Transcript Slide 1

Telecommunication Systems Design
October 10, 2007
Akiyuki Goto
Faculty of Information Technology
King Mongkut’s Institute of Technology North Bangkok
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Revision
1 Nov.15, 2007
First Edition
2 Nov.22, 2007
Network Planning
3 Jan.16, 2008
Workshop 0 ~ 13
4 Jan.17, 2008
VoIP
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CONTENTS
1. Preface
2. Overview of Telecommunication Systems
3. Network Planning
( Master plan, QoS, GoS, CoS, Proposal, Quality,
Network management )
4. OSI
5. Network Configuration
( PSTN, ISDN, ATM, Packet switch, LAN switch, Internet,
Ethernet, Wireless network )
6. Network Analysis and Design
7. Trouble Shooting
8. Standardization
9. GLOSSARY
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1. Preface
Telecommunications play an ever-increasing role in improving the quality of
life of all peoples. For example, advanced communications system and
meteorology help to boost efficiency and safety of our transportation system.
Telecommunication and postal services lessen the need to travel and thus
reduce traffic congestion and thereby cut economic, social and environmental
costs associated either directly or indirectly therewith. A reliable weather
forecast and an effective natural-disaster warning system can prevent or
mitigate damages and loss of lives. These are few examples of how
telecommunications can better our lives.
The 21st century will mark the entrance to what we call the "Information Age".
As the world economy becomes increasingly competitive, the need for a
modern and reliable telecommunications network is an compelling as ever.
Access to high-quality communications services at competitive prices will
bolster economic growth and boost efficiency and productivity in business,
government and social services sectors. With the emergence of the
"information highway', citizens across the world can exchange, access and
learn from all sorts of information made available on line. Moreover, they will
also be able to exchange and communicate ideas furthering what is becoming
a borderless society.
Thus, there need to be leaps in telecommunications development, be they
in terms of quantity, quality, access, regulations or competition as well as
privatization of state enterprises in order for the industry to meet the surging
demand for communications services in keeping with the expansion of the
economy, population and rising income level, as well as to prepare for the new
era brought about by the "Information Revolution".
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2. Overview of Telecommunication Systems
1883 - Transformer invented.
1891 - 60 cycle AC system introduced in U.S.
Alexander
1897 - Electron discovered by J. J. Thomson.
Graham Bell
1903 - Electric vacuum cleaner.
Electric washing machine.
1906 - Lee deForest invents the vacuum tube.
1908 - A wireless message was sent long-distance for the first time from the
Eiffel Tower in Paris.
1911 - Air conditioning.
1912 - first Strowger exchange opened in UK at Epsom in Surrey.
1915 - First automatic telephone exchange in Britain.
1919 - Wireless telephone invented, enabled air pilots to talk in flight.
1925 - Bell Telephone Laboratories founded. 1.5 million dial telephones in
service out of 12 million phones in service.
1930 - The BBC begins regular TV transmissions.
1935 - First telephone call around the world. About 6700 telcos in
operation.
1936 - About 200 hundred television sets are in use world-wide.
1947 - The Transistor is invented
1949 - AT&T introduces the famous black rotary Model 500 telephone.
1954 - Bell labs announced first solar battery.
1960 - AT&T installs first electronic switching system in Morris, IL. There
are now 3299 telephone companies.
1965 - Texas Instruments develops the transistor-transistor logic (TTL).
1965 - AT&T Bell Laboratories develop Unix.
1967 - Most TV broadcasts are in color.
1970 - Bell Telephone Labs release design information to Western Electric
for the production of Modular Telephone Cords and Jacks.
1971 - Intel develops the the first processor, the 4004
1974 - Intel’s improved microprocessor chip, the 8080 becomes a standard
in the microcomputing industry.
1976 - The Intel 8086 is introduced.
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1981 - VHDL is proposed and begins development.
1983 - The first hand held mobile phone becomes commercially available
1985 – Bellcore introduces “IN” (Intelligent Network).
1986 - The first fibre-optic cable across the English Channel began service.
1987 - Bellcore introduces the Asymmetric Digital Subscriber Line (ADSL)
concept which has the potential of multimedia transmission over the nation's
copper loops.
1989 - AT&T reported first loss in 103 years; $1.67 billion in 1988.
1991 - The computer Monkey Virus is first discovered in Edmonton, Canada.
The first GSM Mobile Phone network opened in Europe
1992 - The World Wide Web is born - the brain child of CERN physicist Tim
Berners-Lee.
1994 - Worlds First Satellite Digital Television Service Launched
1995 - Microsoft Releases Windows 95, within four days the software sells
more than 1 million copies.
DVD, optical disc storage media format, is announced.
1998 - Microsoft Windows 98 is officially released on June 25, 1998.
1999 - IEEE introduced 802.11b.
Bluetooth announced.
2001 - Microsoft Windows XP home and professional editions are released
October 25, 2001.
2005 - Microsoft Windows XP Professional x64 Edition is released on April 24,
2005.
2007 - Microsoft releases Microsoft Windows Vista and Office 2007 to the
general public January 30, 2007.
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First Generation Cellular standards:
Advanced Mobile Phone System (AMPS) was first launched in the US. It is
an analog system based on FDMA (Frequency Division Multiple Access)
technology. Today, it is the most used analog system and the second
largest worldwide.
