3G/UMTS

  

 

 

 

Channel Mapping : MAC-ehs

 

 

< Overview on MAC-ehs in UTRAN : HSPA+>

 

Now let's look into MAC-ehs which is for HSPA+ (HSPA Evolution). Just by looking at the following figures, it don't see much differences from MAC-hs (figure 4.2.4.3.1). But in reality it has a couple of important difference from MAC-hs.

 

As in MAC-hs, you always have to think of it in connection with MAC-d. So I combined the two entity as follows to help your understanding. Try following each single steps along the red path of MAC-d and all the path in MAC-ehs.

 

 

As a first step, let's just read the path.

i) one ore more DTCH or DCCH RLC PDU gets into MAC-d.

ii) MAC-d associate each block of MAC-d PDUs of a logical channel with the related LCH-ID, regardless whether one or several logical channels are multiplexed onto one MAC-d flow. (MAC-ehs needs LCH-ID because there is possibility that more than one DTCH or DCCH can be multiplexed into a transport block)

iii) MAC ehs distribute the incoming data into each of the priority queues.

iv) As time goes one, multiple MAC-d PDUs will be accumulating into Priority Queues.

v) The HARQ process in MAC-hs choose one of the priority Queues in every TTI and pull out a certain number of MAC-d PDUs based on TFRI and transmit it to the transport channel.

 

Following is an example of MAC-ehs configuration in Radio Bearer Setup. As you see, the MAC hs setup has MAC-d configuration information as well.

 

  +-message ::= CHOICE [radioBearerSetup]

    +-radioBearerSetup ::= CHOICE [later-than-r3]

      +-later-than-r3 ::= SEQUENCE

        +-rrc-TransactionIdentifier ::= INTEGER (0..3) [0]

        +-criticalExtensions ::= CHOICE [criticalExtensions]

          +-criticalExtensions ::= CHOICE [criticalExtensions]

            +-criticalExtensions ::= CHOICE [criticalExtensions]

              +-criticalExtensions ::= CHOICE [r7]

                +-r7 ::= SEQUENCE [00]

                  +-radioBearerSetup-r7 ::= SEQUENCE [00100011010000000000111110]

                  | +-ura-Identity ::= BIT STRING OPTIONAL:Omit

                  | +-supportForChangeOfUE-Capability ::= BOOLEAN OPTIONAL:Omit

                  | +-cn-InformationInfo ::= SEQUENCE OPTIONAL:Omit

                  | +-specificationMode ::= CHOICE [complete]

                  | |   +-dl-DeletedTransChInfoList ::= SEQUENCE OF OPTIONAL:Omit

                  | |   +-dl-AddReconfTransChInfoList ::= SEQUENCE OF SIZE(1..maxTrCHpreconf[32]) [2]

                  | |     +-DL-AddReconfTransChInformation-r7 ::= SEQUENCE [0]

                  | |     | +-dl-TransportChannelType ::= CHOICE [hsdsch]

                  | |     | | +-hsdsch ::= NULL

                  | |     | +-tfs-SignallingMode ::= CHOICE [hsdsch]

                  | |     | | +-hsdsch ::= SEQUENCE [11]

                  | |     | |   +-harqInfo ::= SEQUENCE OPTIONAL:Exist

                  | |     | |   | +-numberOfProcesses ::= ENUMERATED [n6]

                  | |     | |   | +-memoryPartitioning ::= CHOICE [implicit]

                  | |     | |   |   +-implicit ::= NULL

                  | |     | |   +-dl-MAC-HeaderType ::= CHOICE [mac-ehs] OPTIONAL:Exist

                  | |     | |     +-mac-ehs ::= SEQUENCE [10]

                  | |     | |       +-mac-ehs-AddReconfQueue-List ::= SEQUENCE OF SIZE(1..maxQueueIDs[8])

                  | |     | |       | +-MAC-ehs-AddReconfReordQ ::= SEQUENCE [0]

                  | |     | |       |   +-mac-ehs-QueueId ::= INTEGER (0..7) [1]

                  | |     | |       |   +-reorderingReleaseTimer ::= ENUMERATED [rt50]

                  | |     | |       |   +-reorderingResetTimer ::= ENUMERATED OPTIONAL:Omit

                  | |     | |       |   +-mac-ehsWindowSize ::= ENUMERATED [mws16]

