Transcript Slaid_01 - narod.ru

Series of lectures
“Telecommunication networks”
Lecture#9
Concluding session,
part I
Instructor: Prof. Nikolay Sokolov, e-mail: [email protected]
The Bonch-Bruevich Saint-Petersburg State
University of Telecommunications
Main definition
Telecommunication.
“Any transmission, emission or
reception of signs, signal, writing,
images and sounds or intelligence of
any nature by wire, radio, visual or
other electromagnetic systems“.
International Telecommunication
Conference, Atlantic City, 1947.
Black box
Input
Output
Instructions
Reports
A(t)
D(t)
Black box
B(t)
Controlled
subsystem
Management
C(t)
To carry
To take
Controlling
subsystem
Communication effectiveness
Communication effectiveness
2 people at
whiteboard
2 people
on phone
2 people
on mail
Videotape
Audiotape
Paper
Form of communication
Telecommunication system
Customer Premises
Network
Access Network
Core Network
Service Nodes
Responsibility of the Telecom Operator
This model is proposed by ITU-T for the GII (Global Information Infrastructure).
On the other hand, this model is useful for any telecommunication network.
Definitions of term “Network”
ITU-T, E.164 (2005): Internationally interconnected physical
nodes and operational systems operated and maintained by one or
more ROAs (Recognized Operating Agency) to provide public
telecommunications services. Private networks are not included in
this definition.
ITU-T, G.998.1 (2005): All equipment and facilities, including
loop plant, located on the carrier side of the network interface.
ITU-T, G.805 (2000): All of the entities (such as equipment, plant,
facilities) which together provide communication services.
ITU-T, Y.101 (2000): A set of nodes and links that provide
connections between two or more defined points to facilitate
telecommunication between them .
International Telecommunication Union
ITU is the leading United Nations agency for
information and communication technologies. As the
global focal point for governments and the private
sector, ITU's role in helping the world communicate
spans 3 core sectors: Radiocommunication,
Telecommunication Standardization and
Telecommunication Development. ITU also organizes
TELECOM events and was the lead organizing agency
of the World Summit on the Information Society.
ITU is based in Geneva, Switzerland, and its
membership includes 191 Member States and more
than 700 Sector Members and Associates.
ETSI
ETSI was created by CEPT (European Conference of
Postal and Telecommunications Administrations) in
1988. Based in Sophia Antipolis (France), ETSI is
officially responsible for standardization of
Information and Communication Technologies (ICT)
within Europe. ETSI has 696 members from 62
countries/provinces inside and outside Europe,
including manufacturers, network operators,
administrations, service providers, research bodies
and users — in fact, all the key players in the ICT
arena.
Maslow's Hierarchy of Needs (1)
Abraham Maslow
developed the
Hierarchy of Needs
model in 1940-50s
USA, and the
Hierarchy of Needs
theory remains
valid today for
understanding
human motivation,
management
training, and
personal
development.
Telephone conversations
Maslow's Hierarchy of Needs (2)
Telephone communications system
"Telephone communications system" term is usually
refers to base principles of telephone network’s
construction, operation and development. These
principles usually include the following positions:
•purpose of the system;
•supported services;
•network structure;
•quality of service ratings;
•numbering plan;
•maintenance;
•equipment requirements;
•main directions of system development.
Revenue distribution
Other services
International and
long-distance
communications
Mobile
communications
Internet (access)
Local telephone
communications
Transit of traffic
Market evolution
Per 100 people
Source: ITU
80
70
60
50
Mobile contracts
Internet users
Fixed telephone lines
Mobile broadband access contracts
Fixed broadband access subscribers
40
30
20
10
Year
0
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
Distribution of the amount
of calls during the day
Amount of calls
Time of
day
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
0
In the PSTN, required bandwidth is identical for any connection.
Traffic on a Monday morning
Equipment evolution
Single-wire line
(voice channel)
xDSL
Two-wire line
(voice channel)
FTTx
.