Nordic Mobile Telephone (NMT) was mainly developed in the Nordic
countries. (4.5 million in 1998 in some 40 countries including Nordic
countries, Asia, Russia, and other Eastern European Countries)
Total Access Communications System (TACS) was first used in the UK in
1985. It was based on the AMPS technology.
2G Cellular
With second-generation networks, or 2G, wireless technology progressed
from analog to digital. These networks are still the most prevalent
standard in use today. There are three main 2G network standards:
CDMA (Code Division Multiple Access), GSM (Global System for Mobile
Communications), and TDMA (Time Division Multiple Access). Each
type has its own characteristics and features. For instance, GSM
networks are global, and the mobile devices connecting to them can be
used in the United States and abroad.
But 2G networks were primarily intended for digital voice services. Under
ideal circumstances, 2G networks are painfully slow at sending data,
reaching 10 to 19 kilobits per second, which is much less than half the
speed of a traditional 56-kbps dial-up modem. And unless they've been
especially optimized, most Web pages accessed from a 2G network
inch across a handheld screen, which makes surfing the Web on a 2G
wireless device as efficient as running underwater. To date, network
service providers have had a difficult time luring the masses onto the
wireless Web
PDC, PHS
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3G Cellular
Mobile telephony allowed us to talk on the move. The internet turned raw data
into helpful services that people found easy to use. Now, these two
technologies are converging to create third generation mobile services.
In simple terms, third generation (3G) services combine high speed mobile
access with Internet Protocol (IP)-based services.
The 3G technology primarily consists of two standards, WCDMA (Wideband
CDMA) and CDMA2000.
Third generation: It is in the mid-1980s that the concept for IMT-2000,
"International Mobile Telecommunications", was born at the ITU as the third
generation system for mobile communications. After over ten years of hard
work under the leadership of the ITU, a historic decision was taken in the year
2000 : unanimous approval of the technical specifications for third generation
systems under the brand IMT-2000. The spectrum between 400 MHz and 3
GHz is technically suitable for the third generation. The entire
telecommunication industry, including both industry and national and regional
standards-setting bodies gave a concerted effort to avoiding the fragmentation
that had thus far characterized the mobile market. This approval meant that for
the first time, full interoperability and interworking of mobile systems could be
achieved.
IMT-2000 offers the capability of providing value-added services and
applications on the basis of a single standard. The system envisages a
platform for distributing converged fixed, mobile, voice, data, Internet and
multimedia services. One of its key visions is to provide seamless global
roaming, enabling users to move across borders while using the same number
and handset. IMT-2000 also aims to provide seamless delivery of services,
over a number of media (satellite, fixed, etc…). It is expected that IMT-2000
will provide higher transmission rates: a minimum speed of 2Mbit/s for
stationary or walking users, and 348 kbit/s in a moving vehicle. Secondgeneration systems only provide speeds ranging from 9.6 kbit/s to 28.8 kbit/s.
Third generation standard: The basic 3G standards were developed largely
by the private sector rather than formal standards organizations. However, the
International Telecommunication Union has adopted International Mobile
Telecommunications 2000 (IMT-2000) to formally standardize the already
developed 3G-wireless flavors, to let them offer a consistent set of services
throughout the world, and to provide a roadmap for upgrades
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4G cellular
WiMAX WiBro
Smart antennas
Multiple-Input-Multiple-Output Systems
Space-Time Coding
Dynamic Packet Assignment
Wideband OFDM
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Generation
Speed
1G
Technology
System
Analog
NMT,AMPS,TACS
2G
64Kbps
TDMA
PDC,GSM,PHS
2.5G
100Kbps
CDMA
Cdma One(IS-95),GPRS
3G(IMT-2000)
5 ~ 10 Mbps
CDMA
W-CDMA,CDMA-2000,EVDO
3.5G
14.4Mbps
CDMA
HSDPA,E-HSPA
Pre-4G
75Mbps
OFDM
WiMAX, WiBro, UMB
4G
100M~1Gbps
OFDM
AMPS: Advanced Mobile Phone System
EV-DO: Evolution-Data Optimized
GPRS: General Packet Radio Service
GSM: Global System for Mobile Communications
HSDPA: High Speed Downlink Packet Access
IMT: International Mobile Telecommunications
NMT: Nordic Mobile Telephone
OFDM: Orthogonal Frequency Division Multiplexing
PDC: Personal Digital Cellular
PHS: Personal Handy-phone System
TACS: Total Access Communications System
TDMA: Time Division Multiple Access
UMB: Ultra Mobile Broadband
W-CDMA: Wideband - Code Division Multiple Access
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Early telecommunications included smoke signals and drums. Drums
were used by natives in Africa, New Guinea and South America, and
smoke signals in North America and China. Contrary to what one might
think, these systems were often used to do more than merely announce
the presence of a camp.
In 1792, a French engineer, Claude Chappe built the first visual
telegraphy (or semaphore) system between Lille and Paris. This was
followed by a line from Strasbourg to Paris. In 1794, a Swedish engineer,
Abraham Edelcrantz built a quite different system from Stockholm to
Drottningholm. As opposed to Chappe's system which involved pulleys
rotating beams of wood, Edelcrantz's system relied only upon shutters
and was therefore faster. However semaphore as a communication
system suffered from the need for skilled operators and expensive towers
often at intervals of only ten to thirty kilometres (six to nineteen miles). As
a result, the last commercial line was abandoned in 1880.
