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One of the highly promising radio access strategies for enhancing performance in the next generation cellular communications is non-orthogonal multiple access (NOMA). NOMA offers a number of advantages including better spectrum efficiency. This paper focuses primarily on proposing an energy efficient system for transmitting medical data, such as electroencephalogram (EEG), collected from patients for the sake of continuous monitoring. The framework proposes the use of deep reinforcement learning (DRL) to provide smart data compression in uplink-NOMA protocol. DRL enforces the data compression ratios for the nodes in order to avoid outage constraints at any sensor node. Jointly, it optimizes the power consumption of these sensor nodes. The data compression for such sensor network is vital in order to minimize the power every sensor consumes to maximize its service lifetime. We minimize the expected distortion under practical channel realization and outage probability constraints using NOMA-uplink protocol. Meanwhile, we optimize the power efficiency of the user node in order to increase the battery lifetime. 2020 IEEE. Qatar National Research Fund Scopus

IoT networks with grant-free radio access, like SigFox and LoRa, offer low-cost durable communications over unlicensed band. These networks are becoming more and more popular due to the ever-increasing need for ultra durable, in terms of battery lifetime, IoT networks. Most studies evaluate the system performance assuming single radio access technology deployment. In this paper, we study the impact of coexisting competing radio access technologies on the system performance. Considering K technologies, defined by time and frequency activity factors, bandwidth, and power, which share a set of radio resources, we derive closed-form expressions for the successful transmission probability, expected battery lifetime, and experienced delay as a function of distance to the serving access point. Our analytical model, which is validated by simulation results, provides a tool to evaluate the coexistence scenarios and analyze how introduction of a new coexisting technology may degrade the system performance in terms of success probability and battery lifetime. We further investigate solutions in which this destructive effect could be compensated, e.g., by densifying the network to a certain extent and utilizing joint reception. Conference code: 138282; Export Date: 30 October 2018; Conference Paper; Funding text: This study is supported by EU Celtic Plus Project SooGREEN Service Oriented Optimization of Green Mobile Networks.QC 20211025

Being inspired by the Hopfield neural networks (Hopfield (1982) and Hopfield and Tank (1985)) and the nonlinear sigmoid power control algorithm for cellular radio systems in Uykan and Koivo (2004), in this paper, we present a novel discrete recurrent nonlinear system and extend the results in Uykan (2009), which are for autonomous linear systems, to nonlinear case. The proposed system can be viewed as a discrete-time realization of a recently proposed continuous-time network in Uykan (2013). In this paper, we focus on discrete-time analysis and provide various novel key results concerning the discrete-time dynamics of the proposed system, some of which are as follows: (i) the proposed system is shown to be stable in synchronous and asynchronous work mode in discrete time; (ii) a novel concept called Pseudo-SINR (pseudo-signal-to-interference-noise ratio) is introduced for discrete-time nonlinear systems; (iii) it is shown that when the system states approach an equilibrium point, the instantaneous Pseudo-SINRs are balanced; that is, they are equal to a target value. The simulation results confirm the novel results presented and show the effectiveness of the proposed discrete-time network as applied to various associative memory systems and clustering problems.

5th generation mobile networks will have to cope with a high degree of heterogeneity in terms of services, mobility, number of devices and so on. Thus, diverse and often contradicting key performance indicators need to be supported, but having multiple radio access technologies for multi-service support below 6GHz will be too costly. FANTASTIC-5G will develop a new multi-service air interface through a modular design. To allow the system to adapt to the anticipated heterogeneity, some properties need to be pursued, like simplicity, flexibility, scalability, versatility, efficiency and future proofness. Based on these properties, a selected set of use cases and link and network design will be presented. The paper will also comprise validation and system level simulations through some indicative results and will conclude with the overall impact to 5G standardisation. Copyright (c) 2016 John Wiley & Sons, Ltd.

