1,931 research outputs found
Wireless Broadcast with Physical-Layer Network Coding
This work investigates the maximum broadcast throughput and its achievability
in multi-hop wireless networks with half-duplex node constraint. We allow the
use of physical-layer network coding (PNC). Although the use of PNC for unicast
has been extensively studied, there has been little prior work on PNC for
broadcast. Our specific results are as follows: 1) For single-source broadcast,
the theoretical throughput upper bound is n/(n+1), where n is the "min
vertex-cut" size of the network. 2) In general, the throughput upper bound is
not always achievable. 3) For grid and many other networks, the throughput
upper bound n/(n+1) is achievable. Our work can be considered as an attempt to
understand the relationship between max-flow and min-cut in half-duplex
broadcast networks with cycles (there has been prior work on networks with
cycles, but not half-duplex broadcast networks).Comment: 23 pages, 18 figures, 6 table
On distributed scheduling in wireless networks exploiting broadcast and network coding
In this paper, we consider cross-layer optimization in wireless networks with wireless broadcast advantage, focusing on the problem of distributed scheduling of broadcast links. The wireless broadcast advantage is most useful in multicast scenarios. As such, we include network coding in our design to exploit the throughput gain brought in by network coding for multicasting. We derive a subgradient algorithm for joint rate control, network coding and scheduling, which however requires centralized link scheduling. Under the primary interference model, link scheduling problem is equivalent to a maximum weighted hypergraph matching problem that is NP-complete. To solve the scheduling problem distributedly, locally greedy and randomized approximation algorithms are proposed and shown to have bounded worst-case performance. With random network coding, we obtain a fully distributed cross-layer design. Numerical results show promising throughput gain using the proposed algorithms, and surprisingly, in some cases even with less complexity than cross-layer design without broadcast advantage
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Periodic wireless broadcast
A periodic wireless data transmission has improved access latency obtaining information regarding users' interest in the information and by arranging the information on an transmission in order of descending popularity. In one embodiment, each adjacent pair of topics on the transmission. The topics' positions on the transmission are exchanged if the exchange decreases the average latency for all users. This may be repeated for all of the topics on the transmission. The transmission structure may also be arranged so that the transmission combines a number of transmission channels to obtain greater aggregate capacity. This may be done using, for example, an FDMA transmission structured to be theoretically comparable to a plurality of “striped” disks known as a RAID (redundant array of inexpensive disks).Board of Regents, University of Texas Syste
Wireless Broadcast with Network Coding in Mobile Ad-Hoc Networks: DRAGONCAST
Network coding is a recently proposed method for transmitting data, which has
been shown to have potential to improve wireless network performance. We study
network coding for one specific case of multicast, broadcasting, from one
source to all nodes of the network. We use network coding as a loss tolerant,
energy-efficient, method for broadcast. Our emphasis is on mobile networks. Our
contribution is the proposal of DRAGONCAST, a protocol to perform network
coding in such a dynamically evolving environment. It is based on three
building blocks: a method to permit real-time decoding of network coding, a
method to adjust the network coding transmission rates, and a method for
ensuring the termination of the broadcast. The performance and behavior of the
method are explored experimentally by simulations; they illustrate the
excellent performance of the protocol
Hamiltonian cycles in faulty random geometric networks
In this paper we analyze the Hamiltonian properties of
faulty random networks.
This consideration is of interest when considering wireless
broadcast networks.
A random geometric network is a graph whose vertices
correspond to points
uniformly and independently distributed in the unit square,
and whose edges
connect any pair of vertices if their distance is below some
specified bound.
A faulty random geometric network is a random geometric
network whose vertices
or edges fail at random. Algorithms to find Hamiltonian
cycles in faulty random
geometric networks are presented.Postprint (published version
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