Signaling alternatives in a wireless ATM network

The world of wireless telecommunications is rapidly changing. The capabilities of wireless networks are improving at a steady pace. This paper presents two possible protocols for implementing mobility for wireless users in an asynchronous transfer mode (ATM) network. The vision of the authors is of one “wireless ATM telecommunications network” that is capable of supporting a variety of today's applications with room to grow for advanced applications of the future. We first visit database architectures that can support mobility in a wireless ATM network. We then discuss one of two signaling architecture alternatives, the “overlay signaling”, for overlay support of mobile users in the ATM-based wireless telecommunications network. “Overlay signaling” aims at minimizing the modification needed to the existing ATM protocols. We then describe a native “migratory signaling” approach that further integrates wireless and wireline users into one global wireless ATM network at the expense of requiring some modifications to the existing ATM protocols. A performance analysis of the proposed signaling architecture alternatives is also presented. We conclude by pointing out some challenges in merging ATM with wireless telecommunications     

Unified support for integrated all-optical multicast and burst amplification in transparent optical network

To better support transparent optical network, we present a novel scalable structure design based on multi-wavelength conversion (MWC) for integrated optical multicast and burst amplification in this paper. We also propose a corresponding wavelength assignment algorithm to minimize the cost of wavelength conversions in the multicast tree. MWC-based multicast strategy makes it possible to generate data copies through less processes and simplifies the wavelength assignment problem. Meanwhile, the generated data copies are used as complementary signals to compensate the power variations of original signal for Erbium-doped fiber amplifiers transient suppression. Experiments are conducted to demonstrate the performance of both burst amplification and multicast data generation in one MWC process. Simulation results are given for our new wavelength assignment algorithm, and advantages are shown over greedy algorithms.     

Reservation-based bandwidth allocation in a radio ATM network

The comparative performance of a number of reservation-based bandwidth sharing policies that could be used to maximize the link utilization and/or offer equally fair or preferential treatment to a class of supported users, is examined in the context of a radio asynchronous transfer mode local-area network (ATM LAN). Our analytical results, based an a recursion for the link occupancy distribution originally suggested by Kaufman (1981) and Roberts (1981) independently and subsequently extended to include finite source population models, are further extended in the cases of equal sharing of the resources with retries, and a dynamic sharing mechanism in which, when the available capacity is exceeded, weighted reductions for the active users' rates and queueing are employed. Next, examining the application of the above sharing schemes in an indoor radio environment, we apply switched diversity and a Reed-Solomon-based forward error correction (FEC) scheme to recover radio-related (Rayleigh fading) packet losses. The performance and the effects of the fading-mitigating switched-antenna-diversity mechanism and the required on a packet-basis coding protection are taken into account in order to establish the actual radio link throughput under the above conditions     

ATM network resilience

With the prospect of widespread deployment of ATM by public network operators, it is crucial to ensure resilience to network outages caused by cable breaks and node failures. The general aim of resilience is to make network failures transparent to users. If a failure happens to affect a circuit, it would be very desirable to reconfigure that circuit as quickly as possible with no information loss. However, if this functionality incurs a significant cost overhead, it may be necessary to charge customers according to the resilience they receive. Since user requirements vary from service to service, it is highly likely that different customers will demand variable levels of resilience. For example, mission-critical business-oriented data services will rely on virtually fault-transparent service, whereas residential customers may tolerate breaks in service as long as they do not occur frequently or last a long time. Fortunately, different ATM restoration mechanisms are possible which suit varied customer requirements. This article summarizes a range of research papers describing ATM restoration techniques. The viable options to provide ATM network resilience are discussed, along with the customer requirements which they satisfy and aspects of ATM resilience being assessed by standards bodies. Taking all such matters into consideration, conclusions are drawn on the current and future scope for ATM resilience     

Economic evaluation of a mature ATM network

The economic evaluation of a mature ATM network is presented. The authors discuss the issues involved and present two examples. Four customer categories are taken into account, namely residential, small business, medium business, and large business customers. The aim is to introduce a simple meaningful model, which incorporates the most important factors that influence the economic viability of an asynchronous transfer mode (ATM) network, and to present the limits and limitations of the area of economic evaluation. The revenue, cost, and net income (of the network operator) are calculated for two different scenarios, that is with and without residential customers     

ATM access through a passive optical network

A system is described that transports asynchronous transfer mode (ATM) cells through a passive optical local network. It distributes a 155.52 Mbit/s ATM stream to 64 customer ends, synchronising return cells to interleave at the exchange end. A variant to the Orwell protocol is used for bandwidth control.<>     

Worst-case traffic in a tree network of ATM multiplexers

We study tree networks of discrete-time queues loaded with periodic traffic sources. By using the so-called Benes method, exact closed-form expressions are obtained for the queue length distributions. The models developed can be used to study the superposition of periodic sources emitting bursts of cells in ATM networks. The results obtained show the significant effect that this kind of traffic can have on the performance of these systems     

