telecommunications network

Report
Telecommunication (302)
Theory: 2x3 hours/week (Monday 15.20-17.55, room:
TA 323, Friday 13.30- 16.05, room: TG 107)
Last lecture: 20. october, test: until 31. october
If the test result is 4 or 5, we accept it as an exam
result, otherwise exam at the end of semester!
Condition of the signature: completion of all
laboratory excercises with documentations
Laboratory excercises: 6 excercises: 3 „traditional” (in
the first part of semester), 3 programming (in the
second part of semester), room: TA 15/A
Telecommunication
Instructor responsible: Dóra Maros
Theory: 39 hours
Teachers:
Dóra Maros: standardization, concepts(6 hours)
Tibor Gudra: networks basics (12 hours)
Péter Antók: optical networks (3 hours)
György Lukács: radio transmission (6 hours)
Sándor Gyányi : IP (9 )
József Kármán: network management (3 hours)
Test: 2 hours
Specifications,
Standardization and
Related Bodies
Szabályozási
szervezetek
Standardization Bodies
WORLD
International Telecommunication
Union
International Electrotechnical
Commission
International Organization for
Standardization
EUROPE
European Telecommunications
Standards Institute
Comité Européen
de Normalisation Électrotechnique;
Other Important Organizations
Institute of Electrical
and Electronics
Engineers
International Federation
for Information
Processing
Internet Engineering
Task Force
International
Telecommunication Union
(www.iti.int)
ITU (International Telecommunication Union) is the
United Nations specialized agency for information and
communication technologies – ICTs..
193 Member States, ITU membership includes ICT
regulators, leading academic institutions and some 700
private companies.
Goals: allocate global radio spectrum and satellite orbits,
develop the technical standards that ensure networks and
technologies seamlessly interconnect, and strive to improve
access to ICTs to underserved communities worldwide.
International Telecommunication
Union
International
Telecommunication Union
Sectors
Sectors:
ITU-R: Radiocommunication
ITU-T: Telecommunication Standardization
ITU-D: Telecommunication Development
https://www.youtube.com/watch?v=S_BCkvTM4wk
ITU-R
The ITU Radiocommunication Sector (ITU-R) plays a
vital role in the global management of the radiofrequency spectrum and satellite orbits.
Global Management of services (land, sea, sky):
•fixed, mobile telecommunications
•broadcasting
•amateur radio
•space research
•emergency telecommunications
•meteorology
•global positioning systems
•environmental monitoring and communication services
ITU-T
Assemble of experts from around the world to
develop international standards known as ITU-T
Recommendations which act as defining elements in the global
infrastructure of information and communication technologies
(ICTs).
Standards are critical to the interoperability of ICTs and whether
we exchange voice, video or data messages, standards enable
global communications by ensuring that countries’ ICT networks
and devices are speaking the same language.
ITU-D
Core mission: foster international cooperation and solidarity in
the delivery of technical assistance and in the creation,
development and improvement of telecommunication
equipment and networks in developing countries.
Most important projects:
Climate change: Facilitating carbon emission reductions and
monitoring, mitigating impact and adapting to change.
Emergency telecommunication: Maximizing the contribution of
ICTs to disaster predication, detection and coordination.
Cyber security: Fostering the integrity of ICT systems that is
essential for their continued development.
And others like: Regulatory & market environment (e.g roaming),
ICT applications (e-health, e-government), Digital Inclusion
(special solutzions for persons with disabilities, children etc.)
ITU
Study Groups (SG)
ITU-R
ITU-T (2013-2016)
ITU-T Documents
ITU-T Recommendations: so called normative documents
(more than 4000)
ITU-T Recs have non-mandatory status until they are
adopted in national laws.
Technical papers (SG reports, case studies etc)
Handbooks (on operation, network planning, quality of
service, implementation guidelines)
European Telecommunications
Standards Institute
European
Telecommunications
Standards Institute
(www.etsi.org)
Officially recognized by the European Union
as a European Standards Organization.
ETSI is a not-for-profit organization with more
than 750 ETSI member organizations drawn
from 63 countries across 5 continents worldwide.
ETSI Membership
(www.etsi.org)
Nemzeti Média és Hírközlési Hatóság
European Telecommunications
Standards Institute
ETSI Products and Services
(www.etsi.org)
European Telecommunications
Standards Institute
Different types of ETSI
standards
Different types of documents allows us to meet the variety of
needs within the different industries we serve:
European Standard (EN) – Used when the document is intended to meet needs
specific to Europe and requires transposition into national standards, or when
the drafting of the document is required under a mandate from the European
Commission (EC)/European Free Trade Association (EFTA). An EN is drafted by a
Technical Committee and approved by European National Standards
Organizations.
ETSI Standard (ES) – Used when the document contains technical requirements.
An ES is submitted to the whole ETSI membership for approval.
ETSI Guide (EG) – Used for guidance to ETSI in general on the handling of
