Huawei eRAN 7.0 VoLTE feature deep dive_20140515.pptx

HUAWEI TECHNOLOGIES CO., LTD.
Security Level:
Feature Deep Dive
VoLTE

TTI Bundling
Content
 Basic VoLTE features or functions
› Voice strategy selection
› Basic QoS management
› Mobility management
 Enhanced VoLTE features or functions
› TTI bundling
› RoHC
› Semi-persistent scheduling
› Delay based scheduling
› DRX
› VQM
› VoLTE off

Part I: Basic VoLTE features or functions
SGi
S12
S3
S1-MME
PCRF
Gx
S6a
HSS
IMS
Rx
S10
UE
SGSN
LTE-Uu
E-UTRAN
MME
S11
S5
Serving
Gateway
PDN
Gateway
S1-U
S4
UTRAN
GERAN
• VoLTE=Voice over LTE, based on IMS
• IMS is not a single element but comprises all CN elements for provision of IP multimedia services ,such as VoIP
over the PS domain.
• E-UTRAN is composed of eNodeBs, whose functions for radio resource management can guarantee the QoS
requirement of VoIP User.
EUTRAN: Evolved UMTS Terrestrial Radio Access Network GERAN: GSM/EDGE Radio Access Network
MME: Mobility Management Entity HSS：Home Subscriber Server
SGSN: Serving GPRS Support Node UE: User Equipment
UTRAN: Universal Terrestrial Radio Access Network PCRF：Policy and Charging Rule Function

Voice strategy selection
UE is set to IMS
voice preferred,
CS voice
secondary
UE initiates EPS
attach procedure
(non combined)
UE checks for IMS
voice supported
Indication from
Network
UE uses IMS
Voice
Supported
UE performs
combined TAU for
CSFB as in TS
23.272
Not
supported
UE uses CSFB
Success with no “SMS-only”
and no “CSFB
Not Preferred” indication
UE checks for
voice centric or
data centric setting
UE stays in current
RAT
Data centric
Voice centric
UE reselects to
other RAT
TAU performed
Fail or Success with “SMS only”
indication or Success with
“CSFB Not Preferred” indication
• Voice strategy selection depend on:
1. UE’s capability
2. MME’s strategy
From 3GPP TS23.221 Annex A

Basic QoS management
• VoLTE bearers
• QCI1: voice packet -dedicated bearer
• QCI5: IMS signaling –default bearer
• QCI2: video –dedicated bearer
QCI
Packet
Delay
Budget
Packet
Error
Loss Rate
Scheduling
priority
1 100 ms 10-2 2
5 100 ms 10-6 1
2 150 ms 10-3 4
• QoS requirement (from 3GPP TR23.203)：

VoLTE call setup procedure
• From eNodeB side:
1. RRC connection setup
2. IMS bearer setup (QCI5)
3. SIP negotiation via QCI5 (application
packet and transparent to eNB)
4. voice bearer setup (QCI1)

Mobility management
RSRP
PESQ Delay(ms) SINR
23.05K
L2L
12.65K
L2L
12.65K
L2U
23.05K
L2L
12.65K
L2L
12.65K
L2U
23.05K
L2L
12.65K
L2L
12.65K
L2U
-80 dBm 4.20 4.07 3.88 129 119 226 25 25 22
-90 dBm 4.20 4.05 3.89 123 121 220 16 15 15
-100 dBm 4.20 4.07 3.89 115 123 236 8 8 5
-110 dBm 3.36 4.00 1.07 149 123 429 -5 -2 -5
-120 dBm 2.26 3.62 238 143 -5 2 -10
• The intra-LTE mobility procedure is the same for VoLTE and data.
• The intra-LTE mobility related parameter could be adjusted separately for VoLTE and data
• Considering MOS requirement for VoLTE, the VoLTE requirement is suggested to “RSRP>-110dbm
& SINR>-3db”

