ETSI TR 102 805-1 V1.1.1 (2009-11)

User Group; End-to-end QoS management at the Network Interfaces; Part 1: User's E2E QoS - Analysis of the NGN interfaces (user case)

DTR/USER-00029-1

General Information

• Status: Published
• Publication Date: 19-Nov-2009
• Technical Committee: USER - User Group
• Current Stage: 12 - Completion
• Due Date: 19-Nov-2009
• Completion Date: 20-Nov-2009

Standards Content (Sample)

Technical Report
User Group;
End-to-end QoS management at the Network Interfaces;
Part 1: User's E2E QoS -
Analysis of the NGN interfaces (user case)

2 ETSI TR 102 805-1 V1.1.1 (2009-11)

Reference
DTR/USER-00029-1
Keywords
control, interface, interworking, QoS, signalling
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3 ETSI TR 102 805-1 V1.1.1 (2009-11)
Contents
Intellectual Property Rights . 4
Foreword . 4
Introduction . 4
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 8
4 User QoS requirements information . 10
4.1 User case description . 10
4.2 User QoS . 13
4.2.1 QoS assessment . 13
4.2.2 Application to the User case . 13
5 Identification of InterWorking unit (IWU) . 15
5.1 Scenario 1: User mobility in mobile network . 16
5.2 Scenario 2: User mobility between mobile and fixed network, and service mobility . 17
5.3 Scenario 3: Terminal mobility in mobile network . 18
5.4 QoS framework in 3GPP and ETSI TISPAN . 19
5.4.1 QoS framework in ETSI TISPAN . 19
5.4.2 QoS framework in 3GPP . 20
6 QoS and E2E user-centric session . 21
6.1 Sequence diagram in ETSI TISPAN based architecture . 21
6.2 Sequence diagram in 3GPP based architecture . 25
7 Conclusion . 26
Annex A: Mapping of services and QoS requirements . 27
A.1 ITU-T Recommendation Y.1541 QoS class . . 32
A.2 UMTS Classes of Service (CoS) . 32
A.2.1 Conversational class . 33
A.2.2 Streaming class . 33
A.2.3 Interactive class . 33
A.2.4 Background class . 34
A.2.5 Summary and QoS Information processing . 34
A.3 ITU-T Recommendation G.1010 QoS categories . . 34
A.3.1 Key parameters impacting the user . 35
A.3.1.1 Delay . 35
A.3.1.2 Delay variation . 35
A.3.1.3 Information loss . 35
A.3.2 Application . 35
A.4 Per Hop Behaviour parameters (DIFFSERV) . 36
A.4.1 Assured Forwarding . 36
A.4.2 Best Effort . 36
A.4.3 Expedited Forwarding . 36
A.5 QoS criteria depending classes (INTRADIFF) . 37
Annex B: Bibliography . 38
History . 39

ETSI
4 ETSI TR 102 805-1 V1.1.1 (2009-11)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI User Group (USER).
The present document is part 1 of a multi-part deliverable covering the End-to-end QoS management at the Network
Interfaces, as identified below:
Part 1: "User's E2E QoS - Analysis of the NGN interfaces (user case)";
Part 2: "Control and management planes solution - QoS continuity";
Part 3: "QoS informational structure".
Introduction
In all parts of this multi-part deliverable, the Quality of Service (QoS) should be seen from the end-user standpoint. This
means that the QoS assessment should be performed with regards to the users' requirements. Telecommunication world
evolves and is now user centric in opposition to system centric (behaviours are constrained by the system) and network
centric (behaviours are constrained by the network).
User-centric requirements are expressed through user-related information, such as QoS parameters and end-user's
preferences. The QoS commitments of the related providers should match that of the end-user's requirements and can be
defined in his contract as unilateral commitments or with a Service Level Agreement negotiated with the customer
(generally corporate end-user).
As networks are evolving towards NGN (Next Generation Network), the network environment is becoming more and
more complex. Heterogeneity and mobility are two specific characteristics in NGN that take into account end-user
terminals, access networks, core networks and services. Mobility allows end-users to communicate regardless of
location, device used, access mode or network across multiple spatial domains.