specific technical standardization activities. It is submitted to the whole ETSI
membership for approval.
European Telecommunications
Standards Institute
Different types of ETSI
standards
ETSI Technical Specification (TS) – Used when the document contains
technical requirements and it is important that it is available for use
quickly. A TS is approved by the Technical Committee that drafted it.
ETSI Technical Report (TR) – Used when the document contains
explanatory material. A TR is approved by the Technical Committee
that drafted it.
ETSI Special Report (SR) – Used for various purposes, including to
make information publicly available for reference. An SR is approved
by the Technical Committee which produced it.
ETSI Group Specification (GS) – Provides technical requirements or
explanatory material or both. Produced and approved within our
Industry Specification Groups (ISGs).
European Telecommunications
Standards Institute
IMPORTANT!
HOW we can find
technical
specifications?
IF YOU'RE INTERESTED IN THE TECHNICAL
SPECIFICATIONS AUTHENTIC SOURCES ALWAYS WORK!
Use ETSI documentations libary!
ALL STANDARDS ARE AVAILABLE ON WEBPAGE AND
FREE OF CHARGE!
Let’s look: www.etsi.org
ETSI Clusters
European Telecommunications
Standards Institute
ETSI clusters
provide a simple,
easy to grasp
overview of ETSI
activities in ICT
standardization.
grasp: to
understand sth
completely
Third Generation Partnership Project
Technical
Committees
3GPP
specialised for
mobile
broadban
standards
3GPP the Main Body of Mobile
Communicatons Standards
Members :
3GPP produces Technical Specifications, to be
transposed by relevant Standardization Bodies
(Organizational Partners) into appropriate deliverables
(e.g., standards).
3GPP Specifications Releases
and Numbering
The RELEASE is a group of specificitaions. First was R99 (about
2000)! Then: R4…..R12 (Better way to find mobile standards!)
Internet Engineering
Task Force
www.ietf.org
IETF is a large open international community of network
designers, operators, vendors, and researchers concerned
with the evolution of the Internet architecture and the
smooth operation of the Internet. It is open to any
interested individual.
Memos in the Requests for Comments (RFC) document
series contain technical and organizational notes about the
Internet. They cover many aspects of computer
networking, including protocols, procedures, programs,
and concepts, as well as meeting notes, opinions.
IETF WG-k
www.ietf.org
Working Groups (WGs) work on special fields:
IETF RFC
www.ietf.org
Eye-triple-E
Institute of Electrical
and Electronics
Engineers
www.ieee.org
•IEEE is the world's largest professional association dedicated to
advancing technological innovation and excellence for the benefit
of humanity.
•Its members inspire a global community through IEEE's highly
cited publications, conferences, technology standards, and
professional and educational activities.
•IEEE’s roots go back to 1884 when electricity began to become a
major influence in society. There was one major established
electrical industry, the telegraph, which since the 1840s had come
to connect the world with a data communications system faster
than the speed of transportation.
IEEE Membership
Institute of Electrical
and Electronics
Engineers
www.ieee.org
more than 430,000 members in more than 160 countries,
more than 50 percent of whom are from outside the United
States;
more than 120,000 Student members from 80 countries;
333 sections in ten geographic regions worldwide;
432 affinity groups - IEEE Affinity Groups are non-technical
sub-units . Eg. IEEE-USA Consultants' Network, Graduates of
the Last Decade Young Professionals (YP), Women in
Engineering (WIE), and Life Members (LM).
IEEE Xplore
Institute of Electrical
and Electronics
Engineers
http://ieeexplore.ieee.org/
Date: 7 September 2014
Journals from 1872!
IEEE Xplore Standards
Institute of Electrical
and Electronics
Engineers
http://ieeexplore.ieee.org/
xpl/standards.jsp
IEEE standards
Institute of Electrical and
Electronics Engineers
www.ieee.org
The best known IEEE standard is IEEE 802.11 WLAN
Hungarian Authority
www.nmhh.hu
Nemzeti Média és Hírközlési Hatóság
Its task is to ensure the undisturbed operation, in
compliance with pertaining legislation in force, of
the media and the markets for electronic
communications, postal and information technology
services.
The Authority has an active role in the work of
international organisations: ITU, ETSI, IETF and
others
NMHH Main
Activities
Nemzeti Média és Hírközlési Hatóság
Legistlation: Becoming familiar with the most important
items of Hungarian legislation on the regulation of electronic
communications, postal services, and the regulation of the
IT and media markets (acts and decrees).
Official statements: Statements include publication of notices
on given procedures where the law requires publication
through notice. Statements describing the details of given
procedures and calling attention to them in this way help
accurate high-standard fulfilment of provisions of law and
supply of current information to the consumers and
customers.
NMHH Main
Activities
Nemzeti Média és Hírközlési Hatóság
Frequency management: is an activity performed in order to
ensure the undisturbed operation of radio communications
and other, non-telecommunications services
