Volte Solutions Workshop V1.2

Huawei VoLTE Solutions

Wednesday, 28August, 2014

Kyle Tang / [email protected] Zhang Jianhui / [email protected] Wilson Zheng / [email protected]

HUAWEI TECHNOLOGIES CO., LTD.

Content  VoLTE Updates & Trends  VoLTE Introduction  VoLTE Coverage  VoLTE Capacity  VoLTE Performance  VoLTE Mobility Strategy  Case Study

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 2

Voice revenue still important Voice is still the biggest revenue source until 2018

ARPU still increase after VoLTE launched in South Korean market

Mobile data& voice revenue forecast(M$)

$700,000 $600,000 $500,000 $400,000 $300,000 $200,000 $100,000

VoLTE launched

Source from : LG Uplus_Investor_Presentati on_February_v12

$0

2011

2012

2013

voice

2014

2015

none voice

HUAWEI TECHNOLOGIES CO., LTD.

2016

2017

2018

Source: Mobile Voice and Data Forecast- 2013-18, OVUM

Company Confidential

Page 3

VoLTE contributes to LTE success VoLTE accelerates LTE network development

VoLTE provides a good platform for competing with OTT

60%

IMS

50%

6 months after VoLTE launched

40% 30%

VoLTE launched

20%

19%

10%

30%

10%

0% 1%

5%

11%

36%

42%

47%

52%

19%

4Q11 1Q12 2Q12 3Q12 4Q12 1Q13 2Q13 3Q13 4Q13 LTE user penetration in korea

Source from : LG Uplus_Investor_Presentati on_February_v12

LTE user growth rate almost doubled after VoLTE launch in South Korean market

HUAWEI TECHNOLOGIES CO., LTD.

Contact

IM

File Video transfer share

Voice CameraLocatio chart n

20 operators launch in 14 countries; 87 operators commitment across 35+ countries

Company Confidential

Page 4

VoLTE deployment is speeding up VoLTE status of deployment

Operators

29

8 operators have launched in global 61 operators are investing in VoLTE studies, trials or deployments USA,JAPAN,KOREA is the mainly

10

7

* Source : from GSA June

8

6 1

country Planned

Trialling

Trialled

Subs enjoying VoLTE

20M Subs will enjoy VoLTE in 2014

VoLTE User forecast

3.8M Subs 6.6M Subs 4.0 M Subs

HUAWEI TECHNOLOGIES CO., LTD.

launched

288

User More than14.4M

indeployment Soft-launched

118 48

8

20

2013

2014

2015 VoLTE Subs

Company Confidential

2016

2017 * Source : VoLTE forecasted infonetics

Page 5

VoLTE ecosystem becoming more mature Capable of SRVCC

Band

Terminal & ChipSet 50 40

• Qualcomm 8974 • Hisilicon 910 • Intel XMM7160

39

30 20

13

12 6

10 0 1800

SRVCC, SPS,DRX,TTIBundling supported

38

2100

850

2600

AWS

1800,850 band is current main stream

TDD, 11

Huawei P7

XPhone 6

Sumsung S5

8 smartphones support SRVCC to UTRAN 100%

10 75%

75%

LGU

29

SKT

50%

KT

27 8 FDD, 62

other

* Source : from GSA

ROHC

Supports more FDD than TDD HUAWEI TECHNOLOGIES CO., LTD.

Mostly in Korea market without SRVCC Company Confidential

TTIB

SPS

>50% SRVCC Smartphone support VoLTE enhancement feature Page 6

VoLTE terminal on the market No

Terminal Model

5 6

SamsungGalaxy 5(Korean version ) SamsungGalaxy 5(European version ) SamsungGalaxy 4LTE-A（ Korean version ） SamsungGalaxy 4（Korean version ） Samsung Note III LG Optimus Vu2 F200L

7

LG Optimus G2 F320L

1 2 3 4

8

Xphone 6

9

Huawei P7

10

Sharp

HUAWEI TECHNOLOGIES CO., LTD.

ChipSet

Operator

VoLTE

SRVCC UTR AN

SRVCC GERAN

RoHC

TTIB

SPS

QC 8974

LGU+

Y

Y

N

Y

Y

Y

QC 8974

Europe （VDF D2、EE ）

Y

Y

N

Y

Y

Y

QC 8974

LGU+

Y

Y

N

Y

N

N

QC 8974

LGU+

Y

Y

N

Y

N

N

QC 8974 QC 8960

HK-PCCW LGU+

Y Y

Y N

N N

Y N

Y N

Y N

QC 8974

LGU+

Y

N

N

N

N

N

QC 9635

Global （SBM/Canad a /H3G）

Y

Y

Y

Y

Y

Y

Europe （DT）

Y

Y

Y

Y

Y

Y

Japan SBM

Y

Y

N

Y

Y

Y

Hislicon Kirin910 QC8974

Company Confidential

Page 7

Content  VoLTE Updates & Trends  VoLTE Introduction  VoLTE Coverage  VoLTE Capacity  VoLTE Performance  VoLTE Mobility Strategy  Case Study

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 8

VoLTE Architecture Basic function in eNodeB

VoLTE E2E framework 省网管/计费中心

O SS/BSS La ye r CCF

DM Server

MMTel AS/SCC AS/IP-SM-GW

Se rvic e La ye r

SPG

BOSS

OMU

C o re La ye r

MGCF/IM-SSF/SRVCC IWF/CSFB IWF/Anchor AS

HLR/SAE-HSS FE

MRFP

ENS FE

BE

CCTF

I/S-CSCF/BGCF/E-CSCF/MRFC

IMS-HSS FE

IM-MGW

IGW

Legacy 2G/3G Network/PSTN MSC Server MGW

PCRF FE

A-SBC/P-CSCF/ATCF/ATGW

A c c e ss La ye r

Admission and congestion control

RCS AS

SCP

SingleSDB

RRC

eMSC

PDCP

ROHC

Segmentation Dynamic scheduling/Semi-persistent/Dynamic MAC delay based scheduling/non-GBR PHY TTI Bundling/ UL COMP RLC

