A framework for fast handoff schemes in wireless ATM networks

Includes bibliographical references.In this research, we focus on providing a framework that extends the fixed ATM standard to support user mobility in future WATM networks. The WATM architecture allows for the migration of fixed ATM networks without major modifications. Thus most of the mobility functions are implemented on the wireless access network. The most important component supporting mobility in a cluster is the Mobility Enhanced Switch (MES). We propose using direct links between adjacent MESs to support Permanent Virtual Channels (PVCs) in order to facilitate fast inter-cluster handoffwith minimum handofflatency. This research addresses a framework on handoff mobility by proposing three fast handoff re-routing schemes based on the support of PVCs

Ethernet - a survey on its fields of application

During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal

A Two-Phase Handoff Scheme for Mobility Management in Wireless ATM Networks

Mobility management in Wireless ATM networks poses a number of technical issues. An important issue is the ability to manage and reroute on-going connections during handoff as mobile users move among base stations. We propose a two- phase handoff management scheme using permanent virtual paths reserved between adjacent Mobility Enhanced Switches (MES). The virtual paths are used in the first phase to rapidly reroute user connections. In the second phase, a distributed optimization process is initiated to optimally reroute handed-off connections. The paper also describes an adaptive optimization scheme to achieve high reserved bandwidth utilization. We analytically calculate and study the bandwidth requirement for the reserved virtual paths and handoff blocking probability. We also study the impact of processing and signaling load due to the second-phase route optimization. Both ATM CBR and VBR traffic types were considered for mobile users

A Two-Phase Handoff Scheme for Mobility Management in Wireless ATM Networks

Mobility management in Wireless ATM networks poses a number of technical issues. An important issue is the ability to manage and reroute on-going connections during handoff as mobile users move among base stations. We propose a two- phase handoff management scheme using permanent virtual paths reserved between adjacent Mobility Enhanced Switches (MES). The virtual paths are used in the first phase to rapidly reroute user connections. In the second phase, a distributed optimization process is initiated to optimally reroute handed-off connections. The paper also describes an adaptive optimization scheme to achieve high reserved bandwidth utilization. We analytically calculate and study the bandwidth requirement for the reserved virtual paths and handoff blocking probability. We also study the impact of processing and signaling load due to the second-phase route optimization. Both ATM CBR and VBR traffic types were considered for mobile users

Periodic Route Optimization for Handed-off Connections in Wireless ATM Networks

In Wireless ATM networks, user connections need to be rerouted during handoff as mobile users move among base stations. The rerouting of connections must be done quickly with minimal disruption to traffic. In addition, the resulting routes must be optimal. A reasonable approach is to implement handoff in two phases. In the first phase connections are rapidly rerouted and in the second phase a periodic route optimization procedure is executed. The route optimization should impose minimal signaling and processing load on the ATM switches. In this paper, we propose and study a periodic execution of route optimization for a two-phase handoff scheme. We study two types of execution: non-adaptive and adaptive. For the adaptive optimization, we consider two adaptation schemes that are dependent on network conditions. A simulation model is developed to study system performance. The adaptive route optimization is shown to minimize signaling and processing load while maximizing utilization of reserved resources

A Two-Phase Handoff Scheme for Mobility Management in Wireless ATM Networks

Mobility management in Wireless ATM networks poses a number of technical issues. An important issue is the ability to manage and reroute on-going connections during handoff as mobile users move among base stations. We propose a two- phase handoff management scheme using permanent virtual paths reserved between adjacent Mobility Enhanced Switches (MES). The virtual paths are used in the first phase to rapidly reroute user connections. In the second phase, a distributed optimization process is initiated to optimally reroute handed-off connections. The paper also describes an adaptive optimization scheme to achieve high reserved bandwidth utilization. We analytically calculate and study the bandwidth requirement for the reserved virtual paths and handoff blocking probability. We also study the impact of processing and signaling load due to the second-phase route optimization. Both ATM CBR and VBR traffic types were considered for mobile users

Performance Study of a Two-Phase Handoff Scheme for Wireless ATM Networks

This paper presents an analytical and simulation study of a two-phase handoff scheme for rerouting user connection in Wireless ATM networks. The two-phase handoff scheme provides a rapid rerouting of user connections in the first phase utilizing permanent virtual paths reserved between adjacent Mobility Enhanced Switches (MES). In the second phase, a non-realtime route optimization procedure is executed to optimally reroute handed-off connection. In this paper, we study the performance of such a scheme as a function of various system load parameters. These parameters include originating call arrival rate, call holding time, and radio cell residual time. We examine the relation between the required bandwidth resources and optimization rate. Also we calculate and study the handoff blocking probability due to lack of bandwidth for resources reserved to facilitate the rapid rerouting

Performance Study of a Two-Phase Handoff Scheme for Wireless ATM Networks

This paper presents an analytical and simulation study of a two-phase handoff scheme for rerouting user connection in Wireless ATM networks. The two-phase handoff scheme provides a rapid rerouting of user connections in the first phase utilizing permanent virtual paths reserved between adjacent Mobility Enhanced Switches (MES). In the second phase, a non-realtime route optimization procedure is executed to optimally reroute handed-off connection. In this paper, we study the performance of such a scheme as a function of various system load parameters. These parameters include originating call arrival rate, call holding time, and radio cell residual time. We examine the relation between the required bandwidth resources and optimization rate. Also we calculate and study the handoff blocking probability due to lack of bandwidth for resources reserved to facilitate the rapid rerouting

Performance Study of a Two-Phase Handoff Scheme for Wireless ATM Networks

This paper presents an analytical and simulation study of a two-phase handoff scheme for rerouting user connection in Wireless ATM networks. The two-phase handoff scheme provides a rapid rerouting of user connections in the first phase utilizing permanent virtual paths reserved between adjacent Mobility Enhanced Switches (MES). In the second phase, a non-realtime route optimization procedure is executed to optimally reroute handed-off connection. In this paper, we study the performance of such a scheme as a function of various system load parameters. These parameters include originating call arrival rate, call holding time, and radio cell residual time. We examine the relation between the required bandwidth resources and optimization rate. Also we calculate and study the handoff blocking probability due to lack of bandwidth for resources reserved to facilitate the rapid rerouting

The Media Layers of the OSI (Open Systems Interconnection) Reference Model: A Tutorial

The Media Layers of the open systems interconnection (OSI) reference model convert bits to packets. It is a very important aspect of network communication and consists of various networking protocols. At the lowest level the physical layer deals with Media, Signal and Binary Transmission of Bits. Then there is the Data Link layer which deals with media access control (MAC) and logical link control (LLC) Physical Addressing of Frames, for example Ethernet. Finally, there is the Network layer which deals with Path Determination and IP Logical addressing of Packets. This article gives a review of these Media Layers and will contribute to adding knowledge for a networking novice while consolidating concepts for an experienced professional or academic