Identifying Design Requirements for Wireless Routing Link Metrics

In this paper, we identify and analyze the requirements to design a new routing link metric for wireless multihop networks. Considering these requirements, when a link metric is proposed, then both the design and implementation of the link metric with a routing protocol become easy. Secondly, the underlying network issues can easily be tackled. Thirdly, an appreciable performance of the network is guaranteed. Along with the existing implementation of three link metrics Expected Transmission Count (ETX), Minimum Delay (MD), and Minimum Loss (ML), we implement inverse ETX; invETX with Optimized Link State Routing (OLSR) using NS-2.34. The simulation results show that how the computational burden of a metric degrades the performance of the respective protocol and how a metric has to trade-off between different performance parameters

Review of Parallel Decoding of Space-time Block Codes toward 4G Wireless and Mobile Communications

AbstractThis paper presents a review of recent developments in the area of STBC decoding particularly parallel decoding of full-rate full-diversity STBCs toward real-time 4G wireless communications. After reviewing some parallel STBC decoding techniques and presenting one of the most promising types of parallel processors suitable for the 4G SDR the SIMD processor, the paper shows that parallel decoding of the Golden Code on the ClearSpeed CSX700 SIMD processor achieves a speedup of up to 30 times. The paper highlights the potential to achieve real-time decoding of high-rate STBCs with the use of robust parallel processors

Kinematic and Inverse Dynamic Analysis of a C5 Joint Parallel Robot

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Context-aware VoIP congestion control service

IP networks can have difficulty coping with delay-sensitive VoIP traffics during emergency situations caused by fires and related disasters. During emergencies there is a huge increase in voice and video traffic, causing a huge strain on the network. The strain on the network is as a result of both essential and non-essential traffic. In such crisis situations, calls originating from or destined for rescue personnel, such as doctors and police, are considered essential. Any other calls from eyewitnesses and the public are considered non-essential, since they degrade the quality of service for the emergency response teams by consuming the scarce network resources. Providing the rescue team with the quality of service that they require necessitates network access restriction for non-essential traffic. In this paper, the authors present a voice and video service that uses Context-Awareness and Semantic Web technologies to restrict network access to privileged users during crisis situations. The service monitors the network for crisis conditions, enables the network to respond appropriately when a crisis occurs, detects the end of the crisis and reverts to its default state

Context-Aware Voip congestion control service

Published in The African Journal of Information and Communication, Issue no 11 2010/2011IP networks can have difficulty coping with delay-sensitive VoIP traffics during emergency situations caused by fires and related disasters. During emergencies there is a huge increase in voice and video traffic, causing a huge strain on the network. The strain on the network is as a result of both essential and non-essential traffic. In such crisis situations, calls originating from or destined for rescue personnel, such as doctors and police, are considered essential. Any other calls from eyewitnesses and the public are considered non-essential, since they degrade the quality of service for the emergency response teams by consuming the scarce network resources. Providing the rescue team with the quality of service that they require necessitates network access restriction for non-essential traffic. In this paper, the authors present a voice and video service that uses Context-Awareness and Semantic Web technologies to restrict network access to privileged users during crisis situations. The service monitors the network for crisis conditions, enables the network to respond appropriately when a crisis occurs, detects the end of the crisis and reverts to its default state.IP networks can have difficulty coping with delay-sensitive VoIP traffics during emergency situations caused by fires and related disasters. During emergencies there is a huge increase in voice and video traffic, causing a huge strain on the network. The strain on the network is as a result of both essential and non-essential traffic. In such crisis situations, calls originating from or destined for rescue personnel, such as doctors and police, are considered essential. Any other calls from eyewitnesses and the public are considered non-essential, since they degrade the quality of service for the emergency response teams by consuming the scarce network resources. Providing the rescue team with the quality of service that they require necessitates network access restriction for non-essential traffic. In this paper, the authors present a voice and video service that uses Context-Awareness and Semantic Web technologies to restrict network access to privileged users during crisis situations. The service monitors the network for crisis conditions, enables the network to respond appropriately when a crisis occurs, detects the end of the crisis and reverts to its default state

GPS Multipath Detection in the Frequency Domain

Multipath is among the major sources of errors in precise positioning using GPS and continues to be extensively studied. Two Fast Fourier Transform (FFT)-based detectors are presented in this paper as GPS multipath detection techniques. The detectors are formulated as binary hypothesis tests under the assumption that the multipath exists for a sufficient time frame that allows its detection based on the quadrature arm of the coherent Early-minus-Late discriminator (Q EmL) for a scalar tracking loop (STL) or on the quadrature (Q EmL) and/or in-phase arm (I EmL) for a vector tracking loop (VTL), using an observation window of N samples. Performance analysis of the suggested detectors is done on multipath signal data acquired from the multipath environment simulator developed by the German Aerospace Centre (DLR) as well as on multipath data from real GPS signals. Application of the detection tests to correlator outputs of scalar and vector tracking loops shows that they may be used to exclude multipath contaminated satellites from the navigation solution. These detection techniques can be extended to other Global Navigation Satellite Systems (GNSS) such as GLONASS, Galileo and Beidou.Comment: 2016 European Navigation Conference (ENC 2016), May 2016, Helsinki, Finland. Proceedings of the 2016 European Navigation Conference (ENC 2016

Image Based Navigation System for Pedestrians in an Indoor Environment

Indoor navigation systems provide means to guide pedestrians to their various destinations. While many tools that take advantage of the Global Positioning System (GPS) for outdoor navigation exists, their usefulness is limited to the availability of GPS signal reception, which is usually poor in indoor environments. In this research, we propose a method that employs only images for indoor pedestrian navigation. In the proposed method, a map of the indoor environment is first transformed into a graph model where features of indoor environment are attached to graph nodes and their distances represented by the graph edges. Feature images of initial and destination locations are provided by the pedestrian who needs to be guided. These images are fed into the created graph model and thereafter the Speeded-Up Robust Features (SURF) is then used to find a match to these images to discover their corresponding graph nodes. Graph nodes are identified in a manner that corresponds to pedestrian localized position and destination. Leveraging on these nodes in the graph, models are proposed to find the shortest path to user’s destination with instructions and graphical navigation path to enhance maneuverability. Experiment carried out on an indoor environment of the French South African Institute of Technology building, (Tshwane University of Technology) shows encouraging results

Optimal Control of Transmission Power Management in Wireless Backbone Mesh Networks

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