRC AM or NAS DT normal priority13640 msec1281368 bit RLC12816 bit RLC14424 bit MAC14424 bit MACMAC layer136 bits in 10 msec => 13.6 kbps128 bits in 10 msec => 12.8 kbps168168CRC 161841848 tail bits376Rate 1/2 Convolutional Coding 7521st InterleavingRate Matching 1080No animations2nd Interleaving72Slot segmentation728TFCI bits8S-CCPCH = 60ksps => SF = 64
101Downlink PS DATA CELL_FACH (DTCH on FACH) (figure 5-47) 320Max user plane = 320 bits in 10msec => 32 kbps320AM => 16 bit RLC header33624 bit MAC header360CRC 1637612 trellis termination bits1128Turbo Coding1st interleavingRate Matching 1080No animations2nd Interleaving72Slot segmentation728TFCI bits8S-CCPCH = 60ksps => SF = 64
102Uplink PS 64 RAB mapping (figure 5-48) Up to 4X320 TBs in 20 msec => max data rate = 64 kbpsRRC UMRRC AM or NAS DT normal priority1st Interleaving 4236Turbo Coding 42242118224612343201633616 bit RLCCRC 1613640 msec1281368 bit RLC12816 bit RLC1444 bit MAC1444 bit MACMAC Layer148CRC 1612 Trellis termination bits1648 tail bits516 Rate 1/3 CC1st interleavingFrame segmentation129129129129Rate matching1541541541542nd speech block2246No animations154224615415216768#1 11015216768#2 1102nd interleaving2nd interleaving60060016016016016040404040I Branch QDPDCH 240kbps => SF=16DPDCH 240kbps => SF=16600 bits (600 symbols)600 bits (600 symbols)QPILOTTFCITPCDPCCH 15kbps622
103Downlink PS 64 RAB mapping (figure 5-49) RRC UMRRC AM or NAS DT normal priorityFrame segmentation1st interleaving1966Rate matching12 Trellis termination bitsTurbo Coding 42243932Up to 4X320 TBs in 20 msec => max data rate = 64 kbps12343201633616 bit RLCCRC 1613640 msec1281368 bit RLC12816 bit RLC1444 bit MAC1444 bit MACMAC Layer148CRC 161648 tail bits516 Rate 1/3 CC5361st interleaving1341341341342nd speech block19661341966134No animations2nd interleaving2nd interleaving1601601601604 / 8 / 8TPC/TFCI/PILOTDPDCH 120ksps => SF=32DPDCH 120kbss => SF=32600600
104Downlink PS 128 RAB mapping (figure 5-50) Up to 8X320 TBs in 20 msec => max data rate = 128 kbpsRRC UMRRC AM or NAS DT normal priority13640 msec128320163201632016320163201632016320163201616 bit RLC1368 bit RLC12816 bit RLC1444 bit MAC1444 bit MAC1616161616161616CRC 16MAC Layer148CRC 161648 tail bitsTurbo Coding 844812 Trellis termination bits516 Rate 1/3 CC8376Rate matching52883761st interleaving1st interleaving41884188Frame segmentation1321321321322nd speech block41881324188132No animations2nd interleaving2nd interleaving2882882882888 / 8 / 16TPC/TFCI/PILOTDPDCH 240ksps => SF=16DPDCH 240ksps => SF=16600600
105Downlink PS 384 RAB mapping (figure 5-51) RRC UMRRC AM or NAS DT normal priorityUp to 12X320 TBs in 10 msec => max data rate = 384 kbps13640 msec1281368 bit RLC12816 bit RLC1444 bit MAC1444 bit MACMAC Layer320163201632016320163201632016320163201632016320163201632016148CRC 1612 Trellis termination bits1648 tail bits161616161616161616161616516 Rate 1/3 CCTurbo Coding 12672380Rate matching90251st interleaving1st interleaving95959595Next 3 blocks902595No animations2nd interleaving6086088 TCI 8 TPC 18 PilotDPDCH 480ksps => SF=8600600600
106Uplink MultiRAB, Speech RAB + PS 64/64 RAB mapping (figure 5-52) RRC UMRRC AM or NAS DT normal priority20 msec of each subflow12346013640 msec8110312832032032032016 bit RLC1368 bit RLC12816 bit RLC81CRC 12336336336336CRC 161444 bit MAC1444 bit MAC93103608 tail bits148CRC 16Turbo Coding 42241/31/31/21648 tail bits1st Interleaving 4236303+1333+1136516 Rate 1/3 CC1st interleaving304334136211821181291291291291481481581588888188118811251251251251481588818811251481588818811252nd interleaving2nd interleaving160160160160No animationsI Branch QDPDCH 60kbps => SF=16DPDCH 60kbps => SF=16PILOTTFCITPCDPCCH 15kbps622
107Downlink MultiRAB, Speech RAB + PS 64/64 RAB mapping (figure 5-53) RRC UMRRC AM or NAS DT normal priority40 msecUp to 4X320 TBs in 20 msec => max data rate = 64 kbps13612820 msec of each subflow1368 bit RLC12816 bit RLC811036012341444 bit MAC1444 bit MAC81CRC 1232032032032016 bit RLC148CRC 1693103608 tail bits336336336336CRC 161648 tail bits303 (1/3)333 (1/3)136 (1/2)CCTurbo Coding 422412 Trellis termination bits516 Rate 1/3 CCRM 258RM 276RM 154RM 32944361st Int. 2581st Int. 2761st Int. 1541st Int. 32941st interleaving129129138138777716471647109109109109129138771647109No animations2nd interleaving1601604 TPC 8 Pilot 8 TFCIDPDCH 120 ksps => SF=32