w(Level3)-Wcdma Rno Qos in Umts Network-20041217-A-1[1].0

April 11, 2023 By Ying weiminApril 11, 2023 By Ying weimin

QoS in UMTS Network

UMTS QoSUMTS QoS

UMTS QoS conceptQoS requirement on UMTSQoS mechanism in UMTS QoS in UMTS network UTRAN mechanism

CONTENT:

UMTS QoS conceptUMTS QoS concept

Quality of Service (QoS) refers to the collective effect of service performance that determines the degree of satisfaction of the end-user of the service.

Why UMTS QoS is so important -1G cellular system (AMPS) Analog voice/ circuit switch -2G cellular system (GSM) Digital voice/circuit switch -2.5G cellular system (GPRS) Digital data/ packet switch Address QoS issues but not required to implement. -3G cellular system (wcdma) Digital voice/data/ packet switch QoS features are designed in and ready for providing packet multi-medium service. Cellular system can server as “mobile internet”.



UMTS QoS classes(1) :

Conversational class speech, video telephony most delay sensitive Streaming class can tolerate some delay jitter should be minimized

Interactive class web browsing less stringent delay better error rate


UMTS QoS classe(2) :

Background class

Email, downloads

Error rate minimized

Lower priority in scheduling than interactive class

Uses resource only when interactive class don’t need the them


Delay tolerant

Bit error tolerant

background

conversational

streaming

interactive

UMTS QoS classe(3) :


Qos impact on resources

RequiredNetwork

Resources

Delay Delay

RequiredBufferingResources


QoS attibutes(1):Traffic Class:

Conversational , Streaming, Interactive, Background;

Traffic class indicates the type of application for which the UMTS bears is optimized.

Max Bit Rate

Maximum bit rate is defined as maximum number of bits delivered by the UMTS and within a period of time, divided by the duration of the period.

Guaranteed Bit Rate

Guaranteed bit rate is defined as the guaranteed number of bits delivered by the UMTS within a period of time, divided by the duration of the period.


QoS attibutes(2):Delivery Order

Delivery order indicates whether the UMTS bearer service should offer in-sequence SDU delivery or not.

Max SDU Size

Maximum SDU size indicates the maximum allowed size of an SDU.

Transfer Delay

Transfer delay is defined as the maximum delay for the 95th percentile of the distribution of delay for all delivered SDUs during the lifetime of the bearer service.


QoS attibutes(3):SDU Format Information

List of possible exact sizes of SDUs. SDU Error Ratio

SDU error is defined as the fraction of lost or erroneous SDUs.

Residual Bit Error Ratio

Residual bit error ratio indicates the undetected bit error ratio in the delivered SDUs if error detection has been requested, otherwise it indicates the bit error ratio (BER) in the delivered SDUs.


QoS attibutes(4):Delivery of Erroneous SDUs

Indicates whether SDUs detected as erroneous shall be delivered or discarded Traffic Handle Priority

Specifies the relative importance for handling of all SDUs belonging to the UMTS bearer compared to the SDUs of other bearers.

Allocation/Retention Priority Specifies the relative importance compared to other

UMTS bearers for allocation and retention of the UMTS bearer. The Allocation/Retention Priority attribute is a subscription attribute which is not negotiated from the mobile terminal.


Call Setup Quality:― Accessibility

• No coverage• Network equipment down• Cell barred• Generic call setup failure (signaling or other

reason)― Call Blocking Probability

• A blocking event occurs when the network admission controller denies the user’s access attempt.

― Call Setup Delay• The call setup delay is measured from the time

instant when the user places an access request, or query, to the instant when the user data exchange become possible with the other end of the call entity.


Call Quality ( Key parameters are covered by QoS Atributes )― Acceptable Delay Variation

• This is used to define how much jitter the application can tolerate, beyond which the packet is treated as being lost.

― Acceptable Transport Service Interruption Duration

• This defines to what degree an interrupt to transport services is regarded as acceptable, provided it happens only occasionally during a call.

