RTWP Optimization Solutions for High Traffic Cells

8/20/2019 RTWP Optimization Solutions for High Traffic Cells

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238213649.xls.ms_office document secret level

R10 R11 R12 R13

Optimization of CQI feedback

period All RNC/Cell

Access parameter optimization

(indoor distribution) All Cell

10 ms fixed PO optimization All RNC

The link release problem of

IPhone 4R12 RNC

State transition/EFD R12 RNC

2 ms fixed PO optimization R10 RNC

HSUPA PO adaptive adjustment R13 RNC

HSUPA TTI selection and

switchover solution enabled + 2

ms periodic retry disabled.

R10 RNC

Reception using multiple

antennas All Cell

0.5/0.5 reconstruction All Cell

Multiple-RRU demodulation R13 NodeB

HSUPA target retransmission

times changed to 10%. All RNC

PS R99 target BLER changed to

10% All RNC

Disable the HSUPA 2 ms

function.R10 RNC/NodeB

Limit the maximum number ofHSUPA users in the cell.

All Cell

√√Value optimization of SIB 7

broadcast RTWPR12

RTWP Optimization

Optimization SolutionSupported

Version

Impact

Range

Cell

7/14/2014 Huawei secrets, no distribution without permissionPage 1, 18 pages total


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238213649.xls.ms_office document secret level

Internal parameters are involved in

versions earlier than R13.

The solution is merged into RNC

R12SPC516.

This affects KPIs.EFD is implemented on a network

with a high iPhone penetration rate.

This is merged into NodeB

R12SPC430.This is used for 10 ms, and not used

with the fixed PO optimization at the

same time.

HSUPA TTI selection and

switchover solution includes the TTI

switchover realized on R10 and

based on load, the TTI switchover

realized on R12 and based on

admission CE, and the access state

TII selection realized on patch

release R3 (RNC R13SPH529).

This is a non-standard solution. It is

recommended that on-site

engineers select a site to try first.

This is directly

implemented by on-

site engineers.

This is a standard solution and

should be implementedpreferentially.

This needs to be

analyzed by R&D

engineers.

Internal parameters are involved.

Implementation Remarks

7/14/2014 Huawei secrets, no distribution without permissionPage 2, 18 pages total


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No. ClassSupported

Version

Controlled by a

License or Not

Impact

Range

1 R13 Yes RNC

2 All No RNC

3 All No RNC

TTI

switchover

based on

load

R10 No RNC

HSUPA TTI

Parameter

HSUPA PO adaptive

reconfiguration enabled

10 ms fixed PO optimization

2 ms fixed PO optimization

Feature

algorithm


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TTI

switchover

based on

admission

R12 No RNC

TTI selection

of access

state

RNC

RAN13SPH

529No RNC

5 All No RNC/Cell

6 R12 No RNC

7 All No Cell

8 All No Cell

selection and

switchover

solution enabled

+ 2 ms periodic

retry disabled.

CQI feedback period

EFD is recommended for the

networks with high ratio of state

transition switch/iPhone.

Reception using multiple

antennas

4

0.5/0.5 reconstruction


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9 R13 No NodeB

10 No RNC

11 No RNC

12 No Cell

13 YesRNC/Node

B

All No Cell

All No Cell

All No Cell

All No Cell

All No Cell

All

Access

parameter

Solution

Preamble retry times

Step

Maximum number of cycles

Multiple-RRU demodulation

HSUPA target retransmission

times modification for 10 ms

(10%)

Target BLER modification for

PS R99 network (10%)

Reduce the maximum number

of HSUPA subscribers in the

cell.

Disable the HSUPA 2 ms

function.

Modify the constant value of

the initial transmit power

14

Upper limit of random rollback


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15NodeB R12

SPC430No Cell

16Special

terminal

RNC RAN12

SPC516No RNC

Stands for

non-

standardsolution

modification

Value optimization of SIB 7

broadcast RTWP

iPhone4 problem


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Baseline

Configuration After Optimization

Internal

ParameterInv

olved or Not

Description

OFF ON No

If the subscriber rate is lower than a certain threshold,

and the air interface load is limited, increase the

HSUPA reference PO to reduce the SIR working point

of lower rate subscribers, and to improve uplink

capacity.

/ / Yes

Configure higher reference PO for 10 ms TTI to

reduce DPCCH SIR working point, and reduce the

uplink cost of the control channel. Therefore, the

throughput of the HSUPA cell with multiple

subscribers is improved.

/ / Yes

Configure higher reference PO for 10 ms TTI to

reduce DPCCH SIR working point, and reduce the

uplink cost of the control channel. Therefore, the

throughput of the HSUPA cell with multiple

subscribers is improved.