Subscriber premises' network architectures in a broadband ATM environment

In future broadband networks residential and business users will be distinguished, each with their own characteristic requirements. Whereas business users almost exclusively need interactive switched services, the huge number of residential users, on the country, mainly aim at entertainment services, either switched or distributed, at a low, possibly fixed, price. Based on the user requirements a twotier SPN architecture is derived, consisting of a TDN (terminal distribution network) and a BBN (broadband backbone network). Alternative structures for TDN are analysed and compared. A passive tree solution is found to be most suitable for the above-mentioned needs. Although the physical appearance may be quite different, all the given examples have a number of elements in common. This enables common components to be developed. Inside the SPN, especially the residential SPN, the absence of any channel aggregate in ATM is of great advantage. Only the total available bandwidth imposes a restriction on the set up of new calls. This is very important, because SPN encounters a wide variety of user needs, together with a relatively small amount of users. In order to preserve the advantages of ATM in the subscriber area, it is essential to bring ATM down to the terminal.     

Wireless ATM network architectures

Emulated LAN technology supports mobile hosts in wireless ATM networks. This paper introduces virtual LAN (VLAN) services using ATM LAN emulation technology which operates on a client/server model. One of the attractive features of the VLAN is the capability to group users into a broadcast domain. The focus of this paper is the issue of supporting quality of service to mobiles in a wireless ATM network. Copyright © 2001 John Wiley & Sons, Ltd.     

Multiple-availability-level ATM network architecture

Because of their high flexibility, ATM networks have the potential to achieve two objectives: switch cost reduction and multi-level network availability. For that purpose, this article proposes to use virtual circuit (VC) route self-healing schemes to achieve a multiple-availability-level ATM network. Flexible multi-QoS logical ATM network (Full-Net), a new concept for ATM networks, is now being studied at NTT Laboratories. Full-Net is a very flexible network design strategy for survivable networks that is based on a self-healing VC network. Defining several logical configurations of the VC network allows us to support multiple levels of network availability, simplifies the adaptation to future and unknown service requirements, and significantly reduces overall ATM network cost. Offering different levels of availability not only saves the network's resources, but also allows the network operator to provide its customers with services at the most appropriate cost. We introduce the advantages of VC route restoration for ATM networks, and compare virtual path (VP) level and physical level restoration strategies. We explain Full-Net's concept, propose a VC route self-healing scheme, and show the impact of the logical network configurations on network survivability and resource management     

Warren: a low-cost ATM home area network

This article introduces the concept of the ATM Warren. The Warren is an arbitrary mesh subnetwork of very simple ATM switches and end stations connected to the wide-area B-ISDN at one or more points. The Warren differs from other ATM networks in that both switches and end stations are designed to be implemented entirely in hardware with all control software banished to external computers     

TMN-based broadband ATM network management

ATM has rapidly transitioned from a standards and prototyping concept to become the next-generation switching technology used in products available on the market. With the rapid introduction of ATM switches into networks, there is an urgent need to manage them. The article discusses the telecommunication management network (TMN) interfaces being defined for management systems to communicate with ATM network elements (NEs) and other management systems. ATM management systems will have to communicate with ATM NEs in their jurisdiction using TMN interfaces. Networks will usually contain equipment from different suppliers. Thus, it is vital that there be standard management interfaces so that these different NEs can be managed. Some standard interfaces for ATM networks are defined, while others are being defined. The status of these interfaces is reviewed in the article. Communication between different networks is also needed, both between public networks and between public and private networks. Management personnel of one network need to exchange information with other networks for certain functions (e.g., initial service provisioning), and so management systems of different networks will exchange information through a combination of mechanized and manual interfaces. The status of these interfaces is also reviewed in the article     

Architectures for ATM network survivability

This article surveys the restoration architectures for asynchronous transfer mode (ATM) network survivability that have been actively studied in this decade. Network reliability is critical for recent and future networks that will advance the information era. Moreover, it is one of the biggest factors in designing and managing networks. Since the early telecom network era, many restoration systems have been developed for plesiochronous digital hierarchy (PDH), synchronous digital hierarchy (SDH), synchronous optical network (SONET), leased lines and so on; and they were surveyed in many papers and books. This article focuses on new restoration techniques for ATM networks. First, the requirement studies are introduced. This includes the scant results published on the influence of failure and the state of failure analysis. Next, restoration schemes are categorized and briefly introduced. Examples include centralized control, automatic protection switch (APS), self-healing ring (SHR), self-healing network (SHN) and failure resistant virtual path (FRVP). In order to achieve adequate restoration probability with minimum cost, a network design scheme is necessary; thus, network design issues are introduced. Finally, this article focuses on the issues, future work, and problems that remain to be solved.     