MGW

MME S/P-GW

EPC

ICS 2G/3G Network

Te rm in a lLa ye r LTE

2G/3G

CPE

Data card

Handset

POTS

coverage

mobility

Handset

 VoLTE deployment is a systematic Engineering, Including BSS, service layer, Core network and the Access layer and Terminals.  The workload of the deployment in core layer -IMS is far greater than access layer HUAWEI TECHNOLOGIES CO., LTD.

capacity

 The main consideration in terms of the access layer is coverage, capacity and mobility  Compatibility of terminal should need massive IOT and industry maturity Company Confidential

Page 9

VoLTE procedure in eNodeB The procedure is as follows: ① The calling UE sets up an RRC connection. ② The calling UE sets up an E-RAB for IMS signaling. ③ The called UE is instructed to set up an RRC connection and an E-RAB for IMS signaling. ④ The UEs negotiate session information through IMS signaling. ⑤ After the negotiation, the calling UE and the called UE set up E-RABs for conversational voice. ⑥ At this time, the entire EPS bearer from the calling UE to the called UE is set up. ⑦ The called UE sends a ring back tone to the calling UE through IMS signaling. ⑧ The called UE answers the call and the VoIP conversation begins. ⑨ The scheduler in each eNodeB chooses dynamic scheduling or semi-persistent scheduling ⑩ based on the scheduling policy, and then performs VoIP scheduling.

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Page 10

VoLTE QoS management 1

2 3

① The IMS (P-CSCF) sends QCI information to the PCRF over the Rx interface. ② Based on the received QCI information and subscription information, the PCRF generates a QoS rule (including key QoS parameters, QCI, ARP, GBR, and MBR) and sends the rule to the P-GW over the Gx interface. ③ Based on the QoS rule sent from the PCRF, the P-GW instructs the S-GW, MME, and eNodeB to set up EPS bearers. Services of different QoS requirements are carried by radio bearers with different QCIs. According to 3GPP specifications, the QCIs for conversational voice and IMS signaling are 1 and 5, respectively. QCIs are set in StandardQci, and the Radio Link Control (RLC) modes for setting up conversational voice and IMS signaling E-RABs are specified by the RlcPdcpParaGroup.RlcMode parameter. QCI requirement& MBR setting : QCI

Resource Priority Type

delay

Packet loss

Typical service

1

GBR

2

100ms

10-2

VoIP

2

GBR

4

150ms

10-3

Telephone conference, video call(live streaming)

5

Non-GBR

1

100ms

10-6

IMS signaling

•VoLTE AMR-WB 12.65kbps+IPV4：MBR=GBR=31kbps •VoLTE AMR-WB 23.85kbps+IPV4：MBR=GBR=44kbps

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Company Confidential

Page 11

VoLTE Basic QoS- transmission delay requirement VoLTE is a delay sensitive service

The delay of S1-U interface should less than 50ms

Determination of the effects of absolute delay by the E-model (ITU-T G.114)

The data flow of VoLTE

SBC

<275ms

<135ms

MME

<50ms

SGi INF.

S/PGW

S1-U INF.

MME

~85ms

S/PGW S1-U INF.

~50ms

eNodeB

eNodeB UEVoLTE

UEVoLTE

<275ms

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Company Confidential

Page 12

Two level LTE admission control UE

eNodeB

MME

User admission process

Level1:user admission Random Access

User initiates access

target: keep system stable RRC Connection Request

Y

RRC Connection Setup RRC Connection Setup Complete

Y

If CPU resource limited N If pucch resource limited

N Initial UE Message

RRC Connection Reconfiguration RRC Connection Reconfiguration Complete

Initial UE Context Setup Request

Y

If the user number limited N

UE admission failed

UE access succeed

UE enter the preemption process

RRC establishment phase to execute the user admission HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 13

Two level LTE admission control (continued.) UE

eNodeB

Service admission process

MME

User initiates service

Random Access RRC Connection Request

N

Is PUCCH resource available ？ Y

RRC Connection Setup

Is NonGBR or emergency RRC Connection Setup Complete

Y

N Initial UE Message

N

Is Ue support this GBR? Y

Level2:service admission Target : guarantee the QoS of GBR

RRC Connection Reconfiguration RRC Connection Reconfiguration Complete

Initial UE Context Setup Request

N

Fail

Is cell overloading? N Do admission process based on satisfaction rate

Service admission failed

enter the service preemption process

ERAB establishment phase to use service admission. The service admission in downlink and uplink is independent

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Success

Service admission succeed

Page 14

Voice congestion handling & preemption Congestion trigger  Uplink cell congestion: any one of the following two conditions met, congestion will be triggered  Any GBR-QCI satisfaction rate is below the threshold  uplink PRB high utilization above the threshold or waiting time of

QCI1 uplink scheduling > 100ms  Downlink congestion: Any downlink GBR-QCI satisfaction rate is lower

Voice preemption VoLTE preemption only depends upon ARP priority of the user or service ,except emergency call A service can preempt other services only if its ARP information element (IE) "pre-emption capability" is set to "may trigger preemption".

than the congestion threshold

Only GBR service can be preempted Congestion handle

 The low priority (ARP) GBR services(such as QCI2~QCI4, e.g. video

Currently there is no way to distinguish voice user in RRC connect phase

call ) will be preempted Voice satisfaction rate definition

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 15

Emergency call solutions in VoLTE network Solution overview

Solutions

Terminal choose Solution 1：

Network & terminal requirement

UE recognizes emergency

UE support CSFB

number and perform a emergency

&recognize emergency

call in CS domain

number list

Comments

emergency

call based on CSFB

Network indicates a redirect to CS

If UE can not recognize the emergency number ,the network

will recognize and indicate a

UE support CSFB

redirect to CS Use special dedicated bearer

Solution 2：emergency call based on IMS

(higher ARP) to make emergency

Terminal requires IMS emergency call support

call in IMS

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Company Confidential

Up to now , no terminal support this function

Page 16

DRX - Basic concepts DRX technology enables a UE to turn on its receiver and enter the active state only when the UE needs to receive downlink (DL) data or signaling. The UE turns off its receiver and enters the sleep state in other situations to reduce power consumption. On Duration UE shall monitor PDCCH