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On September 11, 1940 George Stibitz was able to transmit problems using
teletype to his Complex Number Calculator in New York and receive the
computed results back at Dartmouth College in New Hampshire. This
configuration of a centralized computer or mainframe with remote dumb
terminals remained popular throughout the 1950s. However it was not until
the 1960s that researchers started to investigate packet switching — a
technology that would allow chunks of data to be sent to different computers
without first passing through a centralized mainframe. A four-node network
emerged on December 5, 1969 between the University of California, Los
Angeles, the Stanford Research Institute, the University of Utah and the
University of California, Santa Barbara. This network would become
ARPANET, which by 1981 would consist of 213 nodes. In June 1973, the first
non-US node was added to the network belonging to Norway's NORSAR
project. This was shortly followed by a node in London.
ARPANET's development centred around the Request for Comment process
and on April 7, 1969, RFC 1 was published. This process is important
because ARPANET would eventually merge with other networks to form the
Internet and many of the protocols the Internet relies upon today were
specified through this process. In September 1981, RFC 791 introduced the
Internet Protocol v4 (IPv4) and RFC 793 introduced the Transmission Control
Protocol (TCP) — thus creating the TCP/IP protocol that much of the Internet
relies upon today. A more relaxed transport protocol that, unlike TCP, did not
guarantee the orderly delivery of packets called the User Datagram Protocol
(UDP) was submitted on 28 August 1980 as RFC 768. An e-mail protocol,
SMTP, was introduced in August 1982 by RFC 821 and HTTP/1.0 a protocol
that would make the hyperlinked Internet possible was introduced on May
1996 by RFC 1945.
However not all important developments were made through the Request for
Comment process. Two popular link protocols for local area networks (LANs)
also appeared in the 1970s. A patent for the Token Ring protocol was filed by
Olof Soderblom on October 29, 1974. And a paper on the Ethernet protocol
was published by Robert Metcalfe and David Boggs in the July 1976.
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Telecommunication is the technique of transmitting a message, from one
point or place to another with the typical additional attribute of being bidirectional. In practice it also recognizes that something may be lost in the
process; hence the term 'telecommunication' covers all forms of distance
communications, including radio, telegraphy, television, telephony, data
communication and computer networking.
The elements of a telecommunication system are a transmitter, a
medium (line) and possibly a channel imposed upon the medium, and a
receiver. The transmitter is a device that transforms or encodes the
message into a physical phenomenon; the signal. The transmission
medium, by its physical nature, is likely to modify or degrade the signal on
its path from the transmitter to the receiver. The receiver has a decoding
mechanism capable of recovering the message within certain limits of
signal degradation. In some cases, the final "receiver" is the human eye
and/or ear (or in some extreme cases other sense organs) and the
recovery of the message is done by the brain.
Telecommunication can be point-to-point, point-to-multipoint or
broadcasting, which is a particular form of point-to-multipoint that goes only
from the transmitter to the receivers.
The art of the telecommunications engineer is to analyse the physical
properties of the line or transmission medium, and the statistical properties
of the message in order to design the most effective encoding and
decoding mechanisms.
When systems are designed to communicate through human sense
organs (mainly vision and hearing), physiological and psychological
characteristics of human perception will be taken into account. This has
important economic implications and engineers will research what defects
may be tolerated in the signal yet not affect the viewing or hearing
experience too badly.
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Bell Labs scientist Claude E. Shannon published A Mathematical Theory of
Communication in 1948. This landmark publication was to set the
mathematical models used to describe communication systems called
information theory. Information theory enables us to evaluate the capacity
of a communication channel according to its bandwidth and signal-to-noise
ratio.
At the time of publication, telecommunication systems were predominantly
based on analog electronic circuit design. The introduction of massproduced digital integrated circuits has enabled telecom engineers to take
full advantage of information theory. From the demands of telecom circuitry,
a whole specialist area of integrated circuit design has emerged called
digital signal processing.
He designed and built chessplaying, maze-solving, juggling
and mind-reading machines.
These activities bear out
Shannon's claim that he was
more motivated by curiosity than
usefulness.
In his words "I just wondered how
things were put together."
Claude Shannon's clever
electromechanical mouse, which
was one of the earliest attempts
to "teach" a machine to "learn"
and one of the first experiments
in artificial intelligence.
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A telecommunication system consists of three basic elements:
1.a transmitter that takes information and converts it to a signal;
2.a transmission medium that carries the signal; and,
3.a receiver that receives the signal and converts it back into usable
information.
For example, in a radio broadcast, the broadcast tower is the transmitter,
free space is the transmission medium and the radio is the receiver. Often
telecommunication systems are two-way, and a single device acts as both a
transmitter and receiver or transceiver. For example, a mobile phone is a
transceiver.
Telecommunication over a phone line is called point-to-point communication
because it is between one transmitter and one receiver. Telecommunication
through radio broadcasts is called broadcast communication because it is
between one powerful transmitter and numerous receivers.
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During the next ten years great changes are expected in the ways of doing
business on the telecommunications markets. The relative importance of
traditional transmission and switching services will decrease. This is due both
to liberalisation of telecommunications and to developments in the
technology. We anticipate that in the future transmission and switching are
done using generic technology based on international standards.
In telecommunications there are currently several architectures that need
proper services. 1) Intelligent Network (IN), 2) Telecommunications
Management Network (TMN), 3) Telecommunications Information Networking
Architecture (TINA), and 4) the third generation mobile systems (UMTS and
FPLMTS/IMT-2000).