This is related to

the configuration

on the live

network.

TTI switchover:

ON

2 ms periodic

retry: OFF

No

If the air interface load exceeds the target node, and 2

ms TTI is configured for the service. the rate cannot

reduce because the scheduling algorithm guarantees

one RLC PDU. The related minimum rate is 168 kbit/s

(336) or 328 kbit/s (656). At this time if the TTI is

switched from 2 ms to 10 ms, the actual subscriber

rate is reduced, and also the cell load. The RTWP

overshoot caused by data burst because of high

minimum rate of 2 ms subscribers is reduced. The 2

ms periodic retry is disabled to prevent TTI ping-pong

switchover.


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This is related to

the configuration

on the live

network.

TTI switchover:

ON

2 ms periodic

retry: OFF

No

In admission, the consumed admission CE of the 2 ms

subscriber is more than that of the 10 ms subscriber.

Therefore, when the admission CE is limited,

switching the subscriber from 2 ms to 10 ms improves

the admission subscriber number of the system. The

RTWP overshoot caused by data burst because of

high minimum rate of 2 ms subscribers is reduced.The 2 ms periodic retry is disabled to prevent TTI ping-

pong switchover.

This is related to

the configuration

on the live

network.

TTI switchover:

ON

2 ms periodic

retry: OFF

No

The HSUPA subscriber selects the initial TTI based

on the actual resource (RTWP/Iub/CE) congestion

state. This prevents that in the network with a large

amount of subscribers, subscribers access with 2 ms

TTI all the time. Therefore, The RTWP overshoot

caused by data burst because of high minimum rate of

2 ms subscribers reduces.

2 8 YesThe shorter the CQI feedback period is, the better the

downlink data transmission is. The longer the CQI

feedback period is, the lower the load occupation is.

OFF ON No

Transit the light-traffic subscribers to the FACH state,

reduce dedicated channel resources occupation of

light-traffic subscribers, and reduce uplink and

downlink load. EFD is used for networks with high

iPhone penetration rates.

This is related to

the configuration

on the live

network.

This is related to

the configuration

on the live

network.

No

For the same transmission rate, the reception using

multiple antennas reduces the signal power that each

antenna receives, that is, the uplink load. For the

same load, the reception using multiple antennas

allows the UE to send larger transmission blocks,

which means the uplink capacity is improved.

This is related to

the configuration

on the live

network.

This is related to

the configuration

on the live

network.

No

The dual-antenna demodulation reception is realized

on the baseband side. The baseband side and the RF

side do not merge raw data, and the RTWP is the

same as that in the regular dual-antenna cell.


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This is related tothe configuration

on the live

network.

This is related tothe configuration

on the live

network.

No

Basic principle: The NodeB independently

demodulates and merges several received RRUsignals in the baseband processing module, and

duplicates a cell signal branch to several RRUs for

transmission.

1% 10% NoModify the 10 ms target retransmission times of

HSUPA from 1% to 10%.

1% 10% NoModify the BLER of PS subscribers in the R99

network from 1% to 10%.

This is related to

the configuration

on the live

network.

This is related to

the configuration

on the live

network.

No

Reduce the maximum number of HSUPA access

subscribers in the cell, and reduce the RTWP cost of

HSUPA subscribers.

ON OFF Nodisabling the HSUPA 2 ms function makes only 10 ms

available for HSUPA subscribers.

-20 -30

20 40

2 1

8 3

0 10

Basic principle: By reducing the spike of the preamble

open-loop power control on the uplink RTWP in RACH

initial access, the RTWP is significantly reduced in the

cell with frequent RACH access (thousands of times

per hour).

No


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-90

This is based on

the

implementation

impact on the live

network.

No

Reduce the spike of the preamble open-loop power

control on the uplink RTWP in RACH initial access,

especially in high load scenarios. The RTWP in SIB7

is broadcast in real time. If you reduce the RTWP in

SIB7, the effect is essentially the same as that of

reducing the Constvalue. Both are for reducing the UEpower of transmitting the first preamble.

OFF ON No

When iPhone releases the link, the iPhone retransmits

the RRC CONN REL CMP signaling message.

However, the network side releases the link before

UE. As a result, the uplink power control is abnormal

and the RTWP

spike occurs. Solution: When iPhone releases the

link, the network side delays to releasing the link.


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Effect

Gain: When the subscriber amount is large and

the rate is low, the gain of this feature is obvious.

For example, more than fifteen 10 ms subscribers

that only have small amounts of data to beretransmitted are online and uploading at the same

time. If the power offset of data channels for these

subscribers all can be adjusted, the HSUPA

capacity of the cell can improve by more than 40%

without object load increase, which is shown by the

increase of the average throughput or the increase

of uplink data transmission subscriber number at

the same time.

