Mobility management in wireless ATM networks

Mobile ATM offers a common wired network infrastructure to support mobility of wireless terminals, independent of the wireless access protocol. In addition, it allows seamless migration to future wireless broadband services, such as wireless ATM, by enabling mobility of end-to-end ATM connections. In spite of the diversity in mobile networking technologies (e.g., cellular telephony, mobile-IP, packet data services, PCS), all of them require two fundamental mechanisms: location management and handoff. This article describes different schemes for augmenting a wired ATM network to support location management of mobile terminals and handoff protocols for rerouting a connection data path when the endpoint moves. A prototype implementation of mobile ATM integrating mobility support with ATM signaling and connection setup, is presented. It shows how mobile ATM may be used to provide mobility support to an IP terminal using non-ATM wireless access     

Low-latency handover in a wireless ATM LAN

The micro- and picocellular architectures proposed for wireless ATM LANs lead to wireless terminals frequently changing their point of attachment to the network. Because ATM connections have quality of service (QoS) guarantees which must be maintained, handover must be as seamless as possible. We present a novel architecture and protocol which primarily aims to keep the interruption period due to handover low, rather than seeking to keep the process entirely lossless. We compare the tradeoffs made, with those in other schemes from the literature, and give quantitative results from an implementation of our scheme on a 10 Mbits/s^-1 prototype wireless ATM LAN     

Mobility management and control protocol for wireless ATM networks

The introduction of wireless ATM (WATM) in customer premises network environments necessitates the design of mobility protocols, since the existing versions of B-ISDN signaling do not support terminal mobility. Such protocols can be deployed either as extensions to the standard signaling capabilities, or as individual solutions that have little or no impact on existing infrastructures (switches, signaling software, etc.). A WATM architecture that adopts the latter approach is presented. After a discussion of the problems encountered in the integration of wireless networking and B-ISDN ATM technologies, a mobility management and control (MMC) protocol is proposed. Finally, in the framework of the proposed MMC protocol, algorithms for implementing mobility procedures (handover and registration) are described     

Wideband local access: wireless LAN and wireless ATM

An overview of the status of wideband wireless local access technologies is provided. Service scenarios and availability of the market and products for wireless LAN and wireless ATM technologies are discussed. Similarities among IEEE 802.11 and HIPERLAN standards for wireless LANs and the developing prototypes for wireless ATM are evaluated. An update on the status of the available unlicensed bands in the United States as well as the status of the wideband wireless projects in the European Community and Japan are presented     

A LAN emulation model for wireless ATM

An architecture based on emulated LAN is proposed which can efficiently provide the required bandwidth of mobiles as they migrate between cells. The proposed solution (1) ensures the required bandwidth of a mobile when its path changes because of handoff, (2) efficiently reserves bandwidth resulting in higher bandwidth/network utilization, (3) has the flexibility of reserving bandwidth depending upon the mobility (rate of handoff). Copyright © 2001 John Wiley & Sons, Ltd.     

An integrated multicast connection management solution for wiredand wireless ATM networks

With the prospect of commercializing wireless ATM networks fast becoming a reality, and ATM becoming one of the main network technologies for multimedia computing, the design of ATM connection management solutions has to take into consideration these recent developments. Unfortunately, current ATM signaling solutions standardized by the ATM Forum have to be modified extensively in order to support wireless ATM. Furthermore, these solutions have not delivered a suitable multicast service which can support the communication requirements found in today's computer-based multimedia applications. The work described here therefore addresses these shortcomings by proposing a new multicast connection service architecture and its related algorithms. Some of the important concepts elaborated in the design include the notion of open signaling, the use of logical multicast groups to handle all connections, and seamless support for host mobility     

Mobility support for IP over wireless ATM

A wireless ATM system consists of a core network infrastructure that provides mobility support to end terminals and a wireless access link. This article outlines two schemes for supporting mobility of IP terminals in this network. In the first scheme, location management and handoff support is integrated within the ATM signaling and control framework (“mobile ATM”), and mobility is transparently supported at the IP layer by mobile ATM underneath. In the second approach, the IP protocol stack is directly executed on ATM switches (without an intermediate ATM signaling stack) using an IP switching technique called IPSOFACTO (IP Switching Over Fast ATM Cell Transport), and terminal mobility is supported via mobile IP     

Forward error control for MPEG-2 video transport in a wireless ATM LAN

The possibility of providing multimedia services to mobile users has led to interest in designing broadband wireless networks that can guarantee quality of service for traffic flows. However, a fundamental problem in these networks is that severe losses may occur due to the random fading characteristics of the wireless channel. Error control algorithms which compensate for these losses are required in order to achieve reasonable loss rates. In this paper, the performance of error control based on forward error correction (FEC) for MPEG-2 video transmission in an indoor wireless ATM LAN is studied. A random bit error model and a multipath fading model are used to investigate the effect of errors on video transport. Combined source and channel coding techniques that employ single-layer and scalable MPEG-2 coding to combat channel errors are compared. Simulation results indicate that FEC-based error control in combination with 2-layer video coding techniques can lead to acceptable quality for indoor wireless ATM video.Work performed while the author was at AT&T Bell Laboratories on a D.O.E. fellowship program.     

