10_HSDPA_HSUPA.ppt

HSDPA (HS-DSCH) and HSUPA (E-DCH)implementation in RNC CallPEwa KulinskiNovember 5, 2007

All Rights Reserved Alcatel-Lucent 2006, 2007

AgendaHSDPA (HS-DSCH) OverviewHSUPA (E-DCH) OverviewCell SetupUE Capabilities AnalysisCall SetupSource ConformanceStandalone RLC ReconfigurationMobilityUni-directional DCH workaroundDocumentation


1HSDPA (HS-DSCH) Overview


HSDPA High Speed Downlink Packet AccessIt uses the HS-DSCH transport channel - High Speed Downlink Shared ChannelThe corresponding physical channel is denoted by HS-PDSCHSignaling is conducted on the HS-SCCH (High-Speed Shared Control Channel) common to all usersHS-DPCCH the uplink physical channel - is used for Channel Quality Indication and ACKIt uses Adaptive Modulation and Coding (AMC) - QPSK and 16-QAMRepetition is handled with Hybrid Automatic Repeat reQuest (HARQ)Fast scheduling is performed in the NodeB - MAC-hs entity located in the NodeBSpreading Factor is fixed to SF16 - time and code multiplex, 1 to 16 SF codesThe Transmission Time Interval (TTI) is short 2 msIt is not a new RRC state, but it is performed in CELL_DCH stateHSDPA Overview - Characteristics


HSDPA Overview - BenefitsHSDPA improves system capacity, reduces transmission delay and increases user data rates in the downlink directionShared channel provides resources optimization and good solution for bursty dataNew modulation enhances spectral efficiency, provides higher peak data rate and better throughputShort 2 ms TTI reduces link adaptation delays, increases the granularity in the scheduling process, facilitates better tracking of varying radio conditionsHARQ means fast retransmissions in the Node B (conventional RLC retransmissions can still be performed but will be needed less often)Fast scheduling in the Node B is closer to the air interface and its measurementsAdaptive modulation and coding provides ability to adapt the modulation scheme according to the quality of the radio link


2HSUPA (E-DCH) Overview


HSUPA High Speed Uplink Packet AccessIt uses the E-DCH transport channel Enhanced Dedicated ChannelHSUPA introduces new physical channels, in uplink: E-DPCCH (E-DCH Dedicated Physical Control Channel) and E-DPDCH (E-DCH Dedicated Physical Data Channel) in downlink: E-AGCH (E-DCH Absolute Grant Channel), E-RGCH (E-DCH Relative Grant Channel), E-HICH (E-DCH Hybrid ARQ Indicator Channel), E-DPDCH is used to carry the E-DCH Transport Channel E-DPCCH is used to carry the control information associated with the E-DCHHARQ is used, similar as in HSDPA caseIt supports 10 ms and 2 ms TTIOne or more radio links are used (it supports macro-diversity) one serving E-DCH radio link which is the same as HSDPA, several non-servingScheduled or non-scheduled mode - in the scheduled mode the packet scheduler operates on a request/grant principle (UE requests, Node B grants)HSUPA Overview - Characteristics


HSUPA Overview - BenefitsBenefits are similar to those of HSDPA but in the uplink direction.HSUPA improves performance of uplink dedicated transport channel increases capacity and throughput and reduces delayNode B scheduling allows faster adaptation to interference variations and tighter control of uplink noise rise


3Cell Setup


HSxPA Cell SetupFor HSDPA and E-DCH, codes and power in downlink (for common and shared channels) are allocated in the cell setup phaseDynamic Code Tree Management can modify allocation of channelization codes for HSDPANOBCCH invokes CELLRRM when Physical Shared Channel Reconfiguration message is going to be sent over NBAP (containing HSDPA and E-DCH parameters)A cell cannot be configured with EDCH and without HSDPACELLRRM performs allocation of channelization codes and powerParameters are provided by CELLRRM to NOBCCHHS-PDSCH and HS-SCCH codesHSDPA total power


HSxPA Cell Setup

Audit Request

Node B

RNC

Common Measurements Setup

System Information Update Procedure

Physical Shared Channel Reconfiguration Response

Physical Shared Channel Reconfiguration Request

Common Channels Setup Procedure

Cell Setup Response

Cell Setup Request

Audit Response


HSDPA and E-DCH channelization codes


HSDPA and E-DCH Power


HSxPA Cell Setup Management of E-DCH CapabilityCell capability (HSDPA-capable, E-DCH-capable, TTI 2ms, min-SF) is updated from Node B:NBAP Audit ResponseNBAP Resource Status IndicatorNOB handles these messages and updates DDR with the latest information.It also provides HSDPA cell indicator and E-DCH cell indicator to the UE via SIB 5.


