15,783 research outputs found
DyPS: Dynamic Processor Switching for Energy-Aware Video Decoding on Multi-core SoCs
In addition to General Purpose Processors (GPP), Multicore SoCs equipping
modern mobile devices contain specialized Digital Signal Processor designed
with the aim to provide better performance and low energy consumption
properties. However, the experimental measurements we have achieved revealed
that system overhead, in case of DSP video decoding, causes drastic
performances drop and energy efficiency as compared to the GPP decoding. This
paper describes DyPS, a new approach for energy-aware processor switching (GPP
or DSP) according to the video quality . We show the pertinence of our solution
in the context of adaptive video decoding and describe an implementation on an
embedded Linux operating system with the help of the GStreamer framework. A
simple case study showed that DyPS achieves 30% energy saving while sustaining
the decoding performanc
Band Codes for Energy-Efficient Network Coding with Application to P2P Mobile Streaming
A key problem in random network coding (NC) lies in the complexity and energy
consumption associated with the packet decoding processes, which hinder its
application in mobile environments. Controlling and hence limiting such factors
has always been an important but elusive research goal, since the packet degree
distribution, which is the main factor driving the complexity, is altered in a
non-deterministic way by the random recombinations at the network nodes. In
this paper we tackle this problem proposing Band Codes (BC), a novel class of
network codes specifically designed to preserve the packet degree distribution
during packet encoding, ecombination and decoding. BC are random codes over
GF(2) that exhibit low decoding complexity, feature limited and controlled
degree distribution by construction, and hence allow to effectively apply NC
even in energy-constrained scenarios. In particular, in this paper we motivate
and describe our new design and provide a thorough analysis of its performance.
We provide numerical simulations of the performance of BC in order to validate
the analysis and assess the overhead of BC with respect to a onventional NC
scheme. Moreover, peer-to-peer media streaming experiments with a random-push
protocol show that BC reduce the decoding complexity by a factor of two, to a
point where NC-based mobile streaming to mobile devices becomes practically
feasible.Comment: To be published in IEEE Transacions on Multimedi
Effect of oil palm empty fruit bunches (OPEFB) fibers to the compressive strength and water absorption of concrete
Growing popularity based on environmentally-friendly, low cost and lightweight building materials in the construction industry has led to a need to examine how these characteristics can be achieved and at the same time giving the benefit to the environment and maintain the material requirements based on the standards required. Recycling of waste generated from industrial and agricultural activities as measures of building materials is not only a viable solution to the problem of pollution but also to produce an economic design of building
Evaluation of the Performance/Energy Overhead in DSP Video Decoding and its Implications
Video decoding is considered as one of the most compute and energy intensive
application in energy constrained mobile devices. Some specific processing
units, such as DSPs, are added to those devices in order to optimize the
performance and the energy consumption. However, in DSP video decoding, the
inter-processor communication overhead may have a considerable impact on the
performance and the energy consumption. In this paper, we propose to evaluate
this overhead and analyse its impact on the performance and the energy
consumption as compared to the GPP decoding. Our work revealed that the GPP can
be the best choice in many cases due to the a significant overhead in DSP
decoding which may represents 30% of the total decoding energy
Secure Layered Transmission in Multicast Systems with Wireless Information and Power Transfer
This paper considers downlink multicast transmit beamforming for secure
layered transmission systems with wireless simultaneous information and power
transfer. We study the power allocation algorithm design for minimizing the
total transmit power in the presence of passive eavesdroppers and energy
harvesting receivers. The algorithm design is formulated as a non-convex
optimization problem. Our problem formulation promotes the dual use of energy
signals in providing secure communication and facilitating efficient energy
transfer. Besides, we take into account a minimum required power for energy
harvesting at the idle receivers and heterogeneous quality of service (QoS)
requirements for the multicast video receivers. In light of the intractability
of the problem, we reformulate the considered problem by replacing a non-convex
probabilistic constraint with a convex deterministic constraint. Then, a
semidefinite programming relaxation (SDR) approach is adopted to obtain an
upper solution for the reformulated problem. Subsequently, sufficient
conditions for the global optimal solution of the reformulated problem are
revealed. Furthermore, we propose two suboptimal power allocation schemes based
on the upper bound solution. Simulation results demonstrate the excellent
performance and significant transmit power savings achieved by the proposed
schemes compared to isotropic energy signal generation.Comment: 7 pages, 3 figures, accepted for presentation at the IEEE
International Conference on Communications (ICC), Sydney, Australia, 201
How to Solve the Fronthaul Traffic Congestion Problem in H-CRAN?
The design of efficient wireless fronthaul connections for future heterogeneous networks incorporating emerging paradigms such as heterogeneous cloud radio access network (H-CRAN) has become a challenging task that requires the most effective utilization of fronthaul network resources. In this paper, we propose and analyze possible solutions to facilitate the fronthaul traffic congestion in the scenario of Coordinated Multi-Point (CoMP) for 5G cellular traffic which is expected to reach ZetaByte by 2017. In particular, we propose to use distributed compression to reduce the fronthaul traffic for H-CRAN. Unlike the conventional approach where each coordinating point quantizes and forwards its own observation to the processing centre, these observations are compressed before forwarding. At the processing centre, the decompression of the observations and the decoding of the user messages are conducted in a joint manner. Our results reveal that, in both dense and ultra-dense urban small cell deployment scenarios, the usage of distributed compression can efficiently reduce the required fronthaul rate by more than 50% via joint operation
Hardware/Software Co-design Applied to Reed-Solomon Decoding for the DMB Standard
This paper addresses the implementation of Reed-
Solomon decoding for battery-powered wireless
devices. The scope of this paper is constrained by the
Digital Media Broadcasting (DMB). The most critical
element of the Reed-Solomon algorithm is implemented
on two different reconfigurable hardware
architectures: an FPGA and a coarse-grained
architecture: the Montium, The remaining parts are
executed on an ARM processor. The results of this
research show that a co-design of the ARM together
with an FPGA or a Montium leads to a substantial
decrease in energy consumption. The energy
consumption of syndrome calculation of the Reed-
Solomon decoding algorithm is estimated for an FPGA
and a Montium by means of simulations. The Montium
proves to be more efficient
Invited Abstract: A Simulation Package for Energy Consumption of Content Delivery Networks (CDNs)
Content Delivery Networks (CDNs) are becoming an integral part of the future
generation Internet. Traditionally, these networks have been designed with the
goals of traffic offload and the improvement of users' quality of experience
(QoE), but the energy consumption is also becoming an indispensable design
factor for CDNs to be a sustainable solution. To study and improve the CDN
architectures using this new design metric, we are planning to develop a
generic and flexible simulation package in OMNet++. This package is aimed to
render a holistic view about the CDN energy consumption behaviour by
incorporating the state-of-the-art energy consumption models proposed for the
individual elements of CDNs (e.g. servers, routers, wired and wireless links,
wireless devices, etc.) and for the various Internet contents (web pages,
files, streaming video, etc.).Comment: Published in: A. F\"orster, C. Minkenberg, G. R. Herrera, M. Kirsche
(Eds.), Proc. of the 2nd OMNeT++ Community Summit, IBM Research - Zurich,
Switzerland, September 3-4, 2015, arXiv:1509.03284, 201
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