Transport architecture evolution in UMTS/IMT-2000 cellular networks

Abstract

Mobile evolution from the second generation (2G) to the third generation (3G) raises several important questions for operators and manufacturers. How to ensure that the old and current investments can still be utilized in the future? What is the optimum architecture? ATM or IP? Voice or data? There is no single correct answer to these questions, as it all depends on individual cases. In this paper, we discuss the transport architecture evolution for the universal mobile telecommunications system (UMTS)/international mobile telecommunications—year 2000 (IMT‐2000), or 3G cellular networks and interworking aspects between 2G and 3G cellular networks. The interfaces between access nodes in a cellular network and the changes incorporated to support packet data services are described. Emerging services such as mobile data, virtual private networks (VPN) and location aware networking are described. Role of ATM and IP in this new transport architecture is presented. Control and data plane interworking issues between different transport technologies are described. The new ATM standard, ATM adaptation layer type 2 (AAL2) and its applicability for transporting compressed speech in an ATM based cellular network is described. A similar approach in IP, multiplexing in real‐time transport protocol (RTP) payload to transport compressed speech on selective interfaces of 3G network, is introduced. Transport network architecture evolution within four different scenarios is evaluated. Special interest is focused on the protocol stacks and flexible layered solutions that allow smooth migration from one transport technology to another. Copyright © 2000 John Wiley & Sons, Ltd.

Third generation and beyond wireless systems

“…The UTRAN comprises 3G-capable BSs and Radio Network Controllers (RNCs, which in (JSM terminology correspond to the BS Controllers (BSCs)). Studies indicate four possibilities for the evolution of the fixed part of the cellular network [9]:…”

FlexPath NP

“…The requirements for high flexibility and performance result from a rapid growth in new networking applications on the one hand, and the fact that these new protocols and services are deployed and tested in the market before being finally standardized. Example application areas for NPs include QoS (Quality of Service)-based IP routers [1,2], secure VPN (Virtual Private Network) gateways [3], multimedia IP service integration in wireless (GSM / UMTS) base station controllers [4], alternative VoIP telephony networks [5] and broadband IP service provisioning to the home via DSL (Digital Subscriber Line) or Cable Modem technologies. NPs in various performance classes will evolve as a key technology component for future generations of packet switching systems deployed in both private and public communication networks.…”