TINA-C, a world wide consortium developing the Telecommunication
Information Networking Architecture (TINA), has the goal to define and to
validate an open architecture for future telecommunications services. The
architecture is based on distributed computing, object orientation, and other
standards and recommendations in telecommunications and distributed
processing fields, especially Open Distributed Processing (ODP), Intelligent
Networks (IN), Telecommunications Management Networks (TMN),
Asynchronous Transfer Mode (ATM), and Common Object Request Broker
Architecture (CORBA).
TINA: The purpose of these principles is to insure interoperability, portability
and reusability of software components and independence from specific
technologies, and to share the burden of creating and managing a complex
system among different business stakeholders, such as consumers, service
providers, and connectivity providers.
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Examples of telecommunications systems:
Telegraphy
Public Switched Telephone Network (PSTN)
Radio
Television
Communications satellites
Mobile Phone
Local Area Network (LAN), Ethernet : best effort type
Internet : best effort type
xDSL : ADSL、RADSL、SDSL、HDSL、VDSL
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3. Network planning
The Master Plan provides a realistic and achievable image of the County,
both present and future, through a framework of goals and policies. The
goals provide general statements reflecting the desires of county residents
regarding the use of land and lay the groundwork for zoning and the land
use decision making process. The policies provide the County's positions
relating to the identified goals and establish guidelines for direction or
action.
The physical development of the County has direct and indirect effects on
property rights, natural resources and property values. This Master Plan
seeks a balance that respects both, in an effort to maintain the county
residents' quality of life. Therefore, it is the intent to allow development that
is responsible and consistent with the goals and objectives set out in this plan.
Country Goal
Master Plan
5~10 Years
Demand
Quality of Life
Country Development Plan
Execution Plan
Several Projects
Projects Plan
Project Selection
Proposal Specification
Vendor’s Proposal
P/D/C/A
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Example of Master Plan:
e-Japan : Summary (2001~2005)
(January 22, 2001)
Japan must take revolutionary yet realistic actions promptly in order to create
a "knowledge-emergent society,"where everyone can actively utilize IT and
fully enjoy its benefits. We will strive to establish an environment where the
private sector, based on market forces, can exert its full potential and make
Japan the world's most advanced IT nation within five years.
1. Philosophy
In order for Japan to continue its economic prosperity and raise the quality of
life, it is vital to promptly establish a new national infrastructure, including
legal frameworks and information infrastructures, suitable for a new society.
The United States, European and Asian nations are aggressively developing
their IT infrastructures as part of their national strategies, in order to secure
world competitive leadership in the 21st century, in recognition of the
importance of creating a "knowledge-emergent" environment.
In order to implement necessary institutional reforms and measures quickly
and steadfastly aiming at the world's most advanced IT environment, Japan
must establish a national strategy and ensure its common and shared
understanding among the nation's citizens. The government should promptly
establish an infrastructure that functions according to market forces, so that
the private sector can engage in various creative activities through free and
fair competition.
(1). Establishment of the ultra high-speed network infrastructure and
competition policies
Aim to provide high-speed constant access networks to at least 30million
households and ultra high-speed (100Mbps) constant access to 10million
households. Promote the shift to the Internet networks equipped with IPv6,
FTTH/CATV/XDSL/FWA.
(2). Facilitation of electronic commerce
(3). Realization of electronic government
(4). Nurturing high-quality human resources
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Wireless Telecommunications Master Plan
A Wireless Telecommunications Master Plan must be fluid and capable of
evolving to accommodate additional carriers, services, (i.e., wireless internet,
a commodity that was not envisioned when Telecommunications Act of 1996
was written and is the next major impending technology), as well as
population growth and future local infrastructure development.
The Master Plan is more than a set of prepackaged guidelines for wireless
development; rather it is a functional representation of the community's
physical space and demonstrates existing and potential wireless facilities.
With a Master Plan, the community will know how and where future
telecommunications infrastructure deployments will occur, rather than
reacting to demands from multiple service providers or tower owners.
The Master Plan, as enabled by the Ordinance, lessens the burden on staff
by streamlining the application process for those applicants who develop in
accordance to the Ordinance and Master Plan, as well as shifting the
technical review from staff to a third party who is certified in those disciplines
necessary to conduct and certify such reviews.
The Master Plan combines land-use planning strategies used in public policy
with industry-accepted radio frequency engineering standards to create an
illustrative planning tool that complements the Development Ordinance. The
first step is to identify existing tower locations and their corresponding signal
coverage conditions. Second, compare this information to the locations of
public-owned land and existing public policy; followed by a series of
evaluations founded on land use principles and engineering practices. The
plan offers strategies to reduce tower infrastructure by improving efforts to
"merge" wireless deployments from various service providers, thereby
minimizing tower proliferation by increasing shared sites.
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On a worldwide market viewpoint, the next several phases of wireless are
inevitable. In Japan and Europe, 3G is already being deployed and utilized by
the citizens in those countries. According to the wireless telephone
manufacture Nokia, the Nokia 3G network solution was available for operators
in 2001 and 2002. The first locations to have 3G services were Japan in 2001
and Europe in 2002.
The United States is starting to experience the first deployments of 3G; other
parts of the world are being introduced to 4G. Proving to early skeptics that
while the deployment of wireless services in the United States have slowed
down, 3G services will continue to evolve and be sold here and abroad. The
article below explains the type of wireless services now being promoted in Asia
which will eventually be promoted in the United States.
