Chap10 edge 03_kh

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  • TS 45.002 V5, chap. 3 (darstellung wurde stark vereinfacht!)
  • TS 43.064, chap. 6.5.4
  • TS 43.064, chap. 6.5.5.1.1. Beachte, daß die oberen Layers die radio blocks ohne USF und BCS in der richtigen groesse liefern muessen. Aber das geht ohne probleme, da der RLC, der für segmentation verantwortlich ist, den verwendeten CS kennt.
  • TS 43.064, chap. 6.5.5.1.1. Beachte, daß die oberen Layers die radio blocks ohne USF und BCS in der richtigen groesse liefern muessen. Aber das geht ohne probleme, da der RLC, der für segmentation verantwortlich ist, den verwendeten CS kennt.
  • Aus dem TC UMTS Rel 4, 5, 6 Kurs entnommen TC 1105 chap. 5
  • TS 45.002 V5, chap. 3 (darstellung wurde stark vereinfacht!)
  • TS 45.002 V5, chap. 3 (darstellung wurde stark vereinfacht!)
  • TS 45.002 V5, chap. 3 (darstellung wurde stark vereinfacht!)
  • TS 45.002 V5, chap. 3 (darstellung wurde stark vereinfacht!)
  • TS 45.002 V5, chap. 3 (darstellung wurde stark vereinfacht!)
  • Chap10 edge 03_kh

    1. 1. Chapter 10 (E)GPRS protocols 10.1 GPRS Protocols 1. The RLC/MAC protocol 2. The Medium Access control (MAC) header DL 3. The GPRS Medium Access Control header UL 4. DL + UL control blocks 5. Control Messages 6. DL control header 7. GPRS Downlink RLC/MAC data block 8. DL RLC header 9. GPRS Uplink RLC/MAC data block 10. UL RLC header 10.2 Coding Schemes and Link Adaptation 1. GPRS Channel Coding 2. Differentiation of the Coding Schemes 3. GPRS Link Adaptation 4. Link Adaptation Algorithm
    2. 2. Chapter 10 (E)GPRS Protocols 10.3 Enhancements of EDGE versus GPRS 1. Enhancements of EDGE versus GPRS 2. 8PSK 3. 8-PSK phase transitions 4. Burst types 5. Detailed 8-PSK 6. GPRS and EDGE TS sharing 10.4 Protocol structures 1. EGPRS Channel Coding 2. EGPRS MCS Families 3. The padding option 4. Combined RLC/MAC Header for EDGE user data 5. Differences in the Headertypes 6. MAC part of combined RLC/MAC header 7. Other new fields in the RLC/MAC header 8. The RLC part of combined RLC/MAC Header 9. Channel coding in EGPRS 10. Coding and Interleaving 11. Coding Process Example: MCS-2 DL 12. Coding Process Example: MCS-8 DL 13. EGPRS Coding Parameters 14. EDGE coding compared with GPRS 10.5 RLC MAC enhancements 1. EDGE specific RLC/MAC modifications 2. Network access mechanism 3. EGPRS Packet Channel Request 4. other new RLC/MAC messages for EGPRS
    3. 3. The RLC/MAC protocol Radio Link Control (RLC) and Medium Access Control (MAC) realize OSI layer 2 functions. Both, RLC and MAC are described in GSM 04.60 (44.060). The main functions of RLC are: -The segmentation of LLC frames -The provision of an acknowledged and unacknowledged operation mode The main functions of MAC are: -The control of the access to the network resources: -The sharing of the network resources to several mobiles: RLC For the DL: Usage of the TFI For the UL: Usage of the USF (and TFI) -The control of the release of the network resources MAC -Release of Uplink TBF: Countdown Procedure -Release of Downlink TBF: Final Block Indicator Both, for data transfer and transfer of control messages different RLC/MAC blocks are specified in UL and DL direction. That means, that in total 4 different types of RLC/MAC blocks are used in GPRS: -DL RLC/MAC control blocks (used for GPRS and E-GPRS) -UL RLC/MAC control blocks (used for GPRS and E-GPRS) -GPRS DL RLC/MAC data blocks -GPRS UL RLC/MAC data blocks
    4. 4. Radio Block Structures Radio Block for data transfer Radio blocks for data transfer may be encoded using CS-1 to CS-4. MAC Header RLC Header RLC Data BCS 8 bits octets of one or several LLC PDUsA GPRS radio block for data transmission holds following fields:• MAC header; 8 bits, different content in UL and DL• RLC header; This is a variable length field holding control data.• RLC data; This field contains octets from one or several LLC PDUs.• BCS field; Block Check Sequence is used for error detection. Radio Block for control message For Radio blocks carrying RLC/MAC control messages CS-1 has to be used MAC Header RLC/MAC Control Message BCSThe GPRS radio block for control messages holds an 8 bit long MAC header, one RLC/MAC controlmessage in the RLC/MAC Control Message field, and a BCS field for error detection