Basic VoLTE KPI
KPI items Counter
VoLTE call setup
L.E-RAB.AttEst.QCI.1
L.E-RAB.SuccEst.QCI.1
VoLTE call drop
L.E-RAB.AbnormRel.QCI.1
L.E-RAB.NormRel.QCI.1
VoLTE packet loss
L.Traffic.UL.PktLoss.Loss.QCI.1
L.Traffic.UL.PktLoss.Tot.QCI.1
L.Traffic.DL.PktUuLoss.Loss.QCI.1
L.Traffic.DL.PktUuLoss.Tot.QCI.1
L.PDCP.Tx.Disc.Trf.SDU.QCI.1
L.PDCP.Tx.TotRev.Trf.SDU.QCI.1
VoLTE handover rate
L.HHO.IntraeNB.IntraFreq.PrepAttOut.VoIP
L.HHO.IntraeNB.InterFreq.PrepAttOut.VoIP
L.HHO.IntraeNB.IntraFreq.ExecAttOut.VoIP
L.HHO.IntraeNB.InterFreq.ExecAttOut.VoIP
L.HHO.IntraeNB.IntraFreq.ExecSuccOut.VoIP
L.HHO.IntraeNB.InterFreq.ExecSuccOut.VoIP
L.HHO.IntereNB.IntraFreq.PrepAttOut.VoIP
L.HHO.IntereNB.InterFreq.PrepAttOut.VoIP
L.HHO.IntereNB.IntraFreq.ExecAttOut.VoIP
L.HHO.IntereNB.InterFreq.ExecAttOut.VoIP
L.HHO.IntereNB.IntraFreq.ExecSuccOut.VoIP
L.HHO.IntereNB.InterFreq.ExecSuccOut.VoIP
• The whole VoLTE KPI could
refer to performance counter
reference

Part II: Enhanced VoLTE features or functions
eRAN6.0：
TTI bundling
RoHC
eRAN6.0：
Semi-persistent
RoHC
eRAN7.0：
UL delay based
scheduling
eRAN6.0：
DRX
VQM
eRAN7.0：
VoLTE OFF
Coverage enhancement Capacity enhancement Other enhancement

TTI bundling

TTI Bundling introduction
LOFD-001048 TTI bundling
TTI Bundling
HARQ retransmission RLC Segmentation TTI Bundling
D1
D1 D1 D1 D1
D1 D1 D1
NACK Re-
transmission
4 consecutive TTIs are
bundled together for a
single transmit block.
Advantage:
• Uplink control signaling saving
• More efficient usage of radio
resources because of less packet
headers
performs non-adaptive
retransmission
a single HARQ
process with one
ACK/NACK feedback.

TTI Bundling trigger & exit
TTI Bundling
SINR
Time
Trigger:
SINR average in trigger
observation window <
trigger threshold
Exit:
SINR average in exit
observation window >
exit threshold
Trigger
•UE supports TTI Bundling
•Only VoIP service of && talk spurt state
•RB number limited by UE power is 3
•SINR drops below a threshold for an
observation window
Exit
•SINR increase beyond a threshold for an
observation window
Note: window and threshold is internal parameter

TTI Bundling
TTI Bundling activation & dependency
• Activation method
Parameter
ID
Parameter
Name
Description Activation
method
UlSchSwitch Uplink schedule switch Indicates whether to enable or disable TTI bundling MOD CELLALGOSWITCH
TtiBundlingSwitch: On
• Dependency
› Should be supported by UE. If UE doesn’t support, TTI Bundling will not be triggered by eNodeB.
Counter Description
L.Traffic.User.TtiBundling.Avg Average number of UEs on which TTI bundling takes effect in a cell
L.Signal.Num.TtiBundling.Enter Number of messages sent for instructing UEs to enter TTI bundling mode
L.Signal.Num.TtiBundling.Exit Number of messages sent for instructing UEs to exit TTI bundling mode

RoHC

LOFD-001017 RObust Header Compression (ROHC)
ROHC
Background of header compression
• Same information in the different packet header
• Some information can be deduced
Redundancy info. in the different packet header Minor change in the header of packet stream
• Minor change in the header compared with previous
packet in the packet stream

