Showing papers on "Heterogeneous network published in 2011"

A survey on 3GPP heterogeneous networks

Abstract: As the spectral efficiency of a point-to-point link in cellular networks approaches its theoretical limits, with the forecasted explosion of data traffic, there is a need for an increase in the node density to further improve network capacity. However, in already dense deployments in today's networks, cell splitting gains can be severely limited by high inter-cell interference. Moreover, high capital expenditure cost associated with high power macro nodes further limits viability of such an approach. This article discusses the need for an alternative strategy, where low power nodes are overlaid within a macro network, creating what is referred to as a heterogeneous network. We survey current state of the art in heterogeneous deployments and focus on 3GPP LTE air interface to describe future trends. A high-level overview of the 3GPP LTE air interface, network nodes, and spectrum allocation options is provided, along with the enabling mechanisms for heterogeneous deployments. Interference management techniques that are critical for LTE heterogeneous deployments are discussed in greater detail. Cell range expansion, enabled through cell biasing and adaptive resource partitioning, is seen as an effective method to balance the load among the nodes in the network and improve overall trunking efficiency. An interference cancellation receiver plays a crucial role in ensuring acquisition of weak cells and reliability of control and data reception in the presence of legacy signals.

PathSim: meta path-based top-K similarity search in heterogeneous information networks

Abstract: Similarity search is a primitive operation in database and Web search engines. With the advent of large-scale heterogeneous information networks that consist of multi-typed, interconnected objects, such as the bibliographic networks and social media networks, it is important to study similarity search in such networks. Intuitively, two objects are similar if they are linked by many paths in the network. However, most existing similarity measures are defined for homogeneous networks. Different semantic meanings behind paths are not taken into consideration. Thus they cannot be directly applied to heterogeneous networks.In this paper, we study similarity search that is defined among the same type of objects in heterogeneous networks. Moreover, by considering different linkage paths in a network, one could derive various similarity semantics. Therefore, we introduce the concept of meta path-based similarity, where a meta path is a path consisting of a sequence of relations defined between different object types (i.e., structural paths at the meta level). No matter whether a user would like to explicitly specify a path combination given sufficient domain knowledge, or choose the best path by experimental trials, or simply provide training examples to learn it, meta path forms a common base for a network-based similarity search engine. In particular, under the meta path framework we define a novel similarity measure called PathSim that is able to find peer objects in the network (e.g., find authors in the similar field and with similar reputation), which turns out to be more meaningful in many scenarios compared with random-walk based similarity measures. In order to support fast online query processing for PathSim queries, we develop an efficient solution that partially materializes short meta paths and then concatenates them online to compute top-k results. Experiments on real data sets demonstrate the effectiveness and efficiency of our proposed paradigm.

Enhanced intercell interference coordination challenges in heterogeneous networks h et n ets : a n ew p aradigm f or i ncreasing c ellular c apacity a nd c overage

Abstract: GPP LTE-Advanced has recently been investigating heterogeneous network (HetNet) deployments as a cost effective way to deal with the unrelenting traffic demand. HetNets consist of a mix of macrocells, remote radio heads, and low-power nodes such as picocells, femtocells, and relays. Leveraging network topology, increasing the proximity between the access net- work and the end users, has the potential to pro- vide the next significant performance leap in wireless networks, improving spatial spectrum reuse and enhancing indoor coverage. Neverthe- less, deployment of a large number of small cells overlaying the macrocells is not without new technical challenges. In this article, we present the concept of heterogeneous networks and also describe the major technical challenges associat- ed with such network architecture. We focus in particular on the standardization activities within the 3GPP related to enhanced intercell interfer- ence coordination.