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Network planning and design is an iterative process, encompassing
topological design, network-synthesis, and network-realization, and is aimed
at ensuring that a new network or service meets the needs of the subscriber
and operator. The process can be tailored according to each new network or
service.
This is an extremely important process which must be performed before the
establishment of a new telecommunications network or service.
A traditional network planning methodology involves four layers of
planning, namely:
1.business planning
2.long-term and medium-term network planning
3.short-term network planning
4.operations and maintenance.
The network planning process begins with the acquisition of external
information. This includes:
1.forecasts of how the new network/service will operate;
2.the economic information concerning costs; and
3.the technical details of the network’s capabilities.
Before the network planning process begins, choices must be made,
involving protocols and transmission technologies .
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Once the initial decisions have been made, the network planning process
involves three main steps:
Topological design: This stage involves determining where to place the
components and how to connect them. The (topological) optimisation
methods that can be used in this stage come from an area of mathematics
called Graph Theory. These methods involve determining the costs of
transmission and the cost of switching, and thereby determining the optimum
connection matrix and location of switches and concentrators.
Network-synthesis: This stage involves determining the size of the
components used, subject to performance criteria such as the Grade of
Service (GoS). The method used is known as "Nonlinear Optimisation", and
involves determining the topology, required GoS, cost of transmission, etc.,
and using this information to calculate a routing plan, and the size of the
components.
Network realization: This stage involves determining how to meet capacity
requirements, and ensure reliability within the network. The method used is
known as "Multicommodity Flow Optimisation", and involves determining all
information relating to demand, costs and reliability, and then using this
information to calculate an actual physical circuit plan.
These steps are interrelated and are therefore performed iteratively, and in
parallel with one another. The planning process is highly complex, meaning
that at each iteration, an analyst must increase his planning horizons, and in
so doing, he must generate plans for the various layers outlined above.
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During the process of Network Planning and Design, it is necessary to
estimate the expected traffic intensity and thus the traffic load that the
network must support. If a network of a similar nature already exists, then it
may be possible to take traffic measurements of such a network and use
that data to calculate the exact traffic load. However, as is more likely in
most instances, if there are no similar networks to be found, then the
network planner must use telecommunications forecasting methods to
estimate the expected traffic intensity .
The forecasting process involves several steps as follows :
1.Definition of problem;
2.Data acquisition;
3.Choice of forecasting method;
4.Analysis/Forecasting;
5.Documentation and analysis of results.
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In telecommunication, and in particular teletraffic engineering, the quality of
voice service is specified by two measures: the grade of service (GoS)
and the quality of service (QoS).
Grade of service is the probability of a call in a circuit group being blocked
or delayed for more than a specified interval, expressed as a vulgar fraction
or decimal fraction. This is always with reference to the busy hour when the
traffic intensity is the greatest. Grade of service may be viewed
independently from the perspective of incoming versus outgoing calls, and
is not necessarily equal in each direction or between different sourcedestination pairs.
On the other hand, the quality of service which a single circuit is designed
or conditioned to provide, e.g. voice grade or program grade is called the
quality of service. Criteria for different qualities of service may include
equalization for amplitude over a specified band of frequencies, or in the
case of digital data transported via analogue circuits, include equalization
for phase also. Criteria for mobile quality of service in cellular telephone
circuits include the probability of abnormal termination of the call.
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When a user attempts to make a telephone call, the routing equipment
handling the call has to determine whether to accept the call, reroute the
call to alternative equipment, or reject the call entirely. Rejected calls occur
as a result of heavy traffic loads (congestion) on the system and can result
in the call either being delayed or lost. If a call is delayed, the user simply
has to wait for the traffic to decrease, however if a call is lost then it is
removed from the system.
The Grade of Service is one aspect of the quality a customer can expect
to experience when making a telephone call. In a Loss System, the Grade
of Service is described as that proportion of calls that are lost due to
congestion in the busy hour. For a Lost Call system, the Grade of Service
can be measured using Equation 1.
GOS =
No. of lost calls
No. of offered calls
For a delayed call system, the Grade of Service is measured using three
separate terms:
The mean delay td – Describes the average time a user spends waiting for
a connection if their call is delayed.
The mean delay to – Describes the average time a user spends waiting for
a connection whether or not their call is delayed.
The probability that a user may be delayed longer than time t while waiting
for a connection. Time t is chosen by the telecommunications service
provider so that they can measure whether their services conform to a set
Grade of Service.
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Class of Service :
Different telecommunications applications require different Qualities of
Service. For example, if a telecommunications service provider decides to
offer different qualities of voice connection, then a premium voice connection
will require a better connection quality compared to an ordinary voice
connection. Thus different Qualities of Service are appropriate, depending
on the intended use. To help telecommunications service providers to
market their different services, each service is placed into a specific class.
Each Class of Service determines the level of service required.
To identify the Class of Service for a specific service, the network’s
switches and routers examine the call based on several factors. Such
factors can include:
1.The type of service and priority due to precedence
2.The identity of the initiating party
3.The identity of the recipient party
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Quality of Service:
In broadband networks, the Quality of Service is measured using two
criteria. The first criterion is the probability of packet losses or delays in
already accepted calls. The second criterion refers to the probability that a
new incoming call will be rejected. To avoid the former, broadband networks
limit the number of active calls so that packets from established calls will
not be lost due to new calls arriving. As in circuit-switched networks, the
Grade of Service can be calculated for individual switches or for the whole
network.