There is growing realization that on-line model maintenance is the key to realizing long term benefits of a predictive control scheme. In this work, a novel intelligent nonlinear state estimation strategy is proposed, which keeps diagnosing the root cause(s) of the plant model mismatch by isolating the subset of active faults (abrupt changes in parameters/disturbances, biases in sensors/actuators, actuator/sensor failures) and auto-corrects the model on-line so as to accommodate the isolated faults/failures. To carry out the task of fault diagnosis in multivariate nonlinear time varying systems, we propose a nonlinear version of the generalized likelihood ratio (GLR) based fault diagnosis and identification (FDI) scheme (NL-GLR). An active fault tolerant NMPC (FTNMPC) scheme is developed that makes use of the fault/failure location and magnitude estimates generated by NL-GLR to correct the state estimator and prediction model used in NMPC formulation. This facilitates application of the fault tolerant scheme to nonlinear and time varying processes including batch and semi-batch processes. The advantages of the proposed intelligent state estimation and FTNMPC schemes are demonstrated by conducting simulation studies on a benchmark CSTR system, which exhibits input multiplicity and change in the sign of steady state gain, and a fed batch bioreactor, which exhibits strongly nonlinear dynamics. By simulating a regulatory control problem associated with an unstable nonlinear system given by Chen and Allgower [H. Chen, F. Allgower, A quasi infinite horizon nonlinear model predictive control scheme with guaranteed stability, Automatica 34(10) (1998) 1205–1217], we also demonstrate that the proposed intelligent state estimation strategy can be used to maintain asymptotic closed loop stability in the face of abrupt changes in model parameters. Analysis of the simulation results reveals that the proposed approach provides a comprehensive method for treating both faults (biases/drifts in sensors/actuators/model parameters) and failures (sensor/ actuator failures) under the unified framework of fault tolerant nonlinear predictive control., © Elsevier

Process equipment that exhibits significant spatial variation of system properties, such as temperature or concentration in a fixed bed reactor, are typically modeled as distributed parameter systems. While some properties of the final product exiting the equipment may depend on the states concerning the endpoint, others may be a function of the history of processing within the equipment. In such instances, control of the spatial property profile may be beneficial. In this work, we explore the idea of profile control using extended MPC and outline the additional challenges that must be addressed in this context. In case that the target profile is unachievable, we present an MPC formulation that uses lexicographic optimization to prioritize the different sections of the profile. Simulation of a simple representative system namely a hypothetical plug flow reactor is used to demonstrate that the lexicographic optimization based MPC provides a systematic approach to profile control and spans between the endpoint control strategy and the whole profile control strategy. The benefits of lexicographic optimization based MPC were also demonstrated on a large-scale distributed parameter system of industrial size, namely the continuous pulp digester., © Elsevier

We have considered the problem of providing greater throughput in cellular networks. We propose a novel packet data cellular architecture, the Multi-Power Architecture for Cellular networks (MuPAC), based on multi-hop relaying with multiple channels. MuPAC has the unique capability of providing a coarse grained frequency reuse factor that contributes to its enhanced throughput. MuPAC utilizes multi-hop wireless relaying in the presence of the infrastructure nodes such as base station (BS) in order to provide a very high network capacity. Multiple data channels each of which is designated to operate at a different transmission power are used in order to provide a coarse grained frequency reuse factor. MuPAC also includes solutions to problems faced in multi-hop networks: performance degradation at high mobility, partitions, etc. MuPAC provides increased throughput compared to existing schemes such as the current day cellular systems which can be classified as single-hop cellular network (SCN), and the recently proposed multi-hop cellular network (MCN). We provide an analytical treatment of MuPAC to support its superiority over SCN and MCN. We also show using extensive simulations, that MuPAC performs well over a range of node densities, under high mobility, varying traffic generation characteristics and also improves fairness across a cell. � 2006 Elsevier B.V. All rights reserved.

In this paper, we consider an amplify-and-forward hybrid satellite-terrestrial co-operative network in the presence of cochannel interference (CCI). More specifically, we assume that both the satellite-destination and the satellite-relay links undergo the shadowed-Rician fading and the relay-destination link follows the Nakagami-m fading. By applying the amplify-and-forward (AF) protocol at the terrestrial relay, both the relay and the destination are corrupted by cochannel interference from the terrestrial network. Based on this setup, we first derive the approximate statistical distributions signal-to-interference-plus noise ratio (SINR) and then analyze the system performance. To obtain more insights into the system performance, some asymptotical bit-error rate (BER) results are provided. Moreover, we extend our analysis to a multiple-relay network and analyze the asymptotic performance. Finally, some numerical results are provided to verify our analysis. Scopus

Contemporary wireless communications are based on digital communications technologies. The recent commercial success of mobile cellular communications has been enabled in part by successful designs of digital signal processors with appropriate on-chip memories and specialized accelerators for digital transceiver operations. This article provides an overview of fixed point digital signal processors and ways in which they are used in cellular communications. Directions for future wireless-focused DSP technology developments are discussed.