.
.
BWA
Time
XX century
Switchers
Manual exchange
XXI century
Step-by-step
exchange
Crossbar exchange
Digital
exchange
NGN
Time
XX century
XXI century
Broadband channel
Access Networks
Distribution
box
Phone jack
Terminal
Access network (1)
Main
distribution
frame
Distribution
cabinet
Multipair cable
20%
80%
Distribution
box
Phone jack
Terminal
a) model of the old subscriber line
20%
Main
distribution
frame
Remote module
Fiber optic cable
conversion “о/е” and “е/о”
80%
b) model of the modern subscriber line
Terminal
Distribution
box
Terminal
Distribution
box
Access network (2)
Distribution
cabinet
ADSL (up to 8 Mbit/s) or
ADSL2+ (up to 24 Mbit/s)
Main
distribution
frame
Remote module
Fiber To The Remote (FTTR)
e.g. VDSL2 (up to 100 Mbit/s)
LR
Terminal
Fiber To The Premises (FTTP)
LP
BP>100 Mbit/s
Optical fiber
Spectral range
First data transmission systems
for the mainframe
Data Link
Mainframe
Mainframe
a) Connection between two mainframes
Terminal
Subscriber Line
Terminal
Subscriber Line
Mainframe
Terminal
Subscriber Line
b) Connections for terminals
Traffic growth
Internet (RFC 3935 )
The Internet: A large, heterogeneous collection of
interconnected systems that can be used for communication
of many different types between any interested parties
connected to it. The term includes both the "core Internet"
(ISP networks) and "edge Internet" (corporate and private
networks, often connected via firewalls, NAT – network
address translation – boxes, application layer gateways and
similar devices). The Internet is a truly global network,
reaching into just about every country in the world. The
IETF community wants the Internet to succeed because we
believe that the existence of the Internet, and its influence
on economics, communication, and education, will help us
to build a better human society.
Example of the Internet network structure
AS1
AS2
AS3
AS5
AS4
AS – Internet autonomous system
Interconnection of two local networks
R
R
R
R
LAN
LAN
R
R
R
R
R
R – router, LAN – Local Area Network
Forecast of the access demands
Households, %
100
80
Sources: Alcatel Telecommunications Review, 2nd Quarter 2003,
Telektronikk, Volume 100, No. 4, 2004.
100 Mb/s
60
24 Mb/s
40
6 Mb/s
1.5 Mb/s
20
Year
1995
2000
2005
2010
2015
2020
2025
Internet in our life
Research company “Yougov” carried out survey among
broadband Internet users in Great Britain. The main goal
was to define goods and services that citizens will be eager to
sacrifice during economic depression. Approximately 3% of
the respondents were ready to save money by limiting
expenses on Internet access.
About 30% of respondents (near 5 million) were ready to cut
down expenses related to newspapers & magazines, alcohol,
cigarettes but will use Internet. On the other hand, only 60%
of respondents were going to use services from their
Provider. Remainder will find Provider with inexpensive
services.
Cellular topology with seven
different frequency ranges
D
R
F6
F7
F5
F1
F4
F6
F2
F3
F7
F5
F1
F4
F2
F3
Handover and roaming
Network 1
Network 2
BS12
T
BS11
BS13
BS21
...
