10,534 research outputs found
Exploiting the power of multiplicity: a holistic survey of network-layer multipath
The Internet is inherently a multipath network---for an underlying network
with only a single path connecting various nodes would have been debilitatingly
fragile. Unfortunately, traditional Internet technologies have been designed
around the restrictive assumption of a single working path between a source and
a destination. The lack of native multipath support constrains network
performance even as the underlying network is richly connected and has
redundant multiple paths. Computer networks can exploit the power of
multiplicity to unlock the inherent redundancy of the Internet. This opens up a
new vista of opportunities promising increased throughput (through concurrent
usage of multiple paths) and increased reliability and fault-tolerance (through
the use of multiple paths in backup/ redundant arrangements). There are many
emerging trends in networking that signify that the Internet's future will be
unmistakably multipath, including the use of multipath technology in datacenter
computing; multi-interface, multi-channel, and multi-antenna trends in
wireless; ubiquity of mobile devices that are multi-homed with heterogeneous
access networks; and the development and standardization of multipath transport
protocols such as MP-TCP.
The aim of this paper is to provide a comprehensive survey of the literature
on network-layer multipath solutions. We will present a detailed investigation
of two important design issues, namely the control plane problem of how to
compute and select the routes, and the data plane problem of how to split the
flow on the computed paths. The main contribution of this paper is a systematic
articulation of the main design issues in network-layer multipath routing along
with a broad-ranging survey of the vast literature on network-layer
multipathing. We also highlight open issues and identify directions for future
work
Wireless Network Design for Control Systems: A Survey
Wireless networked control systems (WNCS) are composed of spatially
distributed sensors, actuators, and con- trollers communicating through
wireless networks instead of conventional point-to-point wired connections. Due
to their main benefits in the reduction of deployment and maintenance costs,
large flexibility and possible enhancement of safety, WNCS are becoming a
fundamental infrastructure technology for critical control systems in
automotive electrical systems, avionics control systems, building management
systems, and industrial automation systems. The main challenge in WNCS is to
jointly design the communication and control systems considering their tight
interaction to improve the control performance and the network lifetime. In
this survey, we make an exhaustive review of the literature on wireless network
design and optimization for WNCS. First, we discuss what we call the critical
interactive variables including sampling period, message delay, message
dropout, and network energy consumption. The mutual effects of these
communication and control variables motivate their joint tuning. We discuss the
effect of controllable wireless network parameters at all layers of the
communication protocols on the probability distribution of these interactive
variables. We also review the current wireless network standardization for WNCS
and their corresponding methodology for adapting the network parameters.
Moreover, we discuss the analysis and design of control systems taking into
account the effect of the interactive variables on the control system
performance. Finally, we present the state-of-the-art wireless network design
and optimization for WNCS, while highlighting the tradeoff between the
achievable performance and complexity of various approaches. We conclude the
survey by highlighting major research issues and identifying future research
directions.Comment: 37 pages, 17 figures, 4 table
A review on routing protocols for application in wireless sensor networks
Wireless sensor networks are harshly restricted by storage capacity, energy
and computing power. So it is essential to design effective and energy aware
protocol in order to enhance the network lifetime. In this paper, a review on
routing protocol in WSNs is carried out which are classified as data-centric,
hierarchical and location based depending on the network structure. Then some
of the multipath routing protocols which are widely used in WSNs to improve
network performance are also discussed. Advantages and disadvantages of each
routing algorithm are discussed thereafter. Furthermore, this paper compares
and summarizes the performances of routing protocols.Comment: 20 pages, 16 figures, 2 table
Survey of Important Issues in UAV Communication Networks
Unmanned Aerial Vehicles (UAVs) have enormous potential in the public and
civil domains. These are particularly useful in applications where human lives
would otherwise be endangered. Multi-UAV systems can collaboratively complete
missions more efficiently and economically as compared to single UAV systems.
However, there are many issues to be resolved before effective use of UAVs can
be made to provide stable and reliable context-specific networks. Much of the
work carried out in the areas of Mobile Ad Hoc Networks (MANETs), and Vehicular
Ad Hoc Networks (VANETs) does not address the unique characteristics of the UAV
networks. UAV networks may vary from slow dynamic to dynamic; have intermittent
links and fluid topology. While it is believed that ad hoc mesh network would
be most suitable for UAV networks yet the architecture of multi-UAV networks
has been an understudied area. Software Defined Networking (SDN) could
facilitate flexible deployment and management of new services and help reduce
cost, increase security and availability in networks. Routing demands of UAV
networks go beyond the needs of MANETS and VANETS. Protocols are required that
would adapt to high mobility, dynamic topology, intermittent links, power
constraints and changing link quality. UAVs may fail and the network may get
partitioned making delay and disruption tolerance an important design
consideration. Limited life of the node and dynamicity of the network leads to
the requirement of seamless handovers where researchers are looking at the work
done in the areas of MANETs and VANETs, but the jury is still out. As energy
supply on UAVs is limited, protocols in various layers should contribute
towards greening of the network. This article surveys the work done towards all
of these outstanding issues, relating to this new class of networks, so as to
spur further research in these areas.Comment: arXiv admin note: substantial text overlap with arXiv:1304.3904 by
other author
On Distributed Routing in Underwater Optical Wireless Sensor Networks
Underwater optical wireless communication (UOWC) is becoming an attractive
technology for underwater wireless sensor networks (UWSNs) since it offers
high-speed communication links. Although UOWC overcomes the drawbacks of
acoustic and radio frequency communication channels such as high latency and
low data rate, yet, it has its own limitations. One of the major limitations of
UOWC is its limited transmission range which demands to develop a multi-hop
network with efficient routing protocols. Currently, the routing protocols for
UOWSNs are centralized having high complexity and large end-to-end delay. In
this article, first, we present the existing routing protocols for UOWSNs.
