The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The following topics are dealt with: digital information systems; resource management; QoS; wireless networks; data communications; optical networking; and wireless communication systems.
Over recent years the depth to which we have grown to rely on networked computer systems as part of the critical national infrastructure has become ever more apparent. Concern over difficulties caused by accidental failures has led to a realisation of the potential for damage that could be caused by targeted attacks and cyber warfare. Current approaches to addressing these problems have tended to...
Web development frameworks (WDFs) that incorporate both Workflow paradigms and the Model View Controller (MVC) are known as WMVC-WFDs. Such frameworks guide the developer in generating the flow of control between the various components. Despite the pressing need for a visual environment to help developers manage the overwhelming number workflows during development, we have not come across any work...
This paper presents a novel approach to overcome the limitation inherited in statistical machine translation services where the translation of new terms is not covered. The proposed approach is based on the power of user generated content to drive Arabic translations of English words. Our initial pilot experiment reveals the potential of our approach. This approach can act as an add-on to improve...
This work is concerned with the measure and, most importantly, the prediction of software development projects in terms of cost estimate. The purpose of this paper is to explore the usefulness of recording, in the software project data, the cultural and leadership characteristics of the development team. As a result of the study, a new model for identifying and analyzing was developed. The paper tests...
A web usage mining and visualization tool for analyzing the efficiency of design and structure of index pages is presented. The tool uses visual views to identify optimal locations for links and classes of links in a page. The tool automatically generates the recommended redesign of the page. Measures used to accomplish that are visit frequencies, time spent, and a combined time and visit approach...
In this paper we present a new admission control (AC) for IEEE 802.16. The AC aims to accept new connections according to the negotiated service class (UGS, rtPS, nrTPS, and BE). To achieve this goal we propose to use the token bucket concept that provide QoS for real time traffics without degrading the QoS of non real time traffic. To show the benefit of the proposed AC, an analytical model based...
This work analyzes the downstream impediments of centralized local access networks with LAN capability and proposes an efficient downstream scheme over a distributed upstream control plane, where OLT is relieved from the burden of upstream control function and inter-ONU communication.
There are real challenges in both the IEEE 802.11 wireless local area network (WLAN) protocol and the medium access control (MAC)-functions providing the required quality-of-service, high throughput and minimum latencies. The IEEE 802.11 layer supports both the distributed coordination function (DCF) and the enhanced DCF (EDCF). The different access categories (AC) within the EDCF can enhance the...
In wireless sensor networks, sensor data messages are transmitted to a sink node by using wireless multihop transmission with help of intermediate sensor nodes. In event-based sensor networks, no or few sensor data messages are transmitted in usual and burst sensor data messages are required to be transmitted when a sensor detects occurrence of a certain event. It may cause congestion along a multihop...
Although IEEE 802.11e standard is approved for better QoS support, the bandwidth allocation to individual access categories (ACs) can unpredictably vary, preventing efficient QoS provisioning. In this paper, we propose a scheme that jointly maximizes channel capacity and provides network-wide service differentiation to provide fine grained proportional bandwidth allocation to ACs without depending...
Due to the rapid and independent developments of systems, heterogeneity has become a common feature of current networks. In order to harmonize two different networks and close the gap between their technologies, we need to develop a good mechanism for network selection, and access that best satisfy user requirements. Many public areas (collages, airports, hotels...etc) have different systems for providing...
We study a multiple-access system with a primary user (PU) and a secondary user (SU) utilizing the same frequency band and communicating with a common receiver. Both users transmit with a fixed transmission rate by employing a channel inversion power control scheme. The SU transmits with a certain probability that depends on the sensing outcome, its queue length and whether it has a new packet arrival...
The problem of blind channel estimation in Multiple-Input-Multiple-Output (MIMO) Orthogonal Frequency-Division Multiplexing (OFDM) systems is investigated in this study, assuming that the transmitted symbols are independent and identically distributed. In particular, by utilizing a generalized linear non-redundant precoder, a simple blind channel estimation technique for MIMO-OFDM systems is developed...
In highly spatially correlated channels the diversity gain achieved by space-frequency (SF) coding is significantly low. Nevertheless, when full or partial channel state information is available at the transmitter, improved performance can be obtained by combining transmit beamforming with SF coding. In this paper we propose two novel transmit beamforming techniques based on the minimum pair-wise...
New method for equalization and symbol detection for 8-PSK EDGE system is investigated in this study. The exact solution to this problem, Maximum Likelihood Sequence Estimation (MLSE) turns out to be too complex for practical purposes, but this method introduce a new version of Delayed Decision Feedback Sequence Estimation (DDFSE) equalizer that has less complexity and totally comparable performance...
Scheduling is a fundamental component in resource (bandwidth and power) management in NG wireless networks and plays the main role in providing QoS requirements such as delay, throughput and packet loss for different classes of service in 802.16d networks. In this paper we propose a novel scheduling algorithm Strict Priority Based Adaptive modulation and Coding (SP_AMC_Based) that can grantee QoS...
In this paper, we present a Failure Prediction System (FPS) using a novel algorithm that extracts frequent anomalous behaviors based on multi-scale trend analysis of multiple network parameters. The proposed Correlation Analysis Across Parameters algorithm (CAAP) utilizes multiple levels of timescale analysis to reveal the frequent anomalous behaviors. The CAAP philosophy is that failures usually...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.