ran0285 hspa multi nrt rabs

1 © Nokia Siemens Networks RU10 Feature Training / CJo

RAN285: HSPA Multi NRT RABs

Feature functionality

Chris Johnson


Background

• Prior to this feature

• HSPA and HSDPA connections could support a maximum of 1 NRT RAB

• Multi NRT RAB were only supported by DCH connections

• Channel type switching was triggered if Multi NRT RAB were requested while using HSPA or HSDPA

• This feature allows 3 NRT RAB (background or interactive) while using HSPA or HSDPA

• This means that 3 simultaneous PDP contexts can be established while using HSPA and HSDPA

• The RAB can be prioritised using their Scheduling Priority Indicator (SPI) if QoS Aware HSPA Scheduling is enabled

• The 3 NRT RAB can be established at the same time as an AMR speech connection if the HSDPA with Simultaneous AMR Voice Call feature is enabled

• The 3 NRT RAB can be established at the same time as a PS Streaming connection if the Streaming QoS for HSPA feature is enabled

HSPA MULTI RAB


Supported RAB Combinations

• The feature provides support for:

• 1, 2 or 3 NRT RAB on HSPA

• AMR service on DCH + 1, 2 or 3 NRT RAB on HSPA

• AMR service on DCH + PS streaming service + 1, 2 or 3 NRT RAB on HSPA

• PS streaming service + 1, 2 or 3 NRT RAB on HSPA

• When NRT RAB are mapped to HSDPA with a DCH uplink return channel

• the supported uplink DCH bit rates are 16, 64, 128 and 384

• the total PS DCH bit rate is limited to 384 kbps

• DCH bit rates of 128 and 384 kbps are supported for AMR Multi-RAB connections

• The maximum uplink and downlink DCH bit rate of 384 kbps is supported for AMR multi-RAB connections when using only DCH. This is a basic capability within RU10 which does not require the HSPA Multi NRT RAB feature

HSPA MULTI RAB


Enabling the Feature

HspaMultiNrtRabSupport

(WCEL)

This cell-specific parameter defines whether the RAN 285 feature 'Multi NRT RABs' is supported in a cell or not. The number of BTSs that support the feature RAN 285 is limited by an ASW capacity license.

Name Range Description

Not supported (0) Supported (1)

Default

0

• RNC databuild parameter used to enable/disable the feature once licensed

• Feature requires licensing in terms of:

– HSDPA

– HSPA Multi NRT RABs

• OR

– HSDPA

– HSDPA Dynamic Resource Allocation

– HSUPA

– HSPA Multi NRT RABs

HSPA MULTI RAB


Multi NRT RAB Multiplexing for HSDPA (I)

Logical Channel 1

MAC-d Flow 1

AAL2 Path 1

Priority Queue 1

Logical Channel 2

MAC-d Flow 2

AAL2 Path 2

Priority Queue 2

MAC-hs

Physical Layer

Single HS-DSCH Transport Channel

HS-PDSCHNode B

RNC

AAL2 connection and CID per MAC-d Flow

Multiplexing done according to QoS Aware HSPA Scheduling if enabled

• Multiplexing of HSDPA NRT RAB is completed within the MAC-hs layer

• Each NRT RAB has its own logical channel and AAL2 connection

• All NRT RAB share the same transport channel

• HSDPA scheduler allocates resources to one Priority Queue at a time

• HS-DSCH transport block is unable to accept MAC-d PDU from a mix of different priority queues

HSPA MULTI RAB


Multi NRT RAB Multiplexing for HSDPA (II)

Version Flag

Priority Queue

Identifier

Transmission Sequence Number MAC-d

PDU Size Identifier

Number of MAC-d PDU

Flag for more SID, N, F fields

• MAC-hs header includes only a single ‘Queue ID’ so all MAC-d PDU within the same transport block must belong to the same Priority Queue

• Multiplexing at the MAC-hs layer is effectively a switching between priority queues for each TTI

HSPA MULTI RAB


Multi NRT RAB Multiplexing for HSUPA (I)

Logical Channel 1

MAC-d Flow 1

AAL2 Path 1

Logical Channel 2

MAC-d Flow 2

AAL2 Path 2

MAC-e

Physical Layer

Single or multiple E-DPDCH depending upon allocated bit rate

E-DPDCHNode B

RNC

AAL2 connection and CID per MAC-d Flow

DDI 1

• In the case of HSUPA, multiple logical channels can be multiplexed within a single transport block

• The RRC layer controls the scheduling by allocating a priority to each logical channel (between 1 and 8, where 1 is the highest priority)

• Logical channels then have absolute priority, i.e. the UE shall maximise the transmission of higher priority data before sending low priority data

• Priorities can be set using the QoS Aware HSPA Scheduling feature

DDI 2

HSPA MULTI RAB


Multi NRT RAB Multiplexing for HSUPA (II)

