Slide 1 Muhamad Asvial http://www.ee.ui.ac.id/~cicer Quality of Service (QoS)
Slide 1Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Quality of Service (QoS)
Slide 2Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
PerfectionPerfection
Fusing the Best Properties of Today’s Networks onto a Common Lowest Cost
Infrastructure
Mobility of the Mobility of the GSM NetworkGSM Network
Ubiquity/ReliabilitUbiquity/Reliability of the PSTNy of the PSTN
Bandwidth Bandwidth of an of an
Optical Optical NetworkNetwork
Latency Latency Control of an Control of an ATM NetworkATM Network
Operational Operational Ease of EthernetEase of Ethernet
Flexibility of Flexibility of the Internetthe Internet
Security of Security of Financial Financial
Funds Funds TransfersTransfers
Characteristics of the Ideal Network
Slide 3Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Mobility of the GSM NetworkMobility of the GSM Network
Ubiquity/Reliability of the PSTN
Ubiquity/Reliability of the PSTN
Bandwidth of an
Optical Network
Bandwidth of an
Optical Network
Latency Control of an ATM Network
Latency Control of an ATM Network
Operational Ease
of Ethernet
Operational Ease
of Ethernet
Flexibility of the InternetFlexibility of the Internet
Content Richness of Cable/TelevisionContent Richness
of Cable/Television
Security of aPrivate
Network
Security of aPrivate
Network
Fusing The Best Properties of Today’s Networks
Slide 4Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS Definition
EQoS = EUROSCOM QoSEUROSCOM (European Institute for Research and Strategic
Studies in Telecommunications)
the degree of conformance of the service delivered to a user by a provider with an agreement between them (EQoS)
Slide 5Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS: IETF Version
• In its broadest sense, QoS refers to “the ability to ensure the quality of the end user (human) experience”
• This can encompass a huge range of technological and other aspects– Multimedia coding and quality measurement– SLA definition and performance verification– Application behaviour to select QoS– High performance physical and link layers– Packet delivery (primary IETF focus)
Slide 6Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS: ITU – T Version
• Real QoS is end-to-end, as the user sees it• QoS and its various performance aspects are core
competencies of the ITU-T• There are many QoS activities in the ITU-T
Slide 7Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS: Users' concerns
• Today, any technical body in any standardization organization refers to users' QoS requirements.
• Each of these TBs has different purposes:– means to improve the technical QoS– measurement methods of the QoS– definition of QoS service classes
• All of them have in mind the technical quality• Few of them are taking into account the users'
concerns about the QoS
Slide 8Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS: Users' concerns• Service fields
– Provision– Operation– Customer services– Billing– Other services
• Market areas– Voice– Data– Internet access– Private/public networks
Slide 9Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Users' QoS criteria (1/4)
• Provision– Preliminary information – Completion efficiency – Respect of allotted time– Contract clarity– Contract flexibility
Slide 10Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Users' QoS criteria (2/4)
• Operation– Service availability– Coverage (mobile networks)– Unsuccessful call ratio– Set-up swiftness – Absence of dropouts– Speech or data quality– Flow rate or transactions time– Exchange security – Terminal protection
Slide 11Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Users' QoS criteria (3/4)
• Customer services– Swiftness of after-sales service to answer calls– Swiftness to repair– Availability of operator services– Efficiency of help line– Number of call to report fault.
Slide 12Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Users' QoS criteria (4/4)
• Billing– Accuracy (counting and tariff)– Number of claims
• Other services – Directory service availability
• Response time • Relevance of the answers
Slide 13Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Lacks in current standards (1/5)
• Provision– Preliminary information – Completion efficiency– Respect of allotted time– Contract clarity– Contract flexibility
Slide 14Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Lacks in current standards (2/5)
• Operation– Service availability– Coverage (mobile networks)– Unsuccessful call ratio– Set-up swiftness – Absence of dropouts– Speech or data quality– Flow rate or transactions time– Exchange security – Terminal protection
Slide 15Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Lacks in current standards (3/5)
• Customer services– Swiftness of after-sales service to answer calls– Swiftness to repair– Availability of operator services– Efficiency of help line– Number of call to report fault.