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Request for Proposal (RFP):
Client
Vendors (Bidders)
RFP
Proposal
RFP:
1. Current network
2. Current system
3. Cabling Requirement
4. Required technology
5. Maintenance
6. Training
7. Equipment specification
8. Equipment quantities
9. Operating services
10. Routing map
11. Uninterrupted power system
12. Guarantee
13. System up grade and change
14. Pre-install cost and post-install cost
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Network Quality:
The question is how to define “ network quality” .
1. Coverage
2. Voice quality
3. Mobility
4. Functionality and services
5. Speed
6. Phone number portability ( same phone number)
7. Easy operation and maintenance
8. Delay
9. Noisy
10. Costly
11. Emergency call
12. Fault tolerance (non stop services)
13. Easy grade up
14. Standardization
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Network management:
Network management refers to the maintenance and administration of
computer networks and telecommunications networks at the top level.
Network management is the execution of the set of functions required for
controlling, planning, allocating, deploying, coordinating, and monitoring the
resources of a network, including performing functions such as initial network
planning, frequency allocation, predetermined traffic routing to support load
balancing, cryptographic key distribution authorization, configuration
management, fault management, security management, performance
management, bandwidth management, and accounting management.
A large number of protocols exist to support network and network device
management. Common protocols include SNMP, CMIP, WBEM, Common
Information Model, Transaction Language 1, Java Management
Extensions - JMX, and netconf.
Note: Network management does not include user terminal equipment.
31
Future’s Network Management System
Network
More Complexity
More Diversification
More High Performance
Network Management System
- Self- Restoration
- Self- Control
- Self- Judgment
- Self- Planning
Need More Intelligent System
Autonomy System
32
New-Built
Up Grade
Network Management
-Master Plan
-Forecast
-Data Collection
(Traffic, GoS, QoS)
-Operation & Maintenance
Present Network
Reconfiguration
33
Common Management Information Protocol (CMIP) :
CMIP was designed in competition with SNMP, and has far more features than
SNMP. For example, SNMP defines only "set" actions to alter the state of the
managed device, while CMIP allows the definition of any type of action. CMIP
was to be a key part of the Telecommunications Management Network vision,
and was to enable cross-organizational as well as cross-vendor network
management.
On the Internet, however, most TCP/IP devices support SNMP and not CMIP.
This is because of the complexity and resource requirements of CMIP agents
and management systems. CMIP is supported mainly by telecommunication
devices.
CMOT is the Common Management Interface Protocol (CMIP) over TCP/IP as
defined in RFC 1189 (a revised version of RFC 1095).
It defines a network management architecture using the International
Organization for Standardization's (ISO) Common Management Information
Services/Common Management Information Protocol (CMIS/CMIP) over
TCP/IP. This architecture provides a way by which control and monitoring
information can be exchanged between a manager and a remote network
entity.
Web-Based Enterprise Management (WBEM):
WBEM is a set of systems management technologies developed to unify the
management of distributed computing environments.
To understand the WBEM architecture, consider the components which lie
between the operator trying to manage a device (configure it, turn it off and on,
collect alarms, etc.) and the actual hardware and software of the device.
Java Management Extensions (JMX):
JMX technology provides the tools for building distributed, Web-based,
modular and dynamic solutions for managing and monitoring devices,
applications, and service-driven networks. By design, this standard is suitable
for adapting legacy systems, implementing new management and monitoring
solutions, and plugging into those of the future.
34
Transaction Language 1 (TL1):
TL1 is a widely used management protocol in telecommunications. It is a
cross-vendor, cross-technology man-machine language, and is widely used
to manage optical (SONET) and broadband access infrastructure in North
America. It is defined in GR-831 by Bellcore (now Telcordia Technologies).
TL1 was developed by Bellcore in 1984 as a standard man-machine
language to manage network elements for the Regional Bell Operating
Companies (RBOCs). It is based on Z.300 series man machine language
standards. TL1 was designed as a standard protocol readable by machines
as well as humans to replace the diverse ASCII based protocols used by
different Network Element (NE) vendors. It is extensible to incorporate vendor
specific commands.
Common Information Model (CIM):
CIM is an open standard that defines how managed elements in an IT
environment are represented as a common set of objects and relationships
between them. This is intended to allow consistent management of these
managed elements, independent of their manufacturer or provider.
Another frequently used way to describe CIM is to say that it allows multiple
parties to exchange management information about these managed
elements. However, this falls short in expressing that CIM not only represents
these managed elements and the management information, but also provides
means to actively control and manage these elements. By using a common
model of information, management software can be written once and work
with many implementations of the common model without complex and costly
conversion operations or loss of information.
The CIM standard is defined and published by the Distributed Management
Task Force (DMTF). A related standard is Web-Based Enterprise
Management (WBEM, also defined by DMTF) which defines a particular
implementation of CIM, including protocols for discovering and accessing
such CIM implementations.
35
Netconf:
Netconf is a network management protocol developed in the IETF by the
Netconf working group. It was published as RFC 4741.
The NETCONF protocol provides mechanisms to install, manipulate, and
delete the configuration of network devices. It also can perform some
monitoring functions. It uses an Extensible Markup Language (XML) based
data encoding for the configuration data as well as the protocol messages.
Wireshark (Ethereal):
In computing, Wireshark (formerly known as Ethereal) is a free software
protocol analyzer, or "packet sniffer" application, used for network
troubleshooting, analysis, software and protocol development, and education.