Figure 1: NGN context
ETSI
5 ETSI TR 102 805-1 V1.1.1 (2009-11)
The end-user wishes to choose any terminal or any access as a mean to use any service in a heterogeneous environment.
Meanwhile, the end-user expects to have a continuous comprehensive service throughout the whole session while
moving (terminal mobility) or changing terminal (user mobility). During this session, service connectivity is considered
as a composition of elements in each layer (User, Terminal, Network and Service).
The solution today is located at the intersection of the three domains defined in [i.9]: User-centric, mobility and
heterogeneity as shown in figure 1. As networks become more and more complex and new services emerge
continuously, the requirement for an end-to-end (E2E) QoS for the end-user is growing.
Taking all the above into consideration, the goal is now to identify at which point end-users could and should enter their
choices and preferences, etc. in the future network. These interactions have been taken into consideration in the user
case. That is why in clause 4, all the scenarios representing and concerning the NGN context are identified as well as
the QoS aspects from the end-user's viewpoint with a particular attention to the sensitivity to QoS criteria of the services
used. In clause 5, the components, which play a key role in the interactions with the end-users, are delineated and
identified. The functional procedures of the scenarios are described in order to define the interworking unit such as AF,
RACS, PCRF, and GGSN. The transfer of the QoS information between networks, included in signalling or managing
messages, is analyzed in clause 6. In clause 7, the conclusion introduces in TR 102 805-2 [i.3].
ETSI
6 ETSI TR 102 805-1 V1.1.1 (2009-11)
1 Scope
The present document provides an analysis of the NGN interfaces by using a user case designed to show how the QoS
could be handled in the NGN context to ensure end-to-end QoS from the end-user's viewpoint.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
Not applicable.
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
[i.1] ITU-T Recommendation G.1010 (11/2001): "End-user multimedia QoS categories".
[i.2] ITU-T Recommendation Y.1541 (02/2006): "Network performance objectives for IP-based
services".
[i.3] ETSI TR 102 805-2 (V1.1.1): "User Group; End-to-end QoS management at the Network
Interfaces; Part 2: Control and management planes solution - QoS continuity".
[i.4] ETSI EG 202 009-1: "User Group; Quality of Telecom Services; Part 1: Methodology for
identification of parameters relevant to the Users".
[i.5] ETSI TS 102 464 (V1.1.1): "Satellite Earth Stations and Systems (SES); Broadband Satellite
Multimedia (BSM); Interworking with DiffServ Qos".
[i.6] ETSI TS 123 107 (2009-01): "Digital cellular telecommunications system (Phase 2+); Universal
Mobile Telecommunications System (UMTS); LTE; Quality of Service (QoS) concept and
architecture (3GPP TS 23.107 version 8.0.0 Release 8)".
ETSI
7 ETSI TR 102 805-1 V1.1.1 (2009-11)
[i.7] ETSI TS 129 207 (2005-09): "Digital cellular telecommunications system (Phase 2+); Universal
Mobile Telecommunications System (UMTS);Policy control over Go interface (3GPP TS 29.207
version 6.5.0 Release 6)".
[i.8] ETSI TS 101 329-2 (V2.1.3): "Telecommunications and Internet Protocol Harmonization Over
Networks (TIPHON) Release 3;End-to-end Quality of Service in TIPHON systems;
Part 2: Definition of speech Quality of Service (QoS) classes".
[i.9] ETSI STF 360 report (January 2009): "Analysis of current E2E QoS standardization state".
[i.10] IETF RFC 1633: "Integrated Services in the Internet Architecture: an Overview".
[i.11] IETF RFC 2474: "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6
Headers".
[i.12] IETF RFC 2475: "Architecture for Differentiated Services".
[i.13] ITU Study Group 19 - Contribution 25 (2007): "Considerations of horizontal handover and vertical
handover".
[i.14] ETSI ES 282 003: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Resource and Admission Control Sub-System (RACS):
Functional Architecture".