Native ATM support for CORBA platforms

The CORBA standard as published by the OMG defines among other things the structure of a middleware platform called an Object Request Broker (ORB) in order to achieve interoperability of applications in distributed and heterogeneous environments. The standard does not prescribe a specific technology for building this middleware platform. In this paper we show how to integrate ATM technology into a CORBA compliant implementation. Making use of the advantages offered by ATM requires the modification of the ORB API. A prototype is based on the freely available CORBA implementation called Mico. We show how to make use of Mico's micro-kernel architecture in order to achieve a seamless integration of a new transport layer. This revised version was published online in August 2006 with corrections to the Cover Date.     

The ATM Forum's private network/network interface

The ATM Forum completed the first version of its private network/network interface (PNNI) in March 1996 and many ATM switch manufacturers are now offering early implementations. PNNI offers a different type of internetwork or internodal interface from the traditional Signalling System No 7 based approach favoured to date by 'public' network operators, such as BT. In spite of its name, however, PNNI may find its place in network service provider networks as well as in 'private' or customer networks. Some of the perceived limitations of the current specification for such an environment are currently being addressed in version 2, tentatively due for completion in the second half of 1998.The PNNI really consists of two parts, a signalling protocol based around the ATM Forum's UNI signalling specification, and a dynamic source routeing protocol. This paper aims to provide an overview of the functionality and mechanics of PNNI, and to compare and contrast with the functionality offered by ITU-T's B-ISUP.     

ATM network testing and measurement

This contribution addresses some very general problems of testing and measuring in ATM networks. The paper outlines important aspects of the basic types of test such as conformance, functionality and performance. Furthermore, it highlights the several aspects and problems of tests at the level of an interface, a switch and a whole network. As ATM traffic has almost no structure, it is impossible to make rules for testing and measurement from traffic modeling. We demonstrate the limitations of the standardized performance parameters, which are generally used as estimators. This e.g. shows that it is possible to obtain with the same estimator completely different cell loss ratios for the same traffic flow.     

Optically transparent integrated metro-access network

High-capacity optical transmission technologies have made possible very high data rates and a large number of wavelength channels. Further, optical network functionality has made progress from simple point-to-point WDM links to automatically switched optical networks. In the future, dynamic burst-switched and packet-switched photonic networks may be expected. This paper describes a novel architecture of transparent WDM metropolitan area network (MAN) that is capable of switching on both packet-by-packet and burst-by-burst basis, thereby having the potential to achieve high throughput efficiency. The optically transparent MAN also includes a large part of the access network infrastructure. It is scalable, flexible, easy upgradeable and able to support heterogeneous network traffic. Some results of a preliminarly study on network performance are shown.     

ATM transport network operation system in Japan

An asynchronous transfer mode (ATM) transport network operation system conforming to the telecommunications management network (TMN) architecture has been designed, implemented, and deployed by NTT Japan. This operation system has a distributed architecture with a managed object location transparency function and has been developed using a state-of-the-art development toolkit in order to reduce the development time and number of developers     

Design of a non-blocking shared-memory copy network for ATM

The design of a copy network is presented for use in an ATM (asynchronous transfer mode) switch supporting BISDN (broadband integrated services digital network) traffic. Inherent traffic characteristics of BISDN services require ATM switches to handle bursty traffic with multicast connections. In typical ATM switch designs a copy network is used to replicate multicast cells before being forwarded to a point-to-point routeing network. In such designs, a single multicast cell enters the switch and is replicated once for each multicast connection. Each copy is forwarded to the routeing network with a unique destination address and is routed to the appropriate output port. Non-blocking copy networks permit multiple cells to be multicasted at once, up to the number of outputs of the copy network. Another critical feature of ATM switch design is the location of buffers for the temporary storage of transmitted cells. Buffering is required when multiple cells require a common switch resource for transmission. Typically, one cell is granted the resource and is transmitted while the remaining cells are buffered. Current switch designs associate discrete buffers with individual switch resources. Discrete buffering is not efficient for bursty traffic as traffic bursts can overflow individual switch buffers and result in dropped cells, while other buffers are under-used. A new non-blocking copy network is presented in this paper with a shared-memory input buffer. Blocked cells from any switch input are stored in a single shared input buffer. The copy network consists of three banyan networks and shared-memory queues. The design is scalable for large numbers of inputs due to low hardware complexity, O (N log₂ N), and distributed operation and control. It is shown in a simulation study that a switch incorporating the shared-memory copy network has increased throughput and lower buffer requirements to maintain low packet loss probability when compared to a switch with a discrete buffer copy network.     

An ATM cell format and media access protocol for a network ofswitch-interconnected shared-medium ATM rings

The asynchronous transfer mode ring (ATMR) protocol suffers from addressing and latency-related limitations when applied to large networks. This paper proposes a cell format and media access protocol (MAP) applicable to a switch-interconnected ATMR (SI-ATMR) network. The SI-ATMR network has a small ring latency, has no addressing limitations, and provides fair access and guaranteed quality of service (QoS)