It has all of the standard features of a protocol analyzer. In June 2006 the
project was renamed from Ethereal due to trademark issues.
The functionality Wireshark provides is very similar to tcpdump, but it has a
GUI front-end, and many more information sorting and filtering options. It
allows the user to see all traffic being passed over the network (usually an
Ethernet network but support is being added for others) by putting the network
card into promiscuous mode.
36
Network Management System (NMS):
A Network Management System (NMS) is a combination of hardware and
software used to monitor and administer a network.
Individual network elements (NEs) in a network are managed by an element
management system.
An element management system (EMS) manages one or more of a specific
type of network elements (NEs). An EMS allows the user to manage all the
features of each NE individually, but not the communication between NEs this is done by the network management system (NMS).
NEs expose one or more management interfaces that the EMS uses to
communicate with and to manage them. These management interfaces use a
variety of protocols including SNMP, TL1, CLI, XML, and CORBA.
37
General relationship of
Telecommunications Management Network (TMN)
Other TMN
A TMN provides management functions for telecommunication networks and
services and offers communications between itself and the
telecommunication networks, services and other TMN. In this context a
telecommunication network is assumed to consist of both digital and
analogue telecommunications equipment and associated support equipment.
A telecommunication service in this context consists of a range of capabilities
provided to customers.
The basic concept behind a TMN is to provide an organized architecture to
achieve the interconnection between various types of Operations Systems
(OS) and/or telecommunications equipment for the exchange of management
information using an agreed architecture with
standardized interfaces including protocols and messages.
38
TMN physical architecture of ITU-T M.3010
DCN: Data Communication Network
NE: Network Element
OS: Operations System
QA: Q-Adapter
QMD: Q-Mediation Device
WS: Workstation
X/F/Q: X/F/Q Interface such as Q.811,Q.812, X.290
39
The Intelligent Network, typically stated as its acronym IN, is a network
architecture intended both for fixed as well as mobile telecom networks. It
allows operators to differentiate themselves by providing value-added
services in addition to the standard telecom services such as PSTN, ISDN
and GSM services on mobile phones.
In IN, the intelligence is provided by network nodes owned by telecom
operators, as opposed to solutions based on intelligence in the telephone
equipment, or in Internet servers provided by any part.
IN is based on the Signaling System #7 (SS7) protocol between telephone
network switching centers and other network nodes owned by network
operators.
The upcoming IP Multimedia Subsystem (IMS) standards can be seen as a
hybrid of intelligent network services and Internet services for cellular
multimedia communication.
Service Management
Service Control Point
(SCP)
No.7 Signaling System
Service Switching Point
(SSP)
Switching
Transmission
40
The main concepts (functional view) surrounding IN services or architecture
are following are connected with SS7 architecture:
Service Switching Function (SSF) or Service Switching Point (SSP) This
is co-located with the telephone exchange itself, and acts as the trigger point
for further services to be invoked during a call. The SSP implements the Basic
Call State Machine (BCSM) which is a Finite state machine that represents an
abstract view of a call from beginning to end (off hook; dialling; answer; no
answer; busy; hang up etc). As each state is traversed, the exchange
encounters Detection Points (DPs) at which the SSP may invoke a query to
the SCP to wait for further instructions on how to proceed. This query is
usually called a trigger. Trigger criteria are defined by the operator and might
include the subscriber calling number or the dialled number. The SSF is
responsible for entertaining calls requiring value added services.
Service Control Function (SCF) or Service Control Point (SCP) This is a
separate set of platforms that receive queries from the SSP. The SCP contains
service logic which implements the behaviour desired by the operator, i.e., the
services. During service logic processing, additional data required to process
the call may be obtained from the SDF. The logic on the SCP is created using
the SCE.
Service Data Function (SDF) or Service Data Point (SDP) This is a
database that contains additional subscriber data, or other data required to
process a call. For example, the subscribers prepaid credit which is remaining
may be an item stored in the SDF to be queried in real time during the call.
The SDF may be a separate platform, or is sometimes co-located with the
SCP.
Service Creation Environment (SCE) This is the development environment
used to create the services present on the SCP. Although the standards permit
any type of environment, it is fairly rare to see low level languages like C used.
Instead, proprietary graphical languages have been used to enable telecom
engineers to create services directly. The languages usually belong to 4G
languages, the user can use Graphical Interface to manipulate between
different functions to formulate a service.
Specialized Resource Function (SRF) or Intelligent Peripheral (IP) This is
a node which can connect to both the SSP and the SCP and delivers
additional special resources into the call, mostly related to voice data, for
example play voice announcements or collect DTMF (Dual-tone multifrequency ) tones from the user.
41
INAP: Intelligent Network Application Protocol
The Service Switching Point (SSP) consists of the hardware switch in
combination with the basic call control software and the added functionality
for the support of IN.
Signal Transfer Point (STP)
In a switching network that contains a separate signalling network based on
SS-7 the transactions between the SSP and SCP are achieved via the STP.
The Service Control Point (SCP) is a real-time database that stores
customer records. When accessed by an enquiry from the SSP, the SCP
executes service logic that has been customised for a particular application.
An Adjunct Processor (AP) is a local SCP. It is tightly coupled to, and colocated with, a single switch. It can use a proprietary protocol for
communication with the switch or it can use the CS-1 standard, Intelligent
Network Application Protocol (INAP).