    5. 5. The Medium Access control (MAC) header DL 8 7 6 5 4 3 2 1 Bit-No USF MAC Header In DL Payload Type RRBP S/P USF MAC header USF The Uplink State Flag (USF) field is sent in all downlink RLC/MAC blocks and indicates who is allowedto send in the next uplink radio block on the same timeslot (see3GPP TS 45.002).The USF field is three bits in length and eight different USF values can be assigned, except on PCCCH, where thevalue 111 (USF=FREE) indicates that the corresponding uplink radio block contains PRACH. S/P 0 RRBP field is not valid The Relative Reserved Block Period (RRBP) 1 RRBP field is valid field specifies a single uplink block in which the RRBP mobile station shall transmit either a PACKET 00 (N+13) mod 2715648 CONTROL ACKNOWLEDGEMENT message or a 01 (N+17 or N+18) mod 2715648 PACCH block to the network Supplementary/Polling (S/P) Bit is used to 10 (N+21 or N+22) mod 2715648 indicate whether the RRBP field is valid or not 11 (N+26) mod 2715648 valid Payload Type 00 RLC/MAC block contains an RLC data block 01 RLC/MAC block contains an RLC/MAC control block that does not include the optional octets of the RLC/MAC control header 10 In the downlink direction, the RLC/MAC block contains an RLC/MAC control block that includes the optional first octet of the RLC/MAC control header. 11 Reserved. In this version of the protocol, the mobile station shall ignore all fields of the RLC/MAC block except for the USF field
    6. 6. The GPRS Medium Access Control header UL 8 7 6 5 4 3 2 1 Bit-No MAC Header In UL Payload Type spare R UL MAC header for control Payload Type Countdown Value SI R UL MAC header for data The Retry (R) bit shall indicate whether the mobile station transmitted the CHANNEL REQUEST R  message (see 3GPP TS 44.018), PACKET CHANNEL REQUEST message, or EGPRS PACKET CHANNEL REQUEST message one time or more than one time during its most recent channel access spare Set to zero - bits are ignored Payload Type 00 RLC/MAC block contains an RLC data block 01 RLC/MAC block contains an RLC/MAC control block 10 Reserved. 11 Reserved. SI The Stall indicator (SI) bit indicates whether the mobiles RLC transmit window can advance (i.e.is not stalled) or can not advance (i.e. is stalled). The mobile station shall set the SI bit in all uplink RLC data blocks. Countdown Value The Countdown Value (CV) field is sent by the mobile station to allow the network to calculate the number of RLC data blocks remaining for the current uplink RLC entity. The CV field is 4 bits in length and is encoded as a binary number with range 0 to 15
    7. 7. DL + UL control blocks DL control block 8 7 6 5 4 3 2 1 Bit-No Payload Type RRBP S/P USF MAC header RBSN RTI FS AC octet 1 optional Control PR TFI D octet 2 octets header octet M Control Message Contents RLC/MAC signaling octet 21 octet 22 UL control block Payload Type spare R For the UL control block no optional control header is preseen Control Message Contents
    8. 8. Control Messages (Rel 97/98) I Control Message Contents (the basic set) Uplink TBF establishment messages: Packet Access Reject Packet Channel Request Packet Queuing Notification Packet Resource Request Packet Uplink Assignment Downlink TBF establishment messages: Packet Downlink Assignment TBF release messages: Packet TBF Release Paging messages: Packet Paging Request RLC messages: Packet Downlink Ack/Nack Packet Uplink Ack/Nack System information messages: Packet System Information Type 1 Packet System Information Type 2 Packet System Information Type 3 Packet System Information Type 3 bis Packet System Information Type 4 Packet System Information Type 5 Packet System Information Type 13
    9. 9. Control Messages (Rel 97/98) II Packet Control Acknowledgement Packet Cell Change Failure Packet Cell Change Order Packet Downlink Dummy Control Block Packet Uplink Dummy Control Block Packet Measurement Report Packet Measurement Order Miscellaneous messages: Packet Mobile TBF Status Packet PDCH Release Packet Polling Request Packet Power Control/Timing Advance Packet PRACH Parameters Packet PSI Status Packet Timeslot ReconfigureDownlink RLC/MAC control messages and Uplink RLC/MAC control messages, except those using the accessburst formats, are received in the RLC/MAC control block format. The different types of messages aredistinguished by the MESSAGE_TYPE field
    10. 10. DL control header RBSN RTI FS AC octet 1 optional Control PR TFI D octet 2 octets header AC The Address Control (AC) bit is used to indicate the presence of the optional TFI/D octet in the header of downlink RLC/MAC control block. FS The Final Segment (FS) bit indicates that the downlink RLC/MAC control block contains the final segment of an RLC/MAC control message . RTI The Radio Transaction Identifier (RTI) field is used to group the downlinkRLC/MAC control blocks that make up an RLC/MAC control message and identifies the segmented control messagesequence with which the downlink RLC/MAC control block is associated. The RTI field is five bits in length with range0 to 31. RBSN The Reduced Block Sequence Number (RBSN) bit carries the sequence number of the downlink RLC/MAC control blocks. The RBSN bit is encoded as a binary number with range 0 to 1. D The Direction (D) bit indicates the direction of the TBF identified by the TFI field in the downlink RLC/MAC control block header.(0-UL, 1-DL). TFI In downlink RLC/MAC control blocks, the TFI identifies the Temporary Block Flow(TBF) to which the RLC/MAC control message contained in the downlink RLC/MAC control block relates. PR The Power Reduction (PR) field indicates the power level reduction of the current RLC block. (important for DL PC).