On Duration

Active Time Sleep Time Ue does not monitor PDCCH

DRX cycle





DRX status： •

Active Time： In active time, the UE turns on its receiver and monitors the PDCCH

•

Sleep Time： In sleep time, the UE turns off its receiver and does not monitor the PDCCH

DRX Cycle： A DRX cycle specifies the periodic repetition of the On Duration followed by a possible period of inactivity ，

A DRX cycle may be a long or short cycle; VoLTE does not support short cycle.



DRX timer：OnDurationTimer、DRXInactivityTimer、HARQRTTTimer、DRXRetransmissionTimer、ShortDRXCycleTimer；

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Page 17

DRX test result & recommendation DRX recommendation

Voice quality comparison in different DRX cycle 400

mA 373

MOS

-2%

4.5

366

350

-28%

4

300 264

250

3.5

200 150

3.81

3.96

3.87

100

3

2.5

50 0

2

DRX Cycle off

DRX Cycle 20ms DRX Cycle 40ms Mos

electric current

Test result from Huawei Lab

The impact of voice quality is negligible from activating DRX for VoLTE  Noticeable power saving from DRX 40ms setting, compared to 20ms setting HUAWEI TECHNOLOGIES CO., LTD.

DRX Settings for QCI5  QCI5 is IMS Signalling and is the default bearer for all services. In most cases QCI5 is set up together with a non-GBR QCI (6, 8 or 9).  Therefore QCI5 needs the same DRX Parameter with QCI9/8，but if Cycle of QCI5 too longer , the setup delay of QCI will be too longer ,so Long DRX cycle of QCI5 is advised to be smaller than 320ms. DRX settings for QCI1  QCI1 is the radio bearer which serves the voice service.  A much shorter DRX cycle time is needed for VoIP service then for non real time traffic.  The recommended parameter DRX Cycle generally is 40ms

Company Confidential

Page 18

VoLTE SRVCC architecture & flow

Iu-cs/A

Um/Uu BS Iu/Gb

SGSN MME Gn/S3

S1-C Uu UE

EMSC

Sv HSS S6a IMS CN

S11 S1-U

eNB

SGi SAE-GW

 Sv interface between MME and MSC-S enhanced for SRVCC

PS service handover to 2G networks when DTM (Dual Transfer Mode) is supported in 2G BSC  PS service suspended when DTM is not supported.

HUAWEI TECHNOLOGIES CO., LTD.

If the value of the SRVCC HO Indication IE is "PS and CS", the MME instructs both the MSC server and SGSN to prepare for a handover If the value of the SRVCC HO Indication information element (IE) is "CS Only" in the Handover Required message sent from the eNodeB to the MME, the MME instructs only the MSC server to prepare for a handover ,the PS services of the UE resume during a routing area update (RAU) procedure in the UTRAN Company Confidential

Page 19

Content  VoLTE Updates & Trends  VoLTE Introduction  VoLTE Coverage  VoLTE Capacity  VoLTE Performance  VoLTE Mobility Strategy  Case Study

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 20

PUSCH is the coverage bottleneck for VoLTE VoLTE link budget is uplink limited (>6dB downlink benefit compared to the uplink)

Codec=23.85

DL

>6dB

UL

Driver test result in D operator HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 21

VoLTE Coverage impact factors and solutions The factors of affecting coverage  Voice codec rate: lower voice codec rate provid longer coverage

 Receiver in network: Better demodulation ability of receiver to enhance voice coverage

 frequency: lower frequency longer coverage

 Terminal: higher TX power of terminal ,more antenna in terminal

The solutions can be implemented easily 12.65K codec rate， ROHC 4 Port Antenna in uplink, TTIbundling,RLC segmentation, UL COMP

 700M,800M low band coverage  Increase maximum TX power of terminal ; 4 TX antenna

 Radio environment: indoor，outdoor urban ，rural area

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Page 22

Low codec rate & low band recommended for initial deployement Cell radius comparison in VoLTE (Unit: KM)

RSRP&MOS comparison in different decode rate 4.20

4.07

4.20

4.05

4.20

4.07

1.40

4.00 3.36

1.15

1.20

3.62

1.00

2.26

>2X

0.80

0.55

0.60 0.40 0.20 0.00

-80 dBm

-90 dBm

-100 dBm

23.85K LTE-LTE

-110 dBm 12.65K LTE-LTE

-120 dBm

voice 12.65K_850

From operator P driver test

voice 12.65K_1800

* Huawei simulation

12.65K decode rate can provide better coverage than 23.85K MOS gain come from high decode rate is less than expecting

 low band VoLTE cell radius is >2 times than high band

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Page 23

VoLTE Coverage Enhancement: TTI bundling Packet size can be transmitted

No RLC Segmentation, no TTI Bundling D0 (~1000 bit)

vs.

• RLC Segmentation enable first In Cell edge scenario.

RLC Segmentation and HARQ Retransmission D1 D2 D3 D4

…

D1 D2 D3 D4

20 TTI

• TTI Bundling transmit same packets 4 times in one scheduling to expand coverage by increase uplink transmission reliability.

TTI Bundling VoIP TTI Bundling with RLC Segmentation D1 D1 D1 D1 D2 D2 D2 D2 D3 D3 D3 D3 D4 D4 D4 D4

TTI_B & ROHC off

TTI_B & ROHC on

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• TTI Bundling is only enabled at cell edge to save TTIs, eNodeB makes the decision by UE SINR.