Slide 16Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Lacks in current standards (4/5)
• Billing– Accuracy (counting and tariff)– Number of claims
• Other services – Directory service availability
• Response time• Relevance of the answers
Slide 17Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
The Challenge: User’s Perspective
How to better take into account the users' concerns about
QoS regulation and standardizationand how to fill the current gaps
Slide 18Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS Objectives
It’s important to satisfy customer expectations for end-to-end Quality of Service and Reliability
for all types of transactions and services
Performance Parameters
Delay & JitterErrored Packets
Packet LossThroughput
Priority, Restoration
SLAsService Level Agreements
ReliabilityAdequate
Service AvailabilityOver a Specific Period of Time
Slide 19Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Service Level Agreement
Slide 20Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Conceptual Model
Slide 21Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Sample QoS Parameters
Slide 22Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS Parameters
Bandwidth– rate of flow of multimedia data
Latency– time required for the end-to-end transmission of a single
data elementJitter
• variation in latency
Loss rate– the proportion of data elements that can be dropped or
delivered late
*
Slide 23Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS in GPRS (1/4)
• Only “Best Effort” for GPRS (no bit rate guaranteed, no delay guaranteed, etc)
• No notion of “connection” in the Access Network => the flows from all users are “mixed” => Impossibility to guarantee any QoS
Slide 24Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
AccessNetwork
GPRS Core
Network
Terminals
Gb interface
Distinction between flows from different users impossible at
transport level on Gb
“Connections” are known by the CN and the Terminals
QoS in GPRS (2/4) : CN/AN interface in GPRS
Slide 25Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS in GPRS (3/4)
• However, QoS parameters are defined to prioritise the individual incoming packets and to specify if retransmissions are impossible and/or requested
Slide 26Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS in GPRS (4/4)
Name Value Delay class From 1 (short
delay) to 4 (background)
Reliability class From 1 (<= 10-5) to 5 (> 5*10-4)
Peak throughput class From 1 (< 16 kbit/s) to 9 (>= 2 Mbit/s)
Precedence class 1, 2 or 3 Mean throughput class defined but not
used 'yes' Reordering Required
(Information in the SGSN and the GGSN PDP Contexts) 'no'
QoS parameters in GPRSQoS parameters in GPRS
Slide 27Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS in UMTS Rel 99 & 4 (1/3)
• Target: try to guarantee end-to-end QoS in Packet from Rel 5 onwards: combine advantages of Packet -efficient use of radio resources- with the advantages of Circuit -guaranteed QoS.
• Potentially get rid of the Circuit domain in the (very) long term.
• Complex problem involving almost all the network elements.
Slide 28Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS in UMTS Rel 99 & 4 (2/3)
• The end-to-end degradation (including delay) is the sum of the degradations caused by each hop
• The handling of QoS parameters has to be consistent on all different interfaces => involvement of many 3GPP groups
Slide 29Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
AccessNetwork 1
CoreNetwork(s)
User 1 AccessNetwork 2
User 2
End-to-end aspects
Hop-by-hop aspects
QoS in UMTS Rel 99 & 4 (3/3)
Slide 30Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Different links defined
TE MT UTRAN CN IuEDGENODE
CNGateway
TE
UMTS
End-to-End Service
TE/MT LocalBearer Service
UMTS Bearer Service External BearerService
UMTS Bearer Service
Radio Access Bearer Service CN BearerService
BackboneBearer Service
Iu BearerService
Radio BearerService
UTRAFDD/TDD
Service
PhysicalBearer Service
Slide 31Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Distinction between 4 QoS classes
Traffic class Conversationalclass
Streaming class
Interactive class
Background
Example of application
Voice Streaming video
Web browsing
Background download of emails
Fundamental characteristics
- Preserve time relation (variation) between information entities of the stream - Conversational pattern stringent and low delay
- Preserve time relation (variation) between information entities of the stream
- Request response pattern - Preserve payload content
- Destination is not expecting the data within a certain time- Preserve payload content
QoS parameters for UMTS (1/2)
Slide 32Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS parameters for UMTS (2/2)
- Traffic class ('conversational', 'streaming', 'interactive', 'background') Then, according to the traffic class, a given subset of these parameters
applies:• Maximum bitrate (kbps) • Guaranteed bit rate (kbps) • Delivery order (yes or no)• Maximum SDU size (octets) • SDU format information (bits)• SDU error ratio• Residual bit error ratio• Delivery of erroneous SDUs (yes, no, don’t check)• Transfer delay (ms) • Traffic handling priority (1, 2 or 3)• Allocation/Retention priority• Source statistics descriptor (‘speech’/’unknown’)
Slide 33Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Possible values
Traffic class Conversational class Maximum bitrate (kbps) < 2 048 Delivery order Yes/No Maximum SDU size (octets) <=1 502 SDU format information tbd Delivery of erroneous SDUs Yes/No/- Residual BER 5*10-2, 10-2, 5*10-3, 10-3, 10-4, 10-6 SDU error ratio 10-2, 7*10-3, 10-3, 10-4, 10-5 Transfer delay (ms) 100 – maximum value Guaranteed bit rate (kbps) < 2 048 Traffic handling priority Allocation/Retention priority 1,2,3
Extract for “Conversational Class”
Slide 34Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
QoS in the low layers
• In the Core Network:– It is operators' option which of QoS capabilities in IP layer
or QoS capabilities in ATM layer is used. For the IP based backbone, Differentiated Services defined by IETF shall be used. The mapping from UMTS QoS classes to Diffserv codepoints is controlled by the operator.
• For Bearer Service:– For IP based BS, Differentiated Services defined by IETF
shall be used. If operator chooses ATM-SVC as an internal dedicated transport bearer, inter operation with IP based networks will be based on Differentiated Services.
Slide 35Muhamad Asvial
http://www.ee.ui.ac.id/~cicer
Mapping of QoS parameters between layers
• From Application Attributes to UMTS Bearer Service Attributes– This is an operator’s choice.
• From UMTS Bearer Service Attributes to Radio Access Bearer Service Attributes– Rules defined by the standard
• From UMTS Bearer Service Attributes to CN Bearer Service Attributes– This is operator's choice.