Services, appliances, constructions: the authority accepts and
judges the notifications of services in conformity with legal
prescriptions, registers the services and service providers
belonging to its competence, determines the obligatory
technical and operational conditions for sake of integrity of
the communications network.
NMHH Main
Activities
Nemzeti Média és Hírközlési Hatóság
Numbering: the numbers, addresses and the ranges of those needed
for operation of communications networks and for the provision of
services - the identifiers – are scarce resources.
The available identifiers are registered in the national allocation
plan of identifiers which stipulates the distribution of all the
identifiers among the activities and services, the type, allocation and
dimension of identifiers.
E-signature, E-advertisement: supervises the services and service
providers connected with the electronic signature, and checks the
operation of the organizations appointed for certifying the
conformance of the electronic signature products.
NMHH Main
Activities
Information on market:
•Communicaton market
data, reports,
•Market analysis,
•Market surveillance,
•Communication statistic
database,
•Market research
Telecommunications
Networks and their
Scope
Telecommunication Networks
Network part which the end user does not see much
Telecommunication Networks
User part which the operator does not see much
…and between..
which no one can see anything
Telecommunication Networks
Definition
The electronic transmission of information over distances,
called telecommunications, has become virtually inseparable
from computers. Computers and telecommunications create
value together.
The information may be in the form of voice telephone calls,
data, text, images, or video.
Today, telecommunications are used to organize more or less
remote computer systems.
A telecommunications network is an arrangement of
computing and telecommunications resources for
communication of information between distant locations.
Telecommunication Networks
Geographical Scope
1. Terminals for accessing the network
2. Computers that process information and are
interconnected by the network
3. Telecommunications links that form a channel
through which information is transmitted from a
sending device to a receiving device.
4. Telecommunications equipment that facilitates the
transmission of information.
5. Telecommunications software that controls
message transmission over the network.
Geographical Scope
Wide Area
Network
Metropolitan
Area Network
Local Area
Network
Personal Area
Network
Techniques in radio communicaton
Computer networks
Basic topologies
Wide Area Network
Swicthing
1. Leased line: Point-to-Point connection between two
computers or Local Area Networks (or users), fix monthly fee
Safe but expensive (e.g ATM bank automats)
2. Circuit switched, (SC): A dedicated circuit path is created
between end points. Best example is dialup connections (phone
call)
Slow, not too expensive
Wide Area Network
Swicthing
3. Packet swiched (PS):
The information is sent in separated packets
Connection oriented: Devices transport packets via a
shared single point-to-point or point-to-multipoint link
across a carrier internetwork. Before information can be
exchanged between two endpoints, they first establish a
Virtual Circuit. Variable length packets are transmitted
Connectionless: Between endpoints no connection is
build; endpoints can just offer packets to the network,
addressed to any other endpoint and the network will try
to deliver the packet. As an example: the Internet
Wide Area Network
Swicthing
4. Cell relay : Similar to packet switching, but uses fixed
length cells instead of variable length packets. Data is
divided into fixed-length cells and then transported across
virtual circuits
Before 2000 this was seen as the best option for
simultaneous use of voice and data. (ATM: Asynchronous
Transfer Mode)
Circuit Switching (CS)
Phone call (fix, mobile)
Data (modem)
Problems: lf Switching node is overloaded the
connection is not established
If connection is established, services quality is good!
Packet Switching (PS)
Internet (fix, mobile)
Data, voice (VoIP), video, audio
Problems: packet delay, congestion in nodes
 Connection established, but some packets are lost
(causes bad quality)
Cell relay (outdated)
Multiple Access, MA
FDMA (Frequency
Division Multiple
Access)
TDMA (Time
Division Multiple
Access)
CDMA (Code
Division Multiple
Access)
1 channel = 1 frequency
1 channek = 1 timeslot
1 channel = 1 code
ITime
Time
Time
Frequency
Frequency
NMT 450
GSM
Frequency
UMTS
MA: Many users share a common resource
Multiple Access, MA
OFDMA
4G mobile and Wlan
Space Division Multiple
Access, SDMA
4G-5G futute networks
FDMA and TDMA
FDMA: user on different
frequency subbands to share
the available bandwith
TDMA: user on same
frequency subbands but in
different times (timeslots)
CDMA transmitter using DS CDMA
• Users transmit on same frequency band in the same time, the
original info is multiplied by a special code
• Each user has a unique code
C1-Cn: channek codes
spreading
Power
Backround noise
f(Hz)
s1(t)
Pseudo-zaj 1
STX
c1(t)
f(Hz)
Modulator
Power
f(Hz)
s2(t)
f(Hz)
c2(t)
Pseudo-zaj 2
Power
f(Hz)
∑
Acos(ωct)
Power
f(Hz)
sn(t)
f(Hz)
cn(t)
Pseudo-zaj 3
DS: Direct sequence
S Tx  [ s1 ( t ) c1 ( t )  s 2 ( t ) c 2 ( t )  ...  s n ( t ) c n ( t )] A cos  w c t 
CDMA receiver using DS CDMA

