Accuver VoLTE Solution v.1.4

www.accuver.com

Presented to:

Preamble

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Thorough performance analysis What is possible

• Voice Quality/MOS (POLQA)

• SIP protocol based analysis : setup related performance

• RTP/RTCP protocol based analysis : throughput, jitter, delay, packet loss, etc.

• KPI reports – drop, setup failure, etc.

• LTE Metrics, RRC/NAS protocol messages in parallel

LTE

TCP/IP

SIP RTP/RTCP

Codec

TCP/IP

SIP RTP/RTCP

Codec

VoLTE Solutions

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Accuver VoLTE solutions

XCAL-Mobile XCAL-Solo XCAL-MPm XCAL-S+ XCAL-M

Handheld Yes Yes No No No

Voice MOS (POLQA) DL/UL DL/UL DL/UL DL/UL No

SIP Analysis Yes Yes Yes Yes Yes

RTP/RTCP Analysis Yes Yes Yes Yes Yes

RRC/NAS/LTE PHY Yes Yes Yes Yes Yes

User Interface Phone GUI Phone GUI PC PC PC

XCAL-M License Required

No No Yes Yes Yes

Number of Phone 1 1 4 2 (two S+ required)

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VoLTE Solutions

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VoLTE Solutions

XCAL-Mobile

• VoLTE ready

• Smartphone based measurement solution

• Runs on Android (Galaxy S2,3,4, HTC One XL, etc.)

• Supports GSM/ GPRS/EDGE/ WCDMA/ HSDPA/ HSUPA/ HSPA+/DC-HSDPA/LTE and WiFi

• Auto call feature for VoLTE, Youtube, iPerf, etc.

• Indoor measurement

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VoLTE Solutions

XCAL-Solo

• VoLTE ready

• Smartphone provides user interface

• A micro PC with CPU, OS, phone driver installed, SD memory, Sound card, Bluetooth and WiFi with Battery.

• XCAL-Solo software on the device interfaces with Smartphone to take LTE, VoLTE traces

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VoLTE Solutions

XCAL-MPm

• VoLTE ready

• Connected to PC with XCAL-M installed

• 4 UE interface with 4 sound cards embedded -> 4 simultaneous MOS (POLQA) measurement configurable

• External power supply required to XCAL-MPm hardware

• Existing XCAL-M license can be used as it is with no additional upgrade cost

• Call control through Bluetooth available

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VoLTE Solutions

XCAL-S+

• VoLTE ready

• Connected to PC with XCAL-M installed

• One UE interface with one sound card embedded

• Two XCAL-S+ can be connected to one XCAL-M license -> two MOS (POLQA) measurement configurable

• Existing XCAL-M license can be used as it is with no additional upgrade cost

USB to Phone &

Audio Jack

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VoLTE Solutions

XCAL-M

• VoLTE ready

• RTP/SIP full analysis available

• Suitable for typical VoLTE performance measurement where no voice MOS (POLQA) is required

• Four VoLTE calls can be traced at the same time

• Call control through ADB interface

RTP Analysis

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RTP Metrics Available Metrics

• Packet Loss : The number of lost packets.

• RTP Throughput

• Delay : Interval between received RTP packets

• Delta Delay : Average Trend of dynamic change of Delay of RTP Packet

• Jitter Delay : Jitter on Packet Delay

• One Way Delay : Time Delay from Sender part to Receiver Part

• RTP Packet Count : Total Packet count received.

• Round Trip Time : Round Trip Time of sender packet

• R-Factor : An Audio Quality based on VoIP (VoLTE) Packet.

• MOS mapped based on R-Factor : Conversion Value of R-Factor on General PESQ MOS Mapping Table.

VoLTE Solutions

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Voice MOS (POLQA) measurement

Ethernet

ICG (Internet Call Generator)

• Compatible with IMS

• Sends audio samples

• Calculates uplink MOS and other POLQA measurements

XCAL-Mobile,Solo,S+,MPm


• Calculates downlink MOS and other POLQA measurements

EUTRAN/IMS

XCAL-Mobile, Solo, S+, MPm


• Calculates downlink MOS and other POLQA measurements

• POLQA is ITU-T.863 recommended voice MOS algorithm

• Calculates voice objective MOS values by comparing received audio waves with the reference waves

VoLTE Solutions

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VoLTE Call Flow & Event Definition

VoLTE Call Flow

VoLTE Call Event Definition

SIP Status Code

VoLTE Event – RTP Drop


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UE(MO) EUTRAN / IMS UE(MT)

