- Communication-efficient Embedded FFT Processing for Acoustic Telemetry in LPWAN-based Beehive Monitoring Systems
- Dual Wide-band Microstrip Antenna for Wireless Communication Systems
- Network Threat Detection in IaaS Environments Based on Flow Log Data
- Machine Learning-based Automatic Modulation Classification for 5G-Advanced and 6G Waveforms: Robust Identification Under Realistic Channel Impairments
No. 3 (2013)
Published:
2013-09-30
ARTICLES FROM THIS ISSUE
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Analysis of the System with Vacations under Poissonian Input Stream and Constant Service Times
Abstract
In the paper approximate formulas for the mean waiting times and the buffer dimensioning in the system with vacations fed by the stream of Poissonian type with constant service times is shown. Furthermore, in the considered system the time intervals of the availability/notavailability of the service are constant and are run alternately according to the assumed cycle. More precisely, presented approach begin with derivation of the mean waiting times and, on the basis of this, the required buffer size for guaranteeing the losses less than predefined value is estimated. The accuracy of the presented analytical formulas is on a satisfactory level. The formulas were used for the System IIP dimensioning.
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Approximation of Message Inter-Arrival and Inter-Departure Time Distributions in IMS/NGN Architecture Using Phase-Type Distributions
Abstract
Currently it is assumed that requirements of the information society for delivering multimedia services will be satisfied by the Next Generation Network (NGN) architecture, which includes elements of the IP Multimedia Subsystem (IMS) solution. In order to guarantee Quality of Service (QoS), NGN has to be appropriately designed and dimensioned. Therefore, proper traffic models should be proposed and applied. This requires determination of queuing models adequate to message inter-arrival and interdeparture time distributions in the network. In the paper the above mentioned distributions in different points of a single domain of NGN are investigated, using a simulation model developed according to the latest standards and research. Relations between network parameters and obtained message inter-arrival as well as interdeparture time distributions are indicated. Moreover, possibility of approximating the above mentioned distributions using phase-type distributions is investigated, which can be helpful in identifying proper queuing models and constructing an analytical model suitable for NGN.
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Traffic Type Influence on Performance of OSPF QoS Routing
Abstract
Feasibility studies with QoS routing proved that the network traffic type has influence on routing performance. In this work influence of self-similar traffic for network with DiffServ architecture and OSPF QoS routing has been verified. Analysis has been done for three traffic classes. Multiplexed On-Off model was used for self-similar traffic generation. Comparison of simulation results was presented using both relative and non-relative measures for three traffic classes. Results were commented and analyzed. The basic conclusion is that performance for streaming and best-effort class for self-similar traffic is higher than performance for the same class with exponential traffic (Poisson). The other important conclusion is relation between performance differences and offered traffic amount.
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Quality Aware Virtual Service Delivery System
Abstract
The problem of providing support for quality of service (QoS) guarantees is studied in many areas of information technologies. In recent years the evolution of software architectures led to the rising prominence of the Service Oriented Architecture (SOA) concept. For Web-based systems there are three attributes that directly relate to everyday perception of the QoS for the end user: availability, usability, and performance. The paper focuses on performance issues of service delivery. The architecture of Virtual Service Delivery System (VSDS), a tool to serve requests for synchronized services is presented. It is proposed suitable monitoring technique used for estimation of values of service parameters and allocation of communication and execution resources by means of service distribution. The paper also presents results of experiments performed in real environment that show effectiveness of proposed solutions.
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Comparison of Resource Control Systems in Multi-layer Virtual Networks
Abstract
This paper describes the performance of various methods of QoS assurance for each connection in an environment composed of virtual networks and dedicate end-to-end connections inside them. The authors worked on the basis of research conducted with the use of the authorial network management system named Executed Management, which uses resources virtualization platforms VMware and Mininet for testing purposes. We briefly describe our system and techniques we used and some alternatives we tested and discarded because of their limitations. Functionality and performance of proposed solution to widespread implemented mechanisms as OpenFlow and MPLS are compared. Reasons for selecting well-known techniques to isolate networks and limit bandwidth on different levels of virtualization are considered. The purpose of this paper is to show out our studies and performance we achieved.
