16,037 research outputs found
About the Capacity of Flat and Self-Organized Ad Hoc and Hybrid Networks
Ad hoc networking specific challenges foster a strong research effort on
efficient protocols design. Routing protocols based on a self-organized
structure have been studied principally for the robustness and the scalability
they provide. On the other hand, self-organization schemes may decrease the
network capacity since they concentrate the traffic on privileged links. This
paper presents four models for evaluating the capacity of a routing schemes on
802.11 like networks. Our approach consists in modeling the radio resource
sharing principles of 802.11 like MAC protocols as a set of linear constraints.
We have implemented two models of fairness. The first one assumes that nodes
have a fair access to the channel, while the second one assumes that on the
radio links. We then develop a pessimistic and an optimistic scenarii of
spatial re-utilization of the medium, yielding a lower bound and an upper bound
on the network capacity for each fairness case. Our models are independent of
the routing protocols and provide therefore a relevant framework for their
comparison. We apply our models to a comparative analysis of the well-known
shortest path base flat routing protocol OLSR against two main self-organized
structure approaches, VSR, and Wu & Li's protocols. This study concludes on the
relevance of self-organized approaches from the network capacity point of view
Multimedia Content Distribution in Hybrid Wireless Networks using Weighted Clustering
Fixed infrastructured networks naturally support centralized approaches for
group management and information provisioning. Contrary to infrastructured
networks, in multi-hop ad-hoc networks each node acts as a router as well as
sender and receiver. Some applications, however, requires hierarchical
arrangements that-for practical reasons-has to be done locally and
self-organized. An additional challenge is to deal with mobility that causes
permanent network partitioning and re-organizations. Technically, these
problems can be tackled by providing additional uplinks to a backbone network,
which can be used to access resources in the Internet as well as to inter-link
multiple ad-hoc network partitions, creating a hybrid wireless network. In this
paper, we present a prototypically implemented hybrid wireless network system
optimized for multimedia content distribution. To efficiently manage the ad-hoc
communicating devices a weighted clustering algorithm is introduced. The
proposed localized algorithm deals with mobility, but does not require
geographical information or distances.Comment: 2nd ACM Workshop on Wireless Multimedia Networking and Performance
Modeling 2006 (ISBN 1-59593-485
Hierarchical Design Based Intrusion Detection System For Wireless Ad hoc Network
In recent years, wireless ad hoc sensor network becomes popular both in civil
and military jobs. However, security is one of the significant challenges for
sensor network because of their deployment in open and unprotected environment.
As cryptographic mechanism is not enough to protect sensor network from
external attacks, intrusion detection system needs to be introduced. Though
intrusion prevention mechanism is one of the major and efficient methods
against attacks, but there might be some attacks for which prevention method is
not known. Besides preventing the system from some known attacks, intrusion
detection system gather necessary information related to attack technique and
help in the development of intrusion prevention system. In addition to
reviewing the present attacks available in wireless sensor network this paper
examines the current efforts to intrusion detection system against wireless
sensor network. In this paper we propose a hierarchical architectural design
based intrusion detection system that fits the current demands and restrictions
of wireless ad hoc sensor network. In this proposed intrusion detection system
architecture we followed clustering mechanism to build a four level
hierarchical network which enhances network scalability to large geographical
area and use both anomaly and misuse detection techniques for intrusion
detection. We introduce policy based detection mechanism as well as intrusion
response together with GSM cell concept for intrusion detection architecture.Comment: 16 pages, International Journal of Network Security & Its
Applications (IJNSA), Vol.2, No.3, July 2010. arXiv admin note: text overlap
with arXiv:1111.1933 by other author
A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks
In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs
Concepts and evolution of research in the field of wireless sensor networks
The field of Wireless Sensor Networks (WSNs) is experiencing a resurgence of
interest and a continuous evolution in the scientific and industrial community.
The use of this particular type of ad hoc network is becoming increasingly
important in many contexts, regardless of geographical position and so,
according to a set of possible application. WSNs offer interesting low cost and
easily deployable solutions to perform a remote real time monitoring, target
tracking and recognition of physical phenomenon. The uses of these sensors
organized into a network continue to reveal a set of research questions
according to particularities target applications. Despite difficulties
introduced by sensor resources constraints, research contributions in this
field are growing day by day. In this paper, we present a comprehensive review
of most recent literature of WSNs and outline open research issues in this
field
A comparative study of clusterhead selection algorithms in wireless sensor networks
In Wireless Sensor Network, sensor nodes life time is the most critical
parameter. Many researches on these lifetime extension are motivated by LEACH
scheme, which by allowing rotation of cluster head role among the sensor nodes
tries to distribute the energy consumption over all nodes in the network.
Selection of clusterhead for such rotation greatly affects the energy
efficiency of the network. Different communication protocols and algorithms are
investigated to find ways to reduce power consumption. In this paper brief
survey is taken from many proposals, which suggests different clusterhead
selection strategies and a global view is presented. Comparison of their costs
of clusterhead selection in different rounds, transmission method and other
effects like cluster formation, distribution of clusterheads and creation of
clusters shows a need of a combined strategy for better results.Comment: 12 pages, 3 figures, 5 tables, Int JournaL, International Journal of
Computer Science & Engineering Survey (IJCSES) Vol.2, No.4, November 201
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