Results 1  10
of
28
Network information flow
 IEEE TRANS. INFORM. THEORY
, 2000
"... We introduce a new class of problems called network information flow which is inspired by computer network applications. Consider a pointtopoint communication network on which a number of information sources are to be mulitcast to certain sets of destinations. We assume that the information source ..."
Abstract

Cited by 1967 (24 self)
 Add to MetaCart
(Show Context)
We introduce a new class of problems called network information flow which is inspired by computer network applications. Consider a pointtopoint communication network on which a number of information sources are to be mulitcast to certain sets of destinations. We assume that the information sources are mutually independent. The problem is to characterize the admissible coding rate region. This model subsumes all previously studied models along the same line. In this paper, we study the problem with one information source, and we have obtained a simple characterization of the admissible coding rate region. Our result can be regarded as the Maxflow Mincut Theorem for network information flow. Contrary to one’s intuition, our work reveals that it is in general not optimal to regard the information to be multicast as a “fluid” which can simply be routed or replicated. Rather, by employing coding at the nodes, which we refer to as network coding, bandwidth can in general be saved. This finding may have significant impact on future design of switching systems.
Towards an Archival Intermemory
 In Proc. of IEEE ADL
, 1998
"... We propose a selforganizing archival Intermemory. That is, a noncommercial subscriberprovided distributed information storage service built on the existing Internet. Given an assumption of continued growth in the memory's total size, a subscriber's participation for only a finite time ca ..."
Abstract

Cited by 106 (1 self)
 Add to MetaCart
(Show Context)
We propose a selforganizing archival Intermemory. That is, a noncommercial subscriberprovided distributed information storage service built on the existing Internet. Given an assumption of continued growth in the memory's total size, a subscriber's participation for only a finite time can nevertheless ensure archival preservation of the subscriber's data. Information disperses through the network over time and memories become more difficult to erase as they age. The probability of losing an old memory given random node failures is vanishingly small  and an adversary would have to corrupt hundreds of thousands of nodes to destroy a very old memory. This paper presents a framework for the design of an Intermemory, and considers certain aspects of the design in greater detail. In particular, the aspects of addressing, space efficiency, and redundant coding are discussed. Keywords: Archival Storage, Distributed Redundant Databases, Electronic Publishing, Distributed Algorithms, Error ...
Network Coding: An Introduction
, 2008
"... The basic idea behind network coding is extraordinarily sim
ple. As it is defined in this book, network coding amounts to no more than performing coding operations on the contents of packetsâperforming arbitrary mappings on the contents of packets rather than the restricted functions of replicatio ..."
Abstract

Cited by 69 (3 self)
 Add to MetaCart
The basic idea behind network coding is extraordinarily sim
ple. As it is defined in this book, network coding amounts to no more than performing coding operations on the contents of packetsâperforming arbitrary mappings on the contents of packets rather than the restricted functions of replication and forwarding that are typically allowed in conventional,
storeandforward architectures. But, although simple, network coding has had little place in the history of networking. This is for good reason: in the traditional wireline technologies that have dominated networking
history, network coding is not very practical or advantageo
us.
Hence the motivation for this book: we feel that network coding may have a great deal to offer to the future design of packet networks, and we would like to help this potential be realized. We would like also to encourage more research in this burgeoning field. Thus, we have aimed the book at two (not necessarily distinct) audiences: first, the practi
tioner, whose main interest is applications; and, second, t
he theoretician, whose main interest is developing further understanding of the properties of network coding. Of these two audiences, we have tended to favor the first, though the content of the book is nevertheless theoretical. We have aimed to expound the theory in such a way that it is access
ible to those who would like to implement network coding, serving an important purpose that was, in our opinion, inadequately served. The theoretician, in contrast to the practitioner, is spoiled. Besides this book, a survey
of important theoretical results in network coding is provi
ded in Yeung et al.âs excellent review, Network Coding Theory [149, 150]. Because of our inclination toward applications, however, our presentation differs substantially from that of Yeung et al.
Network Coding Theory
 FOUNDATIONS AND TRENDS IN COMMUNICATIONS AND INFORMATION THEORY
, 2005
"... ..."
Approximating the Gaussian multiple description rate region under symmetric distortion constraints
, 2008
"... We consider multiple description coding for the Gaussian source with K descriptions under the symmetric mean squared error distortion constraints, and provide an approximate characterization of the rate region. We show that the rate region can be sandwiched between two polytopes, between which the g ..."
Abstract