[i.15] ETSI ES 283 003: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IP Multimedia Call Control Protocol based on Session
Initiation Protocol (SIP) and Session Description Protocol (SDP) Stage 3 [3GPP TS 24.229
[Release 7], modified]".
[i.16] IETF RFC 854: "Telnet Protocol Specification".
[i.17] ETSI TR 102 805-3: "User Group; End-to-end QoS management at the Network Interfaces;
Part 3: QoS informational structure".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
AmbientGrid: information inference (AmbientGrid) based on the profiles' matching, to structure with grid covering the
needed end-user centric environment
class of service: way of traffic management in the network by grouping similar types of traffic and treating them as its
own level of service priority
DiffServ networks: classify packets into one of a small number of aggregated flows or 'classes', based on the DiffServ
codepoint (DSCP) in the packet's IP header
NOTE: This is known as behaviour aggregate (BA) classification (RFC 2475 [i.12]). At each DiffServ router,
packets are subjected to a 'per-hop behaviour' (PHB), which is invoked by the DSCP (RFC 2474 [i.11]).
equipment: any material with its related OS, through its CPU and memory, which contributes to the end-to-end QoS
horizontal handover: handover within homogeneous access networks
NOTE 1: Generally it is referred to as the Intra-AN handover.
NOTE 2: ITU Study Group 19 - Contribution 25: Considerations of horizontal handover and vertical handover,
2007 [i.13].
infosphere: decisional knowledge base managing, in the real time, all the personalization and ambient environment
information
ETSI
8 ETSI TR 102 805-1 V1.1.1 (2009-11)
IntServ (integrated services architecture): set of extensions to the traditional best effort model of the Internet with the
goal of allowing end-to-end QOS to be provided to applications
NOTE 1: One of the key components of the architecture is a set of service; the current set of services consists of the
controlled load and guaranteed services. The architecture assumes that some explicit setup mechanism is
used to convey information to routers so that they can provide requested services to flows that require
them. While RSVP is the most widely known example of such a setup mechanism, the IntServ
architecture is designed to accommodate other mechanisms.
NOTE 2: See RFC 1633 [i.10].
multi-homing: end-user's services can be provided by more than one service or network provider
network mobility: network's ability, where a set of fixed or mobile nodes are networked to each other, to change, as a
unit, its point of attachment to the corresponding network upon the network's movement itself
Per-Hop Behaviour (PHB): externally observable forwarding treatment applied at a differentiated services-compliant
node to a behaviour aggregate
NOTE: See TS 102 464 [i.5].
policy control: adaptation and configuration of QoS according to particular goals dependent of user, network operator
and service provider
QoS Classification: definition of class priority for QoS by describing traffic condition or performance parameters
QoS handover: ensures QoS state establishes when vertical/horizontal handover occurs
QoS Interworking: ensures the transfer of all different types of packet data with different QoS parameters in
heterogeneous environment whenever the ANs and CNs are of different releases and types by mapping the QoS
attributes
service mobility: ability to consistently provide services to the end-user, to maintain the expected QoS, at the system's
initiative, regardless of the end-user's location, terminals, or networks.
NOTE: To maintain the service continuity, the session mobility is used.
session mobility: ability to keep the continuity of a service regardless the mobility of the terminal, of the access
network, of the core network or of any service components as well as the Service Provider
terminal mobility: end-user uses his equipment to move across the same or different networks while having access to
the same set of subscribed services
user mobility: ability for a subscriber to move to different physical locations and be able to use one or more devices
connected to one or more access networks to gain access to their services without interruption
user-centric session: period of communication between one end-user and another or other end-users or servers
characterized by a starting time and a termination time, including setting up the relation of the end-user equipment,
access network, core network and services invoked during this period
userware: innovative user centric middleware (Userware) enhancing the seamless feasibility along with the location
and activity, personalization and end-user's ambient contexts
vertical handover: handover across heterogeneous access networks. Generally, it is referred to as the Inter-AN
handover
NOTE: ITU Study Group 19 - Contribution 25: Considerations of horizontal handover and vertical handover,
2007 [i.13].