ROHC
RoHC
1 Byte
Voice Packtes
32~60 Bytes
RoHC
1 Byte
Voice Packtes
32~60 Bytes
Voice Packtes
32~60 Bytes
IP Header
40~60 Bytes
IP Header
40~60 Bytes
Voice Packtes
32~60 Bytes
Original packet Compressed packet
RTP header
UDP header
IP header
Payload
RoHC header
Payload
Compression
Decompression
Decompression
Compression
• RoHC can achieve compression to as small as 1 byte.
• Smaller header size on air interface expanded uplink cell coverage and increase capacity.
ROHC(Robust Header Compression) introduction

ROHC
Principles & basic framework
The compressor sends the data packets after ROHC compression and also the information about the compressed
header
The compressor and de-compressor maintain the context at the TX and RX ends respectively to ensure the
context synchronization.
The de-compressor restores the original data packets based on the context.

ROHC
Operating Mode of ROHC
The initial operating mode of the compressor must be U-Mode,
which then gradually switches to O-Mode or R-Mode. The
operating mode transition is determined by the de-compressor.
When the eNodeB is the compressor, the UE works as the de-
compressor and orders the eNodeB to change the operating
mode.
When the eNodeB is the de-compressor, it orders the UE to
change the operating mode based on the
PdcpRohcPara.HighestMode parameter.
If the PdcpRohcPara.HighestMode parameter is set to
R_MODE(Bi-Directional Reliable Mode), the UE can switch
to a higher mode (O-Mode or R-Mode) and stay in R-Mode.
If the PdcpRohcPara.HighestMode parameter is set to
O_MODE(Bi-directional Optimistic Mode), the UE can switch
to and stay in O-Mode.
The decompressor orders the compressor to change the
operating mode by providing feedback, such as ACK and NACK.

During initial access, if both the compressor and the decompressor
support ROHC, ROHC is started by default when a bearer for VoIP
service is set up but is not started for non-VoIP services
 ROHC is active for all UE with ROHC capability
During the inter-eNodeB handover of the UE, the source eNodeB informs
the target eNodeB of the ROHC capability of the UE, and the target
eNodeB recalculates the actual capability of the UE. After the handover,
the UE and eNodeB operate with the new ROHC parameters
ROHC
Initial & handover procedure

ROHC parameter&counter
MO Parameter ID Parameter Name Description
PdcpRohcPara RohcSwitch ROHC switch Indicates whether to enable ROHC
Actual Value Range: OFF, ON
PdcpRohcPara HighestMode ROHC Highest mode the operating mode of ROHC
Actual Value Range: U_MODE, O_MODE, R_MODE
PdcpRohcPara Profiles Compression profiles Meaning: Indicates the compression profile supported by the
eNodeB.
As defined by LTE specifications, the eNodeB supports the
following profiles:
profile 0x0001 (RTP/UDP/IP),
profile 0x0002 (UDP/IP),
profile 0x0003 (ESP/IP)
profile 0x0004 (IP)
ROHC
Counter Description
L.Traffic.User.RoHC.Max Maximum number of UEs on which ROHC takes effect in a cell
L.Traffic.User.RoHC.Avg Average number of UEs on which ROHC takes effect in a cell
L.PDCP.DL.RoHC.HdrCompRatio Compression rate of headers of all downlink PDCP SDUs after the ROHC
L.PDCP.DL.RoHC.PktCompRatio Compression rate of all downlink PDCP SDUs (including headers and payloads) after the ROHC
L.PDCP.UL.RoHC.FailDecompRatio Decompression failure rate of all uplink PDCP SDUs after the ROHC
L.PDCP.UL.RoHC.HdrCompRatio Compression rate of headers of all uplink PDCP SDUs
L.PDCP.UL.RoHC.PktCompRatio Compression rate of all uplink PDCP SDUs (including headers and payloads) after the ROHC.