Dual-mode adaptive algorithms with rapid convergence properties are presented for the equalization of frequency selective fading channels and the recovery of time-division multiple access (TDMA) mobile radio signals. The dual-mode structure consists of an auxiliary adaptive filter that estimates the channel during the training cycle. The converged filter weights are used to initialize a parallel bank of filters that are adapted blindly during the data cycle. When the symbol timing is known, this filter bank generates error residuals that are used to perform approximate maximum a posteriori symbol detection (MAPSD) and provide reliable decisions of the transmitted signal. For channels with timing jitter, joint estimation of the channel parameters and the symbol timing using an extended Kaiman filter algorithm is proposed. Various methods are described to reduce the computational complexity of the MAP detector, usually at the cost of some performance degradation. Also, a blind MAPSD algorithm for combining signals from spatially diverse receivers is derived. This diversity MAPSD (DMAPSD) algorithm, which can be easily modified for the dual-mode TDMA application, maintains a global set of MAP metrics even while blindly tracking the individual spatial channels using local error estimates. The performance of these single-channel and diversity MAPSD dualmode algorithms are studied via computer simulations for various channel models, including a mobile radio channel simulator for the IS-54 digital cellular TDMA standard. ? 1996 IEEE.

The applicability of Dynamic Channel Assignment methods to a Reuse Partitioning system in cellular radio systems is investigated in this paper. The investigations indicate that such a system has a tendency to increase the difference between blocking probability for the partitioning two coverage areas in comparison with the conventional Reuse Partitioning system employing Fixed Channel Assignment method. Two schemes using new Channel Rearrangement algorithms are also proposed in order to alleviate the difference as a disadvantage which gives unequal service to the system. The simulation results show that the proposed schemes are able to reduce the difference significantly while increasing the carried traffic by 10% as compared with the conventional system.

The standard interference functions introduced by Yates have been very influential on the analysis and design of distributed power control laws. While powerful and versatile, the framework has some drawbacks: the existence of fixed-points has to be established separately, and no guarantees are given on the rate of convergence of the iterates. This paper introduces contractive interference functions, a slight reformulation of the standard interference functions that guarantees the existence and uniqueness of fixed-points along with linear convergence of iterates. We show that many power control laws from the literature are contractive and derive, sometimes for the first time, analytical convergence rate estimates for these algorithms. We also prove that contractive interference functions converge when executed totally asynchronously and, under the assumption that the communication delay is bounded, derive an explicit bound on the convergence time penalty due to increased delay. Finally, we demonstrate that although standard interference functions are, in general, not contractive, they are all para-contractions with respect to a certain metric. Similar results for two-sided scalable interference functions are also derived., 20 pages, 1 figures

International audience; In this paper, we formulate a delay-power control (DPC) scheme for wireless networking, which efficiently balances delay against transmitter power on each wireless link. The DPC scheme is scalable, as each link autonomously updates its power based on the interference observed at its receiver; no cross-link communication is required. It is shown that DPC converges to a unique equilibrium power and several key properties are established, concerning the nature of channel bandwidth sharing achieved by the links. The DPC scheme is contrasted to the well-known Foschini-Miljanic (FM) formulation for transmitter power control in wireless networks, and some key advantages are established. Based on the DPC and FM schemes, two protocols are developed, which leverage adaptive tuning of DPC parameters. One of them is inspired by TCP and exhibits analogous behavior. This paper primarily focuses on the theoretical underpinnings of DPC and their practical implications for efficient protocol design. The DPC dynamics are also investigated numerically