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
3GPP The 3rd Generation Partnership Project
AA Authentication & Authorization
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9 ETSI TR 102 805-1 V1.1.1 (2009-11)
AAA Authentication, Authorization, and Accounting
AAR AA-Request
ABG Access Border Gateway
ACK Acknowledgement
AF Application Function
AMF Access Management Function
AN Access Network
A-RACF Access Resource and Admission Control Function
AS Application Server
CAC Connection Admission Control
CCA Credit Control Answer
C-BGF Core Border Gateway Function
CLF Connectivity session and repository Location Function
CNG Customer Network Gateway
CODEC COder / DECoder
CPE Customer Premises Equipment
CSCF Call Session Control Function
DHCP Dynamic Host Configuration Protocol
DSCP Differentiated Service Code Point
DiffServ Differentiated services (IETF)
E2E QoS End-to-End QoS
ETSI European Telecommunications Standards Institute
FIFO First In First Out (queue)
GGSN Gateway GPRS Service Node
GPRS General Packet Radio Service
GTP GPRS Tunnelling Protocol
GW Gateway
HSS Home Subscriber Server
I-BGF Interconnection Border Gateway Function
I/CBG Interconnection/Core Border Gateway
IETF Internet Engineering Task Force
IMEI International Mobile Equipment Identifier
IMEISV IMEI Software Version
IMPI IP Multimedia Private Identity
IMPU IP Multimedia PUblic identity
IMS IP based Multimedia Subsystem
INTRADIFF INTRANET-DIFFSERV (an INRIA project)
IntServ Integrated Services (IETF)
IP-CAN IP Connectivity Access Network
IPDV IP packet Delay Variation
IPER IP packet Error Ratio
IPLR IP packet Loss Ratio
IPRR IP Packet Reordering Ratio
IPTD IP packet Transfer Delay
ITU-T International Telecommunication Union - Telecommunication standardization sector
IWU InterWorking Unit
MS GSM Mobile Station
NACF Network Access Configuration Function
NASS Network Attachment Subsystem
NAT Network Address Translation
NGN Next Generation Network
PC Personal Computer
PCEF Policy Enforcement Point
PCRF Policy and Charging Rule Function
P-CSCF Proxy CSCF
PDA Personal Digital Assistant
PDP Pack Data Protocol
PHB Per Hop Behaviour
PPP Point of Presence Protocol
QoS Quality of Service
RACS Resource and Admission Control Subsystem
RCEF Resource Control Enforcement Function
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10 ETSI TR 102 805-1 V1.1.1 (2009-11)
RSVP Resource ReserVation Protocol
SAA Server Assignment Answer
SAR Server Assignment Request
SD Service Data
SDL Session Description Language
SDP Session Description Protocol
SGSN Serving GPRS Support Node
SIP Session Initiation Protocol
SP Service Provider
SPDF Service Policy Decision Function
TCP Transmission Control Protocol
TISPAN Telecommunications and Internet converged Services and Protocols for Advanced Networking
UAAF User Access Authorization Function
UE User Equipment
UMTS Universal Mobile Telecommunications Systems
UPSF User Profile Server Function
4 User QoS requirements information
In this clause, based on a user case (clause 4.1) highlighting the specificities of the NGN context, the QoS information
(clause 4.2) which are relevant to the end-user will be identified.
4.1 User case description
The user case described below is that of an end-user which needs to stay connected both at home and while going and
getting at work. This user case clearly highlights the specificities of the NGN context. It shows how the end-user goes
from end-user mobility to terminal mobility, changing services on heterogeneous networks. Such scenarios details are
described below figure 2.
Figure 2: User case
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11 ETSI TR 102 805-1 V1.1.1 (2009-11)
The Services used by the end-user in the user case are:
• AS12: Video Conference.
• AS31: Telephony Service.
• AS51: Web Services.
• AS22: Video Broadcast Service.
• AS43: Text to Voice Service.