Enhanced intercell interference coordination challenges in heterogeneous networks

Abstract: 3GPP LTE-Advanced has recently been investigating heterogeneous network (HetNet) deployments as a cost effective way to deal with the unrelenting traffic demand. HetNets consist of a mix of macrocells, remote radio heads, and low-power nodes such as picocells, femtocells, and relays. Leveraging network topology, increasing the proximity between the access network and the end users, has the potential to provide the next significant performance leap in wireless networks, improving spatial spectrum reuse and enhancing indoor coverage. Nevertheless, deployment of a large number of small cells overlaying the macrocells is not without new technical challenges. In this article, we present the concept of heterogeneous networks and also describe the major technical challenges associated with such network architecture. We focus in particular on the standardization activities within the 3GPP related to enhanced intercell interference coordination.

Enhanced Inter-Cell Interference Coordination Challenges in Heterogeneous Networks

Abstract: 3GPP LTE-Advanced has started a new study item to investigate Heterogeneous Network (HetNet) deployments as a cost effective way to deal with the unrelenting traffic demand. HetNets consist of a mix of macrocells, remote radio heads, and low-power nodes such as picocells, femtocells, and relays. Leveraging network topology, increasing the proximity between the access network and the end-users, has the potential to provide the next significant performance leap in wireless networks, improving spatial spectrum reuse and enhancing indoor coverage. Nevertheless, deployment of a large number of small cells overlaying the macrocells is not without new technical challenges. In this article, we present the concept of heterogeneous networks and also describe the major technical challenges associated with such network architecture. We focus in particular on the standardization activities within the 3GPP related to enhanced inter-cell interference coordination.

Green Small-Cell Networks

Abstract: The exponentially increasing demand for wireless data services requires a massive network densification that is neither economically nor ecologically viable with the current cellular system architectures. A promising solution to this problem is the concept of small-cell networks (SCNs), which is founded by the idea of a very dense deployment of self-organizing, low-cost, low-power, base stations (BSs). Although SCNs have the potential to significantly increase the capacity of cellular networks while reducing their energy consumption, they pose many new challenges to the optimal system design. We show in this article how a large system analysis based on random matrix theory (RMT) can provide tight and tractable approximations of key performance measures of SCNs.

End-to-End Communication Architecture for Smart Grids

Abstract: Smart grids heavily depend on communication in order to coordinate the generation, distribution, and consumption of energy-even more so if distributed power plants based on renewable energies are taken into account. Given the variety of communication partners, a heterogeneous network infrastructure consisting of IP-based and suitable field-level networks is the most appropriate solution. This paper investigates such a two-tier infrastructure and possible field-level networks with particular attention to metering and supervisory control and data acquisition applications. For the problem of network integration, a combination of gateway and tunneling solutions is proposed which allows a semitransparent end-to-end connection between application servers and field nodes. The feasibility of the approach and implementation details are discussed at the example of powerline communication and IP-based networks investigated in the European research project on real-time energy management via powerlines and internet. Nevertheless, it is shown that the communication architecture is versatile enough to serve as a generic solution for smart grids.

Network energy saving technologies for green wireless access networks

Abstract: The energy consumption problem in the mobile industry has become crucial. For the sustainable growth of the mobile industry, energy efficiency (EE) of wireless systems has to be significantly improved. Plenty of efforts have been invested in achieving green wireless communications. This article provides an overview of network energy saving studies currently conducted in the 3GPP LTE standard body. The aim is to gain a better understanding of energy consumption and identify key EE research problems in wireless access networks. Classifying network energy saving technologies into the time, frequency, and spatial domains, the main solutions in each domain are described briefly. As presently the attention is mainly focused on solutions involving a single radio base station, we believe network solutions involving multiple networks/systems will be the most promising technologies toward green wireless access networks.

Heterogeneous communication architecture for the smart grid

Abstract: The smart grid concept provides a solution to the growing recognition that current utility grids need an ICT deployment infrastructure based upgrade to allow millions of potential market players to operate and to cope with distributed generation, wide-area situational awareness, demand response, electric storage, and efficient electric transportation. Smart grid deployment is mainly about defining the necessary standards for ICT solutions. The design of the communication network associated with the smart grid involves detailed analysis of its communication requirements, a proposal of the appropriate protocol architecture, the choice of the most suitable technologies for each case study, and a scheme for the resultant heterogeneous network management system. Given the smart grid use cases, this article is focused on proposing a heterogeneous communication paradigm for smart grids based on power line communications and wireless networks. The proposal is related to the framework of the ITU ubiquitous sensor network architecture using the ITU next-generation network model. This architecture allows for better management of the QoS in the smart grid and should facilitate interoperability with other technologies.