― Call Drop Probability

• A call drop is defined as an event where the communication connection has

UMTS QoSUMTS QoS

UMTS QoS conceptQoS requirement on UMTSQoS mechanism in UMTS QoS in UMTS network UTRAN mechanism

CONTENT:

QoS requirement on UMTSQoS requirement on UMTS

Errortolerant

Errorintolerant

Conversational(delay <<1 sec)

Interactive(delay approx.1 sec)

Streaming(delay <10 sec)

Background(delay >10 sec)

Conversationalvoice and video

Voice messagingStreaming audio

and videoFax

E-mail arrivalnotificationFTP, still image,

paging

E-commerce,WWW browsing,Telnet,

interactive games

Conversational voice and video

Voice messaging Streaming audio

and video Fax

E-mail arrival notification FTP, still image,

paging

E-commerce, WWW browsing, Telnet,

interactive games


Traffic class

conversational class

Streaming class

Interactive class

Background class

Maximum bit rate (kbps)

< 2048 < 2048 < 2048 < 2048

Delivery order Yes/No Yes/No Yes/No Yes/No

Maximum SDU size <=1500 <=1500 <=1500 <=1500

Delivery of erroneous SDU

Yes/No Yes/No Yes/No Yes/No

Residual BER 5*10-2 – 10-6 5*10-2 – 10-6 4*10-3 – 6*10-8 4*10-3 – 6*10-9

SDU error ratio 10-2 – 10-5 10-1 – 10-5 10-3 – 10-6 10-3 – 10-6

Transfer delay100ms upto FFS

250ms upto FFS 　　

Guaranteed bit rate < 2048 < 2048 　　Traffic handling priority

　　 1,2,3 　

Allocation and retention priority

1,2,3 1,2,3 1,2,3 1,2,3

QoS attributers (Profile) :


QoS example(1):

AMR speech codec payloadBit rate: 4,75 - 12,2 kbit/sDelay: end-to-end delay not to exceed 300ms BER: < 10-3

FER < 1 % (with graceful degradation for higher erasure rates)


QoS example(2):

Videophone carries both video and audio and intended for use in a conversational environment. As such, in principle the same delay requirements as for conversational voice will apply, In fact, due to the long delays incurred in even the latest video codecs, it will be difficult to meet these requirements.

Once again, the human eye is tolerant to some loss of information, so that some degree of packet loss is acceptable depending on the specific video coder and amount of error protection used. It is expected that the latest video codecs will provide acceptable video quality with frame erasure rates up to about 1%.

UMTS QoSUMTS QoS

UMTS QoS conceptQoS requirement on UMTSQoS mechanism in UMTS QoS in UMTS network QoS mechanism in UTRAN

CONTENT:

QoS in UMTSQoS in UMTS

Subscriber#1

PDP context #3PDP context #2

PDP context #1-----------------

PDP context IDAPN Qos Profile

RNC SGSN GGSNUEHLR

UMTS QOS Classes :

Conversational class Steaming classInteractive class

Background class

QoS profile configuration:

QoS in UMTS networkQoS in UMTS network

PDP context

PDP context

1

2

3

3’

4’

4

5’

5

5

5’

Attach

PDP Context Activation

Subscribe time

IP Qos mapping & establishment

RAB establishment

QoS map to radio access bearers

PDP modification

IP-QoS remapping if required

RL/RB estabilishment

RRM to map QoS to channals

RNC SGSN GGSNUE HLR

General idea:


Subscriber#1

PDP context #3PDP context #2

PDP context #1-----------------

PDP context IDAPN Qos Profile

SGSN GGSNUE HLR

Subscriber#1

PDP context #3

PDP context #2

PDP context #1-----------------

PDP context IDAPN PDP address Qos Profile

1.Attach Req2.Insert Sub.Data

4.Attach Acpt

3.Insert sub. Data Ack

Subscribers attach to net work


Subscriber#1

PDP context #3

PDP context #2

PDP context #1-----------------

PDP context IDAPN PDP address Qos Profile

SGSN GGSNUE

Host RNC

1 Activate PDP Context Req (QoS Req)

4 RAB Setup (QoS Neg)

5 RL/RB Establishment

6 RAB Est.Rsp

2 Activate PDP Context Req (QoS Neq)

3 Activate PDP Context Rsp (QoS Neq)

SGSN may restrict requested QoSGiven its capabilities, load and the

Subscribed QoS

SGSN selects radio priority based on QoS negotiated

GGSN may further restrict the QoS given its capabilities a

nd load

RRM Algorithms

Admission control and QoS session establishment:


