Adaptive backbone protocol for heterogeneous wireless networks

We propose Adaptive Backbone Protocol ABP, a lightweight protocol for distributed formation of a backbone over Heterogeneous Wireless Networks. ABP does not require any neighborhood information and consequently scales well with the number of nodes and network size. We present an analytical framework to study the performance of ABP. By making the nodes rotate the role of backbone nodes, we extend the life of the network.     

Automated network selection in a heterogeneous wireless network environment

Service delivery in a heterogeneous all-IP wireless network environment requires the selection of an optimal access network. Selection of a non-optimal network can result in undesirable effects such as higher costs or poor service experience. Network selection in such an environment is influenced by several factors, and currently a complete solution is not available to solve this problem. This article describes a comprehensive decision making process to rank candidate networks for service delivery to the terminal. The proposed mechanism is based on a unique decision process that uses compensatory and non-compensatory multi-attribute decision making algorithms jointly to assist the terminal in selecting the top candidate network     

Multilevel heterogeneous network model for wireless sensor networks

The lifetime of a network can be increased by increasing the network energy. The network energy can be increased either increasing the number of sensors or increasing the initial energy of some sensors without increasing their numbers. Increasing network energy by deploying extra sensors is about ten times costlier than that using some sensors of high energy. Increasing the initial energy of some sensors leads to heterogeneous nodes in the network. In this paper, we propose a multilevel heterogeneous network model that is characterized by two types of parameters: primary parameter and secondary parameters. The primary parameter decides the level of heterogeneity by assuming the values of secondary parameters. This model can describe a network up to nth level of heterogeneity (n is a finite number). We evaluate the network performance by applying the HEED, a clustering protocol, on this model, naming it as MLHEED (Multi Level HEED) protocol. For n level of heterogeneity, this protocol is denoted by MLHEED-n. The numbers of nodes of each type in any level of heterogeneity are determined by the secondary model parameter. The MLHEED protocol (for all level heterogeneity) considers two variables, i.e., residual energy and node density, for deciding the cluster heads. We also consider fuzzy implementation of the MLHEED in which four variables are used to decide the cluster heads: residual energy, node density, average energy, and distance between base station and the sensor nodes. In this work, we illustrate the network model up to seven levels (\(1\le n\le 7\)). Experimentally, as the level of heterogeneity increases, the rate of energy dissipation decreases and hence the nodes stay alive for longer time. The MLHEED-m, \(m=2,3,4,5,6,7\), increase the network lifetime by \(73.05, 143.40, 213.17, 267.90, 348.60, 419.10\,\%\), respectively, by increasing the network energy as \(40, 57, 68.5, 78, 84, 92.5\,\%\) with respect to the original HEED protocol. In case of fuzzy implementation, the MLHEEDFL-m, \(m=2,3,4,5,6,7,\) increases the network lifetime by \(282.7, 378.5, 435.78, 498.50, 582.63, 629.79\,\%\), respectively, corresponding to the same increase in the network energy as that of the MLHEED (all levels) with respect to the original HEED. The fuzzy implementation of the HEED, MLHEEDFL-1, increases the network lifetime by \(176.6\,\%\) with respect to the original HEED with no increase in the network energy.     

Cost-effective WDM backbone network design with OXCs of different bandwidth granularities

We investigate the design of a WDM backbone network with optical cross-connects (OXCs) of different switching granularities to reduce the network-wide OXC port cost. We enhance our proposed graph model (Zhu, H. et al., IEEE/ACM Trans. Networking, vol.11, p.285-99, 2003), and the extended graph model can represent different node architectures in which a node may have multiple OXCs with different switching granularities simultaneously. Based on this model, we propose a provisioning algorithm for a single connection and a framework for network design, which can intelligently determine the type of OXCs at each node according to the traffic so that the benefit of different types of OXCs can be utilized. Numerical examples are presented showing that granularity-heterogeneous networks are more cost-effective than granularity-homogeneous networks.     

Network configuration for optimal utilization efficiency of wireless sensor networks

This paper addresses the problem of configuring wireless sensor networks (WSNs). Specifically, we seek answers to the following questions: how many sensors should be deployed, what is the optimal sensor placement, and which transmission structure should be employed. The design objective is utilization efficiency defined as network lifetime per unit deployment cost. We propose an optimal approach and an approximation approach with reduced complexity to network configuration. Numerical and simulation results demonstrate the near optimal performance of the approximation approach. We also study the impact of sensing range, channel path loss exponent, sensing power consumption, and event arrival rate on the optimal network configuration.     

NMR inspired energy efficient protocol for heterogeneous wireless sensor network

Wireless Networks - This paper presents a naked mole rat (NMR) inspired energy efficient protocol for heterogeneous wireless sensor network. NMR uses strategic deployment among three types of nodes...     

