Convergence Towards Packet Networks Sanjay Kumar Sharma

Life Member, IETE, Assistant Professor, Electronics & Communication Engg. Department Krishna Institute of Engg.& Technology, 13 KM stone, Ghaziabad-Meerut Road, Ghaziabad-201206 (U.P.) India

E-mail: sanjaysharma@kiet.edu

Vibhav Kumar Sachan

Assistant Professor

Electronics & Communication Engg. Department Krishna Institute of Engg.& Technology, 13 KM

stone, Ghaziabad-Meerut Road, Ghaziabad-201206 (U.P.) India

E-mail: vibhavsachan@kiet.edu

ABSTRACT In the last 10 years or more, we have seen an increasing fast integration of computers and

telephony, both equipment and networks. Traditional public network operators (PNOs) have seen a decrease in telephony traffic on their public switched telecommunications networks (PSTNs), due in part to the increasing popularity of mobile telephones and the movement of services from telephone networks to the public Internet. The concept of a new, integrated broadband network has developed over the last few years and has been labeled next-generation network (NGN).The basic characteristics of an NGN can be determined from the problems faced by the network operations e.g. the need to provide services over broadband accesses, the need to merge diverse network services, such as data, voice, telephony, multimedia and emerging popular Internet services, and the desire of customers to be able to access their services from anywhere (internet mobility).Basically, an NGN aims to combine the best of both worlds from the PSTN and the Internet. This paper provides some insight into the history, definition, requirements and future trends of next-generation network standards. The paper concentrates on a high-level overview to provide a strategic direction toward a complete NGN providing fixed-mobile convergence, telebroadcasting, and all aspects of 21st century communications. 1. INTRODUCTION

In this fast changing modern technical age, there has been rapid changes in various technologies such as microelectronics, software, photonics and wireless. These rapid changes are disrupting the fundamental nature of networks. In addition, there are various other contributing factors, which are responsible for disruption of basic nature of networks. These factors include the deregulation in telecommunication markets on a global scale, decreased terminal costs, migration of analog networks to digital networks and the increased competition among service providers. Infact, because of all these contributing factors, the high speed, high capacity data services are driving the next generation network architecture toward a packet network. Basically, these next generation networks (NGNs) are of the following two types: (i) Wired networks (ii) Wireless networks

2. NEXT GENERATION WIRED NETWORKS The modern wired networks may be classified into following two groups:

(i) the public switched telephone network (PSTN), and (ii) the public switched data network (PSDN).

The PSTN incorporates large, centralized, proprietary switches with remote switching modules and digital loop carriers. Infact, the PSTN is a low delay, fixed bandwidth network. On the other hand, the PSDN is based mainly on packet switches which provide very flexible data services. The PSDN is a variable delay, variable bandwidth network that provides no guarantees on the quality of service (QOS).

2.1. FUTURE PROJECTION: The projection is that the data traffic volumes will overtake voice traffic volumes around the world over the next few years. This estimation is based upon the explosive

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growth of the Internet and related intranets and extranets. As data traffic surpasses voice traffic, it will be desirable to converge the multiple networks around a single packet-based core network. Infact, such convergence will support emerging multimedia services, increase the ability of a carrier to support the multiple needs of its customers and reduce the cost of network operations. This convergence around a packet-based core will also allow the many networks to collaborate. As a result of this, the customers will think that they are working with a single, integrated network.

In addition, continuing exponentially increasing advancements in microelectronics, photonics, and wireless technology are supporting the market drive to converged networks. Infact, these technologies provide the cost-effective foundation for the network elements making up the next generation of converged networks. The next generation networks will likely share a high level architecture. The next generation wired networks will contain the following two major ingredients:

(i) Packet - based optical core: This may be called as the backbone networks. In fact the core transport network will be built around dense wave division multiplexing (DWDM) transport systems. As a matter of fact, systems carrying 400 Gbps utilizing 80 wavelengths are now available. They will rapidly evolve to carry significantly more information using an ever-increasing number of wavelengths. Today, building a converged network core that provides a good quality of service requires accommodating following four protocols: -

(a) IP (b) STM (c) ATM (d) DWDM Each protocol provides important network capabilities. (ii) Broadband Access: There shall be multiple broadband access solutions for residences and businesses. Access systems include ADSL and FSO. Asymmetric digital subscriber line (ADSL) protocols allow a few megabits to be carried over the already existing copper wiring in a cost-effective manner. Free space optical (FSO) networking technologies provide an effective and economical solution to the ‘last mile’ problem of connecting to fiber infrastructure in metropolitan areas. In fact, these protocols support both traditional voice services and data oriented Internet connections.

