SCHEDULABILITY ANALYSIS FOR HARD NETWORK LIFETIME WIRELESS SENSOR NETWORKS WITH HIGH ENERGY FIRST CLUSTERING

SCHEDULABILITY ANALYSIS FOR HARD NETWORK LIFETIME WIRELESS SENSOR NETWORKS WITH HIGH ENERGY FIRST CLUSTERING

ABSTRACT

Network lifetime predictability is an essential system requirement for the type of wireless sensor network (WSN) used in safety-critical and highly-reliable applications. All sensor nodes in these time-critical WSNs should meet the lifetime constraint at any time instance, else it may cause severe consequences that involve economic losses, or even fatalities. In the literature, clustering sensors into groups is a popular strategy to maximize the network lifetime, but none of the clustering algorithms address the predictability issue for time-criticalWSNs. 

In this paper, the High Energy First (HEF) clustering algorithm is chosen as a design reference model, which is proved in this paper to be an optimal clustering policy under certain ideal conditions. To address network lifetime predictability in practice, the network lifetime bounds and feasibility test for the HEF are developed via the worst case energy consumption analysis. 

The network simulator 2 (NS2) is used to verify the proposed network lifetime predictability model, and the results show that the derived bounds of the predictability provide accurate estimations of the system lifetime

SELF-RECONFIGURABLE WIRELESS MESH NETWORKS

SELF-RECONFIGURABLE WIRELESS MESH NETWORKS

ABSTRACT

During their lifetime, multi-hop wireless mesh networks (WMNs) experience frequent link failures caused by channel interference, dynamic obstacles and/or applications’ bandwidth demands. These failures cause severe performance degradation in WMNs or require expensive, manual network management for their real-time recovery. This paper presents an Autonomous network Reconfiguration System (ARS) that enables a multi-radio WMN to autonomously recover from local link failures to preserve network performance. 

By using channel and radio diversities in WMNs, ARS generates necessary changes in local radio and channel assignments in order to recover from failures. Next, based on the thus-generated configuration changes, the system cooperatively reconfigures network settings among local mesh routers. ARS has been implemented and evaluated extensively on our IEEE 802.11-based WMN test-bed as well as through ns-2-based simulation. 

Our evaluation results show that ARS outperforms existing failure-recovery schemes in improving channel-efficiency by more than 90%and in the ability of meeting the applications’ bandwidth demands by an average of 200%.

SECURED COMMUNICATION FOR MANETS IN MILITARY

SECURED COMMUNICATION FOR MANETS IN MILITARY 

ABSTRACT

A new way to increase the security of data transmission of mobile ad hoc networks [MANETS] is presented in this work. There is a massive increase in using MANETS for unmanned army system for both surveillance and future combat operations. This has necessitated the development of innovative MANET solutions catering to the reliability, security and scalability needs of the defense communications environment.  Security and reliability are crucial aspects of MANET, especially in security sensitive applications like military. 

Secure Message Transmission SMT[1] protocol  secure the data transmission phase by tailoring an end-to-end secure data forwarding protocol to the MANET communication requirements and increases the reliability through  transmitting the messages in multiple paths with minimal redundancy. This work increases the through the removal of Byzantine Faults [8] in the multiple paths. A binary search probing technique which is resilient to Byzantine failures caused by individual or colluding nodes is incorporated in the SMT protocol to provide more secured transmission. The fault detection algorithm bounds logarithmically (log n –n the number of nodes in the path), so the delay is reduced drastically. 

The simulated implementation of the work in NS2 shows the marginal increase in the throughput. The delay and jitter variants can also be improved if the nodes location can be predicted. Predicting the nodes location and reducing the unnecessary traffic with the aid of Spatial and Temporal mining is the second phase of this work.  

EFFICIENT MULTICAST ALGORITHMS FOR MULTICHANNEL WIRELESS MESH NETWORKS

EFFICIENT MULTICAST ALGORITHMS FOR MULTICHANNEL WIRELESS MESH NETWORKS

ABSTRACT

The wireless mesh network is an emerging technology that provides high quality service to end users as the “last mile” of the Internet. Furthermore, multicast communication is a key technology for wireless mesh networks. Multicast provides efficient data distribution among a group of nodes. However, unlike other wireless networks, such as sensor networks and MANETs, where multicast algorithms are designed to be energy efficient and to achieve optimal route discovery among mobile nodes, wireless mesh networks need to maximize throughput. 