Semi-persistent scheduling

Transient State Talk Spurt Silent Period
20 ms 160 ms
SID Frame
VOIP
Service
States
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.
• Semi-persistent scheduling
improves 40% voice capacity.
• 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.
LOFD-001016 VoIP Semi-persistent Scheduling
VOIP SPS
VoIP scheduling overview

SPS trigger, re-configuration & exit
TTI Bundling
VOIP SPS
20 ms
trigger
Re-configuration if
needed
exit
Trigger condition
UE support SPS
Only VoIP service (QCI=1)
Talk spurt state
Re-configuration
IBLER in observation
window > threshold
Note: internal parameter
Exit condition
the number of empty packets
received by the eNodeB in semi-
persistent scheduling exceeds
the value of
CellUlschAlgo.SpsRelThd

VOIP SPS
SPS parameter
Parameter ID Parameter Name Description Activation method
UlSchSwitch Uplink schedule
switch
Indicates whether to enable or disable uplink semi-
persistent scheduling during talk spurts of VoIP services
MOD CELLALGOSWITCH
SpsSchSwitch: On
DlSchSwitch DL schedule switch Indicates whether to enable or disable downlink semi-
persistent scheduling during talk spurts of VoIP services
MOD CELLALGOSWITCH
SpsSchSwitch: On
CellUlschAlgo Meaning:Indicates the threshold for the number of
consecutive zero-payload packets received by the eNodeB.
After receiving consecutive zero-payload packets of a
number that is equal to the value of this parameter, the
eNodeB performs implicit release of semi-persistent
resources.
MOD CELLULSCHALGO on
Counter Description
L.Sps.UL.SchNum Number of uplink semi-persistent scheduling times in a cell
L.Sps.DL.SchNum Number of downlink semi-persistent scheduling times in a cell
L.Sps.UL.ErrNum Number of failed uplink semi-persistent scheduling transmissions in a cell
L.Sps.DL.ErrNum Number of failed downlink semi-persistent scheduling transmission in a cell

Relationship between Feature
» When uplink semi-Persistent scheduling is adopted, UL semi-Persistent scheduling power
control should be introduced .
» When semi-persistent scheduling is adopted, compress efficiency of ROCH impact the VoIP
capacity.
» If the long DRX cycle for QCI1 is over 20ms, SPS will not be activated.

Delay based scheduling

1. Background
- Ul dynamic scheduling prioritization for VoIP service
 Generally, dynamic scheduling priorities are based on
 the QoS requirements of different services
 the radio channel quality of UE
 the fairness among users
 VoIP service is sensitive to packet delay
 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
VoIP user B
VoIP user A
Ul dynamic scheduling for VoIP
services

2. Solutions Introduction
- Ul delay-based dynamic scheduling prioritization for VoIP service
• Delay-based dynamic scheduling priority calculation
› Apply a delay-weighted scheduling prioritization for VoIP service
» delay=SRperiod/2+scheduling waiting time in eNB
› The larger the VoIP packet delay is, the higher the scheduling priority results
» If the delay is larger than 25ms(hard codec in eNB), the priority will be increased.
» eNB will calculate the priority of VoIP users in each TTI.
› A more balanced scheduling order helps improve the voice quality of UEs suffering from bad radio
channel quality

3. Impact Analysis 1/2
• Positive Impact (Gain)
› VoIP capacity gain around 10%
› Simulation conditions:
» 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 /DDS /SPS；RLC Segment is considered；ROHC is not considered.
• Negative Impacts
› In light load of VoIP scenario, there is no negative impact.
› In heavy load of VoIP scenario:
» The scheduling delay of VoIP in cell center would be a little longer when there are a lot of VoIP users in cell edge. But it will not
impact this VoIP user’s QoE for the 25ms delay factor limitation.
» Because the SR scheduling could not distinguish the specified services, the Pingidle2activeattach delay could be longer. The
uplink data throughput and the downlink TCP service throughput may be impacted by SR delay reason.
Bandwidth
Dynamic scheduling
DS+delay based
scheduling
Uniform Uniform
5M 50 55
10M 120 140
20M 270 320

4. Activation Guide 1
 Dependency on Hardware
 None
 Dependency on other Features
 LBFD-002025 Basic Scheduling
 LOFD-00101502 Dynamic Scheduling
 License
 None
 Trial for eRAN7.0

4. Activation Guide 2
• It is recommended that UDDS be used in all scenarios by default.
• Enabling the UDDS Feature:
› MOD CELLULSCHALGO: LOCALCELLID=0, UlDelaySchStrategy=VOIP_DELAYSCH-1;
• Deactivate the XXX Feature:
› MOD CELLULSCHALGO: LOCALCELLID=0, UlDelaySchStrategy=NO_DELAYSCH-0;

5. Verification
• VoIP capacity test
› For uniform allocation, the satisfied VoIP users(could be evaluated by MOS ) would be
larger for the gain around 10%.