The Service Management System (SMS) operates off-line from the voice
call network and enables an operator to create, update, and validate, such
items as number translation and call charge tables, and download these
together with service logic code, into the SCP and AP.
42
The Service Creation Environment (SCE) is a high-level interface to the
IN that allows TOs to interactively develop, debug, and provision new
services using software engineering tools whose output is compatible with
the IN systems.
An Intelligent Peripheral (IP) is a stand-alone processor that is tightly
coupled to a switch to provide additional functionality to the SSP in the
switch. Such additional functionality could include:
Access to signalling networks
Recorded announcements
Interactive Voice Response (IVR)
Dual Tone Multi-Frequency (DTMF) translation
Speech recognition
FAX management
43
SNMP RMON (Remote Network Monitoring）
SNMP
Agent
SNMP Manager
SNMP
LAN Switch
Monitor
Network
MIB (Management Information Base）
44
Management Information Sequence
SNMP Agent
SNMP Manager
Read Information
Information Control
(Add, Change, Delete)
Information Report
Event Generated
MIB (Management Information Base)
45
Traffic Measurement on MAC address
Others
MAC Address
Sending Packet
Sending Byte
Receiving Packet
Receiving Byte
46
Traffic Measurement on IP address
IP Address
Sending Packet
Sending Byte
Receiving Packet
Receiving Byte
47
Mean Time Between Failure MTBF:
MTBF is the mean (average) time between failures of a system, and is often
attributed to the "useful life" of the device i.e. not including 'infant mortality' or
'end of life'. Calculations of MTBF assume that a system is "renewed", i.e.
fixed, after each failure, and then returned to service immediately after failure.
The average time between failing and being returned to service is termed
mean down time (MDT) or mean time to repair (MTTR).
48
Mean time to recovery (MTTR):
MTTR is the average time that a device will take to recover from a nonterminal failure. Examples of such devices range from self-resetting fuses
(where the MTTR would be very short, probably seconds), up to whole
systems which have to be replaced.
The MTTR would usually be part of a maintenance contract, where the user
would pay more for a system whose MTTR was 24 hours, than for one of, say,
7 days. This does not mean the supplier is guaranteeing to have the system
up and running again within 24 hours (or 7 days) of being notified of the
failure. It does mean the average repair time will tend towards 24 hours (or 7
days). A more useful maintenance contract measure is the maximum time to
recovery which can be easily measured and the supplier held accountable.
49
4. OSI
Open Systems Interconnection (OSI):
the term "OSI" came into use on 12 October 1979.
OSI Model
Data unit
Host
layer
s
Medi
a
layer
s
Data
Layer
Function
7. Application
Network process to application
6. Presentation
Data representation and encryption
5. Session
Interhost communication
Segments
4. Transport
End-to-end connections and reliability (TCP)
Packets
3. Network
Path determination and logical addressing (IP)
Frames
2. Data link
Physical addressing (MAC & LLC)
Bits
1. Physical
Media, signal and binary transmission
50
OSI Layer Examples
Layer
TCP/IP
SS7
7.Application
DHCP, FTP,
Gopher, HTTP,
NFS, NTP,
RTP, SMPP,
SMTP, SNMP,
Telnet
ISUP, INAP,
MAP, TUP,
TCAP
6.Presentation
OSI
Misc. examples
FTAM, X.400,
X.500, DAP
NNTP, HL7, Modbus,
SIP, SSI
MIME, XDR,
SSL, TLS
ISO 8823,
X.226
TDI, ASCII, EBCDIC,
MIDI, MPEG
5.Session
SIP,DNS
ISO 8327,
X.225
Named Pipes,
NetBIOS, SAP, SDP
4.Transport
TCP, UDP,
SCTP
SCCP
TP0, TP1, TP2,
TP3, TP4
NBF
3.Network
IP, ICMP,
IPsec, ARP,
RIP, OSPF
MTP-3
X.25 (PLP),
CLNP
NBF, Q.931
2.Data Link
PPP, SLIP,
PPTP, L2TP
MTP-2
X.25 (LAPB),
Token Bus
802.3 (Ethernet),
802.11a/b/g/n,
WiMAX, MAC/LLC,
802.1Q (VLAN),
ATM, ISDN, CDP,
HDP, FDDI, Fibre
Channel, Frame
Relay, HDLC, ISL,
PPP, Q.921, Token
Ring
MTP-1
X.25 (X.21bis,
EIA/TIA-232,
EIA/TIA-449,
EIA-530,
G.703)
RS-232, V.35, V.34,
I.430, I.431, T1, E1,
10BASE-T,
100BASE-TX,
POTS, SONET/SDH,
DSL, 802.11a/b/g/n
PHY, Cable
1.Physical
51
7 Layers is used for the Scale of function.
Network
Terminal
Router
Router
Server
L1
APL
L1
1
L3
2
L4
L5
L7
n
L6
L2
Terminal
Server
L1
L2
APL
1
L1
L3
2
L4
L7
L5
n
L6
L1: Connecter / Pin, Data speed, Modulation
L2: Frame transmission, error check
(Ethernet, PPP, ATM, FDDI)
L3: Packet transmission, Logical address control (IP)
L4: Segment control for each application (TCP, UDP)
L5: Application connection service (HTTP, SMTP. POP, FTP)
L6: Letter, Music, Figure, Video (JPEG, MPEG, MIDI)
L7: User interface (GUI)
52