388 research outputs found
Effects of Emission from Different UWB Short-Range Communication Devices
No full textUltra-wideband (UWB) technology is a new concept in wireless short-range communication. It has numerous advantages that are resulted in producing different new products in various applications. This technology uses very short duration pulses hence occupies very large transmission bandwidth. This phenomenon may cause harmful interference in the existing wireless devices. The main objective of this study is to evaluate the effective parameters in ultra-wideband communication for indoor short-range devices. In this regard, two commercial UWB devices are utilized and effects of these devices in different experimental configurations are investigated. Three configurations including the effects of distance, narrowband spectrum, and another UWB device on bit error rate performance are evaluated. The results of the performed experiments showed the stability and amenability of the UWB technology to be used in multiple UWB devices
Effects of Emission from Different UWB Short-Range Communication Devices
Get PDFUltra-wideband (UWB) technology is a new concept in wireless short-range communication. It has numerous advantages that are resulted in producing different new products in various applications. This technology uses very short duration pulses hence occupies very large transmission bandwidth. This phenomenon may cause harmful interference in the existing wireless devices. The main objective of this study is to evaluate the effective parameters in ultra-wideband communication for indoor short-range devices. In this regard, two commercial UWB devices are utilized and effects of these devices in different experimental configurations are investigated. Three configurations including the effects of distance, narrowband spectrum, and another UWB device on bit error rate performance are evaluated. The results of the performed experiments showed the stability and amenability of the UWB technology to be used in multiple UWB devices
A base-band I- Q GMSK modulator study / Shipun Anuar Hamzah, Mohd Shamian Zainal and Mahamod Ismail
Get PDFThis paper presents the I - Q Gaussian Minimum Shift Keying (I - Q GMSK) modulation technique. GMSK is a widely used modulation scheme because of its constant envelope property and spectral efficiency. We provide some simulation results of I-Q GMSK modulator which consists of ADC, NRZ -L, Gaussian LPF, integrator, computation of In-phase, and Quadrature-phase terms by using Matlab program. Then, this result is compare with the I-Q MSK modulator signal
Time based traffic policing and shaping algorithms on campus network internet traffic
No full textThis paper presents the development of algorithm on Policing and Shaping Traffic for bandwidth management which serves as Quality of Services (QoS) in a Campus network. The Campus network is connected with a 16 Mbps Virtual Private Network line to the internet Wide Area Network. Both inbound and outbound real internet traffic were captured and analyzed. Goodness of Fit (GoF) test with Anderson-darling (AD) was fitted to real traffic to identify the best distribution. The Best-fitted Cumulative Distribution Function (CDF) model was used to analyze and characterized the data and the parameters. Based on the identified parameters, a new Time Based Policing and Shaping algorithm have been developed and simulated. The policing process drops the burst traffic, while the shaping process delays traffic to the next time transmissions. Mathematical model to formulate the controlled algorithm on burst traffic with selected time has been derived. Inbound traffic threshold control burst was policed at 1200 MByte (MB) while outbound traffic threshold was policed at 680 MB in the algorithms. The algorithms were varied in relation to the identified Weibull parameters to reduce the burst. The analysis shows that the higher shape parameter value that relates to the lower burst of network throughput can be controlled. This research presented a new method for time based bandwidth management and an enhanced network performance by identifying new traffic parameters for traffic modeling in Campus networ
An Improved Active Network Concept and Architecture for Distributed and Dynamic Streaming Multimedia Environments with Heterogeneous Bandwidths
No full textA problem in todays Internet infrastructure may occur when a streaming multimedia application is to take place. The information content of video and audio signals that contain moving or changing scenes may simply be too great for Internet clients with low bandwidth capacity if no adaptation is performed. In order to satisfactorily reach clients with various bandwidth capacities some works such as receiver-driven multicast and resilient overlay networks (RON) have been developed. However these efforts mainly call for modification on router level management or place additional layer to the Internet structure, which is not recommended in the nearest future due to the highly acceptance level and widely utilization of the current Internet structure, and the lengthy and tiring standardization process for a new structure or modification to be accepted. We have developed an improved active network approach for distributed and dynamic streaming