• In the case of HSUPA, multiple, logical channels can be transferred within each transport block

• The Data Description Indicator (DDI) includes the Logical Channel identity, MAC-d Flow identity and the Size of the MAC-d PDU

HSPA MULTI RAB


Connection Release

• Each Radio Bearer is handled separately when evaluating downgrades and releases, e.g. 1 NRT Radio Bearer can be released to a 0/0 kbps connection while the others remain active

• The UE is only moved to CELL_FACH when all Radio Bearers are found to be inactive

HSPA MULTI RAB


RNC Databuild Parameters (I)

FactorEDCHMaxBitRate2NRT

(RNC)

This parameter defines the E-DCH maximum bitrate in relation to RAB parameter UL/DL Maximum Bit Rate in case of 2 NRT RAB combinations. The E-DCH maximum bitrate specifies the rate of the Transport Channel below MAC-e. Node B uses it for E-DCH scheduling decision. The E-DCH maximum bitrate is sent in NBAP Radio Link Setup/Addition/ Reconfiguration to Node B.


0.1...5

Default

1.6

• Parameters below provide an extension to the RAS06 FactorEDCHMaxBitRate parameter. They operate on the sum of the RAB Maximum Bit Rates

FactorEDCHMaxBitRate3NRT

(RNC)

This parameter defines the E-DCH maximum bitrate in relation to RAB parameter UL/DL Maximum Bit Rate in case of 3 NRT RAB combinations. The E-DCH maximum bitrate specifies the rate of the Transport Channel below MAC-e. Node B uses it for E-DCH scheduling decision. The E-DCH maximum bitrate is sent in NBAP Radio Link Setup/Addition/ Reconfiguration to Node B.


0.1...5

Default

1.7

HSPA MULTI RAB


RNC Databuild Parameters (II)

FactorEDCHMaxBRPSstream

(RNC)

This parameter defines the E-DCH maximum bitrate in relation to RAB parameter UL/DL Maximum Bit Rate in case of RAB combinations that include PS streaming service. The E-DCH maximum bitrate specifies the rate of the Transport Channel below MAC-e. Node B uses it for E-DCH scheduling decision. The E-DCH maximum bitrate is sent in NBAP Radio Link Setup/Addition/ Reconfiguration to Node B.


0.1...5

Default

1.8

• Parameter below provides an extension to the RAS06 FactorEDCHMaxBitRate parameter when PS Streaming is established. It operates on the sum of the RAB Maximum Bit Rates

HSPA MULTI RAB


RNC Databuild Parameters (III)

AMRLCBufMaxOverbook2NRT

(RNC)

This parameter defines the maximum overbooking of the AM RLC buffer for all RAB combinations that include 2 PS ( 2 NRT or [1 NRT + 1 PS streaming] ) RABs. Overbooking defines the factor by which the buffer required for the total allocated AM RLC window size exceeds the buffer reported in the UE Capabilities. For example, a value of 2.0 defines that the buffer required by the AM RLC windows in total has twice the size of the UE reported buffer.


1...3

Default

1.3

• Parameters which allow ‘overbooking’ of the UE RLC buffer

AMRLCBufMaxOverbook3NRT

(RNC)

This parameter defines the maximum overbooking of the AM RLC buffer for all RAB combinations that include more than 2 PS ( 3 NRT or [2 NRT+1 PS streaming ] or [3 NRT + 1 PS streaming] ) RABs. Overbooking defines the factor by which the buffer required for the total allocated AM RLC window size exceeds the buffer reported in the UE Capabilities. For example, a value of 2.0 defines that the buffer required by the AM RLC windows in total has twice the size of the UE reported buffer.


1...3

Default

1.8

HSPA MULTI RAB


RNC Databuild Parameters (IV)

MaxNumberHSDSCHMACdFlows

(WCEL)

This parameter defines the maximum allowed number of HS-DSCH MAC-d flows in the cell. When the number of allocated HS-DSCH MAC-d flows equals the value defined by the parameter, the RNC does not set up new HS-DSCH MAC-d flows in the cell if the maximum number is to be exceeded. The RNC may also restrict the number of HSDPA users in addition to the number of HS-DSCH MAC-d flows.


1...255,

0 (not restricted)

Default

0

• Requirement to ensure that the maximum number of MAC-d flows per cell is sufficient

HSPA MULTI RAB


RNC Counters

• The Traffic table within the RNC Radio Network counter collection has been updated to include:

M1002C617 ALLO_AMR_MULTINRT_HSPAM1002C618 ALLO_MULTINRT_HSPAM1002C620 ALLO_AMR_RT_MULTINRT_HSPAM1000C622 ALLO_RT_MULTINRT_HSPA

HSPA MULTI RAB

ran0285 hspa multi nrt rabs

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