Cited by 19 (7 self)
 Add to MetaCart
(Show Context)
We consider multiple description coding for the Gaussian source with K descriptions under the symmetric mean squared error distortion constraints, and provide an approximate characterization of the rate region. We show that the rate region can be sandwiched between two polytopes, between which the gap can be upper bounded by constants dependent on the number of descriptions, but independent of the exact distortion constraints. Underlying this result is an exact characterization of the lossless multilevel diversity source coding problem: a lossless counterpart of the MD problem. This connection provides a polytopic template for the inner and outer bounds to the rate region. In order to establish the outer bound, we generalize Ozarow’s technique to introduce a strategic expansion of the original probability space by more than one random variables. For the symmetric rate case with any number of descriptions, we show that the gap between the upper bound and the lower bound for the individual description rate is no larger than 0.92 bit. The results developed in this work also suggest the “separation ” approach of combining successive refinement quantization and lossless multilevel diversity coding is a competitive one, since it is only a constant away from the optimum. The results are further extended to general sources under the mean squared error distortion measure, where a similar but looser bound on the gap holds.
Relay Subset Selection in Wireless Networks Using Partial DecodeandForward Transmission
"... Abstract — This paper considers the problem of selecting a set of relay nodes to assist a transmitting node in a twohop wireless network. Throughputmaximizing relay subset selection is a difficult problem that depends on variables such as node locations and power constraints. It is proposed that a ..."
Abstract

Cited by 16 (4 self)
 Add to MetaCart
Abstract — This paper considers the problem of selecting a set of relay nodes to assist a transmitting node in a twohop wireless network. Throughputmaximizing relay subset selection is a difficult problem that depends on variables such as node locations and power constraints. It is proposed that all relays employ partial decodeandforward operations to improve the tractability of the relay selection problem. This allows relay selection to be transformed into a simpler relay placement problem which motivates two proximitybased relay selection algorithms. These algorithms are compared with a greedy algorithm based on relay channel gains to the destination and an algorithm that randomly selects relays. The diversity gain achieved by employing multiple relay nodes is derived. The proposed proximitybased algorithms offer good performance in terms of the expected achieved rate. I.
Multilevel Broadcast Networks
"... Abstract—We formulate a broadcast problem, where based on their quality of observations, outputs at various receivers are represented on a graph (called “degradation graph”). If receiver Z is a physically degraded version of receiver Y, then node Z is a child of node Y in this graph. This generaliza ..."
Abstract

Cited by 12 (1 self)
 Add to MetaCart
(Show Context)
Abstract—We formulate a broadcast problem, where based on their quality of observations, outputs at various receivers are represented on a graph (called “degradation graph”). If receiver Z is a physically degraded version of receiver Y, then node Z is a child of node Y in this graph. This generalization of the classical degraded broadcast channel provides a framework for various situations where at least some information should be available to receivers with partial (or noisier) observations. Upper and lower bounds are obtained on the capacity region. The upper bound is based on auxiliary variables, whose structure is described by the mirror image of the channel’s degradation graph. As a special case of our problem, a packet broadcast network is considered. I.
On the solvability of 2pair unicast networks — a cutbased characterization. ArXiv
, 2010
"... ar ..."
(Show Context)
Multilevel diversity coding via successive refinement, International Symposium on Information Theory
 Cornell University
, 1997
"... .Abstract In a hierarchical multilevel diversity coding system, each decoder has access to a certain subset of the full source code, and the decoders are partitioned into fidelity levels in a hierarchical manner. W e show that without loss in ratedistortion performance, this coding system can be s ..."
Abstract

Cited by 5 (1 self)
 Add to MetaCart
.Abstract In a hierarchical multilevel diversity coding system, each decoder has access to a certain subset of the full source code, and the decoders are partitioned into fidelity levels in a hierarchical manner. W e show that without loss in ratedistortion performance, this coding system can be separated into a successive refinement stage followed by a “lossless” multilevel diversity coding stage. I.
Asymmetric Gaussian Multiple Descriptions and Asymmetric Multilevel Diversity Coding
"... We consider asymmetric multiple description (MD) source coding for Gaussian source under mean squared error distortion constraints, and focus on the three description problem. Inner and outer bounds for the rate region are derived, both of which can be represented as the intersection of ten half spa ..."
Abstract

Cited by 4 (2 self)
 Add to MetaCart
(Show Context)
We consider asymmetric multiple description (MD) source coding for Gaussian source under mean squared error distortion constraints, and focus on the three description problem. Inner and outer bounds for the rate region are derived, both of which can be represented as the intersection of ten half spaces with matching normal directions. Moreover, the gap between the inner and outer bounds is shown to be small. The inner bound relies on the rate region characterization of a lossless asymmetric multilevel diversity (MLD) coding problem treated in our earlier work, which is a natural generalization of the symmetric MLD coding problem previously considered by Roche et al.. Different from symmetric MLD coding, superposition coding is not sufficient in the asymmetric case, and idea akin to network coding needs to be used strategically. Equipped with this finding, and motivated by the connection between symmetric MD and symmetric MLD coding, in this work we consider asymmetric MD as a lossy version of the asymmetric MLD coding, which requires coding beyond simple superposition. An outer bound is also derived, which bears a geometric structure particularly suitable for comparison with the inner bound. Combining the inner and outer bounds provides an approximate characterization of the rate region for the asymmetric Gaussian three description problem.