                  | |     | |       +-dummy ::= SEQUENCE OF OPTIONAL:Omit

                  | |     | +-dch-QualityTarget ::= SEQUENCE OPTIONAL:Omit

                  | |     +-DL-AddReconfTransChInformation-r7 ::= SEQUENCE [1]

                  | +-frequencyInfo ::= SEQUENCE OPTIONAL:Omit

                  | +-multi-frequencyInfo ::= SEQUENCE OPTIONAL:Omit

                  | +-dtx-drx-TimingInfo ::= SEQUENCE OPTIONAL:Omit

                  | +-dtx-drx-Info ::= SEQUENCE OPTIONAL:Omit

                  | +-hs-scch-LessInfo ::= SEQUENCE OPTIONAL:Omit

                  | +-mimoParameters ::= SEQUENCE OPTIONAL:Omit

                  | +-maxAllowedUL-TX-Power ::= INTEGER OPTIONAL:Omit

                  | +-ul-DPCH-Info ::= SEQUENCE [1] OPTIONAL:Exist

                  | +-ul-EDCH-Information ::= SEQUENCE [1] OPTIONAL:Exist

                  | +-dl-HSPDSCH-Information ::= SEQUENCE [11] OPTIONAL:Exist

                  | +-dl-CommonInformation ::= SEQUENCE [110] OPTIONAL:Exist

                  | +-dl-InformationPerRL-List ::= SEQUENCE OF SIZE(1..maxRL[8]) [1] OPTIONAL:Exist

                  | +-mbms-PL-ServiceRestrictInfo ::= ENUMERATED OPTIONAL:Omit

                  +-radioBearerSetup-r7-add-ext ::= BIT STRING OPTIONAL:Omit

                  +-v780NonCriticalExtensions ::= SEQUENCE OPTIONAL:Omit

 

Unlike in MAC-hs, in MAC-ehs you see two separate path under HARQ entity. This indicate it can create two transport blocks simultaneously. In turn, it means that it can support MIMO.

Another important difference is that MAC-ehs can multiplex (combine) the data stream from multiple different logical channels and multiple different Priority Queue into a single MAC-ehs PDU. The block labeled as 'Priority Queue MUX' indicate that MAC-ehs can multplex the data from multiple Priority Queue. If you see MAC-esh PDU structure following this figure, it shows a field LCH-ID. It means there can be data coming from multiple different logical channels.

This way.. if you follow each and every component of these figures and try to think of what is the purpose of these component, you will get a lot of information on your own even without reading the description part of the specification.

And also if you do this kind of figure analysis before you read the description part of the specification, you will make much more sense out of the description part of the specification.

 

 

 

 

Field

Field Name

Bits

Description

LCH-ID

Logical channel identifier

4

The LCH-ID field provides identification of the logical channel at the receiver and the re-ordering buffer destination of a reordering SDU.

TSN

Transmission Sequence Number

6

The TSN field provides an identifier for the transmission sequence number on the HS-DSCH. The TSN field is used for reordering purposes to support in-sequence delivery to higher layers.

SI

Segmentation Indication

2

The SI field indicates if the MAC-ehs SDU has been segmented and it shows which part of the segment it is if it is segmented .(See the table 9.2.2.1 following this table)

L

Length

11

The L field provides the length of the reordering SDU in octets. The reordering SDU size can vary for each reordering SDU in the MAC-ehs PDU, and is set for each reordering SDU individually.

F

Flag

1

The F field is a flag indicating if more fields are present in the MAC-ehs header or not. If the F field is set to "0" the F field is followed by an additional set of LCH-ID and L fields and optionally TSN and SI fields. If the F field is set to "1" the F field is followed by a reordering PDU. Each header extension corresponds to one reordering SDU

 

 

 

Example 1 : MAC ehs PDU (See Full Data)

HEX String

EB BC 04 EB BC EB BC E4 7B ...........
BIN String

111010111011110000000100111010111011110011101011101111001110010001111011 ......

LCID(4 bits)

L(11 bits)

TSN(6 bits)

SI(2 bits)

F(1 bit)

BIN

DEC

BIN

DEC

BIN

DEC

BIN

DEC

BIN

DEC

1110

14

10111011110

1502

000000

0

10

2

0

0

1110

14

10111011110

1502

-

-

-

-

0

0

1110

14

10111011110

1502

-

-

-

-

0

0

1110

14

01000111101

573

-

-

-

-

1

1

 

 

< Overview on MAC-ehs in UE : HSPA+ >

 

This is UE side of MAC-ehs. Everything is in reverse order of UTRAN side. You have to read from the bottom of this figure to the top.

