Monitoring is a crucial factor for smooth run of distributed systems such as mobile agent based system. Various activities in such systems require monitoring such as performance analysis and tuning, scheduling strateg...
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Monitoring is a crucial factor for smooth run of distributed systems such as mobile agent based system. Various activities in such systems require monitoring such as performance analysis and tuning, scheduling strategies and fault detection. In this paper we present monitoring and fault tolerance technique for mobile agent based systems. We present mobile agent based fault prevention and detection technique where the team of mobile agents monitor each host in mobile agent based system. This research focuses on building an automatic, adaptive and predictive determining policy where critical host agents are identified in advance by monitoring agents, to avoid their failures. The novelty of proposed approach is constant collection and updating of local as well as global information of the system. This policy is determined by calculating weights; taking into account the criticality of the hosts by their monitoring agents which keep updating the weights of hosts. These weights act are used for decision making of checkpointing. These monitoring mobile agents act together to detect undesirable behaviors and also provide support for restoring the system back to normalcy. We also report on the result of reliability and performance issue of our proposed approach.
A mobile adhoc network (MANET) is formed by a group of wireless mobile hosts or nodes without any fixed infrastructure. As there is no central control in a MANET, a mobile node itself acts as a router. A MANET may fun...
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A mobile adhoc network (MANET) is formed by a group of wireless mobile hosts or nodes without any fixed infrastructure. As there is no central control in a MANET, a mobile node itself acts as a router. A MANET may function in a stand-alone fashion or may be connected to the Internet. Undoubtedly, MANETs play a critical role in situations where a wired infrastructure is neither available nor easy to install. MANETs are found in applications such as short-term events, battlefield communications and disaster relief activities etc. Due to node mobility and scarcity of resources such as energy of nodes and bandwidth of wireless links, it is much tougher to provide QoS guarantee in MANETs. Therefore, while designing such a network we need to look out for a good Quality of Service (QoS) of it. Many approaches have been proposed for MANET QoS but very few have addressed it from the message transmission point of view. In this paper, we discuss different factors that affect QoS and also the challenges of QoS in MANET. We then propose an algorithm to enhance the QoS in mobile adhoc network depending on its type of application it is proposed for.
TCP is a reliable transport layer protocol basically designed for wired networks. In TCP, segment loss in transmission is due to congestion in the network rather than due to unreliable medium, the same is not true for...
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TCP is a reliable transport layer protocol basically designed for wired networks. In TCP, segment loss in transmission is due to congestion in the network rather than due to unreliable medium, the same is not true for Ad-Hoc networks, mainly MANET. MANET, a well known Ad-Hoc network is prone to link failures majorly due to mobility. In MANET, TCP is unable to distinguish between losses because of either route failures or congestion. Sometimes, TCP interprets wireless error as congestion. Aiming at the improvement in TCP over MANET, we focus on TCP New Reno, a widely used TCP variant. Similar to other TCP variant TCP New Reno suffers due to misinterpretation of cause of loss and ultimately degrade throughput. We modify and analyze this TCP variant to improve the transport layer performance over MANET. We know that routing plays an important role in MANET, therefore, we involve DSDV and AODV routing protocol in our study. Along with this, we analyze performance of both actual and modified TCP New Reno implementations in term of Packet Delivery Fraction and Throughput.
the authors firstly think it necessary to design a remote-sensing-oriented cloud Workflow. Then the paper gives a detailed description about the related research of Workflow applied in cloudcomputing andgrid computi...
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ISBN:
(纸本)9781467308724
the authors firstly think it necessary to design a remote-sensing-oriented cloud Workflow. Then the paper gives a detailed description about the related research of Workflow applied in cloudcomputing andgridcomputing. And the authors emphasize the scheduling method of remote sensing data under the cloudcomputing platform. Finally, the authors give the related result about development.
One of the most challenging and critical problem in Wireless Sensor Networks (WSNs) is to reduce energy consumption to prolong network life. Clustering is a popular topology control method for routing data through mul...
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One of the most challenging and critical problem in Wireless Sensor Networks (WSNs) is to reduce energy consumption to prolong network life. Clustering is a popular topology control method for routing data through multi-hop communication. It can improve life time of a WSN as well as its scalability. In this paper, we present a distributed clustering and routing algorithm for WSN called CEBCRA (Cost-based Energy Balanced Clustering and Routing Algorithm). The algorithm comprises of three phases, namely cluster head selection, cluster setup and data routing. The CHs are selected in distributed manner based on residual energy and the neighbour cardinality. In the setup phase, each non-CH sensor node joins a CH within its communication range based on the cost value of the CHs. In data routing phase, CEBCRA first uses single hop communication within each cluster and then perform multi-hop communication between the clusters. For inter-cluster routing, a CH measures the cost of each path from itself towards base station while selecting other CH as a relay node for data forwarding on those paths. The experimental results show the efficiency of the proposed algorithm in terms of energy consumption and number of live sensor nodes. The results are compared with two existing techniques to show the efficacy of the algorithm.
Since storing and accessing a digital data is becoming cheaper, the amount of data in multimedia format is continuously increasing. Indexing and organizing of this data is quite important. There is a blended amount of...