Kilo-NOC: a heterogeneous network-on-chip architecture for scalability and service guarantees

Abstract: Today's chip-level multiprocessors (CMPs) feature up to a hundred discrete cores, and with increasing levels of integration, CMPs with hundreds of cores, cache tiles, and specialized accelerators are anticipated in the near future. In this paper, we propose and evaluate technologies to enable networks-on-chip (NOCs) to support a thousand connected components (Kilo-NOC) with high area and energy efficiency, good performance, and strong quality-of-service (QOS) guarantees. Our analysis shows that QOS support burdens the network with high area and energy costs. In response, we propose a new lightweight topology-aware QOS architecture that provides service guarantees for applications such as consolidated servers on CMPs and real-time SOCs. Unlike prior NOC quality-of-service proposals which require QOS support at every network node, our scheme restricts the extent of hardware support to portions of the die, reducing router complexity in the rest of the chip. We further improve network area- and energy-efficiency through a novel flow control mechanism that enables a single-network, low-cost elastic buffer implementation. Together, these techniques yield a heterogeneous Kilo-NOC architecture that consumes 45% less area and 29% less power than a state-of-the-art QOS-enabled NOC without these features.

System and method for wireless network offloading

Abstract: A method comprising obtaining, by a server, wireless-network performance data from a plurality of end user devices; generating, by the server, a prioritized network list from the wireless-network performance data; and provisioning, by the server, the prioritized network list to an end user device comprising a radio interface for receiving the prioritized network list from the server, the radio interface being identified to receive the prioritized network list based on a characteristic associated with the end user device; a radio configured to identify available wireless networks, the available wireless networks being different than a current wireless network to which the end user device is currently connected; a prioritized network selection engine for using the prioritized network list to select one of the available wireless networks; and a network connection engine configured to initiate disconnection from the current wireless network and connection to the selected wireless network.

Generic topology mapping strategies for large-scale parallel architectures

Abstract: The steadily increasing number of nodes in high-performance computing systems and the technology and power constraints lead to sparse network topologies. Efficient mapping of application communication patterns to the network topology gains importance as systems grow to petascale and beyond. Such mapping is supported in parallel programming frameworks such as MPI, but is often not well implemented. We show that the topology mapping problem is NP-complete and analyze and compare different practical topology mapping heuristics. We demonstrate an efficient and fast new heuristic which is based on graph similarity and show its utility with application communication patterns on real topologies. Our mapping strategies support heterogeneous networks and show significant reduction of congestion on torus, fat-tree, and the PERCS network topologies, for irregular communication patterns. We also demonstrate that the benefit of topology mapping grows with the network size and show how our algorithms can be used in a practical setting to optimize communication performance. Our efficient topology mapping strategies are shown to reduce network congestion by up to 80%, reduce average dilation by up to 50%, and improve benchmarked communication performance by 18%.

Capacity and coverage enhancement in heterogeneous networks

Abstract: Disruptive innovations in mobile broadband system design are required to help network providers meet the exponential growth in mobile traffic demand with relatively flat revenues per bit. Heterogeneous network architecture is one of the most promising low-cost approaches to provide significant areal capacity gain and indoor coverage improvement. In this introductory article, we provide a brief overview of heterogeneous network architectures comprising hierarchical multitier multiple radio access technologies (RAT) deployments based on newer infrastructure elements. We begin with presenting possible deployment scenarios of heterogeneous networks to better illustrate the concepts of multitier and multi-RAT. We then focus on multitier deployments with single RAT and investigate the challenges associated with enabling single frequency reuse across tiers. Based on the spectrum usage, heterogeneous networks can be categorized into single carrier usage, where all devices within the network share the same spectrum, and distinct carrier usage, where different types of devices are allocated separate spectra. For single carrier usage, we show that interference management schemes are critical for reducing the resulting cross-tier interference, and present several techniques that provide significant capacity and coverage improvements. The article also describes industry trends, standardization efforts, and future research directions in this rich area of investigation.