Paging

Rrc Connection Reqeust

Rrc Connection setup

Rrc connection setup complete

Security Mode Command

Security Mode Complete

INVITE

Rrc connection reconfiguration

Rrc connection reconfig. comp

100 Trying

Service request

Idle start Idle start

Setup start

Call start

Dialing Start

VoLTE Call Flow

VoLTE Call Flow : Outgoing Call (MO)

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Paging

Rrc Connection Reqeust

Rrc Connection setup

Rrc connection setup complete

Security Mode Command

Security Mode Complete

Rrc Connection reconfiguration

Rrc Connection reconfig. comp

Service request

INVITE

180 Ring

180 Ring

Setup start

Send Pick up

VoLTE Call Flow

VoLTE Call Flow : Incoming Call (MT)

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200 OK

200 OK for INVITE

ACK

Rrc Connection reconfig. Comp.

Rrc Connection reconfig.

Dedicated bearer context req(QCI1)

Dedicated bearer context accept

Ulinformation Transfer

ACK

RTP(Voice or Video)






Traffic start

Pick Up

VoLTE Call Flow

VoLTE Call Flow : Answer (MO/MT)

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200 OK

200 OK for INVITE

ACK






ACK

RTP(Voice or Video)






Traffic start

Pick Up

BYE BYE

200 OK 200 OK

VoLTE Call Flow

VoLTE Call Flow : Answer (MO/MT)

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VoLTE Events Notes

1 Idle No ‘Rx INVITE’ from MT

2 Error

Dial error • MO : When Request URI of Tx INVITE is different from MIN • MT : When Tx INVITE exists after Rx INVITE

Setup MO : no Tx INVITE even though SEND was sent

No Traffic MT : no Tx 200 OK even though SEND was sent after 180 RING

3 Setup fail – timeout Not the cases above but Setup timer is expired : SIM Resppomse code shall be indicated (4##, 6##)

4 Call Drop

When there are no Rx IP Packets during the Dormant time duration after the following L3/NAS messages LTE- RRC Connection Reestablishment Request LTE- RRC Connection Reestablishment Reject LTE- RRC Connection Reject LTE- EPS MM Tracking area update reject LTE- EPS MM Authentication reject LTE- EPS MM Authentication failure LTE- EPS MM Security mode reject LTE- EPS SM Reject

5 RTP Drop – BYE BYE Method occurs during Traffic status

6 RTP Drop – Time out No Rx RTP Packets during the predefined time duration

VoLTE Call Events

VoLTE Call Events

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Six Classes of SIP Status-Codes <Picked major status codes only below>

1xx (Informational)

180 Ringing 183 Progress

2xx (Success) 200 OK – requested successful

3xx (Redirection) 302 Moved Temporarily – location update of the user

4xx (Client Error) 400 Bad Request - wrong Syntax indicator 401 Unauthorized – user authentication indicator 480 Temporarily not available 486 Busy Here

5xx (Server Error) 500 Internal Server Error 501 Not Implemented

6xx (Global Failure) 603 Decline 606 Not Acceptable


SIP Status Codes

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Reason Table

• RTP Drop – BYE : BYE Method occurs during the traffic status

• RTP Drop – Time out : Rx RTP does not exist during the traffic status

• Call Drop – Air interface Drop


RTP Drop & Air Drop

XCAP-M indicates the Reason codes

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VoLTE Call Statistics

SIP Column

SIP Setup Time Examples

Sig setup time Examples

RTP Analysis Examples

HO DATA Interruption Time


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SIP Analysis Columns

• SIP Setup Time(Invite)

• SIP Setup Time(100Trying)

• SIP Setup Time(180Ringing)

• SIP Setup Time(200OK)

• SIP Setup Time(1st Rx Packet)

• LTE RRC Setup Time

• LTE QoS Setup Time

• Paging Ind(LTE)

• LTE QoS Setup Try Ind(LTE)

• IP Address


VoLTE/VT LTE Call Statistics – SIP Analysis Columns

XCAP-M gives SIP Analysis result for each call

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SIP Setup Time MO MT

SIP Setup Time(Invite) x Paging ~ Invite

SIP Setup Time(100Trying) Invite ~ 100Trying Paging ~ 100Trying

SIP Setup Time(180Ringing) Invite ~ 180Ringing(Real) Paging ~ 180Ringing(Real)