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Quality Management in 4G Wireless Networking Technology Allows to Attend High-Quality Users
Abstract
The 4G networks are all-IP based heterogeneous networks that allow users to use any system at anytime and anywhere, and support a variety of personalized, multimedia applications such as multimedia conferencing, video phones, video/movie-on-demand, education-on-demand, streaming media, multimedia messaging, etc. Personalized services should be supported by personal mobility capability, which concentrates on the movement of users instead of users’ terminals. As the technology matures, traffic congestion increases, and competitive pressures mount, QoS and policy management will become more and more important. Also the users come with a number of new requirements on connectivity, and D2D networking technology must follow the idea of “Internet of things”. Operators must make sure they are working with vendors that have a strong framework to supply end-to-end QoS and are capable of supporting evolving needs. The paper discusses qualitative and quantitative indicators of telecommunication services. Main challenges that need to be addressed by nowadays and future systems are shown, and within them the massive growth in traffic volume and in the number of connected devices seems to play the most key role.
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ILP Modeling of Many-to-Many Replicated Multimedia Communication
Abstract
On-line communication services were evolving from a simple text-based chats towards sophisticated videopresence appliances. The bandwidth consumption of those services is constantly growing due to the technology development and high user and business needs. That fact leads us to implement optimization mechanisms into the multimedia communication scenarios. In this paper, the authors concentrate on many-to-many (m2m) communication, that is mainly driven by the growing popularity of on-line conferences and telepresence applications. An overlay model where m2m flows are optimally established on top of a given set of network routes is formulated and a joint model where the network routes and the m2m flows are jointly optimized. In the models, the traffic traverses through replica servers, that are responsible for stream aggregation and compression. Models for both predefined replica locations and optimized server settlement are presented. Each model is being followed by a comprehensive description and is based on real teleconference systems.
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Minimizing Cost of Network Upgrade for Overlay Multicast – Heuristic Approach
Abstract
A rapid increase of the Internet users and traffic at the rate of 31% in years 2011–2016 contributes to emerging of new approaches to the content distribution. Among other approaches, the overlay multicasting seems to be one of the most interesting concepts according to relatively low deployment costs and large scalability. In this paper, the authors formulate a new incremental multicast overlay design problem. In particular, authors assumed that the overlay network is to be upgraded due to an increase of the number of participating users and the need to improve the streaming quality. However, the existing multicast tree structure is assumed to remain fixed. The goal was to minimize the cost of the upgrade, represented in euro/month. To achieve it, for each peer participating in the transmission, a link type offered by one of the ISPs was selected and overlay trees were constructed, rooted at the source of the content. The authors also present a new heuristic algorithm to efficiently solve this problem. According to experiments, the biggest factor influencing the upgrade cost and determining possible streaming quality values that the system can be upgraded to is the initial tree structure.
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Performance Evaluation of the MSMPS Algorithm under Different Distribution Traffic
Abstract
In this paper, the Maximal Size Matching with Permanent Selection (MSMPS) scheduling algorithm and its performance evaluation, under different traffic models, are described. In this article, computer simulation results under nonuniformly, diagonally and lin-diagonally distributed traffic models are presented. The simulations was performed for different switch sizes: 4×4, 8×8 and 16×16. Results for MSMPS algorithm and for other algorithms well known in the literature are discussed. All results are presented for 16×16 switch size but simulation results are representative for other switch sizes. Mean Time Delay and efficiency were compared and considered. It is shown that our algorithm achieve similar performance results like another algorithms, but it does not need any additional calculations. This information causes that MSMPS algorithm can be easily implemented in hardware.
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Call and Connections Times in ASON/GMPLS Architecture
Abstract
It is assumed that demands of information society could be satisfied by architecture ASON/GMPLS comprehended as Automatically Switched Optical Network (ASON) with Generalized Multi-Protocol Label Switching (GMPLS) protocols. Introduction this solution must be preceded by performance evaluation to guarantee society expectations. Call and connections times are in ASON/GMPLS architecture important for real-time applications. Practical realization is expensive and simulations models are necessary to examine standardized propositions. This paper is devoted to the simulation results of ASON/GMPLS architecture control plane functions in OMNeT++ discrete event simulator. The authors make an effort to explore call/connection set-up times, connection release times in a single domain of ASON/GMPLS architecture.
