211 research outputs found
Fuzzy based load and energy aware multipath routing for mobile ad hoc networks
Routing is a challenging task in Mobile Ad hoc Networks (MANET) due to their dynamic topology and lack of central administration. As a consequence of un-predictable topology changes of such networks, routing protocols employed need to accurately capture the delay, load, available bandwidth and residual node energy at various locations of the network for effective energy and load balancing. This paper presents a fuzzy logic based scheme that ensures delay, load and energy aware routing to avoid congestion and minimise end-to-end delay in MANETs. In the proposed approach, forwarding delay, average load, available bandwidth and residual battery energy at a mobile node are given as inputs to a fuzzy inference engine to determine the traffic distribution possibility from that node based on the given fuzzy rules. Based on the output from the fuzzy system, traffic is distributed over fail-safe multiple routes to reduce the load at a congested node. Through simulation results, we show that our approach reduces end-to-end delay, packet drop and average energy consumption and increases packet delivery ratio for constant bit rate (CBR) traffic when compared with the popular Ad hoc On-demand Multipath Distance Vector (AOMDV) routing protocol
Improving Energy Efficiency in MANETs by Multi-Path Routing
Some multi-path routing algorithm in MANET, simultaneously send information
to the destination through several directions to reduce end-to-end delay. In
all these algorithms, the sent traffic through a path affects the adjacent path
and unintentionally increases the delay due to the use of adjacent paths.
Because, there are repetitive competitions among neighboring nodes, in order to
obtain the joint channel in adjacent paths. The represented algorithm in this
study tries to discover the distinct paths between source and destination nodes
with using Omni directional antennas, to send information through these
simultaneously. For this purpose, the number of active neighbors is counted in
each direction with using a strategy. These criterions are effectively used to
select routes. Proposed algorithm is based on AODV routing algorithm, and in
the end it is compared with AOMDV, AODVM, and IZM-DSR algorithms which are
multi-path routing algorithms based on AODV and DSR. Simulation results show
that using the proposed algorithm creates a significant improvement in energy
efficiency and reducing end-to-end delay
Secure Routing Environment with Enhancing QoS in Mobile Ad-Hoc Networks
A mobile adhoc network is infrastructure-free and self configured network connected without wire. As it is infrastructure-free and no centralized control, such type of network are suitable only for conditional inter communication link. So initially maintaining Quality of Service and security aware routing is a difficult task. The main purpose of QoS aware routing is to find an optimal secure route from source to destination which will satisfy two or more QoS constrain. In this paper, we propose a net based multicasting routing scheme to discovery all possible secure path using Secure closest spot trust certification protocol (SCSTC) and the optimal link path is derived from Dolphin Echolocation algorithm (DEA). The numerical result and performance analysis clearly describe that our provided proposal routing protocol generates better packet delivery ratio, decreases packet delay reduces overhead in secured environment
Securing routing protocols in mobile ad hoc networks
A Mobile Ad Hoc Network (MANET) is more prone to security threats than other
wired and wireless networks because of the distributed nature of the network.
Conventional MANET routing protocols assume that all nodes cooperate without
maliciously disrupting the operation of the protocol and do not provide defence
against attackers. Blackhole and flooding attacks have a dramatic negative impact
while grayhole and selfish attacks have a little negative impact on the performance
of MANET routing protocols.
Malicious nodes or misbehaviour actions detection in the network is an important
task to maintain the proper routing protocol operation. Current solutions
cannot guarantee the true classification of nodes because the cooperative nature
of the MANETs which leads to false exclusions of innocent nodes and/or good
classification of malicious nodes. The thesis introduces a new concept of Self-
Protocol Trustiness (SPT) to discover malicious nodes with a very high trustiness
ratio of a node classification. Designing and implementing new mechanisms that
can resist flooding and blackhole attacks which have high negative impacts on
the performance of these reactive protocols is the main objective of the thesis.
The design of these mechanisms is based on SPT concept to ensure the high
trustiness ratio of node classification. In addition, they neither incorporate the
use of cryptographic algorithms nor depend on routing packet formats which make
these solutions robust and reliable, and simplify their implementations in different
MANET reactive protocols.
Anti-Flooding (AF) mechanism is designed to resist flooding attacks which relies
on locally applied timers and thresholds to classify nodes as malicious. Although
AF mechanism succeeded in discovering malicious nodes within a small time, it
has a number of thresholds that enable attacker to subvert the algorithm and
cannot guarantee that the excluded nodes are genuine malicious nodes which was
the motivation to develop this algorithm. On the other hand, Flooding Attack
Resisting Mechanism (FARM) is designed to close the security gaps and overcome
the drawbacks of AF mechanism. It succeeded in detecting and excluding more
than 80% of flooding nodes within the simulation time with a very high trustiness
ratio.
Anti-Blackhole (AB) mechanism is designed to resist blackhole attacks and relies
on a single threshold. The algorithm guarantees 100% exclusion of blackhole nodes
and does not exclude any innocent node that may forward a reply packet. Although
AB mechanism succeeded in discovering malicious nodes within a small time, the
only suggested threshold enables an attacker to subvert the algorithm which was
the motivation to develop it. On the other hand, Blackhole Resisting Mechanism
(BRM) has the main advantages of AB mechanism while it is designed to close
the security gaps and overcome the drawbacks of AB mechanism. It succeeded in
detecting and excluding the vast majority of blackhole nodes within the simulation
time
Variable power transmission in highly Mobile Ad-Hoc Networks
Mobile Ad Hoc Networks pose challenges in terms of power control, due to their fixed
transmission power, the mobility of nodes and a constantly changing topology. High
levels of power are needed in wireless networks, particularly for routing. As a result of
the increase in the number of communication devices being used, there is the challenge
of increased density within these networks, and a need to extend the battery life of communication
devices.
In order to address this challenge, this thesis presents the development of a new protocol
(Dynamic Power AODV), which is an enhancement of the Ad Hoc On Demand Distance
Vector (AODV) protocol. The new protocol dynamically adjusts the transmission power
based on the range, which depends on node density.
This thesis provides a systematic evaluation of the performance of DP-AODV, in a high
speed and high density environment, in comparison with three other routing protocols.
The experiments demonstrated that DP-AODV performed better than two of the protocols
in all scenarios. As compared to the third protocol (AOMDV), DP-AODV gave
better performance results for throughput and Power Consumption, but AOMDV performed
better in terms of Packet Delivery Fraction rate and End-to-End Delay in some
cases
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