2.2. CHALLENGES

Basically, There are two technical challenges facing the realization of next generation networks. The first challenge is the quality of service. Next generation networks must provide the PSTN’s level of quality of service, which means availability, reliability, performance and integrity in large-scale networks. The second challenge is transition. The transition path each carrier will follow to its next generation will be unique. The specific transition will be dependent on carrier’s present network, the specific regulatory environment and the carrier’s targeted service offerings.

3. NEXT GENERATION WIRELESS NETWORKS Similar to the wired networks, there are numerous forces, which are responsible for driving

the need for change in the wireless infrastructure. The first of such driving forces is the deregulation and the competitive climate. Basically, the process started with the breakup of AT&T in 1984. It gained up speed with the privatization and was explosively accelerated by the U.S. Telecom act of 1996. Infact, the progressing opening up of global telecommunication markets in the late 1990s even accelerated the quest for a change. The second driving force is the increasing customer demand for telecommunication services. With the introduction of personal communications services (PCS), wireless local loop (WLL) and data services such as cellular digital packet data (CDPD), wireless networks will experience significant increases in telecommunication traffic. Further, this increase will have a terms of meeting (QOS) parameters expected by customers or the services requested. The Third driving force is the downward pressure on costs. The last driving force is the pace of technological advances. Infact, the technology particularly in the commercial hardware and software industries is advancing at an unprecedented rate. The Internet is another technological advance whose full impact is yet to be determined. Thus, any one of these forces is sufficient to cause wireless equipment vendors to adapt their product offerings.

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4. CONCLUSION The combined changes in network services, technology and regulation are creating a golden era of

network innovation. Lot of things are certain in this evolution. Just for instance, the networks will have a shared, packet-based, optical-core network using DWDM optical transport with optical add/drop and multiplexing. Wireless communications is expected to be a major driver for growth in the telecommunications industry over the next decade. Future networks (both wireless and wire line) will pave the way for an environment in which information will be made more portable, personal and affordable. 5. REFERENCES [1]. G.E. Fry et al., “Next-generation wireless networks,” Bell Labs Tech., J., pp. 88-96, Autumn 1996. [2]. D.C. Dowden, R.D. Gitlin and R.L. Martin, “Next-generation networks,” Bell Labs Tech. J., pp. 3-14, Dec.,

1998. [3]. A.R. Modarressi and S. Mohan: “Control and management in next-generation networks: Challenges and

opportunities,” IEEE Commun. Mag., pp. 94-102, Oct. 2000. [4]. A.R. Modrressi and S. Mohan, “Advanced signaling and control in next-generation networks, “IEEE

Commun. Mag., pp. 92-93, Oct. 2000. [5] M.Mampaey, “TINA for services and advanced signaling and control in next-generation networks,” IEEE Commun. Mag., pp. 104-110, Oct. 2000. [6] M.N.O. Sadiku, Optical and Wireless Communications: Next-Generation Networks, Boca Raton, FL: CRC Press, 2002.

ApplicationServers

ApplicationServers

ApplicationServers

IN Services

CoreNetwork(s)

Backbone ATM Switch(20 Gb/s and Up)

ApplicationServers

ApplicationServers

ResourceServers

PPC5ESSDCS

PDN

PSTN

SS7 SignalingNetwork

ResourceServers

AccessNetwork(s)

Edge ATMSwitch(2.4 Gb/s)

ATMMUX

Circuit SwitchedATM Transport

CDMACell Site

TDMACell Site

OtherCell Site

CDMAMS

TDMAMS

OtherMS

ATM — Asychronous Transfer Mode

CDMA — Code Division Multiple Access

DCS — Digital Cellular Switch

IN — Intelligent Network

MS — Message Service

MUX — Multiplexer

PDN — Packet Data Network

PPC — Packet Processing Complex

PSTN — Public Switched Telephone Network

SS7 — Signaling System No. 7

TDMA — Time Division Multiple Access

Figure 1 Shows the network topology which results from combining the various needs and approaches into a single network

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