Description of the user case:
While still at home the end-user Tom starts his PC (QoS1) at 8h30 in the morning and engages in a Video Conference
service AS12 (Service 1 for a QoS2) provided by the service provider SP1. Tom uses his home network environment
and accesses to the service through an Access Network AN1, which is a mobile GPRS access.
Before leaving his home, Tom switches terminals (User Mobility), leaving his PC for his PDA (QoS2), keeping both the
same home network environment and Access Network AN1. Tom can still access his services though the same opened
session, while keeping his predefined preferences.
On his way to work (Terminal Mobility), Tom starts another Video Conference service AS12 provided by the same
Service Provider SP1 than before, but using another Access Network AN2 (Vertical Handover).
At this point, Tom, as a pedestrian, prefers to receive his message in vocal mode rather than in text mode, by accessing
the Text to Voice AS43 (Service 4 for a QoS3) provided by the same Service Provider SP1through the same Access
Network AN2.
When arriving at work, Tom's PDA is still attached to the same Access Network AN2 but has changed his Access Point
(Horizontal Handover). Tom decides to end both his Video Conference and listening to his messages.
At work, Tom changes his terminal for another one (User Mobility), switching from his PDA to his laptop.
The laptop is connected to another Access Network AN3 than the one previously used for the PDA, through which Tom
is now able to access different services provided by another Service Provider SP2 (Service mobility): web service AS51
(Service 5 for a QoS1), Telephony Service AS31 (Service 3 for a QoS1) and Video broadcast Service AS22 (Service 2
for a QoS2).
• At 11AM, Tom closes the session, which he opened at home at 8h30AM.
ETSI
12 ETSI TR 102 805-1 V1.1.1 (2009-11)
Table 1: User case scenario detail
Private NW Application
End- Transport
Mobility (User/ Access Network Server
user (IP Network)
corporate) (ASxx)
PC
(GPRS) N.A Video conf
(QoS1) AS12
GGSN N.A x N.A SP1
PDA
(GPRS) N.A
(QoS2)
Video conf
AS12+
PDA N.A GGSN N.A x N.A SP1
Text to voice
AS43
Web service
AS 51+
Telephony
PC CPE IP Edge CBG x CBG service AS31+ SP2
Video broadcast
service
AS22
Video conf
N.A GGSN N.A x N.A SP1
AS12
Video conf
AS12+
N.A N.A x N.A SP1
Text to voice
AS43
Video conf
AS12+
N.A GGSN N.A x N.A SP1
Text to voice
AS43
Video conf
AS12+
N.A GGSN N.A x N.A Text to voice SP1
AS 43
(QoS6)
Web service
AS 51+
Telephony
CPE IP Edge CBG x CBG service AS31+ SP2
Video broadcast
service
AS22
CPE: Customer Premise Equipment.

ETSI
Service Mobility Terminal Mobility
User Mobility
(Session mobility) (User moves, terminal the same)
(User changes terminal)
Scenario 2 Scenario 3
At work At home
At work At work Outside At home
Scenario 2 Scenario 1
Laptop PDA PDA Terminal SIP
CPE
SGSN
SGSN Access NW
ABG (ANE2) SGSN SGSN ABG SGSN
(ANE2) SGSN (ANE1) Edge
(Vertical HO) (Horizontal (ANE2) (ANE1) (Vertical HO) (ANE2)
(Horizontal HO) (ANEx)
HO)
IPCAN Broadband PDP context PDP context
PDP IPCAN Broadband PDP PDP Access NW:
(Vertical HO) (Horizontal HO) (Horizontal PDP context
context (Vertical HO) (QoS3) context context IPCAN
(QoS5) (QoS4) HO) (QoS4)
Access IP
Edge
(access
network) side
Backbone
Server side
Service provider
(SPx)
13 ETSI TR 102 805-1 V1.1.1 (2009-11)
Table 1 describes the different steps, which the end-user goes through technically, while experiencing User Mobility,
Terminal Mobility or Service Mobility (Session Mobility), all of which are done during a single session.
4.2 User QoS
Having defined the QoS assessment criteria (clause 4.2.1), each will be applied to the user case described previously
(clause 4.2.2).