Uykan, Zekeriya (Dogus Author) -- Full conference title: 2011 XXIII International Symposium on Information, Communication and Automation Technologies, ICAT 2011: 27-29 October 2011, Sarajevo, Bosnia Herzegovina. The technological evolution of the wireless cellular systems has been very rapid in last two decades. In the coming decade of "converging wireless networks/systems/ecosystems", there is an increasing demand on achieving very high data rates ubiquitously even with high mobile speeds as if we connected to a wired ADSL! Radio Resource Management (RRM) for the emerging wireless systems will be the key mechanism for achieving such high data rates. Indeed, RRM has already been a hot research area in both academia and industry for decades. And due to the complexity of the emerging wireless systems, an interdisciplinary approach and/or methodology is needed to tackle the new RRM challenges. In this paper, we provide a control engineering view onto some of the RRM challenges in emerging wireless networks, with a special emphasis on distributed power control. For example, we establish a link between power control design and dynamic neural networks, two different areas whose scope of interest, motivations and settings are completely different. Here, we emphasize the importance and the need of interdisciplinary approach. Some subjects to be addressed within the paper shall include future-generation cellular/ "noncellular" systems, radio resource management challenges, energy efficiency and distributed power control algorithms, variable-structure-systems based power control, channel/frequency allocation, spectral-clustering based channel allocation, Hopfield neural networks. bhT,m:tel - imate prijatelije, ENERGOINVEST-SUI - Sistemi upravljanja energijom, Microsoft

In this paper, we consider a multiuser distributed MIMO system, under multipath fading channels, with orthogonal frequency division multiplexing (OFDM) technology. The aim is to extend and evaluate, co-located precoding schemes that have been recently proposed, in a distributed scenario. Assuming knowledge of CSI prior to transmission, we can remove the interference among users by employing precoding schemes for the downlink. We assessed closed form and iterative schemes based on block diagonalization (BD) to improve the performance of the distributed antenna system. The results show that the iterative scheme outperforms the closed one. The simulation results show that the studied schemes can be efficient for distributed MIMO OFDM based systems. FUTON - FP7 ICT-2007-215533 PHOTON FPDC/EEA-TEL/72890/2006

Conference name: IEEE 17th Signal Processing and Communications Applications Conference, SIU 2009 Date of Conference: 9-11 April 2009 Gelecek nesil kablosuz iletişim sistemlerinde öngörülen veri hızlarına ulaşabilmek için bu sistemlerde frekans yeniden kullanım oranının 1 olmasına ihtiyaç¸ vardır, bu ise özellikle hücre sınırlarındaki kullanıcıların önemli ölçüde hücreler arası girişime maruz kalmalarına neden olur. Telsiz erişim terminalleri arasında işbirliği hücreler arası girişimin azaltılmasında önemli bir rol oynamaktadır. Bu bildiride çok hücreli, çok girdili çok çıktılı, dikgen frekans bölmeli çoklu erişim sistemlerinde telsiz erişim terminallerinden kullanıcılara işbirlikli veri iletimi problemini ele alıyoruz. Telsiz erişim terminallerinin aralarında kısıtlı ileti paylaşımı ile çizelgeleme ve veri iletimi yaptıkları etkin bir işbirlikli algoritma öneriyoruz. Achieving the targeted data rates for next generation wireless communication systems requires using frequency reuse ratio 1 in these systems, but this in turn results in significant intercell interference observed especially by the users near cell edges. Cooperation between the base stations plays an important role in reducing the intercell interference. In this paper, we consider the problem of cooperative data transmission from the base stations to the users in multicellular multiple input multiple output (MIMO) orthogonal frequency division multiple access (OFDMA) systems. We propose an efficient cooperative scheduling and data transmission scheme, requiring limited information exchange between the base stations. ©2009 IEEE.

This paper deals with the modeling and analysis of narrowband multiple-input multiple-output (MIMO) mobile- to-mobile (M2M) fading channels in relay-based cooperative networks. Non-line-of-sight (NLOS) propagation conditions are assumed in the transmission links from the source mobile station to the destination mobile station via the mobile relay. A stochastic narrowband MIMO M2M reference channel model is derived from the geometrical three-ring scattering model, where it is assumed that an infinite number of local scatterers surround the source mobile station, the mobile relay, and the destination mobile station. The complex channel gains associated with the new reference channel model are derived and their temporal as well as spatial correlation properties are explored. General analytical solutions are presented for the four-dimensional (4-D) space- time cross-correlation function (CCF), the three-dimensional spatial CCF, the two-dimensional (2-D) transmit (relay, receive) correlation function (CF), and the temporal autocorrelation function (ACF). Closed-formed expressions for different CCFs under isotropic scattering conditions are also provided in this paper. The proposed reference channel model can be used as a starting point to develop stochastic and deterministic channel simulators. Such channel simulators are not only important for analyzing the dynamic behavior of the MIMO M2M channel capacity but also for the development of future MIMO M2M cooperative communication systems. Keywords—Amplify-and-forward relay links, mobile-to- mobile fading channels, MIMO channels, space-time corre- lation function.