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Page 24

VoLTE Coverage Test in live network Drive test result in operator D

Drive test result in Operator O

2dB

TTIbundling can provide 2~3 dB gains in condition TTI bundling, ROHC enabled

HUAWEI TECHNOLOGIES CO., LTD.

In Extended Pedestrian A (EPA) model , TTIBundling can provide 2 dB gains in aspect of Maximum Acceptable Coupling Loss (MACL)

Company Confidential

Page 25

VoLTE Link budget (UL Seg, ROHC and TTI Bundling) The VoLTE enhancement features increase the VoLTE coverage. TTI Bundling has maximum gain but at a cost of capacity. The typical segmentation varies with the feature combination

Typical AMR-WB Uplink Segmentation

FDD

Segmentation Only

14

RoHC

9

RoHC+TTI Bundling

4

FDD VoLTE AMR-WB MAPL (50%/30% DL/UL Load)

AMR-WB 23.85kbps

1.5-2dB

UL Seg+ROHC+TTIBundling UL Seg+ROHC UL Seg

AMR-WB 12.65kbps

135

140

145

150

155

HUAWEI TECHNOLOGIES CO., LTD.

160

Company Confidential

Page 26

VoLTE Coverage:In 1Mbps network ,VoLTE don’t affect the cell radius 1.50 1.15

PS& VoLTE simulation Cell radius comparison in Typical band (unit:KM) 0.86

1.00 0.55

0.44

0.50

0.41

0.33

PS 1Mbps_1800

PS 1Mbps_2100

0.00 voice 12.65K_850 voice 12.65K_1800 voice 12.65K_2100 PS 1Mbps_850

Assumption: Morphology Data Channel Type Duplex Mode User Environment System Bandwidth (MHz) Channel Model MIMO Scheme Cell Edge Rate (kbps) MCS

Dense Urban PUSCH PDSCH FDD Indoor 20.0 ETU 3 1×2 2×2 SFBC 54.00 31.60 QPSK 0.10 QPSK 0.12

HUAWEI TECHNOLOGIES CO., LTD.

TX Max Total Tx Power (dBm) Allocated RB RB to Distribute Power

Tx Antenna Gain (dBi)

RX SINR (dB) Neighbor Load

23.00 3 3 0

46.00 26 100 18

-7.82 50.00%

-10.00 100.00%

Company Confidential

Propagation Model eNodeB/UE Antenna Height (m)

Cost231Hata(Huawei) 25.00

1.50

Page 27

With enhancement features, VoLTE can be co-site constructed with GSM or UMTS Pathloss comparison in same frequency 153 (unit:dB) 152.5

137

152

136

30 users /cell 151.94 in urban outdoor

in urban indoor

135

151 150

Pathloss comparison in same frequency (unit:dB) 136.45 50 users /cell

149.92

134 149.3

149 148 147

In low voice traffic scenario, VoLTE pathloss can reach the UMTS level , even beyond UMTS with VoLTE enhancement feature

HUAWEI TECHNOLOGIES CO., LTD.

133.42 132.94

133

133.1

132 131

In high voice traffic scenario, VoLTE pathloss has significant advantage than UMTS Company Confidential

Page 28

VoLTE coverage: live network test result No any enhancement feature，in Some spectrum。 MPLA of VoLTE is better than GSM

acceptabl e quality

MPLA=Maximum Pathloss with a acceptable voice quality (MOS) and mouth to ear delay Test result in operator D live network HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 29

Content  VoLTE Updates & Trends  VoLTE Introduction  VoLTE Coverage  VoLTE Capacity  VoLTE Performance  VoLTE Mobility Strategy  Case Study

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Company Confidential

Page 30

VoLTE capacity –Definition  How to define VoIP Capacity?[From 3GPP 36.814-A.2.1.4] A VoLTE user is in satisfied if 98% radio interface tail latency of this user is smaller than 50 ms. The system capacity is defined as the number of users in the cell when more than 95% of the users are satisfied.

 VoIP Traffic Model [From 3GPP R1-070674] Consider the simple 2-state voice activity model shown in Figure, In the model, the probability of transitioning from state 1 (the active speech state) to state 0 (the inactive or silent state) is equal to a , while the probability of transitioning from state 0 to state 1 is c . The model is assumed updated at the speech encoder frame rate R= 1/T , where T is the encoder frame duration (typically, 20ms). In Huawei’s simulation, downlink and uplink VoIP traffic are considered at the same tine a

b = 1-c Inactive State State 0

Active State State 1

d = 1-a

c

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Page 31

VoLTE capacity –basic capacity already exceed traditional network Simulation Assumptions and Results

Bandwidth

DS(dynamic scheduling ) Uniform

5M

50-62 (PDCCH limited)

10M

120-140 (PDCCH limited)

20M

270-290 (PDCCH limited)

Network topology：3GPP Case1，7x3 Bandwidth：5M、10M、20M

Carrier Frequency：2.0G Channel model：SCME Traffic mode：VoIP AMR 12.2k，VAF 0.5 Schedule mode：DS ；RLC Segment is considered；ROHC is not considered.

