Evolution of network architectures

INTRODUCTION

Telecommunications has undergone one of the most intensive and significant processes of changes thus far known.

Since 2004, a major crisis factor has arisen in large telecommunication companies, especially for those that have been operating principally as telephone operators or POTS.[1]  This crisis factor is the technological evolution now under way.  It will permanently alter the future and structure of telecommunication sectors worldwide and, therefore, the course and structure of all companies in this sector.  Such evolution is known generically as New Generation Networks or Next Generation Networks (NGNs).

Telecommunication companies and services that formerly operated independently, such as voice companies and services, television companies and services, data companies and services, etc., in technological terms will now be able to be consolidated and to provide all such services at the same time over their own IP networks.

PERIODS FOR THE DEVELOPMENT OF NEXT GENERATION NETWORKS

Thus far, two major periods can be identified in the development of Next Generation Networks.

The period from 2005 to 2010, where: 

• Voice over Internet Protocol (VoIP) and, in general, Internet protocols (IP) and broadband services will become predominant and determining factors.

• The predominance of IP protocols makes possible a new phase of convergence over a single telecommunication network still characterized by “unintelligent” networks (which only transmit) and by “intelligent terminals” (that decode and perform detailed work).

• IP networks and protocols are technologies that have finally made possible the convergence of all telecommunication services on a single technological platform, over the same networks.

• As IP networks have a different architecture from that of traditional telephone networks, from 2005 to 2010, telephone exchanges will gradually disappear and, in general, there will be no further growth of the Public Switched Telephone Network.[2]

• Telecommunication companies will compete to provide increasingly complex and personalized value added services for their customers.

• In fact, new and increasingly intense and aggressive competition is anticipated among telecommunication companies.  It is likely that the most intense competition will be between evolving telephone companies and cable companies or those will external plant (copper) and the new VoIP companies.

The period from 2007 to 2012:

Experts predict a second stage in the development of New Generation Networks, in which there may potentially be “intelligent networks” that open up an unimaginable universe of possibilities for increasingly complex telecommunication services of ever greater added value.

TYPES OF TELECOMMUNICATION NETWORKS

Today, the telecommunication world consists of three interrelated networks: 

1.     The first is the Public Switched Telephone Network (PSTN).

This is the traditional telephone network, with dedicated lines, telephone exchanges, the telephone node as the network’s core, and a universal numbering system.  As such, these components are tending to disappear as technology evolves.  The numbering system may change.  The dedicated line concept is extremely expensive, as dedicated lines require maintenance of the costly PSTN which, most of the time, is not in use.

2.          The second network is the wireless network, led by cellular telephony.

In fact, new wireless technologies (WiFi and WiMax) presage the growing development of wireless technology.  What happened with mobile cellular telephony may herald this process.  In the past 15 years, the mobile cellular telephony network has witnessed spectacular progress marked by four technological generations (the first analog generation; second digital GSM system generation; second and half generation (the GPRS, Edge, and Bluetooth systems); and third generation.

Third generation (cellular telephony) 

·   Symmetric/asymmetric transmission

§  384 kbits/s in open spaces

§  2Mbit/s in low mobility   

§  Dynamic use of bandwidth

§  Supports both packet switching and circuit switching

§  Different simultaneous services, a single connection

§  Voice quality similar to that of the fixed network

§  Greater capacity and more efficient spectrum use

This intensive technological evolution has also been accompanied by intensive growth.  In 15 years, the number of mobile lines has grown to more than twice the number of fixed lines worldwide.

3.     The third network is the INTERNET network

These are networks that switch and transmit data, which is sent as a sequence of “packets,” each of which contains a number of bites of information.  The “numbering” system for domain names and IP addresses is alphanumeric.  The network sends each data packet to the addressee’s address.  The route is not dedicated as in the telephone network and, therefore, this network utilizes any available route.

The Internet is designed to transmit data over a variety of communications media.  Therefore, it is highly flexible.  The Internet may be accessed via the PSTN and copper pair utilizing a modem or via dedicated broadband access, whether radio, fiber optic, ADSL, HFC[3], or coaxial cable.  There is no central node.  The Internet service provider provides connection to the trunk network utilizing relatively simple routers that enable each packet to be switched (routed) towards the destination address.

Utilizing the applications of the user’s terminal, any information – whether text, information, voice, music, television, videoconference, e-commerce, etc. – can be converted into data and sent as packets over the Internet.  When converted into bites, voice can be transmitted over the Internet as data packets.  This is the basic principle of Voice over Internet Protocol (VoIP).

VoIP is a technology where telephone calls can be made using the Internet protocol.  It is a technology now evolving rapidly in telecommunications.  VoIP networks are replacing traditional telephony operators and not only reduce the cost of traditional voice services, but also provide a much wider variety of services:  They afford an opportunity to integrate voice into the different Internet protocol applications.

The IP protocol has the following characteristics:  efficiency, flexibility, and reliability.  In general terms, the Internet protocol (IP):

• Operates at the network layer level;

• Provides logical network addressing;

• Provides dynamic route selection;

• Operates via any transmission scheme.

The evolution of the architectures of networks now consolidated under the IP protocol, and VoIP may be seen as only the start of a first stage of Next Generation Networks.  The value of the existing PSTN network is rather little unless it evolves rapidly, efficiently, and competitively to become a Next Generation Network.  This is one of the most important challenges facing traditional telephone companies, whose network, from the customer standpoint, will become one of several to be utilized in accessing new services.

To summarize, the technological evolution of telecommunications involves two main elements:

• Services:   IP protocols and broadband, led by VoIP services, voice, data, and video (triple play), networks, games, etc.

• Customer access technology (connectivity): copper (ADSL), cable, WiFi, WiMax, PLC,[4] and satellite.

Although VoIP is the immediate challenge, we must not lose sight of its broad context, which is one of long-range technological evolution.

MARKET TRENDS

VoIP transmission is now replacing telephone exchanges.

The market trend is to provide a wide variety of services over a single, scalable, and flexible convergent network platform.  In the new NGN scenarios, customers will be able to select from among different connection options and receive the same services without knowing whether their company is a telephone, cable TV, VoIP, or other type of company.  Companies will be distinguished by the variety of services they offer their customers, tariffs, and, to a large extent, service quality.

Translations:  Management and backup LAN; Production LAN; Server Config.; Real-time billing; Administration, monitoring, and provisioning; Redundant database system (master/slave); Interconnection exchange; VoIP gateways; Broadband access; User softphone.

The strategy of such companies is clear:  to evolve the traditional telephone network to a high-technology Next Generation Network in order to retain existing customers and fully enter the competition for new clients as broadband services become generalized.
 

Maria Josefina Cano de Ahrens
Head of Divion Statistics of networks and Quality of Service .
COPACO, S.A