Topology Control and Routing in Mobile Ad Hoc Networks with Cognitive Radios

Cognitive radio (CR) technology will have significant impacts on upper layer performance in mobile ad hoc networks (MANETs). In this paper, we study topology control and routing in CR-MANETs. We propose a distributed Prediction-based Cognitive Topology Control (PCTC) scheme to provision cognition capability to routing in CR-MANETs. PCTC is a midware-like cross-layer module residing between CR module and routing. The proposed PCTC scheme uses cognitive link availability prediction, which is aware of the interference to primary users, to predict the available duration of links in CR-MANETs. Based on the link prediction, PCTC constructs an efficient and reliable topology, which is aimed at mitigating re-routing frequency and improving end-to-end network performance such as throughput and delay. Simulation results are presented to show the effectiveness of the proposed scheme

Common Metrics for Analyzing, Developing and Managing Telecommunication Networks

The metrics play increasingly fundamental role in the design, development, deployment and operation of telecommunication systems. Despite their importance, the studies of metrics are usually limited to a narrow area or a well-defined objective. Our study aims to more broadly survey the metrics that are commonly used for analyzing, developing and managing telecommunication networks in order to facilitate understanding of the current metrics landscape. The metrics are simple abstractions of systems, and they directly influence how the systems are perceived by different stakeholders. However, defining and using metrics for telecommunication systems with ever increasing complexity is a complicated matter which has not been so far systematically and comprehensively considered in the literature. The common metrics sources are identified, and how the metrics are used and selected is discussed. The most commonly used metrics for telecommunication systems are categorized and presented as energy and power metrics, quality-of-service metrics, quality-of-experience metrics, security metrics, and reliability and resilience metrics. Finally, the research directions and recommendations how the metrics can evolve, and be defined and used more effectively are outlined.Comment: 5 figures, 18 table

Performance study and simulation of an anycast protocol for wireless mobile ad hoc networks

This paper conducts a detailed simulation study of stateless anycast routing in a mobile wireless ad hoc network. The model covers all the fundamental aspects of such networks with a routing mechanism using a scheme of orientation-dependent inter-node communication links. The simulation system Winsim is used which explicitly represents parallelism of events and processes in the network. The purpose of these simulations is to investigate the effect of node s maximum speed, and different TTL over the network performance under two different scenarios. Simulation study investigates five practically important performance metrics of a wireless mobile ad hoc network and shows the dependence of this metrics on the transmission radius, link availability, and maximal possible node speed.Comment: 15 pages, 20 figures, 1 tabl

An Energy Efficient Decoding Scheme for Wireless Body Area Sensor Networks

One of the major challenges in Wireless Body Area Networks (WBANs) is to prolong the lifetime of network. Traditional research work focuses on minimizing transmit power; however, in the case of short range communication the consumption power in decoding is significantly larger than transmit power. This paper investigates the minimization of total power consumption by reducing the decoding power consumption. For achieving a desired Bit Error Rate (BER), we introduce some fundamental results on the basis of iterative message-passing algorithms for Low Density Parity Check Code (LDPC). To reduce energy dissipation in decoder, LDPC based coded communications between sensors are considered. Moreover, we evaluate the performance of LDPC at different code rates and introduce Adaptive Iterative Decoding (AID) by exploiting threshold on the number of iterations for a certain BER (0.0004). In iterative LDPC decoding, the total energy consumption of network is reduced by 20 to 25%.Comment: Journal of Basic and Applied Scientific Research. 2013. arXiv admin note: substantial text overlap with arXiv:1309.075

Smart Routing: Towards Proactive Fault-Handling in Software-Defined Networks

Software-defined networking offers numerous benefits against the legacy networking systems through simplifying the process of network management and reducing the cost of network configuration. Currently, the management of failures in the data plane is limited to two mechanisms: proactive and reactive. Such failure recovery techniques are activated after occurrences of failures. Therefore, packet loss is highly likely to occur as a result of service disruption and unavailability. This issue is not only related to the slow speed of recovery mechanisms, but also the delay caused by the failure detection process. In this paper, we define a new approach to the management of fault tolerance in software-defined networks where the goal is to eliminate the convergence process altogether, rather than speed up failure detection and recovery. We propose a new framework, called Smart Routing, which works based on the forewarning signs on failures in order to compute alternative paths and isolate the risky links from the routing tables of the data plane devices. We validate our framework through a set of experiments that demonstrate how the underlying model runs