Voice Users per 5MHz In different system Multi-CELLs (Model : Voice 12.65,3Sites,3Sectors per site, Site to Site distance=500m,uniform)

110 85

60 46 36

GSM-FR

UMTS-CS

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DS

SPS

Company Confidential

SPS+ROHC Page 32

Less impact to data in normal traffic, enhancement features are required in heavy traffic scenarios UL refarming will result in VoLTE user increasing CS requirement per cell forecast in busy hour (Unit:Erlang)

57 50

Source : huawei study

43 36 29

21 13

3

4

7

6

In Top cell or big events, VoLTE will impact cell THP

8

10

11

20 18 16 14 12 10 8 6 4 2 0

Cell throughput impact simulation come from VoLTE (unit :Mbps) 18.17 17.67

16.7 13.31 11.79 8.73

>10%

5.53 3.3

Erlang 0

10

20

40

80

120

160

200

2.05

240

23.85K VoLTE 2012

2013

2014

2015

Top5 CS Volume per cell

2016

2017

2018

AVG CS Volume per cell

M country Top5 cell peak voice traffic will up to 36 ~ 43 Erlang in next two years If all the UMTS refarming to LTE cell, LTE voice traffic per cell will up to 72 ~ 86 Erlang (LTE 10M Cell, 2UMTS cell refarming 2*36~43) HUAWEI TECHNOLOGIES CO., LTD.

when voice traffic > 20 Erlang, the cell throughput fell > 10%. the CCE is the key factor in the special events, while voice users consume more CCE, it can be predicted that the impact to data traffic come from voice will be expand in the special event Company Confidential

Page 33

Radio resource utilization

RB

3.5

14%

3.2 12.20%

3 2.5 2

1.9

7% 1.5

1.2

1.4 5%

1.3 5%

CCE usage ratio

3

4.50%

1 0.5

12% 10%

• Based on Lab test: 10MHz bandwidth

8%

• Codec rate:12.65K

6%

• 2 UE

4%

• Without SPS, ROHC ,TTIB.

2% 1%

0

0% -81

-97

-121

• SINR =6dB,18dB,22dB

RSRP

CELL DL USED RB PER TTI

CELL UL USED RB PER TTI

CELL DL CCE usage ratio PER SECONDE

CELL UL CCE usage ratio PER SECONDE

In cell edge , the CCE & RB resource consumption increase fast .especially the CCE. HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 34

Capacity Enhancement: hardware capacity and software features The factors of affecting VoLTE capacity Resource of control channel: The Fewer resources consumed by voice packet scheduling in the control channel, the higher the cell’s capacity. Resource of user channel: The Fewer resources consumed by voice packet scheduling in user channel, the higher the cell's capacity. Scheduling algorithm: How to get a best balance between voice quality and capacity  capacity of hardware: The hardware processing power is stronger, the higher the cell’s capacity

HUAWEI TECHNOLOGIES CO., LTD.

The solutions can be implemented

Semi Persistent scheduling(SPS)  ROHC UL-delay based dynamic scheduling(DDS)/DL Non-GBR Packet Bundling scheduling (PBS) UBBP board

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Page 35

VoLTE capacity enhancement –Semi-persistent scheduling to save the PDCCH resource

Semi Persistent Scheduler reduce the signalling overhead due to the reduction of grant overheads (dynamic scheduling uses a minimum 5msec SR period; SPS with the current parameterisation 20msec) SPS only works for the radio bearer with QCI1 and is configured to the UE with the setup of this DRB During the voice call SPS can be activated and deactivated via PDCCH message when the UE enter the silent period. Semi Persistent Scheduler required UE support HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 36

VoLTE capacity enhancement -DL Non-GBR Packet Bundling Background • •

Plenty of small packet traffic occupy more control channel resources and decrease cell capacity. Improve the packet delay performance for Downlink Data service.

Solution •

eNB scheduler introduced the delay control. The larger packet delay service can get a higher scheduling priority under the same condition (such as channel quality, data rate). As known, the packet number delayed in buffer is more when the packet delay is large. So Packet Bundling Scheduling strategy based on delay schedules more packets once. This results in the control channel resource save and the performance improvement. saved

PDCCH

CCE

CCE

CCE

PDCCH

CCE

RB assignment by PDCCH 3 times

PDSCH

100bytes

100bytes

100bytes

CCE

CCE

RB assignment by PDCCH once

PDSCH

100bytes+100bytes+100bytes

Advantages • •

Increase scheduling opportunity, so improve DL throughput (especially to edge users) under the same control channel resources when congestion happened in control channel but RBs are still enough. Optimize the packet delay of Non-GBR traffic (Non-GBR Packet Bundling Scheduling). It works with switch ON. HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 37

Use of SPS, DL-NonGBR bundling for different scenarios Network topology

Inter-Site Distance

Carrier Freq/BW

Channel Model

Traffic mode

Antenna

Transmissio n Mode

UE Distributi on

UE Speed

7x3

500m

2.0G/10MHz

SCME

VoIP: AMR;Active Factor:0.5 Data: Full Buffer; 10 user, 15Mbps

eNB:2T2R UE:1T2R

TM3

Uniform

3kmh

Use DL-NoneGBR bundling to improve the throughput Middle or light loaded cell DL non-GBR bundling Simulation result

Voice satisfaction begin to fell

Gains Up to 20%

Simulation assumption :

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 38

Use of SPS, DL-NonGBR bundling for different scenarios(continued) Use SPS in heavy load or special events to relief CCE bottleneck SPS Simulation result (Unit:Mbps) 13.88 12.86

13.69

Gain>10%

12.72

10.81 9.22

9.97

7.7

6.46

7.22

4.55

3.25

VoLTE user number 40

80

120 23.85K DS

HUAWEI TECHNOLOGIES CO., LTD.

160

200

240

23.85K SPS

Company Confidential

Page 39

VoLTE capacity feature-UL delay-based dynamic scheduling Original dynamic scheduling

Challenge

 Generally, dynamic scheduling priorities are based on

 VoIP service is sensitive to packet delay

  

the QoS requirements of different services the radio channel quality of UE the fairness among users

Solution: UL delay-based dynamic scheduling

If user A (at the cell center) is always scheduled prior to user B (at the cell edge), A could get very small packet delay and much better voice quality than B B’s voice quality could be unacceptable, especially in VoIP service scenarios at high load and result in the capacity loss

Apply a delay-weighted scheduling prioritization for VoIP service The larger the VoIP packet delay is, the higher the scheduling priority results A more balanced scheduling order helps reduce the number of voice packet whose air delay <50ms to increase the satisfied voice user number in heavy load scenario Company Confidential HUAWEI TECHNOLOGIES CO., LTD.