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Single Hysteresis Model for Limited-availability Group with BPP Traffic
Abstract
This paper presents a single hysteresis model for limited-availability group that are offered Erlang, Engset and Pascal traffic streams. The occupancy distribution in the system is approximated by a weighted sum of occupancy distributions in multi-threshold systems. Distribution weights are obtained on the basis of a specially constructed Markovian switching process. The results of the calculations of radio interfaces in which the single hysteresis mechanism has been implemented are compared with the results of the simulation experiments. The study demonstrates high accuracy of the proposed model.
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Interworking and Cross-layer Service Discovery Extensions for IEEE 802.11s Wireless Mesh Standard
Abstract
With the rapid popularization of mobile end-user electronic devices, wireless network technologies begin to play a crucial role as networks access technologies. While classic point-to-multipoint wireless access systems, based on fixed infrastructure of base stations providing access to clients, remain the main most popular solution, an increasing attention is devoted to wireless mesh systems, where each connecting client can extend overall resources of the network by becoming a network node capable of forwarding transit traffic. This ability results in severe reduction of the necessary network infrastructure, provides through coverage (thereby offering significant step towards ubiquity of network access) and offers massive redundancy. One of the most promising wireless mesh solutions currently being developed is an IEEE 802.11s standard, based on popular Wi-Fi technology. It combines low deployment costs with comprehensive suite of mechanisms able to operate a self-forming, autoconfigurable, dynamically extending, and secure mesh solution. However, despite its advantages, the standard lacks sufficient support for a number of functionalities, which can lead to significant inefficiency and degradation of service quality in real-world IEEE 802.11s network deployments. In the paper we propose a number of extensions of IEEE 802.11s mechanisms, designed to provide better service quality in case of real-world deployment scenarios, especially in case of large systems. Both propositions introduce modifications to mesh path discovery and interworking procedures, while retaining compatibility with standard solution. Their basic functionality and efficiency have been verified by means of simulation model in large-scale, self-organizing mesh structure. Subsequently they have been implemented and tested in real-world, access network testbed deployment. The results clearly indicate their utility, particularly in case of larger deployments of this network system type.
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Cooperative Games with Incomplete Information for Secondary Base Stations in Cognitive Radio Networks
Abstract
Cognitive radio (CR) technology is considered to be an effective solution for enhancing overall spectrum efficiency. Using CR technology fully involves the providing of incentives to Primary Radio Networks (PRNs) and revenue to the service provider so that Secondary Base Stations (SBSs) may utilize PRN spectrum bands accordingly. In this paper, a cooperative games with incomplete information for SBSs in a CR network is presented. Each SBS can cooperate with neighboring SBSs in order to improve its view of the spectrum. Moreover, proposed game-theory models assume that the devices have incomplete information about their components, meaning that some players do not completely know the structure of the game. Using the proposed algorithm, each SBS can leave or join the coalition while maximizing its overall utility. The simulation results illustrate that the proposed algorithm allows us to reduce the average payoff per SBS up to 140% relative to a CR network without cooperation among SBSs.
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Quasi-Offline Fair Scheduling in Third Generation Wireless Data Networks
Abstract
In 3G wireless data networks, network operators would like to balance system throughput while serving users fairly. This is achieved through the use of fair scheduling. However, this approach provides non-Pareto optimal bandwidth allocation when considering a network as a whole. In this paper an optimal offline algorithm that is based on the decomposition result for a double stochastic matrix by Birkhoff and von Neumann is proposed. A utility max-min fairness is suggested for the derivation of a double stochastic matrix. Using a numerical experiment, new approach improves the fairness objective and is close to the optimal solution.
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Performance Tests of Xen-based Node for Future Internet IIP Initiative
Abstract
In this paper the authors intend to report results for performance evaluation of Xen-based node providing both transport and computational functionalities. This node design is proposed as the implementation platform developed for the Polish Initiative of Future Internet called System IIP. In particular, we search for mutual dependence among transport and computational performance parameters of the node. Our investigations show that there is significant dependence among performance indices, such as virtual link bandwidth and node’s processing power, strongly depending on frame size. The tests and measurements were done according to fundamental methodology designed for network devices, described in RFC 2544. The goal of those investigations is to design a provisioning module allocating both transport and computational resources.
