Correlative coding with clipping and filtering technique in OFDM Systems

The major setbacks of Orthogonal Frequency Multiplexing (OFDM) is its peak-to-average power ratio (PAPR) and intercarrier interference (ICI). The occurrence of these factors restricts its application. Here, the clipping and filtering PAPR reduction technique is king investigated to reduce the PAPR and out-of-band radiation simultaneously by implementing correlative coding. This paper focuses on the preliminaty measurement studies that was canid out. It is shown thmugh simulation that the collaboration of these techniques gives a reasonable PAPR reduction and improves the out-of-band radiation

Transport mechanism for wireless micro sensor network

Wireless sensor network (WSN) is a wireless ad hoc network that consists of very large number of tiny sensor nodes communicating with each other with limited power and memory constrain. WSN demands real-time routing which requires messages to be delivered within their end-to-end deadlines (packet lifetime). This report proposes a novel real-time with load distribution (RTLD) routing protocol that provides real time data transfer and efficient distributed energy usage in WSN. The RTLD routing protocol ensures high packet throughput with minimized packet overhead and prolongs the lifetime of WSN. The routing depends on optimal forwarding (OF) decision that takes into account of the link quality, packet delay time and the remaining power of next hop sensor nodes. RTLD routing protocol possesses built-in security measure. The random selection of next hop node using location aided routing and multi-path forwarding contributes to built-in security measure. RTLD routing protocol in WSN has been successfully studied and verified through simulation and real test bed implementation. The performance of RTLD routing in WSN has been compared with the baseline real-time routing protocol. The simulation results show that RTLD experiences less than 150 ms packet delay to forward a packet through 10 hops. It increases the delivery ratio up to 7 % and decreases power consumption down to 15% in unicast forwarding when compared to the baseline routing protocol. However, multi-path forwarding in RTLD increases the delivery ratio up to 20%. In addition, RTLD routing spreads out and balances the forwarding load among sensor nodes towards the destination and thus prolongs the lifetime of WSN by 16% compared to the baseline protocol. The real test bed experiences only slight differences of about 7.5% lower delivery ratio compared to the simulation. The test bed confirms that RTLD routing protocol can be used in many WSN applications including disasters fighting, forest fire detection and volcanic eruption detection

Prioritization scheme for QoS in IEEE 802.11e WLAN

The exponential growth in demand for multimedia applications in wireless network has resulted in dramatic increased in different devices and connections accessing information.Indeed, this is primarily due to the fact that wireless and multimedia applications have been used quite extensively in business, commercial and communication industry.Supporting multimedia application in wireless environment with different bandwidth and delay requirement is challenging – this can eventually have detrimental impact on the system performance if the necessary quality of service (QoS) requirement has not been provided.This paper presents an approach which prioritizes the application base on its content in order to ultimately support and provide the needed requirements for multimedia application over wireless LAN.Consequently, the throughput of the IEEE 802.11e while maintaining its QoS requirement.The scheme has been simulated using NS2 simulator

Integrating mobile ad hoc network into mobile IPv6 network

In the future more and more devices connected to the Internet will be wireless. Wireless networks can be classified into two types of networks: network with infrastructure (i.e. networks with base stations, gateway and routing support), which is called Mobile IP, and network without infrastructure which is called ad hoc networks. Mobile IP tries to solve the problem of how a mobile node may roam from its network to foreign network and still maintain connectivity to the Internet. Ad hoc network tries to solve the problem if the infrastructure is not available or inconvenient for its use such as in rural environments. Integrating ad hoc into Mobile IP provide new feature for Mobile ad hoc network such as Internet connectivity, streamline communication with another network. This paper presents the development of a test bed for integrating Mobile Ad hoc NETwork (MANET) into Mobile IPv6

Connectivity in mobile multihop relay network

Mobile Multihop Relay (MMR) network is an attractive and low-cost solution for expanding service coverage and enhancing throughput of the conventional single hop network. However, mobility of Mobile Station (MS) in MMR network might lead to performance degradation in terms of Quality of Service (QoS). Selecting an appropriate Relay Station (RS) that can support data transmission for high mobility MS to enhance QoS is one of the challenges in MMR network. The main goal of the work is to develop and enhance relay selection mechanisms that can assure continuous connectivity while ensuring QoS in MMR network using NCTUns simulation tools. The approach is to develop and enhance a relay selection for MS with continuous connectivity in non-transparent relay. In this approach, the standard network entry procedure is modified to allow continuous connectivity with reduced signaling messages whenever MS joins RS that is out of Multihop Relay Base Station (MRBS) coverage and the relay selection is based on Signal to Noise Ratio (SNR). The QoS performances of the proposed relay selections are in terms of throughput and average end-to-end (ETE) delay. The findings for the proposed relay selection in non-transparent relay shows that the throughput degradation between low mobility MS (30m/s) and high mobility MS (50m/s) is only about 2.0%. The proposed relay selection mechanisms can be applied in any high mobility multi-tier cellular network

