| Summary: | 碩士 === 國立臺灣大學 === 電機工程學系 === 85 === Due to the rapid progress of the ATM(Asynchronous Transfer Mode)
technology, ATM has been wildly applied in computer network. ATM
could afford to provide differentservices : constant bit rate
(CBR), variable bit rate (VBR), available bit rate (ABR) and
undefined service rate (UBR). Though every service has its
own request of quality of service(QoS), its QoS will be
affected in real network due to switching nodes. To solve
the problem, a traffic shaper is provided.There are many
discussions about traffic shaper, but not about CBR traffic
shapers. The QoS of
CBR stream is to allow an amount of jitter tolerance at a
fixed period. All different kinds of CBR streams multiplexing on
the multiplexer will result in jitter effect with each other.
Eventually, QoS will be affected. In this paper, we provide a
CBR traffic shaper to solve this problem. A CBR traffic
shaper is divided into two parts: the front stage is the
regulator, whichis to reduce jitter for those incoming streams
and we will proposea simple and reasonable method; the next
stage is the scheduler, which is to schedule the departure
time of the cell from the regulator in avoidance with
the chance of other cells' departure on the same slot
time. FCFS (First Come First Serve) and EDD (Earliest Due-date)
are the most popular methods for scheduling. In addition to
them, we will propose a novel design:the Bipartite Algorithm,
which could predict the possible events in the future and
schedule the departure time of every cellexactly. Besides, we
will discuss the modification of bipartite algorithm on every
possible condition. In the last, we will compare
threealgorithm via simulation results.
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