On exploiting cognitive radio to mitigate interference in macro/femto heterogeneous networks

Abstract: To successfully deploy femtocells underlaying the macrocell as a heterogeneous network, which has been proven to greatly improve indoor coverage and system capacity, the cross-tier interference among the macrocell and femtocells as well as the intratier interference among femtocells must be mitigated. However, some unique features present a challenge in interference mitigation in a two-tier heterogeneous network such as random deployment for femtocells, nonexistence of macro-femto backhaul coordination, and mandates allowing no modifications of existing macrocells. Carefully examining the existing distributed information acquisition mechanisms, cognitive radio is the most promising solution for two-tier heterogeneous networks. We therefore study possible interference mitigation approaches, including orthogonal radio resource assignment in the time-frequency and antenna spatial domains, as well as interference cancellation via novel decoding techniques. According to the information acquired by cognitive radio technology, recent innovations such as game theory and the Gibbs sampler have been explored to mitigate both cross-tier and intratier interferences. Performance evaluations show that considerable performance improvement can be generally achieved, and thus demonstrate the potential of applying cognitive radio in mitigating interference.

On exploiting cognitive radio to mitigate interference in macro/femto heterogeneous networks h et n ets : a n ew p aradigm f or i ncreasing c ellular c apacity a nd c overage

Abstract: To successfully deploy femtocells underlaying the macrocell as a heterogeneous network, which has been proven to greatly improve indoor coverage and system capacity, the cross-tier interference among the macrocell and femtocells as well as the intratier interference among femtocells must be mitigated. However, some unique features present a challenge in interference mitigation in a two-tier heterogeneous network such as random deployment for femtocells, nonexistence of macro-femto backhaul coordination, and mandates allowing no modifications of existing macrocells. Carefully examining the existing distributed information acquisition mechanisms, cognitive radio is the most promising solution for two-tier heterogeneous networks. We therefore study possible interference mitigation approaches, including orthogonal radio resource assignment in the time-frequency and antenna spatial domains, as well as interference cancellation via novel decoding techniques. According to the information acquired by cognitive radio technology, recent innovations such as game theory and the Gibbs sampler have been explored to mitigate both cross-tier and intratier interferences. Performance evaluations show that considerable performance improvement can be generally achieved, and thus demonstrate the potential of applying cognitive radio in mitigating interference.

Enabling coexistence of heterogeneous wireless systems: case for ZigBee and WiFi

Abstract: The ISM spectrum is becoming increasingly populated by emerging wireless networks. Spectrum sharing among the same network of devices can be arbitrated by MAC protocols (e.g., CSMA), but the coexistence between heterogeneous networks remains a challenge. The disparate power levels, asynchronous time slots, and incompatible PHY layers of heterogeneous networks severely degrade the effectiveness of traditional MAC. In this paper, we propose a new mechanism, called the Cooperative Busy Tone (CBT), that enables the reliable coexistence between two such networks, ZigBee and WiFi. CBT allows a separate ZigBee node to schedule a busy tone concurrently with the desired transmission, thereby improving the visibility of ZigBee devices to WiFi. Its core components include a frequency flip scheme that prevents the mutual interference between cooperative ZigBee nodes, and a busy tone scheduler that minimizes the interference to WiFi, for both CSMA and TDMA packets. To optimize CBT, we establish an analytical framework that relates its key design parameters to performance and cost. Both the analytical and detailed simulation results demonstrate CBT's significant throughput improvement over the legacy ZigBee protocol, with negligible performance loss to WiFi. The results are validated further by implementing CBT on sensor motes and software radios.

