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Average Packet Delay (average + packet_delay)

Distribution by Scientific Domains

Engineering	100%

Selected Abstracts

Performance of collaborative codes in CSMA/CD environment

EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 5 2006
F. Gebali
A new medium access control scheme is proposed for implementing collaborative codes in a system using carrier sense multiple access with collision detection protocol (CC-CSMA/CD). We also propose a new backoff algorithm which is simple to implement and to analyse. A discrete-time Markov chain analytical model is developed for CC-CSMA/CD. The resulting model describes the regular CSMA/CD as a special case. Protocol performance measures were studied such as throughput, packet acceptance probability, average packet delay and channel utilisation. It is found that CC-CSMA/CD offers improvements over a system that uses CSMA/CD in terms of throughput, packet acceptance probability, delay and channel utilisation. Copyright © 2006 AEIT. [source]

Performance of the Dual-Banyan ATM switch under arbitrary traffic patterns,

EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 4 2003
Igor Radusinovic
Dual-Banyan (DB) is a buffered banyan asynchronous transfer mode (ATM) switch encompassing multiple input-queueing (bifurcated queueing) as its buffering strategy. This paper describes a new analytical model for a performance evaluation of the DB switch under arbitrary traffic patterns. The model developed and presented enables the computation of the switch normalized throughput and the average packet delay by iterative calculations. The efficiency of the given model is verified through a comparison with simulation results, too. We compare throughputs of DB switch and input buffer banyan, and show that DB switch has significantly better performance levels. Copyright © 2003 AEI. [source]

Performance comparison between fixed length switching and variable length switching

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2008
Chengchen Hu
Abstract Fixed length switching (FLS) and variable length switching (VLS) are two main types of switching architecture in high-speed input-queued switches. FLS is based on a cell-by-cell scheduling algorithm, while VLS operates on the variable packet granularity. This paper aims to make a comprehensive comparison between these two switching modes to guide the industrial design and academic research. We use stochastic models, Petri net models, analysis and simulations to investigate various performance measures of interest. Average packet latency, bandwidth utilization, segmentation and reassembly overhead, as well as packet loss are the identified key parameters that influence the outcome of the comparison. The results achieved in this paper are twofold. On one hand, it is shown that FLS enables smaller packet loss and lower packet delay in case of a short packet. On the other hand, VLS favors better bandwidth utilization, reduced implementation complexity and lower average packet delay. We recommend VLS in the conclusion since its disadvantages can be compensated by some methods, while the problems in FLS are difficult to be solved. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Performance analysis of the IEEE 802.11 MAC protocol for wireless LANs

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6 2005
P. Chatzimisios
Abstract Wireless local area networks (WLANs) are extremely popular being almost everywhere including business, office and home deployments. The IEEE 802.11 protocol is the dominating standard for WLANs. The essential medium access control (MAC) mechanism of 802.11 is called distributed co-ordination function (DCF). This paper provides a simple and accurate analysis using Markov chain modelling to compute IEEE 802.11 DCF performance, in the absence of hidden stations and transmission errors. This mathematical analysis calculates in addition to the throughput efficiency, the average packet delay, the packet drop probability and the average time to drop a packet for both basic access and RTS/CTS medium access schemes. The derived analysis, which takes into account packet retry limits, is validated by comparison with OPNET simulation results. We demonstrate that a Markov chain model presented in the literature, which also calculates throughput and packet delay by introducing an additional transition state to the Markov chain model, does not appear to model IEEE 802.11 correctly, leading to ambiguous conclusions for its performance. We also carry out an extensive and detailed study on the influence on performance of the initial contention window size (CW), maximum CW size and data rate. Performance results are presented to identify the dependence on the backoff procedure parameters and to give insights on the issues affecting IEEE 802.11 DCF performance. Copyright © 2005 John Wiley & Sons, Ltd. [source]