Universität Stuttgart
INSTITUT FÜR
NACHRICHTENVERMITTLUNG
UND DATENVERARBEITUNG
Prof. Dr.-Ing. Dr. h. c. mult. P. J. Kühn
Prof. Dr.-Ing. Dr. h. c. mult. Paul J. Kühn
Institute of Communication Networks and Computer Engineering (IKR)
University of Stuttgart
&
International Advisory Council (IAC)
International Teletraffic Congress (ITC) kuehn@ikr.uni-stuttgart.de
Phone: +49-711-6858027, Fax: +49-711-6857983
ITU/ITC Regional Seminar on Network Evoluation to Next Generation Networks and Fixed Mobile Convergence for CEE, CIS and Baltic States
Moscow, April 27-30, 2004

1 Network Developments
2 Service Developments
3 Quality of Service
4 Conclusion: General Observations and Research Areas
Institute of Communication Networks and Computer Engineering University of Stuttgart

1 Network Developments
- Telecommunication Networks
- Computer Communication Networks
- Technological Developments
Institute of Communication Networks and Computer Engineering University of Stuttgart

Fixed Network
Telefax
Mobile Network
Telephon
Switching
Node
SCP
SDP
MSC
HLR/VLR
BS
Mobile
Stations
• 1200 Million Subscribers (Fixed Network) Annual Growth 10%
• 1400 Million Subscribers (Mobile Networks) Annual Growth 50%
• Intelligent Network Services (IN)
Institute of Communication Networks and Computer Engineering University of Stuttgart

PC
Server
Telephone
Network
POP
Internet
R R
WS
R R
R
Intranet
• Probably more than 100 000 Subnetworks and more than 700 Million Users
• Services: Electronic Mail, Database Access,
File Transfer, Internet Telephony,
Multimedia Communication, World Wide Web,
Peer-to-Peer
Institute of Communication Networks and Computer Engineering University of Stuttgart

Source: ITU News 2/2002
1500
1000
500
0
1990 1995 2000
Institute of Communication Networks and Computer Engineering
Mobile Users
Fixed Telephone
Network
Subscribers
Internet Users
2005
University of Stuttgart

Low Earth Orbit
Satellites
BS
Mobile
Ground
Station
GY
Mobiles MSC
Fixed
ADM
ATM
Photonic
Switch
Fibre Optic Channels
OCC
Institute of Communication Networks and Computer Engineering
NG Internet
University of Stuttgart

1 Network Developments
- Telecommunication Networks
- Computer Communication Networks
- Technological Developments
2 Service Developments
- Service Categories
- Service and Technology Convergence
- Application Scenarios
Institute of Communication Networks and Computer Engineering University of Stuttgart

Telecommunication
Telephonie
Telefax
Multimedia-Mail
Videoconference
E-Mail Telecooperation
Home Working
Computer
Communication
Remote Login
Data Communication
Tele-Education
Information
Electronic Newspaper
Stored Multimedia
Access
Data Base Access
Focused
Advertizing
World Wide Web
Video-on-
Demand
Advanced
Pay-per-view
Distributed
Video Games
Entertainment
Tele-XYZ e-Business
Portals
Business Applications
Institute of Communication Networks and Computer Engineering University of Stuttgart

Service and Technology Convergence
E-mail
VoIP
File Transfer
Audio
Multimedia
E-Commerce
Games
IP
ISDN ATM GSM
B-ISDN UMTS
LAN MAN WLAN FR
SDH WDM FTTX HFC PC
Web
Video
Institute of Communication Networks and Computer Engineering University of Stuttgart

Trust Center
Electronic Ticket
Smart
Card
PDA +
Mobile
Phone
Railway Customer
BSS
MSC
(1)
HLR/VLR
Institute of Communication Networks and Computer Engineering
Bank Railway
Booking
Centre
(3)
(4)
(2)
Conductor
Smart
Card
PDA
(5)
ICE
University of Stuttgart

Navigation Support
Satellite
Sensor
Radio
Access
Network 1
Radio
Access
Network 2
MT
MT
Fixed Network
Federation
Server
...
Data Base
Systems
Congestion ahead
Institute of Communication Networks and Computer Engineering University of Stuttgart