Impact of Backhauling Power Consumption on the Deployment of Heterogeneous Mobile Networks

Abstract: Energy efficiency in cellular mobile radio networks has recently gained great interest in the research community. The development of more energy efficient hardware and software components aside, effect of different deployment strategies on energy efficiency are also studied in the literature. The latter mainly consist of optimizing the number and the location of different types of base stations in order to minimize the total power consumption. Usually, in the literature, the total network power consumption is restricted to the sum of the power consumption of all base stations. However, the choice of a specific deployment also affects the exact implementation of the backhaul network, and consequently its power consumption, which should therefore be taken into account when devising energy efficient deployment. In this paper, we propose a new power consumption model for a mobile radio network considering backhaul. We then handle a case study and perform a comparison of the power consumption of three different heterogeneous network deployments, and show how backhaul has a non-negligible impact on total power consumption, which differs for different deployments. An energy efficiency analysis is also carried out for different area throughput targets.

Macro-femto heterogeneous network deployment and management: from business models to technical solutions

Abstract: The femtocell technique can address the poor in-building coverage problem and increase net work capacity cost efficiently. At present, some wireless service providers have launched their femtocell services, although there are still plenty of challenges unsettled. In this article we discuss the business mode in macro-femto heterogeneous networks. We propose three frameworks according to the deployment types of femtocells, which are joint deployment, WSP deployment, and user deployment frameworks. Their unique characteristics, corresponding challenges, and potential solutions are further investigated to provide deeper insight systematically. We also present two schemes for WSP revenue maximization under the WSP deployment framework. The first scheme jointly handles the interference and users' demand satisfaction via cross-tier channel allocation, and the second scheme further considers the optimal pricing selection for accessing different networks.

A Delay-Aware Data Collection Network Structure for Wireless Sensor Networks

Abstract: Wireless sensor networks utilize large numbers of wireless sensor nodes to collect information from their sensing terrain. Wireless sensor nodes are battery-powered devices. Energy saving is always crucial to the lifetime of a wireless sensor network. Recently, many algorithms are proposed to tackle the energy saving problem in wireless sensor networks. In these algorithms, however, data collection efficiency is usually compromised in return for gaining longer network lifetime. There are strong needs to develop wireless sensor networks algorithms with optimization priorities biased to aspects besides energy saving. In this paper, a delay-aware data collection network structure for wireless sensor networks is proposed. The objective of the proposed network structure is to minimize delays in the data collection processes of wireless sensor networks. Two network formation algorithms are designed to construct the proposed network structure in a centralized and a decentralized approach. Performances of the proposed network structure are evaluated using computer simulations. Simulation results show that, when comparing with other common network structures in wireless sensor networks, the proposed network structure is able to shorten the delays in the data collection process significantly.

System and method for interfacing with heterogeneous network data gathering tools

Abstract: A prevention-based network auditing system includes a plurality of heterogeneous information sources gathering information about the network. An audit server invokes the heterogeneous information sources via a uniform communications interface to gather information about the network, and converts the information gathered by the information sources into a normalized data format such as, for example, into XML (Extensible Markup Language). The converted information is then stored in an audit repository for security and regulatory policy assessment, network vulnerability analysis, report generation, and security improvement recommendations.

MultiAspectForensics: Pattern Mining on Large-Scale Heterogeneous Networks with Tensor Analysis

Abstract: Modern applications such as web knowledge base, network traffic monitoring and online social networks have made available an unprecedented amount of network data with rich types of interactions carrying multiple attributes, for instance, port number and time tick in the case of network traffic. The design of algorithms to leverage this structured relationship with the power of computing to assist researchers and practitioners for better understanding, exploration and navigation of this space of information has become a challenging, albeit rewarding, topic in social network analysis and data mining. The constantly growing scale and enriching genres of network data always demand higher levels of efficiency, robustness and generalizability where existing approaches with successes on small, homogeneous network data are likely to fall short. We introduce MultiAspectForensics, a handy tool to automatically detect and visualize novel sub graph patterns within a local community of nodes in a heterogenous network, such as a set of vertices that form a dense bipartite graph whose edges share exactly the same set of attributes. We apply the proposed method on three data sets from distinct application domains, present empirical results and discuss insights derived from these patterns discovered. Our algorithm, built on scalable tensor analysis procedures, captures spectral properties of network data and reveals informative signals for subsequent domain-specific study and investigation, such as suspicious port-scanning activities in the scenario of cyber-security monitoring.