    11. 11. GPRS Downlink RLC/MAC data block 8 7 6 5 4 3 2 1 Bit-No Payload Type RRBP S/P USF MAC header PR TFI FBI octet 1 BSN E octet 2 Length Indicator M E octet 3 RLC optional header octets Length Indicator M E octet M octet M+1 RLC RLC data data unit octet N-1 octet N Spare bits Spare bits (if present)Optional octets: one octet may be present for each LLC (or part of LLC) contained. Length indicatorindicates the length of the LLC in octetts. Only the last segment of any Upper Layer PDU of a TBF(either this segment carries the entire Upper Layer PDU or not) shall be identified with a LengthIndicator within the corresponding RLC data block.
    12. 12. DL RLC header PR TFI FBI octet 1 BSN E of RLC header octet 2 FBI The Final block indicator (FBI) bit indicates that the downlink RLC data block is the last RLC data block of the downlink TBF. (0 - not the last block, 1 – the last block) TFI In RLC data blocks, the TFI (Temporary Floww Identity) identifies the TemporaryBlock Flow (TBF) to which the RLC data block belongs. For the downlink and the uplink TFI the TFI field is 5 bits inlength. PR The Power Reduction (PR) field indicates the power level reduction of the current RLC block. (important for DL PC). E The Extension (E) bit is used to indicate the presence of an optional octet in the RLC data block header.M E bit in optional part Length Indicator M E Optional octets0 0 if received by the mobile station it shall ignore all fields of the RLC/MAC block except for the fields of the MAC header0 1 no LLC data after the current LLC PDU, no more extension octets1 0 a new LLC PDU starts after the current LLC PDU and there is another extension octet, which delimits the new LLC PDU1 1 a new LLC PDU starts after the current LLC PDU and continues until the end of the RLC information field, no more extension octets BSN The Block Sequence Number (BSN) field carries the sequence absolute Block Sequence Number (BSN) modulo Sequence NumberSpace (SNS) of each RLC data block within the TBF. In GPRS, the BSN is 7 bits in length and is encoded as abinary number with range 0 to 127.
    13. 13. DL RLC header II Optional octets Length Indicator M E LLC 1 and 2 completely contained, LLC 3 starts, continues in next RLC Data block: LLC 3 LLC 2 Y octets LLC 1 X octets Y 1 1 X 1 0 E=0 in RLC header MAC Start of LLC 3 1 optional octet 1 optional octet LLC 1 continued from previous block and LLC fits2 precisely into the RLC: LLC 2 Y octets LLC 1 X octets Y 0 1 X 1 0 E=0 in RLC header MAC Rest of LLC 1 1 optional octet 1 optional octet LLC 1 continued from previous block and continues in next block, no optional octet needed: X octets of LLC1 E=1 in RLC header MAC Part of LLC 1 that started in a former RLC and continuous in next Next radio LLC 2 Y octets Y octets of LLC1 Y 1 0 E=0 in RLC header MAC block Part of LLC 2 Rest of LLC 1 1 optional octetOptional octets are always present, if there is a LLC border, inside the RLC, exceptions are defined for last blocks.
    14. 14. GPRS Uplink RLC/MAC data block 8 7 6 5 4 3 2 1 Bit-No Payload Type Countdown Value SI R MAC header spare PI TFI TI octet 1 BSN E octet 2 Length Indicator M E octet 3 . . . RLC Length Indicator M E octet M header Optional octet M+1 octets TLLI octet M+4 PFI E octet M+5 RLC data octet N-1 RLC octet N data Spare bits Spare bits (if present) unit
    15. 15. UL RLC header spare PI TFI TI octet 1 BSN E of RLC header octet 2 TI The TLLI Indicator (PI) bit indicates the presence of an optional PFI field within the RLC data block. 0- field not present 1- field present TheTLLI field is present during one phase access in all UL datablocks until the TLLI first Acknowledgement is received in DL (Contention resolution procedure). TFI Used as in DL. PI The PFI Indicator (TI) bit indicates the presence of an optional PFI field within the RLC data block. 0- field not present PFI (Packet Flow Indication) 1- field present If the network indicates that it supports packet flow procedures (Network support of packet flow context (PFC) procedures is indicated by the PFC_FEATURE_MODE parameter that is broadcast on either the BCCH or PBCCH) and a PFC exists for the LLC data to be transferred the packet flow identifier has to be present spare E Remaining fields are used as in DL. Length Indicator M E BSN