Mobility management in next-generation wireless systems

This paper describes current and proposed protocols for mobility management for public land mobile network (PLMN)-based networks, mobile Internet protocol (IP) wireless asynchronous transfer mode (ATM) and satellite networks. The integration of these networks will be discussed in the context of the next evolutionary step of wireless communication networks. First, a review is provided of location management algorithms for personal communication systems (PCS) implemented over a PLMN network. The latest protocol changes for location registration and handoff are investigated for mobile IP followed by a discussion of proposed protocols for wireless ATM and satellite networks. Finally, an outline of open problems to be addressed by the next generation of wireless network service is discussed     

Mobility management in heterogeneous wireless networks

In heterogeneous wireless networks, mobile users are able to move from their home networks to different foreign networks while maintaining access capability to their subscribed services, which refers to global mobility. One of the key challenges in global mobility management is intersystem location management, which consists of keeping track of mobile users who roam into foreign networks. This paper presents an overview of mobility management in heterogeneous wireless networks and introduces a scheme which improves location management efficiency in terms of total signaling costs and intersystem paging delay. More specifically, cost reduction reaches about 50% when comparing the proposed architecture with conventional architectures.     

异步转移模式（ATM）与局域网

本文概述了异步转移模式（ＡＴＭ）及其在局域网上的应用。     

Designing a practical ATM LAN

The adaptor cards and driver software for workstations and local asynchronous transfer mode (ATM) switches and switch control software used in an ATM local area network (LAN) system are discussed. It is shown that the ATM hardware and software components together provide services that are essential for ATM to be considered a realistic alternative to current shared-media LANs. These services include: completely transparent support for the TCP/IP protocol suite, an application programming interface for full access to the underlying ATM capabilities, support for AAL5, AAL3/4, and the null AAL, both connection-oriented and connectionless service, dynamic connection establishment or switched virtual circuits, resource reservation of guaranteed bandwidth and quality of service, full-bandwidth multicast and broadcast, virtual path and channel routing among multiple switches, automatic configuration and failure recovery, dynamic address assignment and internetwork address resolution, and network management via the simple network management protocol (SNMP)     

ATM局域网仿真技术

本文介绍了ＡＴＭ局域网仿真技术并从ＡＴＭ仿真局网的组成、工作原理等方面介绍了这一技术的主要特点。     

ATM LAN emulation

Many of the most common protocols at layers two (media access), three (network), and above expect to operate over broadcast media such as IEEE 802.3/Ethernet or IEEE 802.5/token ring. LAN emulation provides a widely applicable means for transitioning these protocols to the connection-oriented ATM environment. A combination of centralized and distributed intelligence allows a star-plus-mesh topology of ATM virtual circuits to emulate broadcast media, while providing most of the advantages of connection-oriented media     

ATM局域网仿真技术

ＡＴＭ局域网仿真技术是由ＡＴＭ论坛提出的一种利用ＡＴＭ网络支持数据通信业务的方法。本文首先简介了引入此项技术的背景，继而分析了ＡＴＭ局域网仿真的基本思想以及仿真局域网的协议体系，网络配置，功能单元与连接种类等基本概念，并详细分析了ＡＴＭ局域网仿真中各项协议规程的工作机制。     

ATM traffic management in an LMDS wireless access network

We investigate the capacity of LMDS to support ATM services in the local loop. In particular, we evaluate the performance of a MAC protocol for this system when transporting voice and IP traffic using the VBR and GFR service categories of ATM, respectively. Our results show that the MAC protocol is well suited for voice traffic but in general lacks efficient bandwidth management mechanisms to support the more dynamic bandwidth requirements of IP traffic     

A control and management network for wireless ATM systems

This paper describes the design of a control and management network (orderwire) for a mobile wireless Asynchronous Transfer Mode (ATM) network. This mobile wireless ATM network is part of the Rapidly Deployable Radio Network (RDRN). The orderwire system consists of a packet radio network which overlays the mobile wireless ATM network. Each network element in this network uses Global Positioning System (GPS) information to control a beamforming antenna subsystem which provides for spatial reuse. This paper also proposes a novel Virtual Network Configuration (VNC) algorithm for predictive network configuration. A mobile ATM Private Network–Network Interface (PNNI) based on VNC is also discussed. Finally, as a prelude to the system implementation, results of a Maisie simulation of the orderwire system are discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Schemes for mobility management of wireless ATM networks

The growing fields of wireless networks and asynchronous transfer mode (ATM) are merging to form wireless ATM networks. This paper addresses dynamic bandwidth allocation, connection admission procedures, routing, and location management strategies in wireless ATM. More precisely, we investigate the issue of extending the private Network to Network Interface, PNNI, and protocols to support mobility. PNNI‐based hierarchical routing, hand‐off, location management and routing schemes are proposed to integrate wireless capabilities into ATM networks. These schemes provide fast and efficient hand‐off connection processing mechanism and a reduction in the connection disruption time during a connection hand‐off session. They also provide a predictable resource requirement of the mobile system during its connection. During a connection hand‐off, misrouted cells can be re‐routed to their destinations. This substantially reduces the overhead due to end‐to‐end re‐transmissions invoked at higher layers. An analytical model is developed to illustrate the hand‐off algorithm. Copyright © 1999 John Wiley & Sons, Ltd.     

Mobility management for wireless systems with unreliable backhaullinks

We consider a wireless system with unreliable microwave backhaul links. Since the links may be disconnected, the location update procedure may be incorrectly exercised, which results in misrouted calls. This paper proposes an analytic model to derive the misrouting probabilities as functions of the link disconnection time distribution. These equations can be used as the design guideline to select the microwave equipment for the wireless system     

Distributed fair scheduling in a wireless LAN

Fairness is an important issue when accessing a shared wireless channel. With fair scheduling, it is possible to allocate bandwidth in proportion to weights of the packet flows sharing the channel. This paper presents a fully distributed algorithm for fair scheduling in a wireless LAN. The algorithm can be implemented without using a centralized coordinator to arbitrate medium access. The proposed protocol is derived from the Distributed Coordination Function in the IEEE 802.11 standard. Simulation results show that the proposed algorithm is able to schedule transmissions such that the bandwidth allocated to different flows is proportional to their weights. An attractive feature of the proposed approach is that it can be implemented with simple modifications to the IEEE 802.11 standard.