Wireless Sensor Network: A Review on Data Aggregation

Abstract: Data aggregation is very crucial techniques in wireless sensor network. Because with the help of data aggregation we reduce the energy consumption by eliminating redundancy. When wireless sensor network deployed in remote areas or hostile environment. In the wireless sensor network have the most challenging task is a life time so with help of data aggregation we can enhance the lifetime of the network .In this paper we discuss the data aggregation approaches based on the routing protocols, the algorithm in the wireless sensor network. And also discuss the advantages and disadvantages or various performance measures of the data aggregation in the network.

A case for heterogeneous on-chip interconnects for CMPs

Abstract: Network-on-chip (NoC) has become a critical shared resource in the emerging Chip Multiprocessor (CMP) era. Most prior NoC designs have used the same type of router across the entire network. While this homogeneous network design eases the burden on a network designer, partitioning the resources equally among all routers across the network does not lead to optimal resource usage, and hence, affects the performance-power envelope. In this work, we propose to apportion the resources in an NoC to leverage the non-uniformity in network resource demand. Our proposal includes partitioning the network resources, specifically buffers and links, in an optimal manner. This approach results in redistributing resources such that routers that require more resources are allocated more buffers and wider links compared to routers demanding fewer resources. This results in a novel heterogeneous network, called HeteroNoC, which is composed of two types of routers -- small power efficient routers, and big high performance routers. We evaluate a number of heterogeneous network configurations, composed of big and small routers, and show that giving more resources to routers along the diagonals in a mesh network provides maximum benefits in terms of performance and power. We also show the potential benefits of the HeteroNoC design by co-evaluating it with memory-controllers and configuring it with an asymmetric CMP consisting of heterogeneous cores.

Cognitive Networks Achieve Throughput Scaling of a Homogeneous Network

Abstract: Two distinct, but overlapping, networks that operate at the same time, space, and frequency is considered. The first network consists of n randomly distributed primary users, which form an ad hoc network. The second network again consists of m randomly distributed ad hoc secondary users or cognitive users. The primary users have priority access to the spectrum and do not need to change their communication protocol in the presence of the secondary users. The secondary users, however, need to adjust their protocol based on knowledge about the locations of the primary users to bring little loss to the primary network's throughput. By introducing preservation regions around primary receivers, a modified multihop routing protocol is proposed for the cognitive users. Assuming m=nβ with β >; 1, it is shown that the secondary network achieves almost the same throughput scaling law as a stand-alone network while the primary network throughput is subject to only a vanishingly small fractional loss. Specifically, the primary network achieves the sum throughput of order n1/2 and, for any δ >; 0, the secondary network achieves the sum throughput of order m1/2-δ with an arbitrarily small fraction of outage. Thus, almost all secondary source-destination pairs can communicate at a rate of order m-1/2-δ.

Hierarchical cooperative relay based heterogeneous networks

Abstract: This article presents a hierarchical cooperative relay-based heterogeneous network (HCRHeNet) to support both unicast and multicast services, where hierarchical cooperative relay nodes are deployed to provide a cost-effective coverage extension based on the convergence of heterogeneous radio networks. The underlined HCR-HeNet divides its coverage into three layers: hierarchical cooperative basic layer, homogeneous cooperative enhanced layer, and heterogeneous cooperative extended layer. In the hierarchical cooperative basic layer, highspeed data transmission is enabled using highorder modulation and coding schemes for unicast services, and hierarchical modulation schemes for multicast services. In the homogeneous cooperative enhanced layer, where users may be located near a cell boundary and thus need the help of relay nodes, cooperative homogeneous diversity gain can be achieved. In the heterogeneous cooperative extended layer, heterogeneous cooperative diversity gain guarantees the convergence and interworking of multiradio access networks. The key techniques in the physical and MAC layers are identified. Issues in the application of cognitive radio and self-organized networking techniques in HCR-HeNet are also discussed. Finally, a physical layer testbed for the proposed HCR-HeNet with multicast services is introduced.