    16. 16. PFI fieldPFI, if the network indicates that it supports packet flow procedures (Network support of packet flow context(PFC) procedures is indicated by the PFC_FEATURE_MODE parameter that is broadcast on either the BCCH orPBCCH) and a PFC exists for the LLC data to be transferred. PFI, if the network indicates that it supports packetflow procedures (If the network indicates it supports multiple TBF (Rel 6) procedures then it shall also indicatesupport for PFC procedures ) and a PFC exists for the LLC data to be transferred. In case no valid PFI value isallocated for the LLC data to be transmitted, and the network indicates support for the PFC procedures, an MSsupporting PFC procedures shall associate and indicate the following PFI values for the LLC data:PFI = 0 (Best Effort) for user data,PFI = 1 (Signalling) for GMM/SM signalling (LLC SAPI 1), orPFI = 2 (SMS) for Short Message Service (LLC SAPI 7), orPFI = 3 (TOM8) for LLC SAPI 8 data.BSS packet flow contexts describe QoS characteristics for the data transmission. BSS Um SGSN Buffer 1 PFC 1 TBF BSS Context Buffer 2 PFC 2 Gb
    17. 17. Chapter 10.2 The Air Interface 10.2 Coding Schemes and Link Adaptation 1. GPRS Channel Coding 2. Differentiation of the Coding Schemes 3. GPRS Link Adaptation 4. Link Adaptation Algorithm
    18. 18. GPRS Channel CodingChannel coding for Radio Block CS-1, CS-2, CS-3 USF BCS convolutionary coding: rate 1/2 Puncturing for CS 2 and 3Coding Parameters Radio Blocks for code USF BCS radio block excl. coded punctured data rate control messages rate bits bits USF and BCS bits bits kbpsCS-1 1/2 3 40 181 456 0 9.05 CS-1CS-2 ≈2/3 3 16 268 588 132 13.4 data transferCS-3 ≈3/4 3 16 312 676 220 15.6 CS-1 CS-2CS-4 1 3 16 428 456 - 21.4 CS-4 CS-3
    19. 19. Differentiation of the Coding Schemes Encoded and punctured bits (456) USF Header + Data + BCS The Radio block is now interleaved onto 4 normal bursts in the same way as for SACCH The 11 11 00 00 Stealing bits in 11 00 10 01 the normal 11 10 00 01 bursts indicate the CS. 11 00 01 10 CS 1 CS 2 CS 3 CS 4In GPRS existing coding techniques are used. In DL blocks the USF is treated separately (strongerencoded) but the same type of encoding is used in UL and DL (That means the first 3 bits of theUL Mac header are unnecessarily strong protected. CS 1 is the same as that used for SACCHcoding (1/2 rate encoding). CS 2 and 3 is a punctured version (some doubled bits are deleted,more for CS 3). CS 4 has no redundancy. The used CS is indicated by the Stealing Bits. Thisallows blind detection. GPRS MS have to support all CSs, the network may support only a subset.
    20. 20. GPRS Link Adaptation CS 1 - 4: Bit Rate Comparison 20 18 CS1 16 CS2 CS3Net Throughput (kbit/s) 14 CS4 12 10 8 6 4 2 0 18 17 16 15 14 13 12 11 10 9 8 7 6 5 Carrier / Interference C/I (dB)
    21. 21. Link Adaptation Algorithm The coding scheme will change based on defined BLER Thresholds The BLER thresholds are a result of simulations CS1 Different thresholds for hopping and non hopping CS2 networks CS3 Net Throughput (kbit/s) 14 CS4 The PCU defines which CS to use in UL and DL Example !!!!! 12 Max CS 2: 12 Kbit/s (no header) From CS1 to CS2 10 CS1 & CS2 Retransmissionrate Crosspoint 5.2Kbit/s 8 CS1 FH 14% CS1 NFH 69% 6 Crosspoint FH 4 From CS2 to CS1 6.8 Kbit/s 2 CS2 FH 43% =(5.2/12) x 100 % 0 CS2 NFH 79% 9 18 8 7 6 5 Carrier / Interference C/I (dB)
    22. 22. LA operation MS BTS BSC UL – LLC data in MS CHNREQ (Uplink TBF) CHNRD (UplinkTBF) RACH IACMD (IMASS) Packet UL Ass.: TFI; USF; CS I (IMASS) IACMD (IMASS) Packet UL Ass.: TFI; USF; CS Initial CS is told to MS AGCH PCU - DL (PDDCB) USF RMAC- DL (PDDCB)USF ( ... ) PDTCH ( ... ) RMAC- UL (PUDCB) PCU - UL (PUDCB) PDTCH RMAC- UL (DATA) TLLI; BSN=0; CV=15 PCU - UL (DATA) TLLI; BSN=0; CV=15 PDTCH ( ... ) ( ... ) RMAC- UL (DATA) TLLI; BSN=x; CV=15 PCU - UL (DATA) TLLI; BSN=x; CV=15 PDTCH PCU - DL (PUAN) TLLI:Cont.R.; Ack BSN=0; USF PCU may command RMAC- DL (PUAN) TLLI: Cont. R.; ... PACCH a new CS RMAC- UL (DATA) TLLI; BSN=x+1; CV=15 PCU - UL (DATA) TLLI; BSN=x+1; CV=15 PDTCHPDDCB Packet Downlink... ) ( Dummy Control Block ( ... )PUDCB Packet Uplink Dummy Control BlockPUAN Packet Uplink Ack/NackPDAN Packet Downlink Ack/NackCont R contention Resolution