Subscriber#1

PDP context #3

PDP context #2

PDP context #1-----------------

PDP context IDAPN PDP address Qos Profile SGSN GGSN

UEHost RNC

9 Active PDP context Acpt (QoS Neg)

7 Update PDP Context Req (QoS Neq)

8 Update PDP Context Rsp (QoS Neq)

In case QoS was downgraded by RNC , SGSN may inform GGSN about the new QoS

MS either accepts the QoS or deactivates the PDP context

Admission control and QoS session establishment:


New SGSN Old SGSNUE

GGSN RNC

5 RA Update Acpt / Complete

1 RA Update Req

4 Update PDP Context Rsp (QoS Neq)

2 SGSN Context Req/Ack.(QoS profile)

3 Update PDP Context Req (QoS Neq)

Inter SGSN RA update:


Old SGSN New SGSNUE GGSN Target RNC

6 Relocation command

1 Relocation required (Source ID, target ID, SRNC-TRNC container)

4 Relocation Req ack ( RABS ok, RABS fail)

2 Forward Rel. Req( PDP Context)

3 Relocation Req (SRNC-TRNC container,RABS)

Serving RNC Relocation:

Source RNC

5 Forward Rel. Rsp

7 Relocation commit

8 Relocation of data

Establishment of RABs, RBs


Old SGSN New SGSNUE GGSN Target RNC

15 Iu release command

9 Relocation detect

12 Relocation Comlete

10 Update PDP context Req(Qos.neq)

Source RNC

13 Forward Rel. comp

11 Update PDP context Rsp

14 Forward Rel. comp.ack

16 Iu release complete

Serving RNC Relocation:

UMTS QoSUMTS QoS

UMTS QoS conceptQoS requirement on UMTSQoS mechanism in UMTS QoS in UMTS network

QoS mechanism in UTRAN

CONTENT:

QoS mechanism in UTRANQoS mechanism in UTRAN

PHY

MAC

RLC

RRC

PDCP

BMC

L1

L2

L3

Signaling Radio Bearers

User Plane Radio Bearers

Transport channel

Logical channel

Radio interface protocals:


PDCP

Packet data convergence protocol :Header compression and decompression of IP data

stream.Maintenance of PDCP sequence number for radio

bearers that are configured to support lossless SRNS relocation.


RLC

RLC mode Transparent mode : no overhead is added to higher layer

data. Unacknowledged mode: no retransmission protocol is

used and data delivery in not guaranteed. Acknowledged mode: Automatic repeat request (ARQ)

mechanism is used for error correction.RLC function: segmentation and reassemble ; ARQ error correction ciphering


TFCS

TrCH#1

TFS

TF

TrCH#2TrCH#3TrCH#4

TFC

MAC function:

• Priority handling between different data flow is done by MAC;

• Transport Formation Selection , It control transport format for each flow.


Prameters valueRadio resource

mapping

Maximum bit rate (kbps) 128 Spreading factor =16

Maximum SDU size 1500 map to transport format

Residual BER 10-6 1/3 Turbo codec,Acknowledged RLC

Delivery of erroneous SDU No RLC configuration

Transfer delay Na interlever 10-80 ms

Guaranteed bit rate 64 Spreading factor =64

SDU error ratio 1%Set appropriate threshold

for open loop power control

delivery order yes RLC configuration

Mapping from QoS attributers to radio resource

w(Level3)-Wcdma Rno Qos in Umts Network-20041217-A-1[1].0

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