3,150 research outputs found
Improving route discovery in on-demand routing protocols using local topology information in MANETs
Most existing routing protocols proposed for MANETs use flooding as a broadcast technique for the propagation of network control packets; a particular example of this is the dissemination of route requests (RREQs), which facilitate route discovery. In flooding, each mobile node rebroadcasts received packets, which, in this manner, are propagated network-wide with considerable overhead. This paper improves on the performance of existing routing protocols by reducing the communication overhead incurred during the route discovery process by implementing a new broadcast algorithm called the adjusted probabilistic flooding on the Ad-Hoc on Demand Distance Vector (AODV) protocol. AODV [3] is a well-known and widely studied algorithm which has been shown over the past few years to maintain an overall lower routing overhead compared to traditional proactive schemes, even though it uses flooding to propagate RREQs. Our results, as presented in this paper, reveal that equipping AODV with fixed and adjusted probabilistic flooding, instead, helps reduce the overhead of the route discovery process whilst maintaining comparable performance levels in terms of saved rebroadcasts and reachability as achieved by conventional AODV\@. Moreover, the results indicate that the adjusted probabilistic technique results in better performance compared to the fixed one for both of these metrics
Low Power, Low Delay: Opportunistic Routing meets Duty Cycling
Traditionally, routing in wireless sensor networks consists of
two steps: First, the routing protocol selects a next hop,
and, second, the MAC protocol waits for the intended destination
to wake up and receive the data. This design makes
it difficult to adapt to link dynamics and introduces delays
while waiting for the next hop to wake up.
In this paper we introduce ORW, a practical opportunistic
routing scheme for wireless sensor networks. In a dutycycled
setting, packets are addressed to sets of potential receivers
and forwarded by the neighbor that wakes up first
and successfully receives the packet. This reduces delay and
energy consumption by utilizing all neighbors as potential
forwarders. Furthermore, this increases resilience to wireless
link dynamics by exploiting spatial diversity. Our results
show that ORW reduces radio duty-cycles on average
by 50% (up to 90% on individual nodes) and delays by 30%
to 90% when compared to the state of the art
A Scale-Free Topology Construction Model for Wireless Sensor Networks
A local-area and energy-efficient (LAEE) evolution model for wireless sensor
networks is proposed. The process of topology evolution is divided into two
phases. In the first phase, nodes are distributed randomly in a fixed region.
In the second phase, according to the spatial structure of wireless sensor
networks, topology evolution starts from the sink, grows with an
energy-efficient preferential attachment rule in the new node's local-area, and
stops until all nodes are connected into network. Both analysis and simulation
results show that the degree distribution of LAEE follows the power law. This
topology construction model has better tolerance against energy depletion or
random failure than other non-scale-free WSN topologies.Comment: 13pages, 3 figure
Resilient Misbehaviour Detection MAC Protocol (MD-MAC) for Distributed Wireless Networks
Chaminda Alocious, Hannan Xiao, B. Christianson, 'Resilient Misbehaviour Detection MAC Protocol (MD-MAC) for Distributed Wireless Networks' paper presented at the 2016 IEEE Wireless Communications and Networking Conference (IEEE WCNC). Doha, Qatar. 3-6 April 2016Wireless network security requirements are becoming more important and critical. The modern network security architectures require more attention to provide security in each network layer. This will require understanding of protocol vulnerabilities in existing protocol architectures. However, providing security requirements are not just limited to confidentiality and integrity, also availability and fairness are important security elements. IEEE 802.11 MAC protocol is one of the most common standard in modern day networks and has been designed without a consideration for providing security protection at MAC layer. IEEE 802.11 assumes all the nodes in the network are cooperative. However, nodes may purposefully misbehave in order to obtain extra bandwidth, conserve resources and disrupt network performance. This research proposes a Misbehaviour Detection MAC protocol (MD-MAC) to address the problematic scenarios of MAC layer misbehaviours, which takes a novel approach to detect misbehaviours in Mobile Adhoc Networks (MANETs). The MD-MAC modifies the CSMA/CA protocol message exchange and uses verifiable backoff value generation mechanism with an incorporated trust model which is suitable for distributed networks. The MD-MAC protocol has been implemented and evaluated in ns2, simulation results suggest that the protocol is able to detect misbehaving wireless nodes in a distributed network environment
Let the Tree Bloom: Scalable Opportunistic Routing with ORPL
Routing in battery-operated wireless networks is challenging, posing a tradeoff between energy and latency. Previous work has shown that opportunistic routing can achieve low-latency data collection in duty-cycled networks. However, applications are now considered where nodes are not only periodic data sources, but rather addressable end points generating traffic with arbitrary patterns.
We present ORPL, an opportunistic routing protocol that supports any-to-any, on-demand traffic. ORPL builds upon RPL, the standard protocol for low-power IPv6 networks. By combining RPL's tree-like topology with opportunistic routing, ORPL forwards data to any destination based on the mere knowledge of the nodes' sub-tree. We use bitmaps and Bloom filters to represent and propagate this information in a space-efficient way, making ORPL scale to large networks of addressable nodes. Our results in a 135-node testbed show that ORPL outperforms a number of state-of-the-art solutions including RPL and CTP, conciliating a sub-second latency and a sub-percent duty cycle. ORPL also increases robustness and scalability, addressing the whole network reliably through a 64-byte Bloom filter, where RPL needs kilobytes of routing tables for the same task
Implementation and evaluation of the sensornet protocol for Contiki
Sensornet Protocol (SP) is a link abstraction layer between the network layer and the link layer for sensor networks. SP was proposed as the core of a future-oriented sensor node architecture that allows flexible and optimized combination between multiple coexisting protocols. This thesis implements the SP sensornet protocol on the Contiki operating system in order to: evaluate the effectiveness of the original SP services; explore further requirements and implementation trade-offs uncovered by the original proposal. We analyze the original SP design and the TinyOS implementation of SP to design the Contiki port. We implement the data sending and receiving part of SP using Contiki processes, and the neighbor management part as a group of global routines. The evaluation consists of a single-hop traffic throughput test and a multihop convergecast test. Both tests are conducted using both simulation and experimentation. We conclude from the evaluation results that SP's link-level abstraction effectively improves modularity in protocol construction without sacrificing performance, and our SP implementation on Contiki lays a good foundation for future protocol innovations in wireless sensor networks
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