    23. 23. Chapter 10 EGPRS Protocols 10.3 Enhancements of EDGE versus GPRS 1. EGPRS enhancements 2. 8PSK 3. 8-PSK phase transitions 4. Burst types 5. Detailed 8-PSK 6. GPRS and EDGE TS sharing
    24. 24. EGPRS enhancements EGPRS is mainly an BSS internal enhancement of existing GPRS protocols. -modified RLC/MAC protocol RLC RLC -Option to use 8PSK on the air -Requires the support of MS MAC MAC -Requires new transport solution on Abis GSM RF GSM RF MS Um BSS RLC RLC New control messages New data block formats MAC MAC PCU Dynamic Abis PCU Frames GSM RF Option to GSM RF Frames use 8PSK PCM PCM MS Um BTS Abis PCU
    25. 25. 8PSK GSM RF enhancement The assignment of the different symbols to the coordinates in the I/Q diagram seems to be Q random. But it follows a GRAY code. If a (0,1,0) symbol is falsely interpreted as one of its neighbours, only one bit is wrong. (0,0,0) (0,1,1) Q0 (0,0,1) (1,1,1) I1 ,1) ,1) (1,1 (0,1 (0,1,0) I (0,0,0) (0,1,1) ,0) ,0) 1 Q (0,1 (1,1 (1,0,1) (1,1,0) (1,0,0) (0,0,1) (1,1,1) I 0 ,0) (1,0With every symbol duration ,0) (0,0(which is equal to the bit duration (1,1,0) (1,0,1)in standard GSM, 3.7 µs), it rotates by 3p/8 ,1) ,1) (1,0,0) (0,0 (1,0corresponding to 67.5° to avoid zero crossings.• 3Π/8-8-PSK which is used for EDGE
    26. 26. 8-PSK phase transitions Q0 Minimum Amplitude -15 dB ‚usefull‘ Amplitude 0 dB I0 maximum Amplitude +4 dB Possible phase transitions in I-Q-diagram (for EDGE several successive symbols define the phase transitions)
    27. 27. Burst types • Frequency Correction Burst, • Synchronisation Burst,Normal Burst: • Access Burst, • Dummy Burst GMSK training only tail sequence tail bits bits bits 000 58 encrypted bits 26 58 encrypted bits 000 8.25 ½ bit ½ bit active part useful part ½ symbol ½ symbol 0 ... 0 174 encrypted bits 78 174 encrypted bits 0 ... 0 24.75 tail training tail bits sequence bits bits 1 Timeslot = 0.577 msec8PSK burst may be used in UL and Downlink for the transfer of user data. The lowershows the 8PSK burst where 1 Symbol=3bits. So it carries 3 times more bits as theGMSK burst.
    28. 28. Detailed 8-PSK burst 3 Tail Symbols 1 Symbol Stealing Flag Power/dB 1.5 0 -10 -20 -30 -40 -50 26 Training sequence Time Guard period Symbols/8PSK but not 8.25 Symbols for reduced subset Ramping 57 Payload Symbols/8-PSKThe payload is 116*3 = 348 bits (minus stealing symbols). Tail bits and training sequenceare also 8PSK modulated, however, they take only advantage of a subset of 8PSKsymbols, which reduces the dynamic range enormously. The training sequence in themid-amble consists of 26 symbols.
    29. 29. GPRS and EDGE TS sharing 1 radio block (20 msec) For synchronisation reasons every MS with an active TBF on that TS has to get a readable block in DL every 360 ms. It is possible to send an USF to a GPRS This means if there was no CS 1-4 block in DL, and there is √ √ MS in a EDGE Radio block. a GPRS MS in UL, the network has to schedule a control GMSK has to be used (MCS 1-4) block every 18 th block (propably this will be dummy block). CS 1 EDGE GPRS EDGE GPRS Control DL block UL Time GPRS EDGE EDGE GPRS +GPRS √ √ It is possible to send an USF to an EDGE and GPRS users can share a TS. 8- EDGE MS in a GPRS Radio block. PSK is allowed in DL (if no GPRS user shall The EDGE user can use any MCS send in the next UL block) and ULTimeslot sharing is possible. The potential throughput for the EDGE user will be degraded. As a consequencethere is the possibility to have separate EDGE and non EDGE resources in one cell or one may enable EDGE inone cell and disable EDGE in the neighbour (with advanced features it is possible to move EDGE MSs to EDGEcells and GPRS MSs to GPRS cells). Additionally the PCU (being responsible for resource allocation) tries to avoidthese situations.
