Transition from MSN (Multi Service Network) conception to NGN (Next

Generation Networks) networks conception

JEMAL BERIDZE

Department of Telecommunication

Georgian Technical University

77 Kostava st., Tbilisi

GEORGIA

jberidze@gtu.ge

TATIANA BURKADZE

Department of Telecommunication

Georgian Technical University

77 Kostava st., Tbilisi

GEORGIA

tburka@rambler.ru

Abstract: - In the given work there are presented our views of transition processes to NGN networks in

telecommunications of Georgia.

Key-words: NGN, computer, Multi service networks, IP technology, SDH technology, data traffic.

1 Introduction Idea of telecommunications development by Multi

service Networks conception appeared with idea of

telephone and computer integration in the middle of

ninetieth. This conception is based on data traffic

priority on voice traffic (traditional for channels

commutation networks) and demanded fundamental

changes of telecommunication networks structure on

all layers [1]. Traditionally telecommunication

networks were built by principle “Primary networks

– Secondary networks” (fig.1). Either of them were

developing and completing each other.

Fig.1. Traditional telecommunication networks’

building principle

Primary network standards were developing by the

way of creation and using of PDH and SDH typical

hierarchies. So were created E1, E2, E3, E4 streams

with 2, 8, 34, 140 Mbp/c speeds and STM-1/4/16/64

with 0,155; 0,622; 2,5; 10 Gbp/c speeds. Secondary

networks standards basic were created by customers

requests on Data transfer. The first such system was

ISDN technology, next was SS №7 and later xDSL

technology etc.

With integration of Primary and Secondary

telecommunication networks possibilities Multi

Service Networks – MSN was developing very

rapidly.

2 Problem Formulation However at the end of ninetieth appeared new

generation notebooks with capability of wide range

of services provided by MSN (traditional and digital

telephony, data transfer channel, videoconference,

ISDN, etc.).

As a result all “multiservices” were concentrated in

data terminal equipment (computer) instead of

network itself. Accordingly was changed

telecommunication networks building conception.

Main accent was made on two subscribers’

intellectual terminals – computers interaction.

3 Problem solution By the new conception main task of

telecommunication is building of such transport

network, which can provide transfer of all type traffic

between any network points. Four layer model NGN

– SCTA (Service/Control/Transport/Access) was

established. NGN telecommunication network

building principle is shown on fig 2.

Fig.2. NGN telecommunication networks building

principle

Users

Secondary

network

Secondary

network

Users

Primary

network (Bank of typical

channels)

Channel Channel Service

Service

Users

Network of

access

Users

Transport

network

Resource

Service

Service

Information

resources

Network of

access

Resource

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ISSN: 1790-5117 290 ISBN: 978-960-474-088-8

Comparing Traditional Networks (fig. 1) with NGN

Networks (fig. 2) it could be concluded, that by the

new concept of the networking the primary network

changes into transport layer, and secondary network

changes into access layer.

User switches the transport layer through the access

network. Within this access layer users are given the

specific resource – access channel. Parameters of

access channel define the quality of NGN and

available services for NGN user.

In NGN Networks after access layer, transport layer

resources are used to achieve the destination point of

information or other users in the network.

Nowadays, need for high speed of information

transmission is increasing, so information

transmission rate of 200-400 Kbps need to be

increased up to 5 Mbps and more. This fact

immediately expels the use of modem transmission,

and as a result the Traditional “Phone-to-Phone”

network is changing into the network “PC-to-PC”.

Moreover, transition of Traditional Networks into

NGN networks caused formulation of four level

model of NGN networks – Service/

Control/Transport/Access (SCTA) (fig. 3).

Fig.3. Modern NGN network architecture

Every level from this model has defined function:

access layer A supports access of user to network

resources;

transport layer T is the basic resource of the

network, accomplishing information transmission

between the users;

control layer C represents new type of commutation,

which is based on use of IP telephony and

Softswitch;

service layer S determines traffic flow of the

network. Here is represented information about

useful traffic of the network, which allows user to

access the source of information.

User receives access channel through which enters

transport layer, as we can see it is in fig. 3. Transport

layer transmits information traffic flow between the

user and source of information. Interaction of source

and destination (user itself) points of information is

accomplished by traffic level, and Service Level

supports of beck-up of appropriate quality of

transmission.

In this work there are represented researches results

of one of the most important layer - transport layer.

Transport layer is the base of the NGN networks. It

represents the principle of connection between users

and information sources. Transport layer architecture

should be built according the scheme, which satisfies

Service Providers’ development strategic plans. In

fig. 4 there is shown how transport layer is

performing. In the given example users of transport

layer resources are access layers.

