Predictive Dynamic Uplink /Downlink Resource Reservation for Vertical Handoff Optimization in 4G Networks

The fourth generation of mobile wireless networks (4G) is expected to be the most promising architecture for QoS provision due to its scalability, convenience for mobility support and capability of interworking heterogeneous radio access networks, which ensure both session continuity and QoS support. One major design issue of the 4G is the support of optimized handoff functionalities. More specifically, total disruption during a handoff should be minimized and its complexity hidden to end users. In this regard, the authors focus on developing new dynamic predictive resource reservation schemes in 4G for both uplink and downlink to maximize handoff success probability. The paper illustrates how to reserve radio resources according to future mobile terminal location expressed in a probabilistic way, to load conditions of target Base Station/Access point BS/AP and to the specificity of the data structure of each access network. Different resource reservation algorithms are devised. The objective is to efficiently utilize wireless radio resources, enhance the handoff performances and improve system performance. DOI: 10.4018/jbdcn.2010100104 International Journal of Business Data Communications and Networking, 6(4), 64-85, October-December 2010 65 Copyright © 2010, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. to make wiser handoff decisions (e.g., Hassan, Nasser, & Hassenein, 2006). These parameters include: signal strength, Quality of Service, cost of service, power requirements, and more particularly, geographical information and velocity. In vertical handoff, the mobile terminal’s future predicted location has a large weight and imperative effect on the handoff decision and must therefore be handled with a particular care. Predictions might be used by mobile terminals for anticipated radio resource reservation in that sense that enough bandwidth is reserved in the probable future cells in order to minimize service disruptions, handoff latency and packet loss. Several mechanisms for the enhancement of vertical handoff performances and resource reservation have been proposed. Todini et al. (2006) describe a packet scheduling algorithm and three resource allocation algorithms, characterized by various degrees of optimality and by different computational complexities. This contribution mainly focuses on OFDMA/TDD system and does not address other types of access networks. The contribution presented by Samaan, Benmammar, Krief, and Karmouch (2005) describes a novel approach for an advanced reservation protocol, to provide seamless real-time services to mobile users in wireless integrated services networks. Two contributions are presented; the first is the utilization of knowledge about user preferences, goals, and analyzed spatial conceptual maps to predict the user’s future location and the second is a predictive advanced resources reservation protocol suitable for mobile environments. The main limitation of this work is that it does not take into account load conditions of access networks where the resource reservation must be done. Huang, Chuang, Guan, Yang, and Chen (2007) present a self-adaptive bandwidth reservation scheme, which adopts a probabilistic mobility prediction model to estimate the bandwidth required in neighboring cells, and to reduce the forced termination probability of multimedia handoffs in 4G mobile WiMAX networks. 4G mobile WiMAX advantages are exploited via cross layer design by using bandwidth reservation for different class traffic. However, the authors only addressed resource reservation for WiMAX networks as part of a 4G environment. Ghosh and Lott (2007) describe uplink downlink imbalance in realistic TDD and FDD wireless networks, its potential causes and its impact on traffic and overhead channel performance, soft handoff, adaptive server selection an sector load control scheme. The authors define imbalance metrics and a model of receive antenna imbalance in their simulation studies of system robustness using cdma2000 1xEV-DO as an example. In particular, they discuss the effect of soft-handoff on system robustness, and the robustness of Computed Load control, in the presence of uplink-downlink partiallycorrelated time-varying shadow fading which models link imbalance in real networks. However, the authors did not quantify and compare the performance degradation across various technologies in the presence of link imbalance neither the physics of the phenomena leading to link imbalance. Su, Han, Wu, and Liu (2007) propose a network aware and source aware video streaming framework to support interactive multiuser communications within single-cell and multicell IEEE 802.11 networks. This framework integrates cross-layer error protection mechanism and performs dynamic resource allocation across multiple users and explores the diversity of content complexity exhibited by different video sequences and the heterogeneity of uplink and downlink channel conditions experienced by different users. Unfortunately, this paper only addresses the resource reservation issue for WLAN networks. Although the above-mentioned papers address resource reservation issues in heterogeneous networks, none of them deals with resource reservation in various access networks. Further, to the best of our knowledge, there is no previous work addressing dynamic radio resource reservation for vertical handoff optimization that takes into account both future 20 more pages are available in the full version of this document, which may be purchased using the "Add to Cart" button on the product's webpage: www.igi-global.com/article/predictive-dynamic-uplinkdownlink-resource/47314?camid=4v1 This title is available in InfoSci-Journals, InfoSci-Journal Disciplines Communications and Social Science. Recommend this product to your librarian: www.igi-global.com/e-resources/libraryrecommendation/?id=2