SIP Setup Time(Virtual 180Ringing) Invite ~ 180Ringing(Virtual) x

SIP Setup Time(200OK) Invite ~ 200OK Paging ~ 200OK

SIP Setup Time(1st Rx Packet) Invite ~ Traffic Start Paging ~ Traffic Start

LTE RRC Setup Time rrcConnectionRequest ~ rrcConnectionReconfigurationComplete

LTE QoS Setup Time

QCI 1,2(8) setup time (VoLTE is for QCI 1) rrc connectionReconfiguration ~ Ul information Transfer NAS Message(Activqte dedicated EPS bearer context request ~ Activqte dedicated EPS bearer context accept)

Paging Ind(LTE) Indication information for its own Paging in case of MT

LTE QoS Setup Try Ind(LTE) Indication for LTE QoS Setup attempt

IP AddresIs IP address of SIP Connecting (its own)


SIP Setup Times

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RTP Columns

• Audio Packet Loss(Tx/Rx)

• Video Packet Loss(Tx/Rx)

• Audio Delta Delay

• Video Delta Delay

• Audio Jitter

• Video Jitter

• Audio One Way Delay(Min/Max/Avg)


VoLTE/VT LTE Call Statistics – RTP Columns

• Video One Way Delay(Min/Max/Avg)

• HO Data Interruption Time(Tx/Rx Audio)(Min/Max/Avg)

• HO Data Interruption Time(Tx/Rx Video)(Min/Max/Avg)

• HO Audio Packet Loss(Rx)

• HO Video Packet Loss(Rx)

• Intra eNB HO Data Interruption Time(Tx/Rx Audio)(Min/Max/Avg)

XCAP-M gives RTP Analysis result for each call

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Packet Loss (Tx/Rx)

• Percentage of Packet Loss during the traffic time

• Packet Loss = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝐿𝑜𝑠𝑡 𝑝𝑎𝑐𝑘𝑒𝑡𝑠

𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑎𝑐𝑘𝑒𝑡𝑠

Delay (ms)

• D(i, j) = (Rj – Ri) – (Sj – Si) = (Rj – Sj) – (Ri – Si)

Delta Delay (ms)

• Delta Delay(t) = Delay(t) – Delay(t-1)

Audio/Video Jitter

• J = J + ( |D(i-1, i)| - J ) / 16


VoLTE/VT LTE Call Statistics – RTP Columns

Sent regularly

Received irregularly

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HO Data Interruption Time (Tx/Rx)

Time difference between the packets before and after the handover. The detail algorithm to take this metrics is explained in the next page.


VoLTE/VT LTE Call Statistics – RTP Column

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HO Data Interruption Time (Tx/Rx)

Intra LTE-HO Attempt

+ - 500ms

RTP HO Data Interruption Time Algorithm

V

Takes maximum time difference between RTP packets within the time window (currently 500ms before and after) centered on the RRC Connection Reconfiguration Request message (Handover attempt)

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RTP Analysis

HO DATA Interruption Time & Pack Loss

HO Audio/Video Packet Loss

Packet Loss

Throughput

Delay & Delta Delay

RTT & One Way Delay

RTP Analysis

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• Displays RTP HO Data Interruption Time for each Hand Over Event

• Supports both Tx and Rx HO data interruption time.

RTP Analysis

RTP – HO Data Interruption time

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RTP Delay(ms) : average RTP Packet delay (ms)

D(i, j) = (Rj – Ri) – (Sj – Si) = (Rj – Sj) – (Ri – Si)

S(j) S(i)

Time = Timestamp / 16000

RTP Analysis

RTP - Delay

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Delta Delay(ms)

• Average of RTP Packet Delay variations

• Delta Delay(t) = Delay(t) – Delay(t-1)

T1

T2

T3

T4

T5

R1

R2

R3

R4

R5

RTP1

RTP2

RTP3

RTP4

RTP5

Same duration

Various delays

Jitter(ms)

• Distribution of RTP Packet Delays

• J = J(i-1) + ( |Delay(i)| - J(i-1) ) / 16

RTP Analysis

RTP – Delta Delay & Jitter

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RTT One Way Delay

• Defines based in SR (Sender Report) and RR (Receiver Report) in RTCP

• RTT = TS2 – TS1 – DLSR

• Assumes one way delay as RTT/2

• RTCP occurs every 3 seconds so compensates based on Delta Delay

RTP Analysis

RTP One Way Delay

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VoLTE Event Analysis

RTP Drop – Time out

RTP Drop – BYE

Bluetooth Call - Setup Fail

Bluetooth Call - Drop

Success - CBQ


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No Rx Packets for 10 seconds

Setup Success


RTP Drop – Time Out

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Setup Success

BYE occurs in SIP Packet


RTP Drop - BYE

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HO Point

no wave

RTP Drop - BYE

Accuver VoLTE Solution v.1.4

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