In this paper, an analysis of a slotted ring type network, the Pierce type ring network, is carried out and characteristics of the ring are derived. The ring type network is one of the fundamental computer network topologies. It is easy to implement and has many merits such as low cost and expansion flexibility. However, possible hogging, or domination of slots by one station, is one of its drawbacks. At first, when we regard vacant slots as usable, we show how system performance is fairly dependent on traffic patterns. We also show quantitatively that when slots are fixed to each station, domination of the ring can be completely prevented, although the performance of the system will be reduced. We propose a method to control the transmission of packets in which we have positively adopted the insertion of shift registers into the transmission line to prevent the deterioration of the performance. With the insertion of shift registers, we show the feasibility of improving the performance of the fixed slot allocation method at the same time as preventing domination of the ring. We will discuss the merits of the shift register insertion method, which is introduced to improve the fixed slot and semi-fixed slot allocation methods. In the slotted ring type system, four types of slot allocation method including a register insertion method are considered for the improvement of the system performance. The merits and demerits of the methods are discussed. We show how system performance depends on the traffic patterns considered. We analyse the characteristics of the ring system under various conditions.

We have previously reported studies [3], [4] of the steady state system throughput in a slotted ring network. In this paper, we analyze the transient state of packet transmission and derive several characteristics of the network.

This paper presents an effective application of Net-theory for all the stages of the communication protocol development process. Net-theory provides a basic mathematical model and tool for development of communication protocol. The special usability of Net-theory is that 1) visual representation of the system's stadic/dynamic structure, so that users may easily understand the represented contents, 2) formal specifications based on mathematical basis of Net-theory admit automatic verification, implementation and conformance testing. We have seen that Net-theory which has the above usability can provide a systematic and advanced paradigm for effective communication protocol development.