Page 40

how the different scheduling works in a voice call Transient State

Talk Spurt

Silent Period

VOIP Service States

Talk Spurt w/ data

SID Frame 20 ms

Silent Period • New voice call is just established in the Transient State.

• Dynamic scheduling is used.

• In Talk Spurt, voice packets are transmitted every 20ms. • Semi-Persistent Scheduling assigns regular resource in one scheduling when only voice.

160 ms • Silent Period happens when stop talking. In this state, only silence insertion descriptor (SID) frame is sent to peer UE every 160 ms by silent UE. • Persistent resource is released at talk to silence transition; Dynamic scheduling is used.

Max 50 ms delay • In Talk Spurt with data traffic, several data packets can be scheduled together.

• Delay based Dynamic Scheduling ensures <50ms delay for voice packets.

Combination of SPS and DDS further improved VoLTE user capacity HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 41

VoLTE Coverage Enhancement: ROHC

IP Header 40~60 Bytes

IP Header 40~60 Bytes

Voice Packtes 32~60 Bytes

Voice Packtes 32~60 Bytes

Payload RoHC 1 Byte

Voice Packtes 32~60 Bytes

RTP header

Payload

RoHC 1 Byte

Voice Packtes 32~60 Bytes

UDP header IP header Decompression

RoHC header

Compression Original packet Compressed packet

• As voice packets often have same source and destination, RoHC can achieve compression to as small as 1 byte. • Smaller header size on air interface expanded uplink cell coverage and increase capacity.

HUAWEI TECHNOLOGIES CO., LTD.

Compression Decompression

• TTI Bundling & RoHC together bring 3dB uplink gain thus increase 20% cell coverage.

Company Confidential

Page 42

ROHC gains and recommendations RoHC test result in D operator

-63%

In good air condition ,the maximum compress rate reach 63%  R-mode have not too much advantage compare with O-mode HUAWEI TECHNOLOGIES CO., LTD.

Different RoHC mode overview Feedback

advantage

U-mode

No feedback

Good for no feedback channel. Compression effciency is poorer than other modes

Omode

NACK/StaticNACK ACK is optional

A trade-off between compression and feedback overhead. All ROHC headers have CRC field. Only if CRC is error, the decompressor sends feedback.

R-mode

ACK/NACK/StaticNACK for each ROHC headers with CRC

Feedback overhead is larger than other modes. The damaged ROHC header without CRC may be delivered

Huawei recommend using O-mode to get the balance between the compression efficiency and radio resource

Company Confidential

Page 43

RoHC can improve the capacity, but recommended only in Uplink due to the CPU consumption Network topology：

VoLTE with ROHC capacity simulation in single cell(with 280 SPS)

3GPP Case1，7x3 Bandwidth：10M

67.20%

70.00%

Carrier Frequency： 2.0G

80.00%

LBBPd2 CPU usage test result in RoHC Omode (with SPS) 63%

60.00%

200

53.00%

180

Channel model：SCME

54.00%

50.00%

47.00%

140

Traffic mode：VoIP

40.00%

AMR 12.65k，VAF 0.5 Schedule mode：

30.00%

SPS；RLC Segment is

20.00%

considered；ROHC is

64.20%

rohc on

33.40%

rohc off

30.86%

10.00%

considered(6bytes). 12.65-10M rohc off

23.85-10M rohc on

With SPS,ROHC , the cell VoLTE(uniform distribution) capacity up to 280 in 10M bandwidth ROHC save 30% RB totally and upgrade 4.5% cell satisfaction ratio under same VoIP users；

HUAWEI TECHNOLOGIES CO., LTD.

VoLTE user number 0.00% 300

600

750

900

ROHC consume much more CPU resource , Huawei recommend use ROHC only On Uplink.

Company Confidential

Page 44

VoLTE feature deployment strategy in RAN 1st stage: VoLTE Basic solution     

Guarantee the high performance of VoLTE basic KPI HD voice(AMR-WB) and video services High VoLTE KPI: call setup\call drop\packet drop…. Seamless mobility: intra system and SRVCC High MOS experience for the whole network

All The features launch plan should comply with the maturity of commercial terminals.

2ndStage ：Performance Enhancement

Transition phase for Terminals IoT’s Verification

   

Provide enhanced experience for VoLTE users Power saving: DRX Coverage enhancement: RoHC/TTI bundling MOS enhancement in interfered area: UL comp 3rd Stage: Capacity Optimization

User booming , and after PDCCH CCE is in congestion

HUAWEI TECHNOLOGIES CO., LTD.

  

Network usage raising for VoLTE services Capacity enhancement: Delay based scheduling/SPS Other optimized solution

Company Confidential

Page 45

Content  VoLTE Updates & Trends  VoLTE Introduction  VoLTE Coverage  VoLTE Capacity  VoLTE Performance  VoLTE Mobility Strategy  Case Study  Summary and Recommendations

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 46

VoLTE call setup performance Note: Test result from operator P

VoLTE call setup delays (unit: ms) 12000

11038 10000

8000 7454

Delays (ms) 6000

5786

5938

6020

6034

4000

3925 3914

4049

4233

4295

2000

3906

4962

3974

3931

2413 1669

1663

1677

1736

643

641

675

714

785

0

RSRP(dBm) -80 dBm

-90 dBm 12.65K LTE-LTE (CONNECT)

12.65K LTE-LTE (IDLE)

-100 dBm 12.65K LTE-3G CONNECT

-110 dBm 12.65K LTE-3G IDLE

-120 dBm 12.2K 3G-3G

 Voice call setup delay is much better on VoLTE compared to 3G  Not much difference for RSRP < -110dBm HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 47

VoLTE Quality VoLTE MOS comparison (Lab Test result in 50% load)

