الفهرس 
Introduction to Computer Networks
Birth-Death ProcessOnly 14 pages are availabe for public view
 |  | from | 177 |  |  |
| | | from | 177 | | |
Abstract
Wacl Mohammad Atteya Omar Performance of Automatic Repeat
Request (ARQ) Protocols. Master of Science dissertation, Ain Shams
University, 2000
Message Delay, Average Message length and throughput efficiency
are the main performance characteristics of a data transmission system
with Automatic Repeat Request (ARQ) error control protocol. ARQ is
classified into three main different types of schemes.’
Those schemes did not consider the system parameters like channel
length or channel noise level, which may lead to changes in the level of
performance with the change in the system characteristics. In other words,
those schemes are independent of the system characteristics that may be
changing during operation. In this thesis, a new method is introduced to
improve ARQ schemes.
The method tries to establish a dependency between the used
scheme and the system characteristics. This method depends on the
continuous measuring of some system parameters during operation, then
using them to improve the system performance through minimizing the
message delay, average message length and throughput efficiency. The
main two measured parameters are channel noise level and the round-trip
delay that are assumed to be sufficient for the optimization procedure. This
new method was applied on SW scheme type as an example. A multi
channel system (more than one channel used as a data link) is assumed in
our analysis.
The proposed protocol reduces the average message length, the
delay and hence, better efficiency is obtained. In addition, the proposed
scheme gives better results than that of the ordinary multi channel case.
Keywords: Automatic Repeat Request (ARQ). Stop and Wait, Go hack N,
Selective repeal.