47,462 research outputs found
Latency Optimal Broadcasting in Noisy Wireless Mesh Networks
In this paper, we adopt a new noisy wireless network model introduced very
recently by Censor-Hillel et al. in [ACM PODC 2017, CHHZ17]. More specifically,
for a given noise parameter any sender has a probability of
of transmitting noise or any receiver of a single transmission in its
neighborhood has a probability of receiving noise.
In this paper, we first propose a new asymptotically latency-optimal
approximation algorithm (under faultless model) that can complete
single-message broadcasting task in time units/rounds in any
WMN of size and diameter . We then show this diameter-linear
broadcasting algorithm remains robust under the noisy wireless network model
and also improves the currently best known result in CHHZ17 by a
factor.
In this paper, we also further extend our robust single-message broadcasting
algorithm to multi-message broadcasting scenario and show it can broadcast
messages in time rounds. This new robust
multi-message broadcasting scheme is not only asymptotically optimal but also
answers affirmatively the problem left open in CHHZ17 on the existence of an
algorithm that is robust to sender and receiver faults and can broadcast
messages in time rounds.Comment: arXiv admin note: text overlap with arXiv:1705.07369 by other author
A Multi-objective Perspective for Operator Scheduling using Fine-grained DVS Architecture
The stringent power budget of fine grained power managed digital integrated
circuits have driven chip designers to optimize power at the cost of area and
delay, which were the traditional cost criteria for circuit optimization. The
emerging scenario motivates us to revisit the classical operator scheduling
problem under the availability of DVFS enabled functional units that can
trade-off cycles with power. We study the design space defined due to this
trade-off and present a branch-and-bound(B/B) algorithm to explore this state
space and report the pareto-optimal front with respect to area and power. The
scheduling also aims at maximum resource sharing and is able to attain
sufficient area and power gains for complex benchmarks when timing constraints
are relaxed by sufficient amount. Experimental results show that the algorithm
that operates without any user constraint(area/power) is able to solve the
problem for most available benchmarks, and the use of power budget or area
budget constraints leads to significant performance gain.Comment: 18 pages, 6 figures, International journal of VLSI design &
Communication Systems (VLSICS
Computation-Communication Trade-offs and Sensor Selection in Real-time Estimation for Processing Networks
Recent advances in electronics are enabling substantial processing to be
performed at each node (robots, sensors) of a networked system. Local
processing enables data compression and may mitigate measurement noise, but it
is still slower compared to a central computer (it entails a larger
computational delay). However, while nodes can process the data in parallel,
the centralized computational is sequential in nature. On the other hand, if a
node sends raw data to a central computer for processing, it incurs
communication delay. This leads to a fundamental communication-computation
trade-off, where each node has to decide on the optimal amount of preprocessing
in order to maximize the network performance. We consider a network in charge
of estimating the state of a dynamical system and provide three contributions.
First, we provide a rigorous problem formulation for optimal real-time
estimation in processing networks in the presence of delays. Second, we show
that, in the case of a homogeneous network (where all sensors have the same
computation) that monitors a continuous-time scalar linear system, the optimal
amount of local preprocessing maximizing the network estimation performance can
be computed analytically. Third, we consider the realistic case of a
heterogeneous network monitoring a discrete-time multi-variate linear system
and provide algorithms to decide on suitable preprocessing at each node, and to
select a sensor subset when computational constraints make using all sensors
suboptimal. Numerical simulations show that selecting the sensors is crucial.
Moreover, we show that if the nodes apply the preprocessing policy suggested by
our algorithms, they can largely improve the network estimation performance.Comment: 15 pages, 16 figures. Accepted journal versio
Multi-criteria scheduling of pipeline workflows
Mapping workflow applications onto parallel platforms is a challenging
problem, even for simple application patterns such as pipeline graphs. Several
antagonist criteria should be optimized, such as throughput and latency (or a
combination). In this paper, we study the complexity of the bi-criteria mapping
problem for pipeline graphs on communication homogeneous platforms. In
particular, we assess the complexity of the well-known chains-to-chains problem
for different-speed processors, which turns out to be NP-hard. We provide
several efficient polynomial bi-criteria heuristics, and their relative
performance is evaluated through extensive simulations
Feasibility Study of Enabling V2X Communications by LTE-Uu Radio Interface
Compared with the legacy wireless networks, the next generation of wireless
network targets at different services with divergent QoS requirements, ranging
from bandwidth consuming video service to moderate and low date rate machine
type services, and supporting as well as strict latency requirements. One
emerging new service is to exploit wireless network to improve the efficiency
of vehicular traffic and public safety. However, the stringent packet
end-to-end (E2E) latency and ultra-low transmission failure rates pose
challenging requirements on the legacy networks. In other words, the next
generation wireless network needs to support ultra-reliable low latency
communications (URLLC) involving new key performance indicators (KPIs) rather
than the conventional metric, such as cell throughput in the legacy systems. In
this paper, a feasibility study on applying today's LTE network infrastructure
and LTE-Uu air interface to provide the URLLC type of services is performed,
where the communication takes place between two traffic participants (e.g.,
vehicle-to-vehicle and vehicle-to-pedestrian). To carry out this study, an
evaluation methodology of the cellular vehicle-to-anything (V2X) communication
is proposed, where packet E2E latency and successful transmission rate are
considered as the key performance indicators (KPIs). Then, we describe the
simulation assumptions for the evaluation. Based on them, simulation results
are depicted that demonstrate the performance of the LTE network in fulfilling
new URLLC requirements. Moreover, sensitivity analysis is also conducted
regarding how to further improve system performance, in order to enable new
emerging URLLC services.Comment: Accepted by IEEE/CIC ICCC 201
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