14,254 research outputs found
An ACO Algorithm for Effective Cluster Head Selection
This paper presents an effective algorithm for selecting cluster heads in
mobile ad hoc networks using ant colony optimization. A cluster in an ad hoc
network consists of a cluster head and cluster members which are at one hop
away from the cluster head. The cluster head allocates the resources to its
cluster members. Clustering in MANET is done to reduce the communication
overhead and thereby increase the network performance. A MANET can have many
clusters in it. This paper presents an algorithm which is a combination of the
four main clustering schemes- the ID based clustering, connectivity based,
probability based and the weighted approach. An Ant colony optimization based
approach is used to minimize the number of clusters in MANET. This can also be
considered as a minimum dominating set problem in graph theory. The algorithm
considers various parameters like the number of nodes, the transmission range
etc. Experimental results show that the proposed algorithm is an effective
methodology for finding out the minimum number of cluster heads.Comment: 7 pages, 5 figures, International Journal of Advances in Information
Technology (JAIT); ISSN: 1798-2340; Academy Publishers, Finlan
A Candour-based Trust and Reputation Management System for Mobile Ad Hoc Networks
The decentralized administrative controlled-nature of mobile ad hoc networks (MANETs) presents security vulnerabilities which can lead to attacks such as malicious modification of packets. To enhance security in MANETs, Trust and Reputation Management systems (TRM) have been developed to serve as measures in mitigating threats arising from unusual behaviours of nodes. In this paper we propose a candour-based trust and reputation system which measures and models reputation and trust propagation in MANETs. In the proposed model Dirichlet Probability Distribution is employed in modelling the individual reputation of nodes and the trust of each node is computed based on the node’s actual network performance and the quality of the recommendations it gives about other nodes. Cooperative nodes in our model will be rewarded for expanding their energy in forwarding packets for other nodes or for disseminating genuine recommenda-tions. Uncooperative nodes are isolated and denied the available network resources. We employed the Ruffle algorithm which will ensure that cooperative nodes are allowed to activate sleep mode when their service is not required in forwarding packets for its neighbouring trustworthy nodes. The proposed TRM system enshrines fairness in its mode of operation as well as creating an enabling environment free from bias. It will also ensure a connected and capacity preserving network of trustworthy node
Cross-layer design of multi-hop wireless networks
MULTI -hop wireless networks are usually defined as a collection of nodes
equipped with radio transmitters, which not only have the capability to
communicate each other in a multi-hop fashion, but also to route each others’ data
packets. The distributed nature of such networks makes them suitable for a variety of
applications where there are no assumed reliable central entities, or controllers, and
may significantly improve the scalability issues of conventional single-hop wireless
networks.
This Ph.D. dissertation mainly investigates two aspects of the research issues
related to the efficient multi-hop wireless networks design, namely: (a) network
protocols and (b) network management, both in cross-layer design paradigms to
ensure the notion of service quality, such as quality of service (QoS) in wireless mesh
networks (WMNs) for backhaul applications and quality of information (QoI) in
wireless sensor networks (WSNs) for sensing tasks. Throughout the presentation of
this Ph.D. dissertation, different network settings are used as illustrative examples,
however the proposed algorithms, methodologies, protocols, and models are not
restricted in the considered networks, but rather have wide applicability.
First, this dissertation proposes a cross-layer design framework integrating
a distributed proportional-fair scheduler and a QoS routing algorithm, while using
WMNs as an illustrative example. The proposed approach has significant performance
gain compared with other network protocols. Second, this dissertation proposes
a generic admission control methodology for any packet network, wired and
wireless, by modeling the network as a black box, and using a generic mathematical
0. Abstract 3
function and Taylor expansion to capture the admission impact. Third, this dissertation
further enhances the previous designs by proposing a negotiation process,
to bridge the applications’ service quality demands and the resource management,
while using WSNs as an illustrative example. This approach allows the negotiation
among different service classes and WSN resource allocations to reach the optimal
operational status. Finally, the guarantees of the service quality are extended to
the environment of multiple, disconnected, mobile subnetworks, where the question
of how to maintain communications using dynamically controlled, unmanned data
ferries is investigated
A New Scheme for Minimizing Malicious Behavior of Mobile Nodes in Mobile Ad Hoc Networks
The performance of Mobile Ad hoc networks (MANET) depends on the cooperation
of all active nodes. However, supporting a MANET is a cost-intensive activity
for a mobile node. From a single mobile node perspective, the detection of
routes as well as forwarding packets consume local CPU time, memory,
network-bandwidth, and last but not least energy. We believe that this is one
of the main factors that strongly motivate a mobile node to deny packet
forwarding for others, while at the same time use their services to deliver its
own data. This behavior of an independent mobile node is commonly known as
misbehaving or selfishness. A vast amount of research has already been done for
minimizing malicious behavior of mobile nodes. However, most of them focused on
the methods/techniques/algorithms to remove such nodes from the MANET. We
believe that the frequent elimination of such miss-behaving nodes never allowed
a free and faster growth of MANET. This paper provides a critical analysis of
the recent research wok and its impact on the overall performance of a MANET.
In this paper, we clarify some of the misconceptions in the understating of
selfishness and miss-behavior of nodes. Moreover, we propose a mathematical
model that based on the time division technique to minimize the malicious
behavior of mobile nodes by avoiding unnecessary elimination of bad nodes. Our
proposed approach not only improves the resource sharing but also creates a
consistent trust and cooperation (CTC) environment among the mobile nodes. The
simulation results demonstrate the success of the proposed approach that
significantly minimizes the malicious nodes and consequently maximizes the
overall throughput of MANET than other well known schemes.Comment: 10 pages IEEE format, International Journal of Computer Science and
Information Security, IJCSIS July 2009, ISSN 1947 5500, Impact Factor 0.42
- …