 

 

 

Correlation of MAC parameter and RRC Information Elements

 

For the details for this, you have to refer to 25.321 8.3.2 Parameters and look up the meaning of each parameters in 25.331. But I would pick up some major parameters which is mainly used in  RRC Connection Request, RRC Connection Setup, RRC Connection Setup Complete, Radio Bearer Setup and summarize them in this section. You can you this section as a kind of dictionary when you are analyzing RRC messages for troubleshooting the protocol stack.

 

UE Information Element

ASN path (RRC Message)

S-RNTI

rrcConnectionSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.rrcConnectionSetup-r7.new-U-RNTI.s-RNTI

SRNC identity

rrcConnectionSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.rrcConnectionSetup-r7.new-U-RNTI.srnc-Identity

C-RNTI

rrcConnectionSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.rrcConnectionSetup-r7.new-c-RNTI

Activation time

rrcConnectionSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.rrcConnectionSetup-r7.activationTime

Primary E-RNTI configured

i) rrcConnectionSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.rrcConnectionSetup-r7.newPrimary-E-RNTI

ii) radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.r6.radioBearerSetup-r6.newPrimary-E-RNTI

Secondary E-RNTI configured

i) rrcConnectionSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.rrcConnectionSetup-r7.newSecondary-E-RNTI

ii) radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.r6.radioBearerSetup-r6.newSecondary-E-RNTI

 

 

RB information elements

ASN path (RRC Message)

Transport channel identity,

  

Logical channel identity,

i) rrcConnectionSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.rrcConnectionSetup-r7.specificationMode.complete.srb-InformationSetupList.SRB-InformationSetup-r7[0].rb-MappingInfo.RB-MappingOption-r7[0].dl-LogicalChannelMappingList.DL-LogicalChannelMapping-r7[0].logicalChannelIdentity

ii) radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.r6.radioBearerSetup-r6.specificationMode.complete.rab-InformationSetupList.RAB-InformationSetup-r6[0].rb-InformationSetupList.RB-InformationSetup-r6[0].rb-MappingInfo.RB-MappingOption-r6[0].dl-LogicalChannelMappingList.DL-LogicalChannelMapping-r5[0].logicalChannelIdentity

MAC logical channel priority

i) rrcConnectionSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.rrcConnectionSetup-r7.specificationMode.complete.srb-InformationSetupList.SRB-InformationSetup-r7[0].rb-MappingInfo.RB-MappingOption-r7[0].ul-LogicalChannelMappings.oneLogicalChannel.mac-LogicalChannelPriority

ii) radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.r6.radioBearerSetup-r6.specificationMode.complete.rab-InformationSetupList.RAB-InformationSetup-r6[0].rb-InformationSetupList.RB-InformationSetup-r6[0].rb-MappingInfo.RB-MappingOption-r6[0].ul-LogicalChannelMappings.oneLogicalChannel.mac-LogicalChannelPriority

DDI mapping table for E-DCH transmission

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.r6.radioBearerSetup-r6.specificationMode.complete.rab-InformationSetupList.RAB-InformationSetup-r6[0].rb-InformationSetupList.RB-InformationSetup-r6[0].rb-MappingInfo.RB-MappingOption-r6[0].ul-LogicalChannelMappings.oneLogicalChannel.ul-TrCH-Type.e-dch.ddi

Indication whether the Logical channel is considered when the Scheduling Information is generated

  

 

 

TrCH information elements

ASN path (RRC Message)

Transport Format Combination Set

  

MAC-hs/ehs reset indicator

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.dl-CommonInformation.mac-hsResetIndicator

MAC-es/e/i/is reset indicator

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.ul-EDCH-Information.mac-es-e-resetIndicator

Re-ordering release timer (T1)

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.specificationMode.complete.dl-AddReconfTransChInfoList.DL-AddReconfTransChInformation-r7[0].tfs-SignallingMode.hsdsch.dl-MAC-HeaderType.mac-ehs.mac-ehs-AddReconfQueue-List.MAC-ehs-AddReconfReordQ[0].reorderingReleaseTimer