multimedia environment with heterogeneous bandwidth, such as the case of the Internet. Friendly active network system (FANS) is a sample of our approach. Adopting application level active network (ALAN) mechanism, FANS participants and available media are referred through its universal resource locator (url). The system intercepts traffic flowing from source to destination and performs media post-processing at an intermediate peer. The process is performed at the application level instead of at the router level, which was the original approach of active networks. FANS requires no changes in router level management and puts no additional requirement to the current Internet architecture and, hence, instantly applicable. In comparison with ALAN, FANS possesses two significant differences. From the system overview, ALAN requires three minimum elements: clients, servers, and dynamic proxy servers. FANS, on the other hand, unifies the functionalities of those three elements. Each of peers in FANS is a client, an intermediate peer, and a media server as well. Secondly, FANS members tracking system dynamically detects the existence of a newly joined computers or mobile device, given its url is available and announced. In ALAN, the servers and the middle nodes are priori known and, hence, static. The application level approach and better performance characteristics distinguished also our work with another similar work in this field, which uses router level approach. The approach offers, in general, the following improvements: FANS promotes QoS fairness, in which clients with lower bandwidth are accommodated and receive better quality of service FANS introduces a new algorithm to determine whether or not the involvement of intermediate peer(s) to perform media post-processing enhancement services is necessary. This mechanism is important and advantageous due to the fact that intermediate post-processing increases the delay and, therefore, should only be employed selectively. FANS considers the size of media data and the capacity of clients bandwidth as network parameters that determine the level of quality of service offered. By employing the above techniques, our experiments with the Internet emulator show that our approach improves the reliability of streaming media applications in such environment
Implementing label filters on a shared tree mobile multicast architecture
Get PDFThis paper describes an architecture that filters packets within a subset of nodes on an existing shared multicast tree. The path connecting the group of nodes that want to communicate privately on the existing tree was given a label. These labels are used to route one-to-one and group communication traffic for selected nodes on a multicast tree. Nodes connected to the tree but are not on this label path do not receive any filtered packets. This filter architecture reduces network resource waste by utilising the existing network resources on the multicast tree like quality of service (QoS). In this paper, we also describe how this architecture can be used for mobile communication when implemented in a shared tree mobile multicast architecture
Performance of a shared tree multicast label filter architecture
Get PDFThis paper defines a new multicast filter algorithm. This algorithm is used to filter packets on a mobile multicast architecture using a multicast shared tree. In a mobile multicast architecture, communications between a corresponding node (source) and the mobile node (receiver) should be private and not be sent to every node (receivers) on the multicast tree. We propose using an algorithm that sets up a label sub-tree on an existing mobile multicast shared tree to filter packets based on these labels. Our proposed label filter architecture is implemented differently to the current MPLS architecture. In this paper, we validate the effectiveness of the label filter in mobile communication compared to the traditional method of creating a new multicast tree by analysing the message and time complexity of the algorithm against the setting up time of a new multicast shared tree
Automated eye blink detection and tracking using template matching
No full textEye blink detection is considered to be one of the most reliable sources of communication in modern human computer interaction (HCI) systems. This paper proposes a new method for eye blink detection using template matching and similarity measure. In order to minimize the false detection due to changing background in the video frame, face detection is applied before extraction of the eye template. Golden ratio concept is introduced for robust eye detection and is followed by eye template creation for tracking. Eye tracking is performed by template matching between template image and surrounding region. The normalized correlation coefficient is computed for successful eye tracking. Eye blink detection is performed based upon the correlation score as the score changes significantly whenever a blink occurs. The proposed system provides an overall precision of 92.8% and overall accuracy of 99.6% with 0.1% false positive rate in different experimental conditions.</p
Mitigating inter-cell interference in 5G ultra-dense femtocell networks: Issues and challenges
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