1 Network Developments
- Telecommunication Networks
- Computer Communication Networks
- Technological Developments
2 Service Developments
- Service Categories
- Service and Technology Convergence
- Application Scenarios
3 Quality of Service (QoS)
- Definition of QoS
- Traditional Solutions
- Challenges for New Services
Institute of Communication Networks and Computer Engineering University of Stuttgart

QoS: Entirety of all features characterizing the perception of a service (application) at the user level
("user perceivable criteria")
Features: Delay (average, peak, distribution, percentile, ...) of information
Loss (average, peak) of information or of a connection
Resolution, audibility, ... of information content
Reliability, dependability, availability, accountability, security of service
Quantifyable
QoS (Q2S): Measurable value ("Metric") in the widest sense
Institute of Communication Networks and Computer Engineering University of Stuttgart

Factor
• Source Traffic
• Network Resources
• Operational Strategies
• Network Management
Reason
Coding Scheme, Human Factors
Capacity Limits, Network Planning
Resource Management
Fault Detection, Resilience
Examples
Institute of Communication Networks and Computer Engineering University of Stuttgart

Start Stop
Session
TCP
Institute of Communication Networks and Computer Engineering
Flow
Packet/Cell
University of Stuttgart

Example: Network File System (NFS)
Client
Server
Application
Data Base System
Local
File
System
NFS
Client
Request sent to Server Port
Response sent to Client Port
Data Base System
NFS
Client
Local
File
System
Institute of Communication Networks and Computer Engineering University of Stuttgart

User
URL
WWW
Browser
DNS
Server
DNS Lookup
Response
TCP Connection Setup
Presentation of
HTML Page
GET/Fakultaet/Welcome.html
HTML Page
WWW
Server
TCP Connection Release
Institute of Communication Networks and Computer Engineering University of Stuttgart

RIP
BGP
RIP
Domain 2
(RIP)
Domain 1
(RIP)
BGP
RIP
OSPF
BGP
Domain Router
Edge Router
Routing Information Protocol
Open Shortest Path First
Border Gateway Protocol
Institute of Communication Networks and Computer Engineering
OSPF
Domain 3
(OSPF)
University of Stuttgart

Example 1: Telecommunication Services
Connection: Reservation of Bandwidth
Network
A B
Admission Control Circuit Switching
Traditional Solution is not feasible for many new applications due to:
• Variable bitrate sources (burst traffic)
• Overhead for connection management (delay, state management, ...)
• Integration of many services with quite different characteristics
• Inflexibility with respect to adaptation to application requirements
• Cost
Institute of Communication Networks and Computer Engineering University of Stuttgart

Example 2: Internet
Network
Client
Datagram routing Server
"Best Effort Service": No admission control
No resource reservation
Unpredictable delays and losses
BES is not feasible for many new applications due to:
• No guarantees on QoS
Institute of Communication Networks and Computer Engineering University of Stuttgart

Traffic Classes in the IntServ-Model
• Guaranteed Service
• Controlled Load Service
• Best Effort Service
(similar to CBR and rt-VBR)
(similar to nrt-VBR)
(similar to UBR)
Use of RSVP
Traffic Classes in the DiffServ-Model
• Expedited Forwarding (Premium Service)
• Assured Forwarding with different Priorities
Hop-by-Hop Control
Institute of Communication Networks and Computer Engineering University of Stuttgart

Source Router Router Destination
PATH Messages
RESV Messages
Periodic Updates of Soft-State
Reservations
Soft-State Soft-State
Flow Description by
Flow Specifications (FlowSpec)
Service Class
Reserve Specification (RSpec)
Traffic Specification (TSpec)
Filter Specification (FilterSpec)
Institute of Communication Networks and Computer Engineering University of Stuttgart