Risk: Four minutes are taken from triggering to

completion of this feature. The gain is not obvious

for frequently link-deleting/

link-establishing subscribers or subscribers with

too short lasting time links.

Gain: For the lab test with dual antennas, 75%

uplink load target threshold, 18 online subscribers

and two uploading subscribers, the gain of the

uplink throughput in the cell is 15%.

Risk: The peak rate of the HSUPA 10 ms

subscriber in commercial network competition is

slightly affected.

Gain: For the lab test with dual antennas, 90%

uplink load target threshold, 7 online subscribers

and two uploading subscribers, the gain of the

uplink throughput in the cell is 15%.

Risk: The peak rate of the HSUPA 2 ms

subscriber in commercial network competition isgreatly affected.

Gain: This reduces load when the uplink load

resource is severely limited, and reduces the

RTWP.

Risk: the peak rate is affected after the subscriber

switches to 10 ms.


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Gain: This alleviates the admission CE congestion

problem after 2 ms TTI is enabled, and improves

the subscriber number specification.

Risk: the peak rate is affected after the subscriber

switches to 10 ms.

Gain: The initial TTI is selected based on the

resource congestion state when the subscriber

accesses. This reduces reconfiguration signaling

and improves power efficiency.

Risk: in the network with a few subscriber access

and high speed uplink transmission, the subscriber

peak rate is affected.

Gain: On the office in country A, the CQI feedback

period is changed from 2 ms to 8 ms. After

optimization, the average value of the realtime

traced RTWP is reduced by about 8 dB. Theaverage RTWP value of hour-level traffic statistics

is reduced by about 10 dB.

Risk: theoretically, this brings loss of downlink

throughput. After this solution is implemented on

office A and B, In the whole network view, no

negative affections occur.

Gain: The gain is related to traffic models and the

permanent online timer.

Risk: This increases PS call drop rate, and

decreases the setup success rate of CS composite

services. Because the EFD is not compatible with

other terminals, currently only iPhone isrecommended to be used.

Gain: Compared with reception using one antenna,

reception using two antennas improves the uplink

capacity by more than 50%. Compared with the

dual-antenna reception, the four-antenna reception

improves the uplink capacity by more than 50%.

Risk: No for now.

Gain: In the multi-area cell networking, compared

with the distributed cell, the 0.5/0.5 reconstruction

does not have noise floor increase.

Risk: The stability of some RRUs is affected.


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Gain: This improves cell capacity and throughput,and reduces the times of subscriber handover

between cells.

Risk: More baseband resource consumption.

Non-standard solution

Modifying the 10 ms target retry to 10% affects

subscriber peak rate. It is recommended that this

solution is carried out in the non-competitionnetwork or networks that have no requirements for

10 ms peak rate.


If you modify the high-speed (such as 384 Kbit/s)

BLER to 10%, the idle subscriber peak rate is

affected. It is recommended that the BLER is

modified based on the traffic mode and rate on the

live network.


Reduce the maximum number of HSUPA access

subscribers in the cell, and reduce the RTWP cost

of HSUPA subscribers. It is recommended that this

solution is carried out in the non-competitionnetwork.


Disabling the2 ms function affects subscriber peak

rate. It is recommended that the 2 ms function is

modified in non-competition network.

Gain: After the Constantvalue parameter is

modified on the office in country C, the RTWP

average value is reduced by 3 dB to 4 dB. After

PreambleRetransMax, PowerRampStep and

Mmax parameters are modified, the average

RTWP value is reduced by 1 dB.

Risk: For indoor coverage scenarios, the accessdelay increases.


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Gain: After the RTWP value of SIB7 broadcast is

optimized on the office in country A, the average

RTWP value is reduced by about 3 dB.

Risk: In the scenario with low load and not obvious

RTWP spike caused by RACH, each RACH

access needs a large amount of preamble ramp

progress, which causes hundred-ms-level delay toincrease.

Gain: The RTWP spike is reduced, especially for

networks with high iPhone penetration rates. After

the solution is implemented on the site in Thailand,

the RTWP average value improves by about 3 dB.

Risk: No for now.


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Command

This is used for 10 ms, and not used with the fixed PO optimization at the same time.

MML Command on RNC:

SET UCORRMALGOSWITCH:

PcSwitch=PC_HSUPA_DATA_CH_PO_ADAPTIVE_ADJ_SWITCH-1;

If need to rollback:


PcSwitch=PC_HSUPA_DATA_CH_PO_ADAPTIVE_ADJ_SWITCH-0;

Versions earlier than R13 refer to internal parameter modification. You need to obtain the

commands for modifying internal parameters from the PDT manager of the product line. It is

recommended that HSUPA PO adaptive adjustment is used on R13 version and later

versions.