4.2.1 QoS assessment
According to the description given in EG 202 009-1 [i.4], the following set of eight QoS criteria is needed for a
comprehensive QoS appraisal:
• Availability, Fidelity/Accuracy, Speed, Capability, Reliability, Flexibility, Usability and Security.
• Each of these criteria should be expressed in quantifiable and measurable parameters.
Nevertheless, the aim of the present document is to focus on a method, which will ensure an End-to End QoS. This QoS
should depend not only on the network performance but also on the equipment and applicative components, which are
co-operating to achieve the End-to-End QoS. A QoS model applicable to these three actors (network, equipment, and
applicative components) will enable the aggregation of the End-to-End QoS.
Among the eight criteria listed above, only four are essential to describe the behaviour of the service: availability,
fidelity/accuracy, speed and capability, all of which will be taken into consideration in this multi-part deliverable.
However, how the information relates to the handling of the whole set of QoS criteria is out the scope of the present
document. To achieve a QoS model applicable to all three actors, the speed criterion is evaluated looking at both the
delay and delay variation and fidelity via information loss.
In addition, a detailed description of the application (function / service, components, etc.) being crucial to ensure an
efficient QoS management, the category of service as defined in [i.1] to which a particular service belongs to will be
identified. Since some services may contain several components, each of them often having different QoS requirements,
a component by component handling of the QoS would be more efficient as long as technology allows it. However, this
is not currently always the case and the following tables should be updated as technology progresses.
A mapping between the services' flows requirements and the network classes of service is provided in annex A.
4.2.2 Application to the User case
As explained earlier, table 2 provides a view of the sensitivity to QoS criteria of the services used in the user case
scenario to the QoS parameters related to the availability, fidelity/accuracy, speed and capability criteria. This
sensitivity is mapped in the classes of services defined in [i.1], [i.2], [i.6], PHB and INTRADIFF (QoS sensitivity
dependent classes).
The table listed bellow highlights management and signalling services which are not mentioned in the user case (AAA
bearer for instance) but which are important in the end-to-end QoS.
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14 ETSI TR 102 805-1 V1.1.1 (2009-11)
Table 2: End-to-end QoS service requirements user case services
(table of sensitivity to four QoS criteria)
Sensitivity to QoS criteria
Authentication,
Authorisation Data < 250 ms Zero
session
Signalling Data < 250 ms Zero
EI
Video < 150 ms PLR
Video Tele-
< 1 %
Conferencing
service
(VTC):
ET
AS12
Audio < 150 ms PLR
< 3 %
Signalling Data < 250 ms Zero
Text to
voice Audio
AS 43
Signalling Data < 250 ms Zero
Web < 2 s/page
service Data (< 4 s/page Zero
AS 51 acceptable)
Video ET
broadcast Video < 10 s PLR
AS 22
< 1 %
ETSI
Service
Medium
Delay
Delay
< 1 ms U U < 1 ms U < 1 ms U U U
variation
Fidelity
(Information
loss)
VBW DBW DBW
16 kbit/s to DBW DBW 4 kbit/s to DBW DBW 16 kbit/s to DBW VBW Capacity
384 kbit/s 32 kbit/s 384 kbit/s
UAT UAI UAI UAI UAT UAI UAI Availability
QoS class
Class 3 Class 3 Class 3 Class 0 Class 3 Class 3
Y.1541
CoS
Streaming Interactive Interactive Convers. Interactive Interactive Interactive
UMTS
ET EI EI EI ET EI EI QoS category

Timely Interactive Interactive Interactive Interactive Interactive Interactive G1010
PHB
AF3.2 AF 3.1 AF4 AF4 EF AF1.2 AF4 AF4
(DIFFSERV)
QoS sensitive
CoS 2 CoS 5.1 CoS 4 CoS 4 CoS 6.0 CoS 6.2 CoS 4 CoS 4.1
classes
(INTRADIFF)
15 ETSI TR 102 805-1 V1.1.1 (2009-11)
Sensitivity to QoS criteria
Telephony
ET
service Audio < 150 ms PLR
AS31 < 3 %
NOTE 1: DBW: Dedicated Bandwidth
ET: Error Tolerant
EI: Error Intolerant
PHB Per Hop Behaviour
PLR: Packet Loss Rate
U: Unspecified
UAI: UnAvailability Intolerant
UAT: UnAvailability Tolerant
VBW: Variable Bandwidth
NOTE 2: Per Hop Behaviour parameters:
AF: Assured Forwarding
BE: Best Effort
EF: Expedited Forwarding
5 Identification of InterWorking unit (IWU)
The study of the user case example highlights the three scenarios, which represent the different situations in the NGN
context:
• User mobility in mobile network.