Fig.4. Access networks interaction through transport

layer

For traffic service transport layer must provide

following NGN procedures: traffic distribution,

traffic leveling, traffic routing on different topology

(point-to-point, point-to-multipoint, etc) networks,

traffic doubling, multiplexing and demultiplexing

and etc. As better networks transport layer is

servicing packages traffic as effective is technical

solution. Transport layer idea as part of NGN, which

can provide any format data transfer, is demanding

data unification. Different data from different access

networks should be transformed to common format

for transfer by transport layer. Requirements for

different access network compatibility for using

transport layer leads to necessity of data packages

standard formatting. That is the base of these

The demanded information (content)

Level of services (S)

Level of management (C)

Level of transport (T)

Level of access (A)

Users

?

Level of management

Transport

network

The incorporated network Access

Network Access 2

Network Access 1

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ISSN: 1790-5117 291 ISBN: 978-960-474-088-8

networks. As common transport for packages

networks is used IP technology. Exactly this

technology is the most convenient frame for modern

networks.

Let’s build multilayer conception of transport

networks NGN from new positions, which are

involving all modern network technologies from

physical layer to transport layer of OSI (fig.5).

Fig.5. Modern conception of NGN transport layer

In modern telecommunication networks, which have

the tendencies of transition from traditional channel

commutation to packages commutation is using two

methods of packages commutation – virtual channel

method and datagram method. In NGN traditional

network TDM (Time Division Multiplexing) and

packages networks segments are integrated into

WDM (Wavelength Division Multiplexing). We can

discuss two ways of integration:

1. Integration on NGSDH (Next Generation SDH) layer;

2. Integration by two channels of WDM system, where one of the channels is used for

packages transfer and another for traditional

digital telecommunication network SDH

(Synchronous Digital Hierarchy).

Networks are integrating on basis of common

transport WDM, but dividing on final multiplexer’s

layer. Possible integration of above mentioned two

versions can provide creation of modern multilayer

conception of transport networks with using of

cabling, analog, packages and TDM technologies.

Transport networks development rejected the idea of

channel and conversed to packages commutation. On

that stage even transferred the meaning of NGN user.

Modern meaning of NGN user includes home

network, which is using so many technologies that

we can call it convergent. Accordingly transport

layer transfers to mechanism for connection of home

networks. The result is developing of LAN-LAN

connections technology.

Let’s consider transition of Georgian

telecommunication infrastructure to NGN.

We can say that nowadays there is the process of

preparing the transition of telecommunication

networks to NGN. There is going the replacement of

all electromechanical and quasielectronical

commutation technologies by new digital (in large

cities by Softswitch) technologies. IP and DSL

technologies are implemented on access networks.

However, as we already mentioned one of the main

component of NGN-SCTA is Transport network.

Reliable Transport network for future NGN in

Georgia could be built on existing optical-mains –

Foptnet and Railway Telecom. Although both

optical-mains are passing same rout over Georgia

now, but there are still some differences between

branches. For example, Foptnet has domestic

branches over Zugdidi and international direction –

to Novorosiisk (and through it to Europe). In its’ tern

Railway Telecom has domestic branches over

Chiatura-Sachkhere and international branches to

Turkey and Bulgaria (Varna Submarine fiber-optic

cable). For NGN both these optical-mains are

completing each other. Certainly there could be some

obstacles as organizational (different belonging), also

technical (using of different suppliers equipment).

However, on our opinion, market economy laws and

state interests will gain and both these optic-mains

will create technical base for main network for future

NGN of Georgia.

Above mentioned modern technologies such as

NGSHDSL and WDM allow to create new transport

main even if there are no free cores in optical cable.

On fig. 6 there is framework scheme of Georgian

NGN Transport network.

4 Conclusions Not only creators and providers of new technologies

are involved in NGN technologies but also wide

range of users.

Considering four layer model of NGN – SCTA,

commutation specialists and administrators are

marking out management layer, which is named as

the main layer of NGN.

Telecommunication services specialists consider that

the kernel of the NGN is Triple Play and Skype

doctrine.

Sublevels:

transport

routing

batch

switching

basic

networks

Levels OSI: transport

Network

Channel

Physical

TCP UDP

Algorithms and reports of routing in

networks IP (RIP, ISIS, OSPF, BGP-4, MPLS)

Applied GE, Switched networks ATM FICON, IP IP Frame ESCON Relay Ethernet

The fiber-optical communication line

SDH

Optical switching

WDM/DWDM

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ISSN: 1790-5117 292 ISBN: 978-960-474-088-8

Fig. 6. Prospective NGN of Georgia

In the view of telecommunication business main

point is payback of networks reconstruction. Also

one of the important (maybe the most important)

point is information packages transportation by

NGN, which is connected with dynamic routing

systems, IP traffic assignment and etc.

The use of telecommunications technology has

operated for NGN (example is the above tracts

Foptnet, Railway Telecom of Georgia) and the

digital distribution network (access network) as a

base, you can quickly and efficiently (from an

economic point of view) go to the NGN-SCTA

model for constructing telecommunication

network of Georgia.

References:

[1] I.G. Baklanov, NGN: Printsipy Postroenia I

Organizatsii (in Russian), M: Eko-Trends, 2008,

pp.400.

to Varna

Sachkhere

Chiatura

Multiplexsor

to ABKHAZIA

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