In this study, applicability of feed-forward and radial-basis neural networks for monthly water consumption prediction from several socio-economic and climatic factors affecting water use is investigated. A data set including a total of 108 data records is divided into two subsets: training and testing. Firstly, the models based on a single input variable are trained and tested by feed-forward and radial methods and feed-forward and radial performances of the models are compared. Then, the models based on multiple input variables are constructed according to performances of the models based on a single input variable. The performances of feed-forward and radial models in training and testing phases are compared with the observations and the best-fit model is identified. For this purpose, several criteria such as normalised root mean square error, efficiency and correlation coefficient are calculated for all models. Subsequently, the best-fit models are also trained and tested by multiple linear regression for comparison. The results indicated that feed-forward and radial methods can be applied successfully for monthly water consumption prediction. © 2009 Thomas Telford.

General black-box system identification techniques such as subspace system identification and FIR/ARX least squares system identification are commonly used to identify multi-input multi-output models from experimental data. However, in many applications there are a priori given structural information. Here the focus is on linear dynamical systems with a cascade structure, and with one input signal and two output signals. Models of such systems are important in e.g. cascade control applications. It is possible to incorporate such a structure in a prediction error method, which, however, is based on rather advanced numerical non-convex optimization techniques to calculate the corresponding structured model estimate. We will instead study how to use model approximation techniques to approximate a general black-box estimate with a structured model. This will avoid the use of numerical optimization and works well with e.g. subspace system identification, which is a standard method in process industry where cascade systems are very common. The problems of cascade structural model approximation and model reduction are rather non-standard, and we will study several new methods. The basic idea is to first find a higher order but structured model approximation using standard H∞ model matching techniques, and then in a second step use so-called structured balanced model reduction to find lower order structured approximation. Structured balanced model reduction is a rather new approach, with powerful model order selection tools and error bound results. The results of the corresponding two step model approximation approach seem promising, as illustrated by a simple numerical example. © 2008 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. QC 20110120

International audience; Driving safely can be achieved by the prevention of risky situations which may require the knowledge of vehicle dynamic state as well as road geometry. It is thus essential to have in real-time a good estimation of the related variables and parameters. Among the parameters of the road that are influencing vehicle longitudinal motion one can find the slope which can not be measured with reduced cost sensor. Vehicle lateral motion is mainly affected by the value of the lateral speed which can not simply measured too. In this paper, an observer based method for the estimation of the vehicle dynamics using a nonlinear vehicle model is proposed. It uses a combination of Extended Kalman filter (EKF) and Luenberger Observer (LO). The observers use several standard measurements such as : the yaw rate, the steering angle and the rotational velocity of the four tires. Experimental tests conducted with a prototype vehicle prove the effectiveness of the proposed approach.

Date of Conference: 20-22 April 2008 Conference name: EEE 16th Signal Processing, Communication and Applications Conference, SIU 2008 Sabit yükseklikte uçtuğu varsayılan insansız Hava Araçları ( İHA) için görü-tabanlı bir Eşanlı Konumlandırma ve Haritalama (EKVH) algoritması sunulmaktadır. Araç üzerindeki kameradan elde edilen görüntülerin öznitelikleri kullanılarak farklı yer işaretleri saptanmaktadır. Yer işaretlerine Genişletilmiş¸ Kalman Süzgeci (GKS) uygulanmış ve EKVH probleminin çözümü için bazı benzetim sonuçları sunulmuştur. In this work, a 2D vision-based simultaneous localization and mapping algorithm is developed for an unmanned aerial vehicle flying at a constant altitude. We use visual features of images obtained from an on-board camera to identify different landmarks. Using these landmarks we apply the well-known extended Kalman filter to the SLAM problem and present some simulation results.