MSC1
MSC2
Interworking functions
CO1
PSTN
Main elements of the network
Intra-network
interfaces
Air interface
Mobile
terminal
Switching
subsystem
Radio subsystem
Internetwork
interface
Other network(s)
Interfaces
MSC – mobile switching center
MS – mobile station
F
BTS – base station
BSC – base station controller
EIR – equipment identification
register
EIR
E
MSC
A
Abis
BSC
Um
C
MSC
B
D
HLR
BTS
MS-SIM
MS
SIM – subscriber identity module
HLR – home location register
SIM
VLR – visited location register
VLR
G
VLR
Typical structure of the radio and
television broadcasting networks
Main Center
Main path
Main path
Main path
Regional
Center
Standby path
Regional
Center
Served area
Local
Centers
Regional
Center
Classification of the television
broadcasting systems
Television broadcasting
On-air broadcasting
Cable television
Satellite television
Combined system
Standard quality television
One-way broadcasting
Analogue
channels
High definition television
Interactive television
Digital
channels
Cycles in the telephone
communication development
Milestones of telephony
development
Emergence of the telephone
communications
Time
80s of the XIX
century
Automation of the telephone
communications network
Utilization of the program
control
20s of the XX
century
60s of the XX
century
Transition towards packet
transmission and switching
technologies
Beginning of the
XXI century
The main goal is the real demands of each customer!
The Death of Distance
*)
Falling costs
100
Transatlantic
telephone call
80
Ocean
freight
Satellite
charge
60
Air
transport
40
20
Year
0
1920
1930
1940
1950
1960
1970
1980
1990
Source: World Development Report 1995, World Bank
*)
F. Cairncross. The Death of Distance. – Harvard Business School Publishing, 1997.
Integration, convergence,
and consolidation (1)
Integration is aggregation or interpenetration. In some cases,
integration is considered as creation of the relationships.
Convergence is a process by which unrelated organisms
independently acquire similar characteristics while evolving in
separate ecosystems. In telecommunications (according to
ITU-T Q.1761), coordinated evolution of formerly discrete
networks towards uniformity in support of services and
applications. It means convergence is approximately the same
as integration.
Consolidations is a reasonable combination of the integration
and convergence.
Integration, convergence,
and consolidation (2)
Typical example of integration is ISDN (Integrated
service digital network). One network supports the
services that were previously provided by number of
the existing networks.
Typical example of convergence is the functions of
the fixed and mobile networks. Mobile networks
support the Internet access. Fixed networks provide
the SMS transfer.
Typical example of consolidations is utilization of
the common cable lines for the transmission of the
different information (voice, data, video).
Integration, convergence,
and consolidation (3)
ITU, Recommendation Q.1702, Converged services:
The integration of Internet, multimedia, e-mail, presence,
instant messaging, m-commerce, etc., services with voice
service.
Sometimes term “convergence” is used instead of word
“integration”. Term “integration” was attractive during
elaboration of the ISDN concept. Market of the ISDN
mostly was not successful. For this reason, number of
experts use term “convergence”.
Global Information Infrastructure (1)
A collection of networks, end user equipment, information, and human resources
which can be used to access valuable information, communicate with each other,
work, learn, receive entertainment from it, at any time and from any place, with
affordable cost on a global scale.
Source: ITU-T, Recommendations Y.101 and Y.110
Global Information Infrastructure (2)
Driving forces:
1. Two predominant factors distinguish a situation for the Global
Information Infrastructure (GII) which is likely to be radically different
from previous information infrastructures. These two factors are:
-the convergence of technologies in use within telecommunications,
computers, consumer electronics and the move of content provision
industries towards digital technology;
- new business opportunities, created by the unbundling of services
made possible or necessary by deregulation, and other commercial
and/or open market pressures.
2. Digitalization (All forms of information, including voice, data or
video/image, are simply reduced to streams of digital bits for transfer
over a bit-way (or digital network). This represents a possible
decoupling between networks and their payloads).
Global Information Infrastructure (3)
Driving forces:
3. Value chain models and business opportunities. The following
properties of an added-value chain are relevant to ITU-T
standardization work:
a)
Every link and item in an added-value chain, from content to
user or user to user, potentially represents a possible business
opportunity.
b)
Every link in the chain establishes sufficient demarcation
points to facilitate potential separate ownership and operation to be
realized within the context of the entire chain.
c)
a) and b) are sources of requirements for the definition of
standards-based functions and/or interfaces.
This model can be used to represent a competitive telecommunications
and information provision environment, involving the interconnection
of networks in parallel or in series, as well as systems which enhance or
modify information content.