Channel despreading means the multiplication (XOR) of
channel signel and the channel code.
Received
channel
Received signal
f(Hz)
Processing gain
fc = c/2
fc = c/2
The received signal is the SUM
of all channels on the carrier
frequency
Band filter
Demodulator
SRX
c1(t)
S Rx ( t ) c1 ( t )  [ s1 ( t ) c1 ( t )  s 2 ( t ) c 2 ( t )  ...  s n ( t ) c n ( t )] A cos  w c t c1 ( t )
'
n
S Rx ( t ) c1 ( t )  [  s i ( t ) c i ( t ) c1 ( t ) ] A cos  w c t   s1 ( t ) c1 ( t ) c1 ( t )  A cos  w c t 
'
'
i2
interference
Channel
c i ( t ) c1 ( t )  1, c1 ( t ) c1 ( t )  1
Channelization Codes (I.)
Auto-correlation and cross-correllation for digital codes

ACF (AC Function):
→ L lengh bit sequence and its
shifted version is compared
ACF  CC  NCC
CC: Number of Equal bit
in the same position
NCC: Number of not Equal
bit in the same position

CCF (CC Function): two totally
different bit sequence is compared
CCF
bit by bit

Orthogonal codes: CCF = 0
 CC  NCC
Chanellization Codes (II.)
Walsh code
• Walsh, or Walsh-Hadamard codes:
• Codes are orthogonal in the same matrix (CCF = 0)
• Walsh matrix: n x n matrix
8
Wi
m: matrix size
i: matrix row (0…n)
m
0
M2  
0
M1  0
M
2N
M
 
M
0

0

M4 
0

0
0

1
N
M
N
N
M
N



0
0
1
0
0
1
1
1
0

1

1

0
W1
0 0 0 0

0 1 0 1

0 0 1 1

0 1 1 0
M8  
0 0 0 0
0 1 0 1

0 0 1 1

0 1 0 01 0 11 0 11  0
0
0
0
0
1
0
0
0
1
0 1 1
1 1 1
1
0
1
1 1
0
1  0 0
0

1

1

0
1
0

0

1  
CDMA FH-Frequency hopping
FH: Many subbands,
transmittion hops
between carriers
For each user a sequence of
frequencies is allocated, there
is no the same carrier for two
or more channels at the same
time
Channel B: 7-9-1-14-10-5-13-2-11
Channek C: 9-2-4-11-8-14-10-6-3
OFDMA (Orthogonal Frequency
Division Multiple Access
Subcarrier are orthogonal, they
don’t disturb each other
LTE (4G) spectrum: one
user transmits on two or
more subcarriers
Narrow band and wide band transmission
Narrow band
GSM channel
Bandwidth: 200 KHz
Wide band
3G UMTS channel
Bandwidth: 5 MHz
OFDMA vs. FH CDMA
OFDMA: more carriers for one user at the same time
FH CDMA: one carrier for one user in different times
Channel 1: A-F
Channel 2: C-H
Channel 3: C-H
Single Carrier and Multi Carrier Systems
t1 (c1)
t3 (c3)
t2 (c2)
TDMA:
Different
timeslots
CDMA:
Different
codes
f1
f2
f3
f4
FDMA: one user,
one carrier
f1
f1 f2 f3 f4 f5
f1 f2 f3 f4 f5
t1
OFDMA: more then
one carriers at the
same time
t2
t1 t2 t3 t3
FH: more carriers,
transmission is
hopping
Duplexing (mobil)
B(dl):bandwidth
Downlink
FDD: Uplink-downlink fr.
Bands (2G és 3G)
fk(dl)
B(ul)
Uplink
fk(ul): middle frequency
Uplink
Downlink
time
B(dl)=B(ul)
fk(dl)-fk(ul)= duplex distance
TDD: same carrier for UL
and DL (4G)
Duplexing (ADSL)
FDD vs. TDD
f
keretidő
t
f
Guard band
t
Traffic problems in the network
Connection is not establish because no free channel, (1) tipical in mobile cells.
Connection is not establish because the switching node (2) is overloaded.
Connection is not establish because the transmission lines (3) are overloaded.
3
1
2
Traffic problems in the network
The cause of congestion: accident (softver upgrade)
Traffic problems in the network
The cause of
congestion: some
users need bigger
bandwidth (youtube,
on-line games etc)
Car vs Truck
Traffic problems in the network
The cause of congestion:
(maintenance in the
network)
Thank you for Attention!

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