Access
Router
Border
Router
Backbone
Internet of ISP
Border
Router
Access
Router
Subnetwork
A
Subnetwork
A
Negotiation of max. Bitrate between User and ISP for Aggregated Traffic Volumes
Classification of Traffic Class by Access Routers
Premium Service: Separate Queues and Prioritized Transport provide virtual leased Line Service
Policing Function by Border Router
Assured Service: Use of Priority to provide QoS for short Bursts
Policing Function and Packet Dropping by Border Router
Appropriate Dimensioning of Transmission Resources by ISP
Per Hop Behaviour (PHB) Routing, Marking of IP Packets within DS-Field
Institute of Communication Networks and Computer Engineering University of Stuttgart

Edge
Router
R
S
Packet Flow
Tag Distribution
R
S
Edge
Router
• Detection of flows
• Assignment of flow labels
• Fast switching along pathes
Institute of Communication Networks and Computer Engineering
State-based switching
University of Stuttgart

Server + Client
(Servent)
Overlay
Network
Query
Hits
Autonomous
System
Underlying unreliable
Internet
(TCP/IP)
Autonomous
System
Autonomous
System
Request
(Query)
Institute of Communication Networks and Computer Engineering University of Stuttgart

• Tremendous increase in bandwidth demand in mobile and fixed networks for new applications
Ahead: Japan and Rep. of Korea (70/60 % mobile Internet users;
US/Europe < 10%)
Asia-Pacific Region leading in broadband penetration
• Rapid decrease of internat. bandw. pricing from 111 TUSD (1998) to
10 TUSD (2002) for US-Japan 1Mbps link per year
• NG Internet Technology and broadband access
• Fast routing algorithms
• Convergence of Internet and Mobility
• Adaptive traffic control (e.g., for Peer-to-Peer applications)
• Negotiable QoS Levels and QoS guarantees
• Accounting and charging for highly variable bitrate services
• Ubiquitous computing and ad hoc communication networks
• Adaptation of source coding and network traffic control
• QoS across multiple layers and heterogeneous network technologies
Institute of Communication Networks and Computer Engineering University of Stuttgart

Architectures & Protocols
• Unified Communication based on IPv6
• Communication across different Networks
• Mobility Management based on Mobile IP Concepts
• Dynamic Address Management
• Horizontal and Vertical Handover
• Integration of Ad Hoc Networks (infrastructureless)
• Middleware Concepts
Abstraction from Underlying Network Infrastructures
• Design & Implementation
• Standardization
Institute of Communication Networks and Computer Engineering University of Stuttgart

Mobility
• Modelling of Mobility of Users and Data
• Modelling of (Communication) Traffic
-spatial and temporal
• Disconnected Operation (information Caching and Fuelling)
• Predictive Information Provision (Hoarding)
• Simulation Methods for Mobility
• Performance
Institute of Communication Networks and Computer Engineering University of Stuttgart

Example
HLR/VLR
BC
MSC
• Tracking of Location May Cause Severe Privacy Problems
• Similar Problems Arise from Recording of User Activities
Institute of Communication Networks and Computer Engineering University of Stuttgart

• Protection Against Concatenation between
Location Data and User Identity
• Methods:
- Pseudonymization
- Authentication
- Multilateral Security concepts:
Negotiation of Protection Aims and Strengths
- Accountability and Non-Repudiation
- Integrity
• Security Protocol Design
Institute of Communication Networks and Computer Engineering University of Stuttgart

• Change of Paradigms in the Communication Sector
- heterogeneous network technologies, broad spectrum of applications
- trend directs to IP-based network and transport protocols
- technology push and market pull
• Success Factors
- time to market
- open platforms
- user acceptance
• Design Processes
- limited development periods
- specialization and limitation to core competences ("make or buy?")
- design automation, design platforms and tools
• Standardization and Quality
- proprietary solutions vs. open platforms
- need for standardization
- product quality and quality of service
Institute of Communication Networks and Computer Engineering University of Stuttgart

• Integration of the various Network Technologies
fixed, mobile and ad hoc networks
internet and photonic technologies
support of autoconfiguration and manageability
• Platforms
advanced middleware concepts
service creation support
application programming interfaces
• New Application Paradigms
location and context based services
nomadic communications and ubiquitious computing
overlay networks
• New Business Models
micropayment
quality of service
scalable security
Institute of Communication Networks and Computer Engineering University of Stuttgart