Optimal network selection in heterogeneous wireless multimedia networks

The complementary characteristics of different wireless networks make it attractive to integrate a wide range of radio access technologies. Most of previous work on integrating heterogeneous wireless networks concentrates on network layer quality of service (QoS), such as blocking probability and utilization, as design criteria. However, from a user’s point of view, application layer QoS, such as multimedia distortion, is an important issue. In this paper, we propose an optimal distributed network selection scheme in heterogeneous wireless networks considering multimedia application layer QoS. Specifically, we formulate the integrated network as a restless bandit system. With this stochastic optimization formulation, the optimal network selection policy is indexable, meaning that the network with the lowest index should be selected. The proposed scheme can be applicable to both tight coupling and loose coupling scenarios in the integration of heterogeneous wireless networks. Simulation results are presented to illustrate the performance of the proposed scheme.     

Multiplicative multi-attribute auction based optimal network selection for heterogeneous wireless networks

One of the remarkable features of the next generation network is the integration of heterogeneous wireless networks,which enables mobile users with multi-mode terminals access to the best available network seamlessly.However,most of previous work only takes account of either maximizing single user’s utility or the whole network’s payoff,rarely considers the negotiation between them.In this paper,we propose a novel network selection approach using improved multiplicative multi-attribute auction(MMA).At first,an improved MMA method is put forward to define the user’s utility.Additionally,user cost is defined by considering allocated bandwidth,network load intensity and cost factor parameter.And last the best suitable network is selected according to the user’s performance-cost-ration.Simulation results confirm that the proposed scheme outperforms the existing scheme in terms of network selection’s fairness,user’s performance-cost-ration,load balancing and the number of accommodated users.     

异构无线网络路由策略研究综述

异构无线网络能够利用各种网络的链路迅速建立连接、实现数据的传递,在军事、水灾、火灾、地震等重大灾害上具有重要的应用价值.因此,设计一种能够提高数据发送效率和网络抗毁性的异构无线网络自适应路由策略具有重要意义.首先介绍了无线局域网、无线蜂窝网络、自组网、延迟容忍网络等各种无线网络的特点;然后对各种异构无线网络路由进行分类并阐述;最后总结现有异构无线网络路由的不足,并对未来研究工作进行了展望.     

Energy efficient radio resource management for heterogeneous wireless network using CoMP

The coordinated multi point (CoMP) transmission technique is considered a key feature in future wireless network to improve both cell edge users throughput by exploiting interference. However, to provide CoMP transmission several BSs need to be active, which eventually increases network energy consumption. The simultaneous active multiple BSs with different transmission characteristics in heterogeneous environment cause interferences on each other. In this paper, we study the energy efficient radio resource management (EE-RRM) scheme for heterogeneous wireless networks to reduce interference. In particular, our aim is to allocate subcarrier power by optimizing EE metric and minimize interference with knowledge of channel state information between BSs and user equipment. The EE-RRM problem is a fractional programming problem. In order to solve, we use Charnes–Cooper transformation technique and transform it into an equivalent concave optimization problem. The numerical results of our work present the effect of different interference, rate and power thresholds on the EE metric.     

The utilization of the redundancy bandwidth of upstream channel inHFC network

In an HFC network, the upstream bandwidth, which subscribers use to send a variety of traffic, is entirely allocated by the headend. Some of the traffic classes (such as voice) only use a part of their allocated bandwidth, thus there is redundant bandwidth. This paper describes a method that uses the redundant bandwidth to transmit other traffic classes so as to increase the utilization of the upstream bandwidth     

博弈论方法在混合无线网络中网络选择问题研究中的应用

随着无线网络技术的日益发展以及人们对无线互联的需求,各种适用于不同工作环境的无线网络技术往往共同应用于人们的日常活动区域中.为了提高网络的利用率与最大化自身收益,用户往往会在不同的无线网络中切换,选择最合适网络的进行连接.这种情况下,一个无线网络用户的行为变化会对其他用户的网络环境带来严重的影响.博弈论在分析研究这类情况具有很大的优势.本文简单介绍了博弈论的基本概念,并总结了当前采用博弈论的方法研究解决混合无线网络中网络选择问题的代表的工作.     

Energy efficiency optimization in MIMO heterogeneous wireless powered communication networks

Telecommunication Systems - This paper studies the energy efficiency (EE) optimization problem in multiple-user multiple-input–multiple-output heterogeneous wireless powered communication...     