Probabilistic topic models with biased propagation on heterogeneous information networks

Abstract: With the development of Web applications, textual documents are not only getting richer, but also ubiquitously interconnected with users and other objects in various ways, which brings about text-rich heterogeneous information networks. Topic models have been proposed and shown to be useful for document analysis, and the interactions among multi-typed objects play a key role at disclosing the rich semantics of the network. However, most of topic models only consider the textual information while ignore the network structures or can merely integrate with homogeneous networks. None of them can handle heterogeneous information network well. In this paper, we propose a novel topic model with biased propagation (TMBP) algorithm to directly incorporate heterogeneous information network with topic modeling in a unified way. The underlying intuition is that multi-typed objects should be treated differently along with their inherent textual information and the rich semantics of the heterogeneous information network. A simple and unbiased topic propagation across such a heterogeneous network does not make much sense. Consequently, we investigate and develop two biased propagation frameworks, the biased random walk framework and the biased regularization framework, for the TMBP algorithm from different perspectives, which can discover latent topics and identify clusters of multi-typed objects simultaneously. We extensively evaluate the proposed approach and compare to the state-of-the-art techniques on several datasets. Experimental results demonstrate that the improvement in our proposed approach is consistent and promising.

Robust Consensus Controller Design for Nonlinear Relative Degree Two Multi-Agent Systems With Communication Constraints

Abstract: Robust static output-feedback controllers are designed that achieve consensus in networks of heterogeneous agents modeled as nonlinear systems of relative degree two. Both ideal communication networks and networks with communication constraints are considered, e.g., with limited communication range or heterogeneous communication delays. All design conditions that are presented are scalable to large and heterogeneous networks because the controller parameters depend only on the dynamics of the corresponding agent and its neighbors, but not on other agents in the network.

Essentials of Lte and Lte-A

Abstract: This practical, one-stop guide will quickly bring you up to speed on LTE and LTE-Advanced. With everything you need to know about the theory and technology behind the standards, this is a must-have for engineers and managers in the wireless industry. First book of its kind describing technologies and system performance of LTE-A Covers the evolution of digital wireless technology, basics of LTE and LTE-A, design of downlink and uplink channels, multi-antenna techniques and heterogeneous networks Analyzes performance benefits over competing technologies, including WiMAX and 802.16m Reflects the latest LTE Release-10 standards Includes numerous examples, including extensive system and link results Unique approach is accessible to technical and non-technical readers alike

Joint Forensics-Scheduling Strategy for Delay-Sensitive Multimedia Applications over Heterogeneous Networks

Abstract: High quality multimedia forensics service is increasingly critical for delay-sensitive applications over heterogeneous networks. Up to now, it is a challenging problem, where the demand for less forensics overhead, higher authentication level and smaller transmission delay needs to be reconciled with the limited and often dynamic network resources. Traditional multimedia forensics mechanisms, however, either overlook the available network resource or neglect the interaction between multimedia forensics and network scheduling. This work presents a novel framework for delay-sensitive multimedia applications over resource-limited heterogeneous networks by jointly considering multimedia forensics, network adaptation, and deadline-driven scheduling. In particular, we develop a joint forensics-scheduling scheme, which allocates the available network resources based on the affordable forensics overhead and expected quality of service, adaptively adjusts the scalable media-aware forensics, and schedules the transmissions to meet the application's delay constraints. Through analysis and simulation, we demonstrate that the proposed scheme not only can provide a satisfying multimedia forensics service with nearly full utilization of the network resource, but also can achieve substantial performance improvements compared to other reference approaches.