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Since storing and accessing a digital data is becoming cheaper, the amount of data in multimedia format is continuously increasing. Indexing and organizing of this data is quite important. There is a blended amount of data exists in the form of audio, such as teleconferences, broadcasted news, reports, interviews, radio broadcasting, etc. To deal with this critical data, users need an effective system for spoken word retrieval. Based on the needs, this paper introduces a novel approach of amplitude independent content-based retrieval system for audio format through speech data. In this study, the input is audio query which is getting through real time or existing data. According to the previous studies, speech retrieval is done with the help of transcribed units, which causes lack of system accuracy. This research work is proposed to increase the efficiency of the retrieval system. Features are used to match the acoustic similarities between the queries with existing documents in the corpus. Furthermore, to fulfill the system efficiency and accuracy requirements, Mel Frequency Cepstral Coefficients and formant feature extraction will be used for feature extraction. The resultant average output of these features will be provided to support vector machine for classification purpose, by considering every average value as a single feature value.
This paper deals with a QoS in 802.11 WLAN (Wireless Local Area Network). WLAN networks provide highest speed of data rate at low cost. However, mobility is not present in WLAN or its services are available in a small...
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This paper deals with a QoS in 802.11 WLAN (Wireless Local Area Network). WLAN networks provide highest speed of data rate at low cost. However, mobility is not present in WLAN or its services are available in a small geographical region. Universal Mobile Telecommunication System (UMTS) is deployable for large areas but it cannot provide sufficient data rate as compared to WLAN, however, cost is also high. To remove these drawbacks the integration of WLAN and UMTS can be a better solution for present needs. The integration of these two technologies provide: better quality of service, load balancing, large geographical area with high data rate at low cost to wireless clients. The data type used is Multimedia data which is hence used to meet the current business needs as well as is required for the collaborative growth of the networking arena. The integration techniques of WLAN and UMTS are based on coupling: open coupling, loose coupling. There is still an uncertainty which remains about the functionality and performance of the integrated architecture. Different techniques are hence been compared in this paper such a result is obtained which will solve our issues and is feasible for the usage of all users.
At the current point of time, health is the important concern for all the peoples all over the world. So, it is very important aspect that how to deal with the diseases effectively and efficiently. In this paper, we p...
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At the current point of time, health is the important concern for all the peoples all over the world. So, it is very important aspect that how to deal with the diseases effectively and efficiently. In this paper, we provide a system that is effective in remote monitoring of the patient and full management of the medical resources like assigning duties to the doctors, nurses etc. Our aim is to design a Low cost patient monitoring device that can measure the temperature, blood pressure and pulse rate of the patients and transmit this data to the Low cost tablet PC and generate an alert message, if there is any critical condition. It can store the data in local database and if the network services are available, then the data automatically send to the central server. This new system provides the multi-level security by assigning different privileges to the different users. All the existing techniques are using expensive devices for monitoring of the patient health such as smart phone, bio-sensor nodes etc. The designed system has very low cost and it can provide proper management of the health care of the patient.
A Man-In-The-Middle(MITM) attack is one of the most well known attack on the computer networks. Out of the several variations of MITM, Address Resolution Protocol(ARP) Spoofing/Poisoning is widely used in packet inter...
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A Man-In-The-Middle(MITM) attack is one of the most well known attack on the computer networks. Out of the several variations of MITM, Address Resolution Protocol(ARP) Spoofing/Poisoning is widely used in packet interception and on-the-fly manipulation. Traditional MITM attacks by ARP Poisoning expose the attacker's identity and thereby physical location. In this paper, to the best of our knowledge it is for the first time that an MITM attack has been added with stealth capabilities. We propose two new attacks namely Stealth MITM(SMITM) and Semi-Stealth MITM(SSMITM) at the Data Link Layer using ARP Spoofing which add stealth capabilities to MITM attacks, thereby concealing the identity of an attacker. Finally, we give a detection and defense technique for the attacks. All the attacks proposed in the paper have been verified and successfully validated in a 300+ node real production network and test beds which include nodes with latest Linux and Windows operating systems under default and secured network scenarios. The results have been 100% effective and have proved the reproducibility of the proposed attacks.
Proliferation of mobile data applications has increased the demand for wireless communication systems which offers high throughput, wide coverage, and improved reliability. The main challenges in the design of such sy...
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Proliferation of mobile data applications has increased the demand for wireless communication systems which offers high throughput, wide coverage, and improved reliability. The main challenges in the design of such systems are the limited resources (like transmission power, scarce frequency bandwidth and limited implementation complexity) and the impairments of the wireless channels which includes noise, interference, and fading effects. Multiple-Input Multiple-Output (MIMO) systems is one of the most promising wireless technologies that can achieve above requirements. Inter-symbol interference (ISI) is still a major concern even in MIMO systems. It degrades the system performance significantly in frequency selective channels. To mitigate ISI, equalization techniques are employed on receiver side. In this paper, Bit error rate (BER) performance improvements of MIMO systems using various equalization techniques like Zero-forcing (ZF), Minimum mean square error (MMSE), ZF-Successive interference cancellation (ZF-SIC), MMSE-SIC, Maximum likelihood (ML) and Sphere decoder (SD) are shown and compared. BER analysis is done under Rayleigh frequency flat and selective as well as under Rician frequency flat channels.
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