Global Information Infrastructure (4)
Definition of the NGN
http://www.itu.int/ITU-T/studygroups/com13/ngn2004/working_definition.html
A Next Generation Network (NGN) is a packet-based
network able to provide services including
Telecommunication Services and able to make use of
multiple broadband, QoS-enabled transport
technologies and in which service-related functions are
independent from underlying transport-related
technologies. It offers unrestricted access by users to
different service providers. It supports generalized
mobility which will allow consistent and ubiquitous
provision of services to users.
Next generation network model
CU2
CU1
CU3
CU4
TS1
TS2
PS5
PS7
PS2
PS1
PC1
PS3
PS4
PS6
PS8
PS9
Local Network 2
Local Network 1
Long-distance network
CU – control unit, PS – packet switch, TS – telephone set,
PC – personal computer
PC2
Integration of the existing
telecommunications networks
NGN
Telephone networks
Data transmission networks
Broadcasting networks
Process of the forming of the NGN
Forming of the NGN
“Saturation”
stage
Active
development
stage
Initial stage
Time
T0
TI
T2
T3
Points of the technology change
under transition to the NGN
TS
TS
Local network
with channels
switching
A
B
Local network
with channels
switching
Long-distance
IP network
TS
TS
G
C
E
IP-TS
Local IP
network
D
Local IP
network
International International network
IP network
with channels
switching
F
IP-TS
Network structure. Some definitions
Network structure
Term is used to describe the method of how data on a
network is organized and viewed.
Network architecture
Also referred to as the network model, the network
architecture is the overall structure of how a network is
laid out. The network architecture is commonly drawn out
as a diagram for a visual representation of the overall
network. A well designed network architecture helps
prevent network bottlenecks and various other issues.
Some authors use term “topology” instead of the word “architecture”
because term “architecture” is widely applied in the publications
concerning telecommunication protocols.
Examples for the graph with six nodes
a2
a2
a3
a3
a1
a1
a4
a4
a6
a6
a5
b) Tree
a) Star
a2
a2
a3
a1
a1
a5
c) Ring
a3
a4
a4
a6
a5
a6
a5
d) Full mesh
Oriented, unoriented and mixed graphs
a2
a1
c23
a4
a6
l23
a2
a3
a2
a3
a4
a) Oriented graph
a6
a5
b) Unoriented graph
a1
l
l
a3
a2
l
a5
c) Mixed graph
Example of finding the Steiner point
l
3
a3
a4
a6
a5
r23
Two variants of the ring
network construction
a2
a2
a3
a3
a1
a1
a4
a4
a6
a5
a) First structure of transport network
a6
a5
b) Second structure of transport network
Example of the several rings creation
7
2
5
11
∞
∞
9
4
12
1
6
8
10
3
0
Transformation of the
optimization problem (1)
Ring I
Ring I
TS
TF
Ring II
Ring III
Subscript “s” – start, subscript “f” – future
Ring II
Transformation of the
optimization problem (2)
p7 << p5
a2
a2
a5
TX
a1
a3
ed
et
el
a3
D
a1
g
ed
e
p6 → 1
a4
a7
a6
a4
P7 → 0
Rational decision
Capital expenditures
Upper bound
Designed value
Actual data
Time
TX
Cost-performance compromise
If π is very small (e.g. 0.1%) cost of the network will be high. For
this reason, cost of service will be supernormal. The number of the
users will be small.
If π is very high (e.g. 50%) cost of the network will be relatively
small. On the other hand, quality of service will be poor. For this
reason, the number of the users will be small as well.
It is obvious there is cost-performance compromise. Therefore we
have to define optimum value of the π. This task is the main one
among problems of the network planning.
Improvement of the
network characteristics
Network planning
Performance
measurement
Network
tuning
Performance
analysis
Concluding session, part I
Questions?
Instructor: Prof. Nikolay Sokolov, e-mail: [email protected]