Based on the existing protocols, we then propose distributed routing protocols
to address the problems of high complexity and large end-to-end delay.
Numerical results have been provided to show that the proposed routing protocol
is superior to the existing protocols in terms of complexity and end-to-end
delay. Finally, we have presented open research directions in UOWSNs.Comment: Submitted to IEEE Communications Magazin
A Jamming-Resistant MAC Protocol for Multi-Hop Wireless Networks
This paper presents a simple local medium access control protocol, called
\textsc{Jade}, for multi-hop wireless networks with a single channel that is
provably robust against adaptive adversarial jamming. The wireless network is
modeled as a unit disk graph on a set of nodes distributed arbitrarily in the
plane. In addition to these nodes, there are adversarial jammers that know the
protocol and its entire history and that are allowed to jam the wireless
channel at any node for an arbitrary -fraction of the time steps,
where is an arbitrary constant. We assume that the nodes cannot
distinguish between jammed transmissions and collisions of regular messages.
Nevertheless, we show that \textsc{Jade} achieves an asymptotically optimal
throughput if there is a sufficiently dense distribution of nodes
A Survey of Protocols for Intermittently Connected Delay-Tolerant Wireless Sensor Networks
Intermittently Connected Delay-Tolerant Wireless Sensor Networks (ICDT-WSNs),
a branch of Wireless Sensor Networks (WSNs), have features of WSNs and the
intermittent connectivity of Delay-Tolerant Networks (DTNs). The applications
of ICDT-WSNs are increasing in recent years, however, the communication
protocols suitable for this category of networks often fall short. Most of the
existing communication protocols are designed for either WSNs or DTNs and tend
to be inadequate for direct use in ICDT-WSNs. This survey summarizes
characteristics of ICDT-WSNs and their communication protocol requirements, and
examines the communication protocols designed for WSNs and DTNs in recent years
from the perspective of ICDT-WSNs. Opportunities for future research in
ICDT-WSNs are also outlined
Wireless Information and Power Transfer for Multi-Relay Assisted Cooperative Communication
In this paper, we consider simultaneous wireless information and power
transfer (SWIPT) in multi-relay assisted two-hop relay system, where multiple
relay nodes simultaneously assist the transmission from source to destination
using the concept of distributed space-time coding. Each relay applies power
splitting protocol to coordinate the received signal energy for information
decoding and energy harvesting. The optimization problems of power splitting
ratios at the relays are formulated for both decode-and-forward (DF) and
amplify-and-forward (AF) relaying protocols. Efficient algorithms are proposed
to find the optimal solutions. Simulations verify the effectiveness of the
proposed schemes.Comment: To be published in IEEE Communications Letter
Towards Reliable Network Wide Broadcast in Mobile Ad Hoc Networks
Network-Wide Broadcast (NWB) is a common operation in Mobile Ad hoc Networks
(MANETs) used by routing protocols to discover routes and in group
communication operations. NWB is commonly performed via flooding, which has
been shown to be expensive in dense MANETs because of its high redundancy.
Several efforts have targeted reducing the redundancy of floods. In this work,
we target another problem that can substantially impact the success of NWBs:
since MAC level broadcasts are unreliable, it is possible for critical
rebroadcasts to be lost, leading to a significant drop in the node coverage.
This is especially true under heavy load and in sparse topologies. We show that
the techniques that target reducing the overhead of flooding, reduce its
inherent redundancy and harm its reliability. In addition, we show that static
approaches are more vulnerable to this problem. We then present a selective
rebroadcast approach to improve the robustness of NWBs. We show that our
approach leads to considerable improvement in NWB coverage relative to a
recently proposed solution to this problem, with a small increase in overhead.
The proposed approaches do not require proactive neighbor discovery and are
therefore resilient to mobility. Finally, the solution can be added to
virtually all NWB approaches to improve their reliability.Comment: 12 pages, 22 figure
Achieving Congestion Diversity in Multi-hop Wireless Mesh Networks
This paper reports on the first systematic study of congestion-aware routing
algorithms for wireless mesh networks to achieve an improved end-end delay
performance. In particular, we compare 802.11 compatible implementations of a
set of congestion-aware routing protocols against our implementation of state
of the art shortest path routing protocol (SRCR). We implement congestion-aware
routing algorithms Backpressure (BP), Enhanced-Backpressure (E-BP) adapted from
[1], [2] suitably adjusted for 802.11 implementation. We then propose and
implement Congestion Diversity Protocol (CDP) adapted from [3] recognizing the
limitations of BP and E-BP for 802.11-based wireless networks. SRCR solely
utilizes link qualities, while BP relies on queue differential to route
packets. CDP and E-BP rely on distance metrics which take into account queue
backlogs and link qualities in the network. E-BP computes its metric by summing
the ETX and queue differential, while CDP determines its metric by calculating
the least draining time to the destination. Our small testbed consisting of
twelve 802.11g nodes enables us to empirically compare the performance of
congestion-aware routing protocols (BP, E-BP and CDP) against benchmark SRCR.
For medium to high load UDP traffic, we observe that CDP exhibits significant
improvement with respect to both end-end delay and throughput over other
protocols with no loss of performance for TCP traffic. Backpressure-based
routing algorithms (BP and E-BP) show poorer performance for UDP and TCP
traffic. Finally, we carefully study the effects of the modular approach to
congestion-aware routing design in which the MAC layer is left intac
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