An Experimental Approach to Examine a Multi-Channel Multi-Hop Wireless Backbone Network

This paper presents an experimental deployment of a multi-channel multi-hop wireless backbone network (WBN) with an OpenFlow-based traffic management method. Specifically, a set of APs, each of which uses a single but different channel, is connected by Ethernet and thus constructs a Virtual AP (VAP), thereby achieving a WBN with multi-ple channels. To exibly control traffic ows transmitted over a multi-channel multi-hop WBN, we propose a simple traffic management method based on the OpenFlow control. In the performance evaluation, we rst conduct a preliminary experiment as a lab scale　and then deploy a 6-hop WBN enabling to provide the Internet access service in a conference (from proof-of-concept to a practical environment). Since the control messages are inherently transmitted with the introduction of OpenFlow, the way of isolation be-tween control plane and data plane will become a critical issue to actually deploy the proposed system for the Internet service. We additionally employ a wireless control network for the conference experiment. The experimental results show that the proposed　WBN can increase the network capacity in accordance with the number of channels, thereby providing significant throughput performance for various applications

A study on stryi-icnos potatorum and pisum sativum as natural coagulants for meat food processing wastewater

Slow maintained load test is widely used by contractors in Malaysia to ensure the driven pile could accommodate the design load of the structure. Slow maintained load test is a test to determine load-settlement curve and pile capacity for a period of time using conventional load test. Conventional static pile load test equipment is large in size thus making it heavier and takes a long time to install. In addition, it consumes a lot of space which causes congestion at construction sites. Therefore, the objective of this thesis is to conduct a conventional load test by replacing the pile kentledge load with anchorage and reaction pile. Preparations of ten designs comprising six commercial designs were reviewed. In addition, four proposed designs were suggested for the setup. Final design was produced based on its safety factors and criteria referred via literature review. The test frame consists of reaction frame with four reaction helical pile with two helixes per reaction pile. The deformation shapes, safety factor, stress, and strain of the design and finite element of the model has been analysed with the use of SolidWorks and Pia.xis 30 software. SolidWorks software emphasizes on the model load-deflection relationship while Plaxis 30 ensures a correlation of reaction between pile uplift force and soil. Then, the model was tested on site to determine the relationship between physical load­deflection and pile-soil uplift force. The results of uplift force and displacement for numerical and physical test were nearly identical which increment of load­displacement graph pattern. The higher the uplift force, the higher the displacement obtained. In conclusion, the result obtained and the design may be considered as a guideline for future application of sustainable slow maintained pile load test

Applications of Soft Computing in Mobile and Wireless Communications

Soft computing is a synergistic combination of artificial intelligence methodologies to model and solve real world problems that are either impossible or too difficult to model mathematically. Furthermore, the use of conventional modeling techniques demands rigor, precision and certainty, which carry computational cost. On the other hand, soft computing utilizes computation, reasoning and inference to reduce computational cost by exploiting tolerance for imprecision, uncertainty, partial truth and approximation. In addition to computational cost savings, soft computing is an excellent platform for autonomic computing, owing to its roots in artificial intelligence. Wireless communication networks are associated with much uncertainty and imprecision due to a number of stochastic processes such as escalating number of access points, constantly changing propagation channels, sudden variations in network load and random mobility of users. This reality has fuelled numerous applications of soft computing techniques in mobile and wireless communications. This paper reviews various applications of the core soft computing methodologies in mobile and wireless communications

WDM and DWDM based RoF system in Fiber Optic Communication Systems: A review

The utilization of Fiber Optic (FO) in 5G communication systems has achieved several advantages such as increasing the capacity and the bit rate with a reduction in the total implementation cost. Radio over Fiber (RoF) systems could form the basis for 5G communication networks, due to several reasons related to its ability to provide the required bandwidth for the broadband data transmission to the end-users, other advantages are related with the lower loss in attenuation and higher immunity to RF (Radio Frequency) interference. Particularly, the utilization of Wavelength – Division - Multiplexing (WDM) and Dense - Wavelength - Division - Multiplexing (DWDM) techniques with the RoF system has gained all the attention of researchers in the last few years. As a result, this paper demonstrates a review of the proposed systems, schemes, and methods that contribute in enhancing the WDM and DWDM based RoF systems

Quantifying Potential Energy Efficiency Gain in Green Cellular Wireless Networks

Conventional cellular wireless networks were designed with the purpose of providing high throughput for the user and high capacity for the service provider, without any provisions of energy efficiency. As a result, these networks have an enormous Carbon footprint. In this paper, we describe the sources of the inefficiencies in such networks. First we present results of the studies on how much Carbon footprint such networks generate. We also discuss how much more mobile traffic is expected to increase so that this Carbon footprint will even increase tremendously more. We then discuss specific sources of inefficiency and potential sources of improvement at the physical layer as well as at higher layers of the communication protocol hierarchy. In particular, considering that most of the energy inefficiency in cellular wireless networks is at the base stations, we discuss multi-tier networks and point to the potential of exploiting mobility patterns in order to use base station energy judiciously. We then investigate potential methods to reduce this inefficiency and quantify their individual contributions. By a consideration of the combination of all potential gains, we conclude that an improvement in energy consumption in cellular wireless networks by two orders of magnitude, or even more, is possible.Comment: arXiv admin note: text overlap with arXiv:1210.843