1,216 research outputs found
Simulation and Performance Analysis of MP-OLSR for Mobile Ad hoc Networks
Mobile ad hoc networks (MANETs) consist of a collection of wireless mobile
nodes which dynamically exchange data without reliance on a fixed base station
or a wired backbone network, which makes routing a crucial issue for the design
of a ad hoc networks. In this paper we discussed a hybrid multipath routing
protocol named MP-OLSR. It is based on the link state algorithm and employs
periodic exchange of messages to maintain topology information of the networks.
In the mean time, it updates the routing table in an on-demand scheme and
forwards the packets in multiple paths which have been determined at the
source. If a link failure is detected, the algorithm recovers the route
automatically. Concerning the instability of the wireless networks, the
redundancy coding is used to improve the delivery ratio. The simulation in NS2
shows that the new protocol can effectively improve the performance of the
networks
Multipath optimized link state routing for mobile ad hoc networks
International audienceMultipath routing protocols for Mobile Ad hoc NETwork (MANET) address the problem of scalability, security (confidentiality and integrity), lifetime of networks, instability of wireless transmissions, and their adaptation to applications. Our protocol, called MP-OLSR (MultiPath OLSR), is a multipath routing protocol based on OLSR. The Multipath Dijkstra Algorithm is proposed to obtain multiple paths. The algorithm gains great flexibility and extensibility by employing different link metrics and cost functions. In addition, route recovery and loop detection are implemented in MP-OLSR in order to improve quality of service regarding OLSR. The backward compatibility with OLSR based on IP source routing is also studied. Simulation based on Qualnet simulator is performed in different scenarios. A testbed is also set up to validate the protocol in real world. The results reveal that MP-OLSR is suitable for mobile, large and dense networks with large traffic, and could satisfy critical multimedia applications with high on time constraints
Local heuristic for the refinement of multi-path routing in wireless mesh networks
We consider wireless mesh networks and the problem of routing end-to-end
traffic over multiple paths for the same origin-destination pair with minimal
interference. We introduce a heuristic for path determination with two
distinguishing characteristics. First, it works by refining an extant set of
paths, determined previously by a single- or multi-path routing algorithm.
Second, it is totally local, in the sense that it can be run by each of the
origins on information that is available no farther than the node's immediate
neighborhood. We have conducted extensive computational experiments with the
new heuristic, using AODV and OLSR, as well as their multi-path variants, as
underlying routing methods. For two different CSMA settings (as implemented by
802.11) and one TDMA setting running a path-oriented link scheduling algorithm,
we have demonstrated that the new heuristic is capable of improving the average
throughput network-wide. When working from the paths generated by the
multi-path routing algorithms, the heuristic is also capable to provide a more
evenly distributed traffic pattern
Flow Allocation for Maximum Throughput and Bounded Delay on Multiple Disjoint Paths for Random Access Wireless Multihop Networks
In this paper, we consider random access, wireless, multi-hop networks, with
multi-packet reception capabilities, where multiple flows are forwarded to the
gateways through node disjoint paths. We explore the issue of allocating flow
on multiple paths, exhibiting both intra- and inter-path interference, in order
to maximize average aggregate flow throughput (AAT) and also provide bounded
packet delay. A distributed flow allocation scheme is proposed where allocation
of flow on paths is formulated as an optimization problem. Through an
illustrative topology it is shown that the corresponding problem is non-convex.
Furthermore, a simple, but accurate model is employed for the average aggregate
throughput achieved by all flows, that captures both intra- and inter-path
interference through the SINR model. The proposed scheme is evaluated through
Ns2 simulations of several random wireless scenarios. Simulation results reveal
that, the model employed, accurately captures the AAT observed in the simulated
scenarios, even when the assumption of saturated queues is removed. Simulation
results also show that the proposed scheme achieves significantly higher AAT,
for the vast majority of the wireless scenarios explored, than the following
flow allocation schemes: one that assigns flows on paths on a round-robin
fashion, one that optimally utilizes the best path only, and another one that
assigns the maximum possible flow on each path. Finally, a variant of the
proposed scheme is explored, where interference for each link is approximated
by considering its dominant interfering nodes only.Comment: IEEE Transactions on Vehicular Technolog
Resilient availability and bandwidth-aware multipath provisioning for media transfer over the internet (Best Paper Award)
Traditional routing in the Internet is best-effort. Path differentiation including multipath routing is a promising technique to be used for meeting QoS requirements of media intensive applications. Since different paths have different characteristics in terms of latency, availability and bandwidth, they offer flexibility in QoS and congestion control. Additionally protection techniques can be used to enhance the reliability of the network.
This paper studies the problem of how to optimally find paths ensuring maximal bandwidth and resiliency of media transfer over the network. In particular, we propose two algorithms to reserve network paths with minimal new resources while increasing the availability of the paths and enabling congestion control. The first algorithm is based on Integer Linear Programming which minimizes the cost of the paths and the used resources. The second one is a heuristic-based algorithm which solves the scalability limitations of the ILP approach. The algorithms ensure resiliency against any single link failure in the network.
The experimental results indicate that using the proposed schemes the connections availability improve significantly and a more balanced load is achieved in the network compared to the shortest path-based approaches
An enhanced Multipath Strategy in Mobile Ad hoc Routing Protocols
The various routing protocols in Mobile Ad hoc Networks follow different
strategies to send the information from one node to another. The nodes in the
network are non static and they move randomly and are prone to link failure
which makes always to find new routes to the destination. This research mainly
focused on the study of the characteristics of multipath routing protocols in
MANETS. Two of the multipath routing protocols were investigated and a
comparative study along with simulation using NS2 was done between DSR and AODV
to propose an enhanced approach to reach the destination maintaining the QoS. A
possible optimization to the DSR and AODV routing protocols was proposed to
make no node to be overburdened by distributing the load after finding the
alternate multipath routes which were discovered in the Route discovery
process. The simulation shows that the differences in the protocol highlighted
major differences with the protocol performance. These differences have been
analyzed with various network size, mobility, and network load. A new search
table named Search of Next Node Enquiry Table (SONNET) was proposed to find the
best neighbor node. Using SONNET the node selects the neighbor which can be
reached in less number of hops and with less time delay and maintaining the
QoS
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