4UE Capabilities Analysis


UE Capabilities AnalysisWhen the RRC Connection is established, UE_CALL invokes UERRM to perform the UE capabilities analysisAccess Stratum Release Indicator (R4, R5, R6) is taken from the RRC Connection RequestOther capabilities (HSDPA-capable, E-DCH capable, UE category, ...) are taken from the RRC Connection Setup Complete The analysis result is stored in the call context (uerrmOutput.ueInfo.ueCapa, copied to uerrmInput.ueInfo.ueCapabilities) to be used when a RAB is going to be setup.


5Call Setup


Call SetupWhen the RANAP RAB Assignment with RAB to setup is received, UE_CALL invokes UERRM to perform RAB Matching.In the transportTypeChoice() box of RAB Matching, after other analysis (UE Capabilities, type of the call), UERRM invokes cellinfo to read the current state of the primary cell from the DDR to know if the cell allows HSDPA and E-DCH.Parameters required to establish the call on DCH/HSDPA or E-DCH/HSDPA are provided by UERRM to UE_CALL. The part relative to HS-DSCH and E-DCH is in uerrmOutput.hsdpaInfo and uerrmOutput.edchInfo.


DCH/HSDPA Call ConfigurationHS-DSCH MAC-d flow for DL traffic.Dedicated part on DCH: signaling and UL trafficBi-directional DCH for the traffic, DL rate 0 kbps (dummy sync frames sent over this DCH).


E-DCH/HSDPA Call ConfigurationHS-DSCH MAC-d flow for DL traffic.E-DCH MAC-d flow for UL traffic.Dedicated part on DCH for signaling.


Call SetupUE_CALL executes the Synchronized RL Reconfiguration (or RL Setup if establishment from CELL_FACH).RNC_CALL dispatches messages to NOBCALLs and fills one of them with HSDPA and E-DCH information, while other contain only the DCH part (signalling + DCH X kbps/0 kbps is case of HSDPA, signalling (only) in case of E-DCH)NOBCALL invokes CELLRRM (via NOBRRM). When HSDPA information is present, CELLRRM manages HSDPA CAC based on number of allowed MAC-d flows and allocates H-RNTI. For E-DCH CELLRRM provides some power information which is configured per cell.


Call Setup H-RNTI allocationFor an UE having an HSDPA call, an H-RNTI is allocated and this H-RNTI needs to be unique within a cell. The mobile is listening to the downlink HS-SCCH channel to determine when it should collect data on the HS-DSCH channels.In order to avoid false detection due to bit corruption over the air interface, the H-RNTI is generated using a code that has Hamming distance of at least 4 (every two values have 4 bits different from each other).We implement a Bose-Chaudhuri-Hocquenghem code. Its Hamming distance is 6 and the average distance is 8.This code is generated using a mask: 0x7F (01111111)


HSDPA H-RNTI Management

1 index (0-127)

2- parity of (index & mask[0])



10- parity of the 15-bit result of operations 1-9


Call SetupNOBCALL allocates CIDs, including these for HS-DSCH and E-DCH MAC-d flows and sends the ASN.1-encoded NBAP message to the Node B, then handles the response and sends it to RNC_CALL.RNC_CALL performs I-Node DTrCh Reconf DCH and responds to UE_CALL.UE_CALL sends the RRC Radio Bearer Setup message to the mobile. This message contains all required information about HSDPA (including H-RNTI) and about E-DCH.In case of DCH/HSDPA, the uni-directional DCH workaround is applied.


6Source Conformance


Source ConformanceIn case of DCH/HSDPA or E-DCH/HSDPA call, the actual bit-rate that is granted to a user is in fact allocated by the Node B, which has no indication of the requested bit rate for the service. The Node B can allocate a larger bandwidth than requested if the core or the mobile are transmitting more information. To avoid that phenomenon, not aligned with QoS management, a solution called source conformance is designed at the GTP-U level to discard data overflowing the requested bandwidth.A leaky bucket algorithm is used.UL and DL Source Conformance parameters are provided by UERRM when the RAB is established (in the output of the uerrmInvoke(RAB_ASSIGNMENT_ALLOC), output->rabWithoutFlow). UE_CALL gives them to IU_CALL, which uses them in the GTP Context Request (IUD_TRANSP_REQ)


7Standalone RLC Reconfiguration


Standalone RLC ReconfigurationWhen adding another RAB, when the existing RAB changes the transport channel type to or from DCH/HSDPA, in case of R5 UE, a standalone RLC reconfiguration is needed, because RLC parameters of an existing RB cannot be reconfigured in this version of RRC Radio Bearer Setup.The standalone RLC reconfiguration is performed right after the synchronized RL reconfiguration that allocated the RAB. An RRC Radio Bearer Reconfiguration message is sent to the mobile and DBearer RB Modification is sent to the U-Plane.Separate value of DeltaCFN is provided for this procedure.In other cases the RLC Reconfiguration is not standalone.