    30. 30. Chapter 10 EGPRS Protocols 10.4 Protocol structures 1. EGPRS Channel Coding 2. EGPRS MCS Families 3. The padding option 4. Combined RLC/MAC Header for EDGE user data 5. Differences in the Headertypes 6. MAC part of combined RLC/MAC header 7. Other new fields in the RLC/MAC header 8. The RLC part of combined RLC/MAC Header 9. Channel coding in EGPRS 10. Coding and Interleaving 11. Coding Process Example: MCS-2 DL 12. Coding Process Example: MCS-8 DL 13. EGPRS Coding Parameters 14. EDGE coding compared with GPRS
    31. 31. EGPRS Channel Coding In total 4 different types of RLC/MAC blocks are used:  DL RLC/MAC control blocks (CS 1, used for GPRS and E-GPRS, content may be different)  UL RLC/MAC control blocks (CS 1, used for GPRS and E-GPRS, content may be different)  E-GPRS DL RLC/MAC data blocks (MCS 1-9)  E-GPRS UL RLC/MAC data blocks (MCS 1-9) For the transfer of user data, nine Modulation and Coding Schemes (MCS) have been specified. Four MCSs use GMSK, the remaining 5 MCSs use 8PSK. The transmission of information is again organised in radio blocks. After the use of a MCS, The resulting bits have to be transmitted on four normal burst on four consecutive TDMA frames In other words, after adding redundancy and performing the modulation scheme, 456 symbols have to be transmitted. EGPRS Modulation and Coding Scheme E-GPRS RLC data unit size (in octets) MCS-1 22 MCS-2 28GMSK MCS-3 37 MCS-4 44 For MCS-5 56 user MCS-6 74 data8PSK MCS-7 2x56 MCS-8 2x68 MCS-9 2x74
    32. 32. EGPRS MCS FamiliesThe modulation and coding schemes are organised in families. Each family is characterised by abasic unit of payload resp. RLC data length:In EDGE basic unit of payload MCS-3are defined. Family A 37 octets 37 octets 37 octets 37 octetsThis allows retransmissionswith another MCS within the MCS-6same family. E.g. one of the 2 MCS-9RLC blocks of MCS 8 may be MCS-3retransmitted using MCS 3 34 +3 octets 34 +3 octets(requires 2 Radio blocks) or Family AMCS 6 (within one padding MCS-6Radioblock). 34 octets 34 octets 34 octets 34 octets MCS-8 37 octets MCS-2 Family B 28 octets 28 octets 28 octets 28 octets 34 octets MCS-5 28 octets MCS-7 MCS-1 22 octets 22 octets 22 octets Family C MCS-4
    33. 33. The padding option MCS 7: 44.8 kbit/s MCS 8: 54.4 kbit/s MCS 9: 59.2 kbit/sWhen switching to MCS-3 or MCS-6 from MCS-8, 6 padding octets are added to the data octets. RLC-1 RLC-2 First transmission with MCS-8 in 1 Radio block 34 octets 34 octets 34 octets 34 octetsRetransmission in case of RLC ack with: Either MCS-8 in 1 Radio block 34 octets 34 octets 34 octets 34 octets Or MCS-6 in 2 Radio blocks 34 +3 octets 34 +3 octets Each RLC within one radio block 34 +3 octets 34 +3 octets Or MCS-3 in 4 Radio blocks 34 +3 octets 34 +3 octets Each RLC within 2 radio blocks 34 +3 octets 34 +3 octets 1 half RLC
    34. 34. Combined RLC/MAC Header for EDGE user data Downlink Stealing Bits in Uplink Normal burst indicate 3GPP the Header type 4.60 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 TFI RRBP ES/P USF TFI Countdown value SI R BSN1 PR TFI BSN1 TFI Header type BSN2 BSN1 BSN1 1 BSN2 BSN2 BSN1 for MCS 7,8,9 sp. PI RSB CPS CPS BSN2 spare TFI RRBP ES/P USF TFI Countdown value SI R BSN1 PR TFI Header type BSN1 TFI BSN1 2 CPS BSN1 for MCS 5,6 spare PI RSB CPS CPS BSN1 spare TFI RRBP ES/P USF TFI Countdown value SI R BSN1 PR TFI Header type BSN1 TFI 3 BSN1 CPS BSN1 for MCS 1,2,3,4 SPB CPS BSN1 sp. PI RSB SPB CPS
    35. 35. Differences in the HeadertypesHeader type 1 RLC-1 RLC-2for MCS 7,8,9 Contains 2 RLC blocks, 2 Block sequence numbers are required. BSN 2 (10 bits) provides the BSN of the second block relative to the first one (11 bits). BSN1 11 bit BSN2 10 bitHeader type 2 RLCfor MCS 5,6 Contains 1 RLC block, 1 Block sequence numbers is required. BSN1 11 bitHeader type 2 ½ RLC 1 RLCfor MCS 1,2,3,4 or Contains 1 or ½ RLC block, 1 Block sequence numbers is required. The case of retransmittedhalf blocks is indicated by the Split Block Indicator field bits SPB 00 No retransmission BSN1 11 bit SPB 01 Reserved 10 Retransmission – first part of block 11 Retransmission – second part of block
    36. 36. MAC part of combined RLC/MAC header 6 5 4 3 2 1 Uplink Countdown value SI R Countdown value, Stall Indication, Retransmission bit, used as for GPRS   7 6 5 4 3 2 1 Downlink RRBP ES/P USF USF is exactly defined as for GPRS. Within EDGE it will be encoded separatly in exactly the same way as for GPRS. This allows sending EDGE blocks (of course GMSK blocks) to EDGE users, while addressing GPRS MSs in Uplink.EGPRS Supplementary/Polling (ES/P) Field ES/P Feedback Request (Poll) Description 00 Nothing (RRBP field invalid) 01 EGPRS PACKET DOWNLINK ACK/NACK message containing FPB (First Partial Bitmap), drop channel quality report 10 EGPRS PACKET DOWNLINK ACK/NACK message containing NPB (Next Partial Bitmap), drop channel quality report 11 EGPRS PACKET DOWNLINK ACK/NACK message containing NPB and Channel Quality ReportRRBP value specifies a single uplink block in which the mobile station shall transmit either aPACKET CONTROL ACKNOWLEDGEMENT message or a PACCH block to the network in thesame way as for GPRS.
