Showing papers by "Masayuki Murata published in 1989"

Effect of speedup in nonblocking packet switch

Abstract: The nonblocking packet switch under consideration has N inputs and N outputs and operates L times as fast as the input and output trunks. The effect of speedup (L) on packet loss probability and average transmission delay in the case of an arbitrary number L, such that 1 >

Analysis of a discrete-time single-server queue with bursty inputs for traffic control in ATM networks

Abstract: To evaluate the performance of an ATM (asynchronous transfer mode) network when it is subject to admission control or traffic smoothing, the authors develop a discrete-time single-server queuing model where a new call joins the existing calls. In this model, it is assumed that the cell arrivals from a new call follow a general distribution. It is also assumed that the aggregated arrivals of cells from the existing calls form batch arrivals with a general distribution for the batch size and geometric distribution for the interarrival times of batches. The authors consider an infinite buffer case and analytically obtain the waiting-time distribution for a new call and for existing calls. The analysis is an exact one. Through numerical examples, the authors investigate how the network performance depends on the statistics of a new call (burstiness, time that a call stays in active or inactive state, etc). They also demonstrate the effectiveness of traffic smoothing in reducing network congestion. >

Performance analysis of token ring networks with reservation priority discipline

Abstract: A token ring network is considered, with priority-mode operation by a reservation discipline which is adopted by an IEEE standard 802.5. In the reservation discipline, a high-priority station can reserve the next transmission right in the reservation field of the message transmitted by the low-priority station when the reservation field passes through the high-priority station. Then the free token at the high-priority level is passed to the high-priority station. After all messages from the high-priority stations are transmitted, the free token is returned to the station in the downstream of the previous low-priority station. To apply this reservation discipline to an interconnected token ring network system, an analytical model is constructed which consists of low-priority stations with single buffer and a single high-priority station with infinite buffer, which is intended to represent a bridge. An exact analysis for the low-priority stations and an approximate analysis for the high-priority station in the reservation discipline is presented. System performance measures (mean waiting times and throughput) derived from the present analysis are compared with a mixed discipline which is an alternative method for priority-mode operation in token ring networks. >