Resource Management of energy-aware Cognitive Radio Networks and cloud-based Infrastructures

The field of wireless networks has been rapidly developed during the past decade due to the increasing popularity of the mobile devices. The great demand for mobility and connectivity makes wireless networking a field whose continuous technological development is very important as new challenges and issues are arising. Many scientists and researchers are currently engaged in developing new approaches and optimization methods in several topics of wireless networking. This survey paper study works from the following topics: Cognitive Radio Networks, Interactive Broadcasting, Energy Efficient Networks, Cloud Computing and Resource Management, Interactive Marketing and Optimization

Mirrored and Hybrid Disk Arrays: Organization, Scheduling, Reliability, and Performance

Basic mirroring (BM) classified as RAID level 1 replicates data on two disks, thus doubling disk access bandwidth for read requests. RAID1/0 is an array of BM pairs with balanced loads due to striping. When a disk fails the read load on its pair is doubled, which results in halving the maximum attainable bandwidth. We review RAID1 organizations which attain a balanced load upon disk failure, but as shown by reliability analysis tend to be less reliable than RAID1/0. Hybrid disk arrays which store XORed instead of replicated data tend to have a higher reliability than mirrored disks, but incur a higher overhead in updating data. Read request response time can be improved by processing them at a higher priority than writes, since they have a direct effect on application response time. Shortest seek distance and affinity based routing both shorten seek time. Anticipatory arm placement places arms optimally to minimize the seek distance. The analysis of RAID1 in normal, degraded, and rebuild mode is provided to quantify RAID1/0 performance. We compare the reliability of mirrored disk organizations against each other and hybrid disks and erasure coded disk arrays

Exploiting the power of multiplicity: a holistic survey of network-layer multipath

The Internet is inherently a multipath network---for an underlying network with only a single path connecting various nodes would have been debilitatingly fragile. Unfortunately, traditional Internet technologies have been designed around the restrictive assumption of a single working path between a source and a destination. The lack of native multipath support constrains network performance even as the underlying network is richly connected and has redundant multiple paths. Computer networks can exploit the power of multiplicity to unlock the inherent redundancy of the Internet. This opens up a new vista of opportunities promising increased throughput (through concurrent usage of multiple paths) and increased reliability and fault-tolerance (through the use of multiple paths in backup/ redundant arrangements). There are many emerging trends in networking that signify that the Internet's future will be unmistakably multipath, including the use of multipath technology in datacenter computing; multi-interface, multi-channel, and multi-antenna trends in wireless; ubiquity of mobile devices that are multi-homed with heterogeneous access networks; and the development and standardization of multipath transport protocols such as MP-TCP. The aim of this paper is to provide a comprehensive survey of the literature on network-layer multipath solutions. We will present a detailed investigation of two important design issues, namely the control plane problem of how to compute and select the routes, and the data plane problem of how to split the flow on the computed paths. The main contribution of this paper is a systematic articulation of the main design issues in network-layer multipath routing along with a broad-ranging survey of the vast literature on network-layer multipathing. We also highlight open issues and identify directions for future work

Improving Network Monitoring and Security via Visualization

Internet networks are handling increasing volume of traffic than ever before. This data is mainly associated to sensitive, distributed, and multimedia applications. In the past years, much attention has been paid to the way network infrastructure must be designed and developed in order to handle the challenges of delivering high quality services for applications such as VoIP and streaming video

Technologies for Web and cloud service interaction: a survey

The evolution of Web and service technologies has led to a wide landscape of standards and protocols for interaction between loosely coupled software components. Examples range from Web applications, mashups, apps, and mobile devices to enterprise-grade services. Cloud computing is the industrialization of service provision and delivery, where Web and enterprise services are converging on a technological level. The article discusses this technological landscape and, in particular, current trends with respect to cloud computing. The survey focuses on the communication aspect of interaction by reviewing languages, protocols, and architectures that drive today's standards and software implementations applicable in clouds. Technological advances will affect both client side and service side. There is a trend toward multiplexing, multihoming, and encryption in upcoming transport mechanisms, especially for architectures, where a client simultaneously sends a large number of requests to some service. Furthermore, there are emerging client-to-client communication capabilities in Web clients that could establish a foundation for upcoming Web-based messaging architectures.Comment: Accepted Version 2015-02-20, 41 pages, 19 figures, 3 tables, Service Oriented Computing and Applications (2015