2,944 research outputs found
Random Linear Network Coding For Time Division Duplexing: When To Stop Talking And Start Listening
A new random linear network coding scheme for reliable communications for
time division duplexing channels is proposed. The setup assumes a packet
erasure channel and that nodes cannot transmit and receive information
simultaneously. The sender transmits coded data packets back-to-back before
stopping to wait for the receiver to acknowledge (ACK) the number of degrees of
freedom, if any, that are required to decode correctly the information. We
provide an analysis of this problem to show that there is an optimal number of
coded data packets, in terms of mean completion time, to be sent before
stopping to listen. This number depends on the latency, probabilities of packet
erasure and ACK erasure, and the number of degrees of freedom that the receiver
requires to decode the data. This scheme is optimal in terms of the mean time
to complete the transmission of a fixed number of data packets. We show that
its performance is very close to that of a full duplex system, while
transmitting a different number of coded packets can cause large degradation in
performance, especially if latency is high. Also, we study the throughput
performance of our scheme and compare it to existing half-duplex Go-back-N and
Selective Repeat ARQ schemes. Numerical results, obtained for different
latencies, show that our scheme has similar performance to the Selective Repeat
in most cases and considerable performance gain when latency and packet error
probability is high.Comment: 9 pages, 9 figures, Submitted to INFOCOM'0
Automatic-repeat-request error control schemes
Error detection incorporated with automatic-repeat-request (ARQ) is widely used for error control in data communication systems. This method of error control is simple and provides high system reliability. If a properly chosen code is used for error detection, virtually error-free data transmission can be attained. Various types of ARQ and hybrid ARQ schemes, and error detection using linear block codes are surveyed
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Survey of traffic control schemes and error control schemes for ATM networks
Among the techniques proposed for B-ISDN transfer mode, ATM concept is considered to be the most promising transfer technique because of its flexibility and efficiency. This paper surveys and reviews a number of topics related to ATM networks. Those topics cover congestion control, provision of multiple classes of traffic, and error control. Due to the nature of ATM networks, those issues are far more challenging than in conventional networks. Sorne of the more promising solutions to those issues are surveyed, and the corresponding results on performance are summarized. Future research problems in ATM protocol aspect are also presented
A Mobile Satellite Experiment (MSAT-X) network definition
The network architecture development of the Mobile Satellite Experiment (MSAT-X) project for the past few years is described. The results and findings of the network research activities carried out under the MSAT-X project are summarized. A framework is presented upon which the Mobile Satellite Systems (MSSs) operator can design a commercial network. A sample network configuration and its capability are also included under the projected scenario. The Communication Interconnection aspect of the MSAT-X network is discussed. In the MSAT-X network structure two basic protocols are presented: the channel access protocol, and the link connection protocol. The error-control techniques used in the MSAT-X project and the packet structure are also discussed. A description of two testbeds developed for experimentally simulating the channel access protocol and link control protocol, respectively, is presented. A sample network configuration and some future network activities of the MSAT-X project are also presented
On the Impact of Link Layer Retransmissions on TCP for Aeronautical Communications
In this article, we evaluate the impact of link layer retransmissions on the performance of TCP in the context of aeronautical communications.We present the architecture of aeronautical networks, which is manly driven by an important channel access delay, and the various retransmission strategies that can be implemented at both link and transport layers. We consider a worst case scenario to illustrate the benefits provided by the ARQ scheme at the link layer in terms of transmission delay.We evaluate the trade-off between allowing a fast data transmission and a low usage of satellite capacity by adjusting link layer parameters
On the Impact of Link Layer Retransmissions on TCP for Aeronautical Communications
In this article, we evaluate the impact of link layer retransmissions on the performance of TCP in the context of aeronautical communications.We present the architecture of aeronautical networks, which is manly driven by an important channel access delay, and the various retransmission strategies that can be implemented at both link and transport layers. We consider a worst case scenario to illustrate the benefits provided by the ARQ scheme at the link layer in terms of transmission delay.We evaluate the trade-off between allowing a fast data transmission and a low usage of satellite capacity by adjusting link layer parameters
Improved Delay Estimates for a Queueing Model for Random Linear Coding for Unicast
Consider a lossy communication channel for unicast with zero-delay feedback.
For this communication scenario, a simple retransmission scheme is optimum with
respect to delay. An alternative approach is to use random linear coding in
automatic repeat-request (ARQ) mode. We extend the work of Shrader and
Ephremides, by deriving an expression for the delay of random linear coding
over field of infinite size. Simulation results for various field sizes are
also provided.Comment: 5 pages, 3 figures, accepted at the 2009 IEEE International Symposium
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