214 research outputs found
Network Coding Over SATCOM: Lessons Learned
Satellite networks provide unique challenges that can restrict users' quality
of service. For example, high packet erasure rates and large latencies can
cause significant disruptions to applications such as video streaming or
voice-over-IP. Network coding is one promising technique that has been shown to
help improve performance, especially in these environments. However,
implementing any form of network code can be challenging. This paper will use
an example of a generation-based network code and a sliding-window network code
to help highlight the benefits and drawbacks of using one over the other.
In-order packet delivery delay, as well as network efficiency, will be used as
metrics to help differentiate between the two approaches. Furthermore, lessoned
learned during the course of our research will be provided in an attempt to
help the reader understand when and where network coding provides its benefits.Comment: Accepted to WiSATS 201
Alien Registration- Thomos, Harley W. (Mars Hill, Aroostook County)
https://digitalmaine.com/alien_docs/34113/thumbnail.jp
Growth Codes: Intermediate Performance Analysis and Application to Video
Growth codes are a subclass of Rateless codes that have found interesting applications in data dissemination problems. Compared to other Rateless and conventional channel codes, Growth codes show improved intermediate performance which is particularly useful in applications where partial data presents some utility. In this paper, we investigate the asymptotic performance of Growth codes using the Wormald method, which was proposed for studying the Peeling Decoder of LDPC and LDGM codes. Compared to previous works, the Wormald differential equations are set on nodes' perspective which enables a numerical solution to the computation of the expected asymptotic decoding performance of Growth codes. Our framework is appropriate for any class of Rateless codes that does not include a precoding step. We further study the performance of Growth codes with moderate and large size codeblocks through simulations and we use the generalized logistic function to model the decoding probability. We then exploit the decoding probability model in an illustrative application of Growth codes to error resilient video transmission. The video transmission problem is cast as a joint source and channel rate allocation problem that is shown to be convex with respect to the channel rate. This illustrative application permits to highlight the main advantage of Growth codes, namely improved performance in the intermediate loss region. © 1972-2012 IEEE
Rate Maximization in Vehicular uRLLC with Optical Camera Communications
Optical camera communication (OCC) has emerged as a key enabling technology
for the seamless operation of future autonomous vehicles. By leveraging the
supreme performance of OCC, we can meet the stringent requirements of
ultra-reliable and low-latency communication (uRLLC) in vehicular OCC. In this
paper, we introduce a rate optimization approach in vehicular OCC through
optimal power allocation while respecting uRLLC requirements. We first
formulate a discrete-rate optimization problem as a mixed-integer programming
(MIP) subject to average transmit power and uRLLC constraints for a given set
of modulation schemes. To reduce the complexity in solving the MIP problem, we
convert the discrete-rate problem into a continuous-rate optimization scheme.
Then, we present an algorithm based on Lagrangian relaxation and Bisection
method to solve the optimization problem. Considering the proposed algorithm,
we drive the rate optimization and power allocation scheme for both
discrete-rate and continuous-rate optimization schemes while satisfying uRLLC
constraints. We first analyze the performance of the proposed system model
through simulations. We then investigate the impact of proposed power
allocation and rate optimization schemes on average rate and latency for
different target bit error rates. The results show that increasing the transmit
power allocation improves the average rate and latency performance.Comment: 30 Pages, 13 Figure
Decoding Delay Minimization in Inter-Session Network Coding
Intra-session network coding has been shown to offer significant gains in terms of achievable throughput and delay in settings where one source multicasts data to several clients. In this paper, we consider a more general scenario where multiple sources transmit data to sets of clients over a wireline overlay network. We propose a novel framework for efficient rate allocation in networks where intermediate network nodes have the opportunity to combine packets from different sources using randomized network coding. We formulate the problem as the minimization of the average decoding delay in the client population and solve it with a gradient-based stochastic algorithm. Our optimized inter-session network coding solution is evaluated in different network topologies and is compared with basic intra-session network coding solutions. Our results show the benefits of proper coding decisions and effective rate allocation for lowering the decoding delay when the network is used by concurrent multicast sessions
Selection of network coding nodes for minimal playback delay in streaming overlays
Network coding permits to deploy distributed packet delivery algorithms that
locally adapt to the network availability in media streaming applications.
However, it may also increase delay and computational complexity if it is not
implemented efficiently. We address here the effective placement of nodes that
implement randomized network coding in overlay networks, so that the goodput is
kept high while the delay for decoding stays small in streaming applications.
We first estimate the decoding delay at each client, which depends on the
innovative rate in the network. This estimation permits to identify the nodes
that have to perform coding for a reduced decoding delay. We then propose two
iterative algorithms for selecting the nodes that should perform network
coding. The first algorithm relies on the knowledge of the full network
statistics. The second algorithm uses only local network statistics at each
node. Simulation results show that large performance gains can be achieved with
the selection of only a few network coding nodes. Moreover, the second
algorithm performs very closely to the central estimation strategy, which
demonstrates that the network coding nodes can be selected efficiently in a
distributed manner. Our scheme shows large gains in terms of achieved
throughput, delay and video quality in realistic overlay networks when compared
to methods that employ traditional streaming strategies as well as random
network nodes selection algorithms.Comment: submitted to IEEE Transactions on Multimedia, January 18th 201
Machine Learning for Multimedia Communications
Machine learning is revolutionizing the way multimedia information is processed and transmitted to users. After intensive and powerful training, some impressive efficiency/accuracy improvements have been made all over the transmission pipeline. For example, the high model capacity of the learning-based architectures enables us to accurately model the image and video behavior such that tremendous compression gains can be achieved. Similarly, error concealment, streaming strategy or even user perception modeling have widely benefited from the recent learningoriented developments. However, learning-based algorithms often imply drastic changes to the way data are represented or consumed, meaning that the overall pipeline can be affected even though a subpart of it is optimized. In this paper, we review the recent major advances that have been proposed all across the transmission chain, and we discuss their potential impact and the research challenges that they raise
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