Viroj Tocharoenvanith creator Nanda, Navnit Kumar Chairperson Huynh, Ngoc Phien Examination Committee Bohez, Erik L.J. Examination Committee The Communications Authority of Thailand Scholarship Donor text th Bangkok Asian Institute of Technology 1990 monographic eng

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90 p. In the standard token ring network, the performance will be deteriorated when the number of stations in the ring is increased and/or the arrival rate of message is increased. To improve the characteristic of the basic token ring, an architecture providing multiple physical channels was found to be the alternative. A bridged token ring architecture is one way to improve the performance of the basic token ring . However, since the allocation of stations to ring and traffic dictated the performance of the bridged token ring architecture, therefore a multiple channel token ring architecture was found to be the suitable solution. A multiple channel tokening architecture with separate buffer, simultaneous transmission has a number of concentric rings with each station attached to all the rings. Each station is capable of transmitting and receiving messages to and from any free rings whenever receiving a free token. The message from the station are not equally distributed among the different rings. There is one transmit buffer in which the message are stored and from which the transmit logic extracts the messages for transmission when any ring becomes available. All of them, the basic token ·ring, the bridged token ring and the multiple channel token ring, were assumed to conform with the IEEE 802.5 standards. They were modeled to work under symmetric traffic, non-exhaustive service discipline, fixed message length and single message token generation policy with source removal. They were then simulated to evaluate the performance. The multiple channel token ring architecture was found to give a better performance than the single ring and the bridged token ring by offering lower delays and yielding the higher throughput under the same load. In addition, it also kept the traffic and allocation of station dependent characteristic as in the basic token ring. In Ethernet, it has been clearly noted from the performance point of view that CSMA/CD is wasteful in that, at any instant, only one successful transmission can be accommodated on a common channel at a time since a successful transmission even between two adjacent stations will render the entire channel inaccessible to all other stations. In addition, in real situation the stations could be located at any point of the network and mostly formed a cluster of nodes . To improve the performance successful transmission protocol is of CSMA/CD, is able to dynamically independent segments, each capable transmission when ever possible. - ii - of Ethernet, simultaneous proposed. Segnet, a variation partition a bus network into of accommodating a successful Therefore it utilizes the channel more efficient than normal CSMA/CD. However, in Segnet the message transmission may not be terminated only because of message collision but also because of blocking by the node at the segmentation point . Thus, buffered Segnet capable of storing the message in the queue of the station at the point of segmentation was also investigated. The simulation models of buffered and non-buffered Segnet were simulated under the clustered condition . Only the best case and the worst case of clustered setup were chosen. It was found that the performance of both buffered and non-buffered Segnet were outperformed over the normal Ethernet due to its ability in simultaneous successful transmission and buffered Segnet was superior to the non-buffered Segnet resulting from its absence of transmission failures due to segmentation which implies fewer retransmissions and lesser mean message transfer delay . In addition, Segnet also improves the fairness of each station for the same reason. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology Thesis (M.Eng.) - Asian Institute of Technology, 1990 Local area networks (Computer networks) Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B18296 http://203.159.5.9/ait-thesis/detail.php?q=B18296 280898 20260818171539.0