DRX

DRX
 ※ Objective
» Tradeoff between VoIP performance and power saving.
 ※ Functionalities
 » For different number VoIP user, the on duration timer is different, the on duration timer ’s length is
increased along with the increase of the VoIP user.

• ※ Parameter
• ※ Command
› MOD DRX
› LST DRX
›Execute command “ LST DRX”, if “DrxAlgSwitch” is ON, it means that the DRX is enable, UE may enter the DRX state.
 DRX Deployment
Drx DrxAlgSwitch DRX switch Indicates the DRX switch.
If this parameter is set to ON, the UE may enter the DRX
state, saving UE power.

Recommended configuration
• QCI5
› The longer of QCI5’s DRX long cycle configuration, the longer delay added for VoLTE
call setup time.
› Suggestion: the same with QCI9’s DRX configuration. But the DRX long cycle
configuration should be less than 320ms.
• QCI1
› No special requirement about voice power saving
» DRX switch is off for QCI1.
› Special requirement about voice power saving
» The DRX long cycle configuration is 40ms. The onduration is 10ms. The inactivity is 5ms.
» Short DRX cycle configuration is off.

VQM

Voice Quality Monitoring
※ Objective
»Evaluation radio access network speech quality.
※ Application Scenario
» The speech codec is Adaptive Multi-Rate(AMR).
» Not multiplexing-speech(there is only one QCI1 Bearer for one user).
※ Functionalities
» UL VQI: Huawei private algorithm
» FER: the loss rate of radio access network
» LFE: the number of max consecutive loss speech packet
» DL VQI: the E-model algorithm
» Calculate the MOS according to the loss rate of radio network and the estimated end to end delay.
Handover
AMR
gle
n
m
LTE Const
Const
LFE
B
FER
A
VQI 


 _
sin
*
*

VQM
• » Five grade:
• » Monitor:
• » counter: the count of every grade in one cell
• » CHR: PrivateVoiceStaistic
• » User Performance Monitoring-> VQI Monitoring
Bad Poor Accept Good Excellent
VQI Threshold <=2.6 2.6~<=3.1 3.1~<=3.6 3.6~<=4 >4
Counter name Description
L.Voice.VQI.UL.Excellent.Times Number of times uplink voice quality is Excellent
L.Voice.VQI.UL.Good.Times Number of times uplink voice quality is Good
L.Voice.VQI.UL.Accept.Times Number of times uplink voice quality is Accept
L.Voice.VQI.UL.Poor.Times Number of times uplink voice quality is Poor
L.Voice.VQI.UL.Bad.Times Number of times uplink voice quality is Bad
L.Voice.VQI.DL.Excellent.Times Number of times downlink voice quality is Excellent
L.Voice.VQI.DL.Good.Times Number of times downlink voice quality is Good
L.Voice.VQI.DL.Accept.Times Number of times downlink voice quality is Accept
L.Voice.VQI.DL.Poor.Times Number of times downlink voice quality is Poor
L.Voice.VQI.DL.Bad.Times Number of times downlink voice quality is Bad

VQM
• ※ Parameter
• ※ Command
› MOD ENODEBALGOSWITCH: VQMAlgoSwitch=**;
› LST ENODEBALGOSWITCH
› MOD VQMALGO: ULDelayJitter=**;
› LST VQMALGO
ENODEBALGOS
WITCH
VQMAlgoSwitch VQMAlgoSwitch
Indicates the VQM switch.
If this parameter is set to ON, the eNB can calculate the
AMR VOIP quality.
VQMALGO ULDelayJitter ULDelayJitter
Indicates the max jitter of UL radio delay.
The value range:1~255.