Mobility prediction method for vehicular network using Markov chain

This paper proposes mobility prediction technique via Markov Chains with an input of user’s mobile data traces to predict the user’s movement in wireless network. The main advantage of this method is prediction will give knowledge of user’s movement in advance even in fast moving vehicle. Furthermore, the information from prediction result will be use to assist handover procedure by reserve resource allocation in advance in vehicular network. This algorithm is simple and can be computed within short time, thus the implementation of this technique will give the significant impact especially on higher speed vehicle. Finally, an experiment is performed using real mobile user data traces as input for Markov chain to predict next user movement. To evaluate the effectiveness of the proposed method, MATLAB simulations are carried out with several users under same location zone. The results show that the proposed method predicts have good performance which is 30 of mobile users achieved 100 of prediction accuracy

Development of PAN (personal area network) for Mobile Robot Using Bluetooth Transceiver

In recent years, wireless applications using radio frequency (RF) have been rapidly evolving in personal computing and communications devices. Bluetooth technology was created to replace the cables used on mobile devices. Bluetooth is an open specification and encompasses a simple low-cost, low power solution for integration into devices. This research work aim was to provide a PAN (personal area network) for computer based mobile robot that supports real-time control of four mobile robots from a host mobile robot. With ad hoc topology, mobile robots may request and establish a connection when it is within the range or terminated the connection when it leaves the area. A system that contains both hardware and software is designed to enable the robots to participate in multi-agent robotics system (MARS). Computer based mobile robot provide operating system that enabled development of wireless connection via IP address

A service oriented middleware for smart home and ambient assisted living

Due to the complexity issue of developing heterogeneous Wireless Sensor Network application such as limited reusability, non-scalability, tight coupling between platform and application, a new middleware needs to be introduced to solve these problems. A distributed system framework such as Service Oriented Architecture (SOA) can definitely resolve these issues. SOA framework is able to hide the complexity lower layer to the application programmer and also create modular programming that can support different platforms. This paper aims to provide the service oriented middleware that supports heterogeneous services in Smart Home and Ambient Assisted Living (SHAAL) application

Stochastic geometry based dynamic fractional frequency reuse for OFDMA systems

Fractional Frequency Reuse (FFR) has been acknowledged as an efficient Interference Management (IM) technique, which offers significant capacity enhancement and improves cell edge coverage with low complexity of implementation. The performance of cellular system greatly depends on the spatial configuration of base stations (BSs). In literature, FFR has been analyzed mostly with cellular networks described by Hexagon Grid Model (HGM). HGM is neither tractable nor scalable to the dense deployment of next generation wireless networks. Moreover, the perfect geometry based HGM tends to overestimate the system's performance and not able to reflect the reality. In this paper, we use the stochastic geometry approach; FFR is analyzed with cellular network modeled by homogeneous Poisson Point Process (PPP). PPP model provides complete randomness in terms of BS deployment, which captures the real network scenario. A dynamic FFR scheme is proposed in this article, which take into account the randomness of the cell coverage area described by Voronoi tessellation. It is shown that the proposed scheme outperforms the traditional fixed frequency allocation schemes in terms of capacity and capacity density

Biological inspired secure autonomous routing mechanism for wireless sensor networks

The field of wireless sensor network (WSN) is an important and challenging research area today. Advancements in sensor networks enable a wide range of environmental monitoring applications. Multihop routing in WSN is affected by new nodes constantly entering/leaving. Moreover, secure routing is a difficult problem due to the resource limitations in WSN. Thus, biological inspired algorithms are reviewed and enhanced to tackle the problems. Ant routing and human security system have shown excellent performance. Certain parameters as energy level, velocity, packet reception, dropping, mismatch rates and packet sending power are considered while making decision. The decision will come up with the optimal route and also to take best action against security attacks. In this paper, the design and initial work of BIOlogical Inspired Secure Autonomous Routing Protocol (BIOSARP) is presented. The proposed bio-inspired mechanism will meet the enhanced WSN requirements, including better delivery ratio, less energy consumption and routing overhead