HARQ Profile parameters

i) radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.specificationMode.complete.dl-AddReconfTransChInfoList.DL-AddReconfTransChInformation-r7[0].tfs-SignallingMode.hsdsch.harqInfo

ii) radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.specificationMode.complete.ul-AddReconfTransChInfoList.UL-AddReconfTransChInformation-r7[0].e-dch.harq-Info

E-DCH TTI duration

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.specificationMode.complete.ul-AddReconfTransChInfoList.UL-AddReconfTransChInformation-r7[0].e-dch.modeSpecific.fdd.tti

Allowed combinations for multiplexing of MAC-d flows into MAC-e PDUs or MAC-i PDUs

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.specificationMode.complete.ul-AddReconfTransChInfoList.UL-AddReconfTransChInformation-r7[0].e-dch.addReconf-MAC-d-FlowList

E-DCH grant type of MAC-d flows (scheduled or non-scheduled)

  

List of HARQ processes on which non-scheduled grants are allowed

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.specificationMode.complete.ul-AddReconfTransChInfoList.UL-AddReconfTransChInformation-r7[0].e-dch.addReconf-MAC-d-FlowList.E-DCH-AddReconf-MAC-d-Flow-r7[0].transmissionGrantType.non-ScheduledTransGrantInfo

 

 

E-DCH configuration elements

ASN path (RRC Message)

E-DPCCH to DPCCH power offset

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.ul-EDCH-Information.modeSpecificInfo.fdd.e-DPCCH-Info.e-DPCCH-DPCCH-PowerOffset

Happy bit delay condition

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.ul-EDCH-Information.modeSpecificInfo.fdd.e-DPCCH-Info.happyBit-DelayCondition

E-TFCI table index

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.ul-EDCH-Information.modeSpecificInfo.fdd.e-DPDCH-Info.e-TFCI-TableIndex

minimum set E-TFCI

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.ul-EDCH-Information.modeSpecificInfo.fdd.e-DPDCH-Info.e-DCH-MinimumSet-E-TFCI

Reference E-TFCI

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.ul-EDCH-Information.modeSpecificInfo.fdd.e-DPDCH-Info.reference-E-TFCIs

Periodicities for Scheduling Information with grant

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.ul-EDCH-Information.modeSpecificInfo.fdd.e-DPDCH-Info.schedulingInfoConfiguration.periodicityOfSchedInfo-NoGrant

Periodicities for Scheduling Information without grant

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.ul-EDCH-Information.modeSpecificInfo.fdd.e-DPDCH-Info.schedulingInfoConfiguration.periodicityOfSchedInfo-Grant

Scheduling Information power offset

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.ul-EDCH-Information.modeSpecificInfo.fdd.e-DPDCH-Info.schedulingInfoConfiguration.powerOffsetForSchedInfo

List of HARQ processes on which scheduled grants are allowed

  

Initial Serving Grant value and type

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.ul-EDCH-Information.modeSpecificInfo.fdd.schedulingTransmConfiguration.servingGrant

Symbol offset (S_offset)

  

Additional E-DCH transmission back off

  

E-DCH transmission continuation back off

  

Maximum period for collision resolution phase

  

Maximum E-DCH resource allocation for CCCH

  

 

DTX-DRX and HS-SCCH less Information Elements

ASN path (RRC Message)

MAC DTX Cycle

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.dtx-drx-Info.dtx-Info.e-dch-TTI-Length.dtx-e-dch-TTI-2ms.mac-dtx-Cycle-2ms

MAC Inactivity Threshold

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.dtx-drx-Info.dtx-Info.mac-InactivityThreshold

UE DTX DRX Offset

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.dtx-drx-TimingInfo.timing.newTiming.ue-dtx-drx-Offset

HS-SCCH less mode of operation

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.hs-scch-LessInfo.hs-scchLessOperation

Inactivity Threshold for UE Grant Monitoring

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.dtx-drx-Info.drx-Info.ue-GrantMonitoring-InactivityThreshold

Inactivity Threshold for UE DTX cycle 2

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.dtx-drx-Info.dtx-Info.ue-dtx-cycle2InactivityThreshold

Default SG in DTX Cycle 2

radioBearerSetup.later-than-r3.criticalExtensions.criticalExtensions.criticalExtensions.criticalExtensions.r7.radioBearerSetup-r7.dtx-drx-Info.dtx-Info.ue-dtx-cycle2DefaultSG

 

 

Others

ASN path (RRC Message)

E-DCH resource index

  

Enhanced Uplink in CELL_FACH and Idle mode process termination