VoLTE off

Background
• There are some areas in EUTRAN that are not suitable to provide IMS
based VoIP as the voice solution of LTE.
• The use case could be one of the followings:
› The transmission performance in some areas could not meet the delay requirement for
VoLTE service.
› The EUTRAN in some areas from other MOCN operators or other vendors could not
provide VoLTE or VoLTE mobility continuity(SRVCC) services.
› There are different strategies of operators to launch VoLTE service in some dedicated
areas and not in other areas.
› There are different strategies of operators to launch VoLTE service in different sites
type(MarcoMicro).
› And so on

Solution introduction-for idle mode
• Idle mode solution
› The serving PLMN shall send an indication toward the UE during the Attach procedure and TAU
procedures if an IMS voice over PS session is supported. This indication is per TAI list.(3GPP
23.401).
› MME should send the different strategies to UEs that it supports VoLTE in some TAIs and doesn’t
support VoLTE in other TAI s(For 3GPP, if not support VoLTE, it should support CSFB for voice).
› So UE will perform VoLTE in VoLTE available TAI area and CSFB in VoLTE unavailable TAI area.
VoLTE unavailable TAI
(CSFB avaialble)
MME
VoLTE available TAI
users users
For idle UE, the voice solution selection is controlled by MME. And the control level of MME is TAIs.

Solution introduction-for active mode
For active UE, the VoLTE mobility is controlled by eNB and the level is TAI too.
UE has a voice call(QCI=1)
eNB filters the
reported cells based
on the VoLTE HO
blacklist
>=1?
Pick the strongest cell to
perform intra frequency HO
N
Y
Y
If UE triggered A3
event
If UE triggered inter
frequency A2
If UE triggered inter
RAT A2
eNB filters the
measuring frequencies
based on VoLTE HO
blacklist
UE reports A4
event?
eNB filters the
reported cells based
on the VoLTE HO
blacklist
>=1?
Pick the strongest cell to
perform inter frequency HO
Y
Y
N
eNB sends the B1
measurement
control
UE reports B1 event
SRVCC
N
N
VoLTE available
(Cell3)
VoLTE unavailable
(Cell2)
MME
VoLTE available
(Cell1) UE
UE
UMTS
VoLTE unavailable
(FDD-F2)
MME
VoLTE available
(FDD-F1) UE
UE
eNB will filter the neighboring cells based on VoLTE forbidden TAI configuration during QCI1 mobility

Impact
• The VoLTE forbidden TAI should be the same with the configuration in
MME to make sure that the active mode solution is consistent with the
idle one.
• Once eNB set VoLTE capability off, it will refuse all the QCI1 services in
setup or handover in or reestablishment procedure and feedback “NOT-
supported-QCI”. So the eNB with VoLTE off indication should be
included in the VoLTE forbidden TAI area.

Activation Guide
• Dependence
› The same TA blacklist configurations in MME and eNB.
• New parameters and activation
› Turn on VoIPHOControlSwitch
› Complete the EUTRANVOIPHOBLKLOST configuration
MO parameter Default value description
ENODEBALGOSWITCH HoAlgoSwitch:
VoIPHOControlSwitch
OFF If turning on, EUTRAN supports VoIP
handover control in intra system HO.
ENODEBALGOSWITCH EutranVoipSupportSwitch ON If turning on, EUTRAN supports VoIP.
EUTRANVOIPHOBLKLIST MCCMNCTAC NA VoLTE HO blacklist means VoLTE
handover in this TAI is allowed

Deployment suggestion
Huawei
eNB-VoLTE ON
VoLTE OFF
VoLTE ON
In Huawei eNB, TAC
blacklist(EUTRANVOIPHOBLKLIST) is suggested to
be configured to control the VoLTE handover out.
VoIP capability (EutranVoipSupportSwitch) is no
need to be configured as Huawei eNB has controlled
the VoLTE HO out.
Other vendor’s
eNB-VoLTE ON
Huawei eNB-
VoLTE OFF
If there is no similar function like TAC blacklist for
VoLTE in other vendor’s eNB, it is suggested to
configure VOIP capability switch
(EutranVoipSupportSwitch) off in Huawei eNB in the
edge of VoLTE off area.

Thank you
www.huawei.com
Copyright©2011 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.

Huawei eRAN 7.0 VoLTE feature deep dive_20140515.pptx

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