A cellular wireless local area network with QoS guarantees for heterogeneous traffic

A wireless local area network (WLAN) or a cell with quality-of-service (QoS) guarantees for various types of traffic is considered. A centralized (i.e., star) network is adopted as the topology of a cell which consists of a base station and a number of mobile clients. Dynamic Time Division Duplexed (TDD) transmission is used, and hence, the same frequency channel is time-shared for downlink and uplink transmissions under the dynamic control of the base station. We divide traffic into two classes: class I (real-time) and II (non-real-time). Whenever there is no eligible class-I traffic for transmission, class-II traffic which requires no delay-bound guarantees is transmitted, while uplink transmissions are controlled with a reservation scheme. Class-I traffic which requires a bounded delay and guaranteed throughput is handled with the framing strategy (Golestani, IEEE J. Selected Areas Commun. 9(7), 1991) which consists of a smoothness traffic model and the stop-and-go queueing scheme. We also establish the admission test for adding new class-I connections. We present a modified framing strategy for class-I voice uplink transmissions which utilizes the wireless link efficiently at the cost of some packet losses. Finally, we present the performance (average delay and throughput) evaluation of the reservation scheme for class-II traffic using both analytical calculations and simulations. This revised version was published online in July 2006 with corrections to the Cover Date.     

一种新的无线异构网络的自适应垂直切换算法

针对当前无线异构网络融合技术中的垂直切换机制,提出了一种以平均接收信号强度为评价指标,并由此指标判断可能的运动趋势的自适应垂直切换算法。仿真结果表明:相比于传统的固定门限的平均接收信号强度垂直切换算法,提出的方法能较好地预测并提前触发该发生的切换,改善切换性能。     

Dynamic bandwidth management and adaptive applications for avariable bandwidth wireless environment

This article describes an approach for providing dynamic quality of service (QoS) support in a variable bandwidth network, which may include wireless links and mobile nodes. The dynamic QoS approach centers on the notion of providing QoS support at some point within a range requested by applications. To utilize dynamic QoS, applications must be capable of adapting to the level of QoS provided by the network, which may vary during the course of a connection. To demonstrate and evaluate the dynamic QoS concept, we have implemented a new protocol called dynamic resource reservation protocol (dRSVP) and a new QoS application program interface (API). The paper describes this new protocol and API and also discusses our experience with adaptive streaming video and audio applications that work with the new protocol in a testbed network, including wireless local area network connectivity and wireless link connectivity emulated over the wired Ethernet. Qualitative and quantitative assessments of the dynamic RSVP protocol are provided     

Estimation of the efficiency of bandwidth request piggybacking to data packets in the wireless network controlled by the IEEE 802.16 protocol

A data transmission process of the centralized wireless network controlled by IEEE 802.16 protocol, in which a set of subscriber stations utilizes the common channel to transmit data to the base station, is discussed. The developed analytical model makes it possible to investigate the efficiency of upstream traffic transmission, including channel reservation using the random multiple access algorithm and packet sending with allowance for bandwidth request piggybacking onto data. The analytical estimates of packet registration and service durations are presented.     

Call blocking probability and bandwidth utilization of OFDM subcarrier allocation in next-generation wireless networks

Various studies have devised OFDM subcarrier-allocation schemes in next-generation wireless networks. However, the subcarrier-allocation system performance has seldom been assessed, especially in terms of the call blocking probability (CBP) and bandwidth utilization.(BU). This study proposes a batch-arrival bath-loss queueing model to evaluate the performance or the subcarrier-allocation system,and derives expressions for calculating two important system performance measurements, CBP and BU. Simulation results. indicate that the measures appear to work. The model should be helpful for constructing OFDM based wireless networks.     

On the feasibility of bandwidth estimation in wireless access networks

Bandwidth estimation refers to the measurement of a bandwidth-related metric over a network path, performed only by the end hosts, without access to the intermediate routers. The problem of fast bandwidth estimation has been extensively studied in the wired Internet. More recently, researchers have shown that tools developed for the wired Internet cannot be used in wireless networks, due to the different characteristics of these networks which invalidate many of the assumptions made for the wired Internet. This observation has led to new tools that take into account the different characteristics of wireless networks. These tools have only been evaluated in controlled environments, under controlled settings and interferers, and only for 802.11 CSMA-based WLANs. In addition, no tool has been reported so far in the literature for cellular networks. This paper presents the first study of the feasibility of fast bandwidth estimation in wireless networks “in the wild”, i.e., in deployed operational networks. We discuss the challenges associated with bandwidth measurements in operational networks in contrast to in controlled lab environments. We study the applicability of a state-of-the-art probe-based tool for 802.11 WLANs in a commercial 1 × EVDO network. In addition, we evaluate the accuracy of the tool in three different WLAN environments, i.e., lab, home, and hotspot. Our results show that bandwidth estimation using a probe-based tool can be challenging in certain WLAN environments, and practically infeasible in EVDO cellular networks, due to the short-scale dynamics in this type of networks.