• User mobility between mobile and fixed networks (vertical handover), and session mobility.
• Terminal mobility in mobile network (horizontal handover).
These scenarios are used to identify the interworking units and their related interfaces in an application session,
establishing between the end-user equipment and the IP multimedia subsystem which is setup by an application level
session (established using SIP before the use of the service) and which requires one or more QoS related resource
reservations to take place in a bearer session ES 282 003 [i.14]. For GPRS, the information about the end-user
equipment (e.g. IMEISV), negotiated QoS, SGSN Address, SGSN country and network codes etc. for the bearer session
are provided in the PDP context (PDP session). For the fixed access network, the QoS and end-user related information
are provided for the connectivity session.
When changes of QoS appear, due to User, Terminal or Service Mobility, requiring to adapt the QoS in a mobility and
heterogeneity environment, each actor (network, equipment, and applicative components) has a role to play. The roles,
which are of interest are: the initiator, the decider and the executor. Each role is identified for each scenario for the
analysis of the end-to-end QoS.
• Initiator is the entity (user, network or Application Server) which notices the change and informs the decider.
• Decider is the entity which makes the decision according to its responsibilities.
• Executor is the entity which performs the related necessary actions.
For the QoS adaptation, the fulfilment of the functional procedures of the QoS control is also described in the 3GPP and
ETSI TISPAN architecture.
ETSI
Service
Medium
Delay
Delay
< 1 ms
variation
Fidelity
(Information
loss)
DBW Capacity
UAT Availability
QoS class
Class 0
Y.1541
CoS
Convers.
UMTS
ET QoS category
Interactive G1010
PHB
EF
(DIFFSERV)
QoS sensitive
CoS 6.0
classes
(INTRADIFF)
16 ETSI TR 102 805-1 V1.1.1 (2009-11)
5.1 Scenario 1: User mobility in mobile network
Figure 3 illustrates the scenario of end-user mobility in GPRS based mobile access network. The most important logical
interfaces required for the interworking of access networks with the IMS core network are drawn with dotted lines.

Figure 3: Scenario 1 User mobility
In GPRS based mobile network, the end-user switches from his PC to his PDA within the opened session. This change
results in altering the QoS parameters. In response to such QoS change, one new PDP context for the new QoS
parameters may be active. The SGSN or the GGSN could initiate this procedure for updating the corresponding PDP
session (as figure 3 shows, from PDP context 1 to PDP context 2) under the control of IMS. The end-user's terminal is
aware of an Access Point Name for which the DNS function provides the address of a GGSN.
In this scenario, the initiator is the user's terminal; the decider and executor for initializing the new PDP context are
located in the access network. The related interworking units are:
1) Bearer entities: SGSN and GGSN. They are responsible for establishing the PDP context of the application
with a well defined QoS. The GGSN receives a PDP context activation request from the MS containing
parameters of the requested QoS .The GGSN creates a GTP tunnel to route IP packet between SGSN and
GGSN.
2) IMS core entities P-CSCF, I-CSCF, S-CSCF. These three entities are responsible for controlling the
application session. The P-CSCF receive a SIP request for establishing a session with the QoS parameters
defined in the message SDP, After the negotiation with the AS through the S-CSCF, the P-CSCF sends the
request to the sub layer responsible for access control (CAC) and resources reservation.