8Mobility


HSxPA MobilityHSDPA Mobility follows the primary cell the HSDPA RL is the primary RL.E-DCH serving RL is always the one that carries HSDPA There can be other E-DCH RL in the Active Set E-DCH Active Set is a sub-set of the Active Set)After the uerrmInvoke(PRL_UPDATE) (which follows RRC Measurement Report reception and different mobility cases) UE_CALL invokes UERRM for HSxPA MobilityUERRM decides if mobility is needed, with or without transport channel type switch


HSxPA MobilityHSxPA Mobility cases without transport channel type switchingE-DCH/HSDPA to E-DCH/HSDPA (UL_RL_MOBILITY_DL_RL_MOBILITY)DCH/HSDPA to DCH/HSDPA (UL_NONE_DL_RL_MOBILITY)HSxPA Mobility cases with transport channel type switchingE-DCH/HSDPA to DCH/HSDPA (UL_TO_DCH_DL_RL_MOBILITY)E-DCH/HSDPA to DCH/DCH (UL_TO_DCH_DL_TO_DCH)DCH/HSDPA to E-DCH/HSDPA (UL_TO_EDCH_DL_RL_MOBILITY)DCH/HSDPA to DCH/DCH (UL_NONE_DL_TO_DCH)DCH/DCH to E-DCH/HSDPA (UL_TO_EDCH_DL_TO_HSDSCH)DCH/DCH to DCH/HSDPA (UL_NONE_DL_TO_HSDSCH)


HSxPA Mobility


HSxPA MobilityThe HSxPA mobility is performed via synchronized radio link reconfiguration:adding and deleting HS-DSCH MAC-d flows and E-DCH MAC-d flowsand also modifying, adding or removing the DCH part in case of transport channel type switching


9Uni-directional DCH workaround


Uni-directional DCH workaroundIn case of DCH/HSDPA configuration, in the access network the DCH part is configured as 0 kbps DL and X kbps in ULBut in the configuration sent to the mobile, the DCH is UL only, and the DL 0 kbps DCH is not sent to the mobile


Uni-directional DCH workaroundRNC/Node B U-Plane ConfUE U-Plane Conf


Uni-directional DCH workaroundThe workaround is needed for HSDPA in downlink with DCH in uplink. It is not needed when HSDPA in downlink with E-DCH in uplink is used (there is no DCH 0 kbps).The workaround removes the DCH 0 kbps from the message sent to the mobile when it is established and when it is deleted.It consists of RB Mapping modification and TrCh Modification


Uni-directional DCH workaround1) RB Mapping modificationwhen adding or reconfiguring an RB, it is mapped to DCH and HS-DSCH (at the Node B side)workaround makes it mapped only to HS-DSCH 2) TrCh Modification there are three possibilitiesa- remove the DCH 0 kbps from DL TrCh To Add or Reconfigureb- remove the DCH 0 kbps from DL TrCh To Deletec- remove the DCH 0 kbps from DL TrCh To Add or Reconfigure and add the DCH Y kbps to DL TrCh To Delete (from the previous DCH / DCH configuration)


Uni-directional DCH workaroundTransitions where the workaround is applicableA) Going to DCH/HSDPAWhen setting up a RAB on DCH/HSDPA we need to 1) modify the RB Mapping and 2) Modify the TrCh (a)When reconfiguring a RAB to DCH/HSDPA from DCH/DCH we need to 1) modify the RB Mapping and 2) Modify TrCh (c)When reconfiguring a RAB to DCH/HSDPA from E-DCH/HSDPA we need to 1) modify the RB Mapping and 2) Modify the TrCh (a)B) Going from DCH/HSDPAWhen releasing a RAB from DCH/HSDPA we need to modify the TrCh (b)When reconfiguring a RAB from DCH/HSDPA to E-DCH/HSDPA we need to modify the TrCh (b)


Uni-directional DCH workaroundMultiple HS-DSCH MAC-d flowsIn this case there are two HS-DSCH MAC-d flows in DL and one DCH UL/DLThe workaround is the same (remove the DCH 0 kbps in DL from RRC Messages when it is added or removed)The number of HS-DSCH MAC-d flows is stored in the UE_RRC context, to differentiate workaround cases from these just adding or removing the second HS-DSCH MAC-d flow


10Documentation


DocumentationUMT/SYS/DD/013319 (V02.14) HSDPA System SpecificationUMT/SYS/DD/018827 (V01.09) Enhanced DCH System SpecificationUMT/RNC/DD/018134 Q01184423 PM 29840 E-DCH Commercial Introduction SFS


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10_HSDPA_HSUPA.ppt

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