12,008 research outputs found
Experimentation with MANETs of Smartphones
Mobile AdHoc NETworks (MANETs) have been identified as a key emerging
technology for scenarios in which IEEE 802.11 or cellular communications are
either infeasible, inefficient, or cost-ineffective. Smartphones are the most
adequate network nodes in many of these scenarios, but it is not
straightforward to build a network with them. We extensively survey existing
possibilities to build applications on top of ad-hoc smartphone networks for
experimentation purposes, and introduce a taxonomy to classify them. We present
AdHocDroid, an Android package that creates an IP-level MANET of (rooted)
Android smartphones, and make it publicly available to the community.
AdHocDroid supports standard TCP/IP applications, providing real smartphone
IEEE 802.11 MANET and the capability to easily change the routing protocol. We
tested our framework on several smartphones and a laptop. We validate the MANET
running off-the-shelf applications, and reporting on experimental performance
evaluation, including network metrics and battery discharge rate.Comment: 6 pages, 7 figures, 1 tabl
A Case for Time Slotted Channel Hopping for ICN in the IoT
Recent proposals to simplify the operation of the IoT include the use of
Information Centric Networking (ICN) paradigms. While this is promising,
several challenges remain. In this paper, our core contributions (a) leverage
ICN communication patterns to dynamically optimize the use of TSCH (Time
Slotted Channel Hopping), a wireless link layer technology increasingly popular
in the IoT, and (b) make IoT-style routing adaptive to names, resources, and
traffic patterns throughout the network--both without cross-layering. Through a
series of experiments on the FIT IoT-LAB interconnecting typical IoT hardware,
we find that our approach is fully robust against wireless interference, and
almost halves the energy consumed for transmission when compared to CSMA. Most
importantly, our adaptive scheduling prevents the time-slotted MAC layer from
sacrificing throughput and delay
Making On-Demand Routing Efficient with Route-Request Aggregation
In theory, on-demand routing is very attractive for mobile ad hoc networks
(MANET), because it induces signaling only for those destinations for which
there is data traffic. However, in practice, the signaling overhead of existing
on-demand routing protocols becomes excessive as the rate of topology changes
increases due to mobility or other causes. We introduce the first on-demand
routing approach that eliminates the main limitation of on-demand routing by
aggregating route requests (RREQ) for the same destinations. The approach can
be applied to any existing on-demand routing protocol, and we introduce the
Ad-hoc Demand-Aggregated Routing with Adaptation (ADARA) as an example of how
RREQ aggregation can be used. ADARA is compared to AODV and OLSR using
discrete-event simulations, and the results show that aggregating RREQs can
make on-demand routing more efficient than existing proactive or on-demand
routing protocols
A link-state based on-demand routing protocol supporting real-time traffic for wireless mobile ad hoc networks
Ankara : The Department of Computer Engineering and the Institute of Engineering and Science of Bilkent University, 2007.Thesis (Master's) -- Bilkent University, 2007.Includes bibliographical references leaves 200-212.Wireless ad hoc networks have gained a lot of popularity since their introduction
and as many wireless network interface cards provide support for ad hoc
networking, such networks have also seen real-life deployment for non-specialized
purposes. Wireless mobile ad hoc networks (MANETs) are currently the most
common type of ad hoc networks, and such networks are especially esteemed for
their mobility support and ease of deployment due to their ad hoc nature. As
most common network applications, such as the Web, FTP, email, and instant
messaging, are data-centric and do not operate under strict time constraints,
MANETs have been deployed to enable such non-real-time applications in the
past. However, with the increasing use of real-time applications over ad hoc
networks, such as teleconferencing, VoIP, and security and tracking applications
where timeliness is of importance, real-time traffic support in multi-hop wireless
mobile ad hoc networks has become an issue.
We propose an event-driven, link-state based, on-demand routing protocol to
enable real-time traffic support in such multi-hop wireless mobile ad hoc networks.
Our protocol, which is named Elessar, is based on link-state topology
dissemination, but instead of the more common periodic link-state messaging
scheme, we employ event-driven link-state messages in Elessar, where topology
changes are the events of interest. Through such an approach, we aim to lower the
overhead of our protocol, especially for low-mobility cases, which is currently the
most commonly encountered case with ad hoc networks deployed with machines
directly interacting with humans, such as PDAs and laptops. Due to its link-state
nature, our protocol is able to support non-real-time traffic without any further
action. In order to support real-time traffic, however, we employ a direct cost
dissemination mechanism, which only operates on-demand when there are one or
more real-time flows in the network. We aim to provide soft quality-of-service
(QoS) guarantees to real-time flows through intelligent path selection, without
any resource reservation. We also aim to provide such QoS guarantees throughout
the lifetime of a real-time flow, even in the face of node failures and mobility,
by dynamic path adaptation during the lifetime of the flow. Elessar is able to
support real-time and non-real-time traffic concurrently, as well as various different
types of concurrent real-time traffic, such as delay- and loss-sensitive traffic.
Our protocol, therefore, does not aim to support a single type of real-time traffic,
but rather a plethora of different types of real-time traffic. Elessar is completely
distributed, dynamic and adaptive, and does not require the underlying MAC
protocol to be QoS-aware.
We analyse our design choices and the performance of our protocol through
realistic simulation experiments conducted on the OMNeT++ discrete event simulation
platform, using the INET framework. We have used the IEEE 802.11b
MAC protocol during our simulations and have employed the random waypoint
mobility model to simulate mobility. Our experimental results show that Elessar
is able to efficiently provide real-time traffic support for different types of traf-
fic flows, even in the face of mobility. Our protocol operates best for smallto-medium-sized
networks where mobility rates are low-to-medium. Once the
mobility rate exceeds a certain threshold, intelligent path selection cannot cope
satisfactorily with the high dynamism of the environment and the overhead of
Elessar exceeds acceptable levels due to its event-driven link-state nature.Görbil, GökçeM.S
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