If internal parameters are involved, you need to obtain the commands for modifying internal

parameters from the PDT manager of the product line.

TTI switchover: ON

SET UCORRMALGOSWITCH: DraSwitch=DRA_BASE_RES_BE_TTI_RECFG_SWITCH-1;

2ms retry period OFF:

SET UFRC: RETRYCAPABILITY=SRB_OVER_HSDPA-1&SRB_OVER_HSUPA-1&TTI_2MS-

0&MIMO-1&64QAM-1&L2_ENHANCE-1&DTX_DRX-1&HSSCCH_LESS_OPERATION-1,


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TTI switchover: ON


DraSwitch=DRA_BASE_ADM_CE_BE_TTI_RECFG_SWITCH-1;

2ms retry period OFF:

SET UFRC: RETRYCAPABILITY=SRB_OVER_HSDPA-1&SRB_OVER_HSUPA-1&TTI_2MS-

0&MIMO-1&64QAM-1&L2_ENHANCE-1&DTX_DRX-1&HSSCCH_LESS_OPERATION-1,

TTI switchover: ON

SET UCORRMPARA: ReservedSwitch0=RESERVED_SWITCH_0_BIT2-1; (R13 uses the

reserved switch)

If internal parameters are involved, you need to obtain the commands for modifying internal

parameters from the PDT manager of the product line.

MML Command on RNC:

SET UCORRMALGOSWITCH: DraSwitch=DRA_HSDPA_STATE_TRANS_SWITCH-

1&DRA_HSUPA_STATE_TRANS_SWITCH-1&DRA_PS_BE_STATE_TRANS_SWITCH-1;

None


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1. Use site configuration (ADD SITE) to configure related site information.

2. Use sector configuration (ADD SEC) to select the sector type as MULTIRRU_SECTOR,

select uplink RRU number in RRU number, and fill in the related cabinet, frame and slot for the

RRU. A new sector type for independent demodulation of multiple RRUs is added.

3. Use uplink resource group configuration (ADD ULGROUP) to configure the needed uplink

board resource. Note that for the resource group with independent demodulation of multiple

RRU, the demodulation mode is configured as dual antennas (DEM_2_CHAN).4. Use downlink resource group configuration (ADD DLGROUP) to configure the needed

downlink board resource.

5. Use local cell configuration (ADD LOCELL) to select the sector type as

MULTIRRU_SECTOR. The RRU mode is configured as UNSYNC (Part of RRUs in the sector

are used) or SYNC (all RRUs are in the sector are used) based on needs. Note that 2T cannot

be configured for the cell with independent demodulation of multiple RRUs. The cell does not

support MIMO, DC+MIMO far cell configuration or desensitization intensity configuration. The

maximum cell radius is limited to 30 km, and the default value is 10 km.

MML Command on RNC:

MOD UTYPRABOLPC: RabIndex=xx, SubflowIndex=xx, TrchType=TRCH_EDCH_10MS,

DelayClass=xx, EdchTargetLittleRetransNum=100;

MML Command on RNC:

MOD UTYPRABOLPC: RabIndex=xx, SubFlowIndex=xx, TrchType=TRCH_DCH,

DelayClass=xx, BLERQuality=-10;

MML Command on RNC:

MOD UCELLCAC: CellId=xx, MaxHsupaUserNum=xx;

If need to rollback:

MOD UCELLCAC: CellId=xx, MaxHsupaUserNum=xx;

MML Command on RNC:

SET UCORRMALGOSWITCH: MapSwitch=MAP_HSUPA_TTI_2MS_SWITCH-0;

Or disable the HSUPA 2 ms License on NodeB side

MML Command on RNC:

MOD UPRACHUUPARAS: CELLID=xx, PHYCHID=4, CONSTANTVALUE=-30,

PREAMBLERETRANSMAX=40, POWERRAMPSTEP=1;

If rollback is needed:

MOD UPRACHUUPARAS: CELLID=xx, PHYCHID=4, CONSTANTVALUE=-20,

PREAMBLERETRANSMAX=20, POWERRAMPSTEP=2;

MOD URACH: CellId=xx, TrChId=xx, NB01max=10, Mmax=3;


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Value optimization of SIB 7 broadcast RTWP

MOD CABINET: CN=x, CD="rtwpsw"

The solution is merged into RNC RAN12 SPC516 version.

MML Command on RNC:

SET URRCTRLSWITCH:

PROCESSSWITCH3=UM_RRCRELCMP_RLDEL_DELAY_SWITCH-1;

RTWP Optimization Solutions for High Traffic Cells

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