    37. 37. Other new fields in the RLC/MAC header CPS MCS Puncturing Schemens MCS-1 PS 1, 2Coding and Puncturing Scheme indicator field (CPS) MCS-2 PS 1, 2In EGPRS header, the Coding and Puncturing MCS-3 PS 1, 2, 3Scheme indicator field is used to indicate the kind ofchannel coding (MCS) and puncturing (PS) used for MCS-4 PS 1, 2, 3data blocks. MCS-5 PS 1, 25 bits - header type 1 CPS MCS-6 PS 1, 23 bits - header type 2 CPS MCS-7 PS 1, 2, 34 bits - header type 3 CPS MCS-8 PS 1, 2, 3 RSB Uplink only MCS-9 PS 1, 2, 3 The Resent Block Bit (RSB) indicates whether any of the RLC data blocks contained within the EGPRS radio block have been sent previously. bit 0 All of the RLC data blocks contained within the EGPRS radio block are being transmitted for the first time 1 At least one RLC data block contained within the EGPRS radio block has been transmitted before.
    38. 38. The RLC part of combined RLC/MAC Header EGPRS RLC Data block Extension and length Indication used Length Indicator E almost in the same way as in GPRS (no ‘more’ bit in EGPRS) Downlink Uplink E FBI EGPRS RLC data unit E TI EGPRS RLC data unit FBI Final Block Indication and TITLLI Indication and E Extension bit give the RLC header E Extension bit give the RLC header 8 7 6 5 4 3 2 1 Bit-No8 7 6 5 4 3 2 1 Bit-No Length Indicator E octet 1 Length Indicator E octet 1 . octet 2 Optional . octet 2 Optional . octets octets Length Indicator E octet M Length Indicator E octet M+1 UL octet M DL RLC octet M+1 RLC TLLI Data data block block octet M+4 RLC data PFI E octet M+5 octet N2-1 RLC data octet N2-1 octet N2 octet N2
    39. 39. Channel coding in EGPRSDownlink RLC/MAC USF Header RLC Data Block RLC Data BlockUplink Two RLC blocks for MCS 7,8,and 9, each block is treated separately. RLC/MAC Header RLC Data Block RLC Data Block Within EDGE the channel coding process is different for USF (only DL), RLC/MAC Header and RLC Data Block. USF Precoding to 12 bits is performed to get the same type of encoding as in GPRS. RLC/MAC Parity bits are calculated and added to the end (For DL RLC/MAC part without USF). Header An 1/3 rate convolutional encoder is used to get 3 times the bits, then some bits are deleted again (punctured) RLC Data BlockParity bits are calculated and added to the end of an RLC data block. Additional tailbits are added. An 1/3rate convolutional encoder is used to get 3 times the bits, then some bits are deleted again (punctured). Forone MCS different Puncturing Schemes (2 or 3) are applied.
    40. 40. Coding and Interleaving RLC/MAC USF Header RLC Data Block The number of bits in header or data part and the number of Header with parity bits RLC with parity and tail bits punctured bits depends on the MCS and direction (UL or DL). GSM rec 3.64 x4 x3 x3 puncturing puncturing Bits sent over the air: For MCS 1-6: 1 RLC block for MCS 7-9: 2 RLC blocks Next step is interleaving. The bits are distributed on 4 bursts of one radio block. USF (only UL) part is interleaved on four bursts Header part is interleaved on four bursts. RLC blocks are interleaved on 4 bursts except for MCS 8 and 9 where each RLC is on interleaved on 2 bursts .
    41. 41. Coding Process Example: MCS-2 DL 3 bits 36 bits 244 bits RLC/MAC USF Header HCS E FBI RLC Data = 22 octets BCS TB convolutionary coding: rate 1/312 bits 108 bits 732 bits Puncturing (P1, P2) SB= 68 bits 12 bits 12 bits 372 bits normal burst normal burst normal burst normal burst
    42. 42. Coding Process Example: MCS-8 DL 3 bits 45 bits 564 bits 564 bits RLC/MAC RLC Data RLC Data USF Header HCS E FBI = 2 x 34 octets BCSTBE FBI = 2 x 34 octets BCSTB convolutionary coding: convolutionary coding: rate 1/3 rate 1/336 bits 135 bits 1692 bits 1692 bits Puncturing Puncturing Puncturing (P1, P2, P3) (P1, P2, P3) SB= 124 bits 8 bits 36 bits 612 bits 612 bits normal burst normal burst normal burst normal burst
    43. 43. EGPRS Coding Parameters RLC RLC blocks header data modu- code BCS HCS block per radio code family rate lation rate length length length block rate (kbps)MCS-1 0.53 176 1 0.53 C 8.8MCS-2 0.66 224 1 0.53 B 11.2 GMSK 296 A 14.8MCS-3 0.85 1 0.53 48+248 A (p) 13.6 12MCS-4 1.0 352 1 0.53 C 17.6MCS-5 0.37 448 1 1/3 8 B 22.4 592 A 29.6MCS-6 0.49 1 1/3 48+544 A (p) 27.2 8PSKMCS-7 0.76 448 2 0.36 B 44.8MCS-8 0.92 544 2 2x12 0.36 A (p) 54.4MCS-9 1.0 592 2 0.36 A 59.2 Please note, different Code Rates for header and data! A (p) = family A padding
    44. 44. EDGE coding compared with GPRS9 Channel coding schemes (MCS) are defined.The MCS is indicated in the RLC/MAC header (blind detection). EDGE MSs have to support all GPRS CS and all MCS in DL, the usage of 8 PSK in UL is optional.Networks may only support a subset of all MCS. 9 MCSs EDGE introduces a new 1/3 rate convolutional coder, which alllows a very strong encoding. Different types of coding are used for the USF (DL only), header- and datapart. Encoding rules are slightly different for UL and DL. Channel codingEDGE introduces introduces for each MCS 2 or 3 different Puncturing Schemes. PuncturingPuncturing is done differently for header- and data-part. Interleaving EDGE defines new interleaving rules. Header- and data-part are treated differently. For the USF the SACCH encoding and interleaving is emulated. For MCS 1-7 the RLC block is interleaved on all 4 bursts of one block, for MCS 8 and 9 one RLC block is found only on two bursts. The idea is to offer better performance of these MCSs in a hopping network.