Note: Test result from Huawei Lab

4.2

4

4

4.02

3.87

3.87

3.94 3.87

3.12

3.13

3.13

MOS

3.8

3.6

3.4

3.2

3 -75

-95 AMR-WB6.6Kbps

AMR-WB12.65Kbps

-105

RSRP(dBm)

AMR-WB23.85Kbps

 VoLTE AMR-WB 23.85k has no significant gain over AMR-WB12.65k  AMR-WB 12.65k is the recommendation for the sake of more radio interface capacity HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 48

Content  VoLTE Updates & Trends  VoLTE Introduction  VoLTE Coverage  VoLTE Capacity  VoLTE Performance  VoLTE Mobility Strategy  Case Study

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 49

VoLTE mobility strategy Intra-freq handover

FDD handover or inter-freq handover

LTE FDD high band Intra-freq handover LTE FDD low band

SRVCC to 2G/3G

UMTS/GSM

Handover direction

Solution

Strategy recommendation

FDD LTE ( intra-freq)

Intra-freq handover based on coverage

Intra-frequency handover is based on the A3 RSRP event trigger, it is recommended as same as data services, using the same measurement and judgment threshold

FDD LTE ( inter-freq)

Inter-freq handover based on coverage

Voice and Data configured independently handover parameters to make the voice handover trigger more easily.

From LTE to 2G/3G

SRVCC

Enable SRVCC only in FDD low band(better coverage layer). No need SRVCC in highband(Weak coverage layer)

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 50

VoLTE & CA • VoLTE users can connect to each carrier • The data of QCI1 radio bear will only be scheduled on Primary CC. (Because the VoLTE service throughput is low, and there is no need to share low traffic on secondary CC. This mechanism is to avoid unnecessary CA activation)

Conclusion: No direct limit and interact between CA and VoLTE

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 51

Content  VoLTE Updates & Trends  VoLTE Introduction  VoLTE Coverage  VoLTE Capacity  VoLTE Performance  VoLTE Mobility Strategy  Case Study

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 52

Operator L case

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 53

Coverage is the key of VoLTE experience 10Mbps experience ,high density cell High density cell lead to very less weak coverageExcellent areas coverage leads to excellent voice experience AVG RSRP 64dBm,100%> -110

MOS-P863

MOS -… 120.00%

MOS>4.0

100.00% 80.00%

4.2, 100.00% 4.1, 86.96%

60.00% 1KM

1KM

AVG square km

AVG SINR 15.1,99.8%> -3

40.00%

230Cell

20.00%

(particular ) AVG square km

0.00%

3.9, 15.53% 3.8, 8.07% 3.7

100Cell Total 60K RRU in Seoul , 850M:2.6G:2.1G≈3:2:1

HUAWEI TECHNOLOGIES CO., LTD.

4, 39.75%

3.8

3.9

Avg Mos:4.0

Company Confidential

4

4.1

4.2

4.3

60% test point >4.0 Page 54

The interference of high band is lower bring a better KPI

The interference of 2.6G is lower than 850M

LGU+ VoLTE KPI of high band is better low band VoLTE KPIthan comparison between 2

The interference comparison between 2 bands

120.00%

bands

0.25%

100.00%

99.95% 99.95%

0.21% 100.00%

0.20%

80.00%

99.90% 99.85%

99.82% 0.15%

60.00%

99.80% 99.75%

40.00%

0.10%

0.08%

20.00%

99.70% 99.65%

0.05%

0.00%

SINR-2.6G

 operator L 850M spectrum near the frequency of policy , it brings a high interference

35 <= x < 40

25 <= x < 30

20 <= x < 25

15 <= x < 20

10 <= x < 15

5 <= x < 10

0 <= x < 5

-3 <= x < 0

-5 <= x < -3

-10 <= x < -5

-15 <= x < -10

x < -15

SINR-850

99.60% 99.55%

0.00%

99.50% 850M

2.6G

call drop rate

call setup success rate

The call drop rate ,call setup success rate of 2.6G is better than 850M

 850M overshooting too much HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 55

Prefer high-band attachment, resulting in a higher proportion of VoLTE activation in high-band The ratio of VoLTE call is significant higher than low band 1.02%

In The same coverage, high -band has the priority be attached

[email protected]

[email protected]

Cell ReselecctPriority= 6 QRxLevMin= -100dBm idle： Choose high band Cell ReselecctPriority= 4 first

0.45%

0.46%

2.1G

800M

QRxLevMin= -114dBm Weak coverage area Choose low-band

10M@850M

2.6G

Cell ReselecctPriority= 2 QRxLevMin= -128dBm HUAWEI TECHNOLOGIES CO., LTD.

VoLTE Service Ratio

Company Confidential

Page 56

VoLTE handover strategy & optimization interFreqHo measurement threshold RSRP= 114dBm(A2) Ho judgment threshold RSRP= -114dBm(A4)

[email protected]

Handover from 2.6 [email protected] almost to 850M， unless signal of 2.1G is very strong (>-100dBm) 2.1G can hand over both to 2.6 & 850

Weekly call drop rate comparison after X2 optimization 0.21%

-10%

interFreqHo measurement threshold RSRP = -100dBm(A2) Ho judgment threshold RSRP = -114dBm(A4)

0.12%

interFreqHo measurement threshold 10M@850M before X2 optimized after X2 optimized RSRP = -140dBm Ho judgment threshold As much as possible using the X2 interface in 850M is the last coverage layer , the threshold ofRSRP = -43dBm intre-site handover to reduce call dropped due to measurement is very low and the threshold of judgment is very high ,almost no handover long delay of handover

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 57

The terminal & tariff in Operator L The strategy of VoLTE tariff

The information of VoLTE terminal 12+ VoLTE Smartphone

Normal / unlimited voice tariff comparison 120,000 100,000

Galaxy S5

Samsung Note2

LG G2

unlimited tariff

(*KRW)