This paper proposes two multicast algorithms: the Level Channel Assignment (LCA) algorithm and the Multichannel Multicast (MCM) to improve the throughput for multichannel and multi-interface mesh networks. The algorithms build efficient multicast trees by minimizing the number of relay nodes and total hop count distances of the trees. The algorithms use dedicated channel assignment strategies to reduce the interference to improve the network capacity. We also demonstrate that using partially overlapping channels can further diminish the interference. 

Furthermore, additional interfaces help to increase the bandwidth, and multiple gateways can further shorten the total hop count distance. Simulations show that those algorithms greatly outperform the single-channel multicast algorithm. We also observe that MCM achieves better throughput and shorter delay while LCA can be realized in distributed manner.

EFFICIENT TARGET TRACKING THROUGH BINARY-DETECTION IN SPARSELY DEPLOYED WSN

EFFICIENT TARGET TRACKING THROUGH BINARY-DETECTION IN SPARSELY DEPLOYED WSN

ABSTRACT

The problem of tracking moving objects with help of wireless sensor network (WSN) has been studied in past. Most of the solutions rely on the use of specialized and expensive sensors, and on dense deployment of sensors. These techniques are infeasible for applications in low budget domains. In this paper, we propose two novel techniques to track targets using binary sensing that does not need overlapping sensing regions. These techniques can track a target, and estimate the distance it has traversed on the basis of the time that target spends in the vicinity of sensors. In the first technique, the path traced by a moving target is approximated by tangent estimations to three circles, each representing range of a sensor. It allows us to convert the original problem into a semi definite program. The other tracking scheme identifies a band of small width where the target is guaranteed to lie. The band is first approximated using the distance travelled after coming out of vicinity of one sensor and before entering the vicinity of second sensor. This band is then reduced using the distance travelled inside the vicinity of the sensors. We simulated the two methods in NS2 and evaluate both the methods.

OPTIMAL ROUTE SELECTION METHOD WITH SATELLITE SYSTEM FOR COGNITIVE WIRELESS NETWORK IN DISASTER INFORMATION NETWORK

OPTIMAL ROUTE SELECTION METHOD WITH SATELLITE SYSTEM FOR COGNITIVE WIRELESS NETWORK IN DISASTER INFORMATION NETWORK 

ABSTRACT 

Cognitive wireless network consisted of multiple different types of wireless interface is one of efficient wireless transmission methods for Disaster Information Network, because it solves single wireless network problems like characteristics of wireless frequency or congestion form the use of same radio frequency.  However, even if Disaster Information Network consisted of Cognitive Wireless Network, some of wireless node might be broken after severe disaster is happened. Therefore, it is necessary  to consider about additional functions which the system never die. In this paper, we introduce Satellite System for optimal transmission control method in Cognitive Wireless Network in order to consider with severe disaster. 

First, as our previous study, proper wireless link and route selection is held by Extend AHP and Extend AODV with Min-Max AHP value methods for optimal transmission control in Cognitive Wireless Network.  Then, check-alive function, alternate data transmission function, possible alternative route suggestion, and network reconfiguration are introduced to our proposed Disaster Information Network by using Satellite System.  

In the simulation, ns2 are used for the computational results to the effectiveness of the suggested transmission methods in the hybrid system of cognitive wireless and satellite network system. 

QUALITY OF SERVICE-BASED MULTI-DOMAIN ROUTING UNDER MULTIPLE QUALITY OF SERVICE METRICS

QUALITY OF SERVICE-BASED MULTI-DOMAIN ROUTING UNDER MULTIPLE QUALITY OF SERVICE METRICS

ABSTRACT

Applications such as voice and video require network paths that satisfy several different quality of service (QoS) metrics, such as delay, jitter, packet loss rate and availability. The calculation of paths under multiple QoS metrics, such as the above four metrics, is a difficult problem since these metrics are in general incompatible. The authors propose a simple method for combining the above four QoS metrics into a single composite QoS metric which can be used as a link cost in Dijkstra’s algorithm in order to calculate a path. 

The authors evaluated the proposed method in a multi-domain routing environment where domain reachability information is available through a service oriented architecture paradigm, and they show that it outperforms two commonly used methods. The results are also applicable to routing within a single domain.