    45. 45. Chapter 10 EGPRS Protocols 10.5 RLC MAC enhancements 1. EDGE specific RLC/MAC modifications 2. Network access mechanism 3. EGPRS Packet Channel Request 4. other new RLC/MAC messages for EGPRS
    46. 46. EDGE specific RLC/MAC modificationsModified Messages Field/IE modificationSI13, PSI1, PSI13 EGPRS capability introduced in GPRS Cell Options IE: EGPRS_SUPPORT, EGPRS_PACKET_CHANNEL_REQUEST, BEP_PERIOD, …PACKET UPLINK ASSIGNMENT EGPRS Channel Coding Command (MCS-1,....,MCS-9), Resegment field (for Incremental Redundancy), EGPRS Window Size, …PACKET RESOURCE REQUEST EGPRS BEP Link Quality Measurements, EGPRS Timeslot Link Quality Measurements,PACKET DOWNLINK ASSIGNMENT EGPRS Window Size, LINK_QUALITY_MEASUREMENT_MODE, BEP_PERIOD2,PACKET UPLINK ACK/NACK EGPRS Modulation and Coding, RESEGMENT field, Control EGPRS Ack/Nack Description,… messagesPACKET TIMESLOT RECONFIGURE EGPRS Modulation and Coding, RESEGMENT field, DOWNLINK EGPRS Window Size, UPLINK EGPRS Window Size LINK_QUALITY_MEASUREMENT_MODE,…New messages: EGPRS PACKET CHANNEL REQUEST EGPRS PACKET DOWNLINK ACK/NACK
    47. 47. Network access mechanism The message used by an EDGE capable MS to gain access to the network depends Sys info 13 on BCCH on some conditions . A new EDGE PACKET CHANNEL REQUEST PSI 13 on PBCCH control message is defined MS Sys info 13: support of PBCCH EGPRS PACKET CHANNEL REQUEST or yes no PACKET CHANNEL REQUEST EDGE support? or CHANNEL REQUEST yes no Use CHANNEL REQUEST on CCCH GPRS only Support of EGPRS PACKET CHANNEL REQUEST? Whether 8 or 11 bit burst is used is indicated in Sys info or PSI yes no Switch to PBCCH: EDGE support? Use CHANNEL REQUEST on RACH yes no Use EGPRS_PACKET_CHANNEL_REQUEST on RACH Use PACKET CHANNEL REQUEST on PRACH (8 or 11 bits) GPRS only Support of EGPRS no Use PACKET CHANNEL REQUEST on PRACH (8 or 11PACKET CHANNEL bits) REQUEST? yes Use EGPRS_PACKET_CHANNEL_REQUEST on PRACH
    48. 48. EGPRS Packet Channel Request EGPRS PACKET CHANNEL REQUEST 11 Bits of Information when used for: One-Phase Packet Access Request 0 Multislot class Radio Random Priority reference Short Access Request 1 0 0 Number of Radio Random slots Priority reference Two-Phase Packet Access Request 1 1 0 0 0 0 Radio Random Priority reference Signalling (GMM/MM) 1 1 0 0 1 1 Random reference There are different Training Sequences defined. By choosing one the MS indicates whether it supports 8-PSK in UL or not. Format of access burst: Tail Encoded data Training Sequence tail 3 36 41 8 Number of Bits
    49. 49. other new RLC/MAC control messages (3GPP 4.60) Global TFI Additional MS Radio capability IE in some messages This information element contains the TFI of the mobile stations uplink TBF, if available, or the TFI of the mobile stations downlink TBF. If no TFI is available, this field is omitted. TLLI IE (32 bit field) MS Radio Access Capability 2 This information element is sent during one phase and two phase access procedures on CCCH or PCCCH . < EGPRS Packet Downlink Ack/Nack message content > ::= EGPRS Packet DL ACK/NACK < DOWNLINK_TFI : bit (5) > < MS OUT OF MEMORY : bit(1)> {0|1 < EGPRS Channel Quality Report : < EGPRS Channel Quality Report IE > >} {0|1 < Channel Request Description : >Channel Request Description IE > >} {0|1 < PFI : bit(7) > } {0|1 < Extension Bits : Extension Bits IE > } < EGPRS Ack/Nack Description : < EGPRS Ack/Nack Description IE >> <padding bits > ;< Packet Downlink Ack/Nack message content > ::= Packet DL ACK/NACK used for GPRS < DOWNLINK_TFI : bit (5) > < Ack/Nack Description : < Ack/Nack Description IE > > { 0 | 1 < Channel Request Description : < Channel Request Description IE > > } < Channel Quality Report : < Channel Quality Report struct > > { null | 0 bit** = <no string> -- Receiver backward compatible with earlier version |1 -- Additional contents for Release 1999 8 { 0 | 1 < PFI : bit(7) > } < padding bits > };

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