WiMAX paves the way for wireless DSL to play a significant role in the broadband wireless access market, especially for rural areas with low population density. Conventional cellular planning methods can be used for point-to-multipoint network design. As an alternative, the Fractional Frequency Reuse (FFR) planning strategy has been recently proposed for cellular systems based on the OFDMA/OFDM radio interface (e.g., WiMAX). In this article we analyze the FFR scheme in rural areas evaluating the increase of the overall system capacity. FFR performances are reported in terms of the average number of bits that can be transmitted per symbol in the area. Finally, comparisons with classical frequency reuse planning are analyzed taking into consideration rural environment characteristics. We show that the FFR scheme can provide extra capacity, slightly penalizing the users at the cell edge.

Camless internal combustion engines offer improvements over traditional engines in terms of torque performance, reduction of emissions, reduction of pumping losses, fuel economy. Theoretically, electromagnetic valve actuators offer the highest potentials for improving efficiency due to their control flexibility. Sensorless control is one of the most important issues with regard to real implementation of this new technology. This paper proposes an observer based on an extended Kalman filter to realize a sensorless control. Current is measured while position as well as velocity of the electromagnetic valve are estimated. Real data from a valve actuator prototype are used to show the effectiveness of the proposed method. © 2008 IEEE. Camless internal combustion engines offer improvements over traditional engines in terms of torque performance, reduction of emissions, reduction of pumping losses, fuel economy. Theoretically, electromagnetic valve actuators offer the highest potentials for improving efficiency due to their control flexibility. Sensorless control is one of the most important issues with regard to real implementation of this new technology. This paper proposes an observer based on an extended Kalman filter to realize a sensorless control. Current is measured while position as well as velocity of the electromagnetic valve are estimated. Real data from a valve actuator prototype are used to show the effectiveness of the proposed method. © 2008 IEEE.

In this paper, new time-varying wireless channel models that capture both the space and time variations of longterm and short-term fading wireless networks are developed. The proposed models are based on stochastic differential equations. These models are more realistic than the static ones usually encountered in the literature. Moreover, optimal power control algorithms based on the new models are proposed. A centralized power control algorithm is shown to reduce to a simple linear programming problem if predictable power control strategies are used. In addition, an iterative distributed stochastic power control algorithm is used to solve for the optimization problem using stochastic approximations. The latter solely requires each mobile to know its received signal to interference ratio unlike common stochastic algorithms found in the literature. Numerical results show that the proposed distributed stochastic power control algorithm under the new time-varying channels provides better power stability and consumption than the deterministic ones. © 2007 IEEE. 3088 3093

The present paper discusses the managerial challenges of the MUSE integrated project on multi service broadband access. It addresses different aspects such as matrix organisation, project office, consensus process, standardisation, dissemination, and quality control.

The present paper discusses the managerial challenges of the MUSE integrated project on multi service broadband access. It addresses different aspects such as matrix organisation, project office, consensus process, standardisation, dissemination, and quality control.

Until recently, research on cellular networks concentrated only in single-hop cellular networks. The demand for high throughput has driven to architectures that use multiple hops in the presence of infrastructure. We propose an architecture for multihop cellular networks (MCNs). MCNs combine the benefits of having a fixed infrastructure of base stations and the flexibility of Ad hoc networks. They are capable of achieving much higher throughput than current cellular systems, which can be classified as single-hop cellular networks (SCNs). In this work, we propose an extended architecture for MCN using the IEEE 802.11 standard for wireless LANs for connection-less service and a TDMA-based solution for real-time support. We provide a general overview of the architecture and the issues involved in the design of MCNs, in particular the challenges to be met in the design of a routing protocol, a channel assignment scheme, and a mobility management scheme. We also propose a routing protocol called Base-Assisted Ad hoc Routing (BAAR) protocol for use in such networks and a model for the performance analysis of MCNs and SCNs. We also conduct extensive experimental studies on the performance of MCNs and SCNs under various load (TCP, UDP, and real-time sessions) and mobility conditions. These studies clearly indicate that MCNs with the proposed architecture and routing protocol are viable alternatives for SCNs, in fact they provide much higher throughput. MCNs are very attractive for best-effort packet radio where they can achieve an increase in throughput up to four when compared to similar SCNs. But for real-time traffic, even though they do outperform SCNs, they also suffer from a few disadvantages such as frequent hand-offs and throughput degradation at high mobility. We also present results from a detailed comparison study of our architecture for MCN with the Hybrid Wireless Network (HWN) architecture and Integrated Cellular Ad hoc Relaying (iCAR) Architecture. ? 2004 Elsevier Inc. All rights reserved.