-1100

normal tariff

A

Normal / unlimited voice data comparison (* GB)

25

unlimited tariff

B +7700

80,000

-4

normal tariff

20

A

15

60,000 

terminal capability 

10

40,000

-1

No TTI

B

5

20,000

bundling/RoHC/SPS/DRX/SRVCC 

850M,2.1G,2.6G



Dual APNs:



Voice call bearers: QCI1(voice

one for IMS, one for data

packet)+QCI5(IMS default bearer )+QCI6(data default

bearer) 

HD voice:

AMR-WB 23.85kbps ，No codec

0

0 1

A B

2

3

4

1

2

3

4

To use data traffic exchange free voice in High-end packages To use small amounts of data traffic + additional charges exchange free voice Low-end packages To use data exchange Free voice , profit of the highend is greater than the low end packages

adjustment in any case

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 58

Intelligent VoLTE guarantee excellent performance of voice HD Voice Quality MOS +0.17

Reliability Call setup success rate +0.05%

4.1

Continuity Call drop rate -0.02% 99.88%

99.83%

0.11%

3.93

0.09% 3.47 0.07%

99.33%

CDMA

VoLTE -E//

VoLTE-HW

 Interference suppressed in cell edge (UL COMP)  Excellent RLC segmentation algorithm

HUAWEI TECHNOLOGIES CO., LTD.

CDMA

VoLTE -E//

VoLTE-HW

 Self-developed chipset, powerful capability of scheduling  Excellent algorithm of scheduling in call setup process

CDMA

VoLTE -E//

VoLTE-HW

 Power Control optimized in handover area for voice  advanced receiver technology of IRC

Company Confidential

Page 59

Operator P case

HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 60

VOLTE terminal & network Single terminal ,network with out any enhancement feature

120.00%

90% area of PCCW network meet the requirement of Typical area RSRP,SINR VoLTE signal CDF in pccw 100%

100.00% 88.42%

80.00% 60.00%

RSRP 97.2%>-110

20.00% 9.17% [-70,0]

[-80,-70]

120.00%

HUAWEI TECHNOLOGIES CO., LTD.

[-90,-80]

[-100,-90] [-110,-100] [-120,-110] [-130,-120]

SINR 95.1%>-3

100.00%

Samsung galaxy Note 3 LTE Spectrum support 800/850/900/1800/2100/2600MHz Support SPS,DRX,TTIbundling(network inactive ) VoLTE decode rate 12.65  SRVCC enabled

80.00%

96.70% 90.20%

40.00% 0.00%

97.10%

65.10%

60.00% 20.00%

99.90%

58.57%

40.00%

0.00%

97.20%

100%

33.40% 12.60% 0.40% 2.90% [-20,-5] [-5,0] [0,5] [5,10]

Company Confidential

[10,15] [15,20] [20,25] [25,30]

Page 61

Setting a low measurement threshold of SRVCC to avoid the influence to voice experience The strategy of VoLTE mobility

The MOS impact of different handover mode comparison 6.00

4.20

4.00

3.32

3.50

inter-freq handover

intra-freq handover

2.87

2.00

FDD 2.6G， Cell Reselect priority =6 QRxLevMin = 128dBm FDD 1.8G， Cell Reselect priority= 4 QRxLevMin =- 128dBm

UMTS 2.1G

0.00 no handover

interFreqHo measurement threshold RSRP =- 113dBm(A2) Ho judgment threshold RSRP =- -106dBm(A4) SRVCC RSRP A2 measurement threshold = -124dBm , UMTS B1 measurement threshold = -100dBm

MOS-P863

The SRVCC proportion in 21460 one week 22209

25000 20000 15000 10000 5000

21015

21138 0.21%

2.00% 1.50%

18673 13192

0.27%

0.15%

0.20%

0.31%

0.20%

0

12822 0.16%

1.00%

0.50% 0.00%

Srvcc rate

if the signal is poor in the 2.6G network , the VoLTE will handover to 1.8G networks, SRVCC only works on 1.8G network , to avoid frequent SRVCC HUAWEI TECHNOLOGIES CO., LTD. handover .

SRVCC

VoLTE Est times

driver test showed that the SRVCC will impact the voice quality, some time even worse than 3G one week statistic showed that SRVCC proportion <1% Company Confidential

Page 62

Excellent VoLTE experience Handover delay comparison (unit:ms)

261

quality voice ratio comparison 88.88 (MOS>3.5) %

212

SRVCC weekly handover success rate of 99% on average 100% 100%

57.58 %

100% 100% 100%

99%

59

100% 45

100%

98%

40

45 27 32 97.83%

30 21 20

97%

10

97% 96.43%

96%

3G-3G handover LTE to 3G SRVCC

Minimum SRVCC delay< 3G intra-RAT handover delay HUAWEI TECHNOLOGIES CO., LTD.

VoLTE

3G

PCCW VoLTE network voice quality comprehensively exceed its traditional network Company Confidential

60 50

58

99% 98%

70

Srvcc attempt times

0

SRVCC HO success rate

the number of SRVCC initiated is few, leading to fluctuations, the overall average success rate of 99%

Page 63

The unified unlimited voice tariff

3G & 4G Unified plan

3G

4G&CSFB

4G&VoLTE

Till 9-Jun-2014: VoLTE Subs reach 47K+，the online user is 6.8K+ in busy hour HUAWEI TECHNOLOGIES CO., LTD.

Company Confidential

Page 64

THANK YOU www.huawei.com

Copyright©2014 Huawei Technologies Co., Ltd. All Rights Reserved. The information in this document may contain predictive statements including, without limitation, statements regarding the future financial and operating results, future product portfolio, new technology, etc. There are a number of factors that could cause actual results and developments to differ materially from those expressed or implied in the predictive statements. Therefore, such information is provided for reference purpose only and constitutes neither an offer nor an acceptance. Huawei may change the information at any time without notice.