3) IMS policy control entity: PCRF. The main function of the PCRF is to control the QoS of the network. It
composed of policy control decision function and flow based charging control functionalities, providing
network control regarding the QoS requested by the service.
The session control protocol-SIP is used between the end-user's terminal and CSCFs (blue dotted line in the figure 3). It
can transmit QoS parameters contained in the SDP field.
Among these SIP-based interface, the Gm interface implements the signalling communication between the IMS user
and the IMS core network by performing the end-user registration and Service request.
The Mw interface implements the signalling communication between the CSCFs for handling end-users' data.
ETSI
17 ETSI TR 102 805-1 V1.1.1 (2009-11)
The ISC interface is used for transferring information pertinent to the terminal capabilities, end-user registration state
and service characteristics between the AS and the S-CSCF.
The red dotted lines in the figure 3 show diameter protocol based interfaces which are related to policy control from the
AF to bearer session (Rx+ and Gx+ interfaces) and end-user data solicitation from subscriber's database (S-CSCF
communicates with HSSs via Cx interfaces and Application Servers communicate with HSS via the Sh interface).
5.2 Scenario 2: User mobility between mobile and fixed
network, and service mobility
Figure 4 illustrates two kinds of mobility in one scenario, one is the end-user mobility between mobile and fixed access
networks (inter-technology handover or vertical handover) and the other is the service mobility among the application
servers belonging to different Service Providers (SP). The most important logical interfaces required for the
interworking of access networks with the IMS core network are drawn with dotted lines.

Figure 4: Scenario 2 User mobility + Vertical handover + Service mobility
The end-user switches from the original terminal, which accessed a GPRS based mobile network, to another terminal,
which accesses a fixed network. As a result, the previous Application Server (AS) cannot fulfil the new demand.
Therefore, the AS initials the handover. Both the IMS-IMS interconnection and the service orchestration find the new
server applications which can fulfil the demand. Meanwhile, the IP-based fixed network establishes a connectivity
session with the QoS required instead of the previous PDP session in the mobile network architecture. In the fixed
network architecture of ETSI TISPAN, two new entities are introduced, which are the Network Attachment Subsystem
(NASS) and the Resource and Admission Control Subsystem (RACS).
The NASS provides registration at access level and initialization of the User Equipment (UE) for accessing the TISPAN
NGN services. The interfaces between NASS and the User, RACS and P-CSCF respectively are diameter-based.
RACS is the NGN subsystem responsible for the interoperation between the IMS control and the bearer enforcement
components of the network, such as policy control, resource reservation and admission control. The interface Gq+
between IMS and RACS is diameter-based.
The SIP-based interfaces are the same, as described in clause 5.1.
ETSI
18 ETSI TR 102 805-1 V1.1.1 (2009-11)
In this scenario, the initiator of the handover is the AS; the decider and executor for initializing the QoS path are located
in the network. The related interworking units are:
1) Bearer entities: SGSN and GGSN. I-BGF (located between two core networks) and C-BGF (located between
access and core network) which control the PDP session with controlling access by packet filtering on IP and
opening/closing gates into the network; IP-Edge and ABG which are functional entities that control flow for
IP-Based access network.
2) IMS core entities, such as P-CSCF, I-CSCF, S-CSCF.
3) ETSI TISPAN admission control, policy and resource control entity: NASS and RACS. The main function
RACS is to control the QoS of the network. It receives the request of resources from the AF, and then it
associates resource requirements of the service layer, with resource allocation of the bearer layer, and performs
such functions as policy control, resource reservation, admission control and Network Address Translation
(NAT). In the Process of the resource allocation, the RACS consults the NASS for the access and transport
layer QoS profile. NASS is responsible for the network attachment of the MS by providing address allocation,
authentication and authorisation, access network configuration and location management to the session
controller and the RACS.
5.3 Scenario 3: Terminal mobility in mobile network
Figure 5 illustrates the scenario of terminal mobility in a GPRS based mobile access network (horizontal handover).
The most important logical interfaces required for the interworking of the access networks with the IMS core network
are drawn with dotted li
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