This paper presents busy/idle signal" scheme for control channel in mobile satellite communication systems. In the design of channel access schemes in mobile satellite communication systems, the following three factors must be taken into account: (1) a control channel is shared by call setup signals and response signals, (2) differences in propagation delays occur depending on the distance between the satellite and the mobile stations, (3) the number of retransmissions of a call setup signal is limited. Traffic performance measures of the proposed channel access scheme, such as throughput, mean setup delay and mean response delay, are compared with those of the random access scheme and the framed access scheme. A numerical method is presented for obtaining these measures, and the method's accuracy is demonstrated by comparing results with those obtained by simulation. This numerical method is very simple and is applicable to channel access schemes for mobile satellite communication systems with the above three factors. Using the numerical method, the proposed scheme is shown to be superior to other schemes.

This paper presents a method for analyzing a Markov process of the generalized loss system which includes the , /M1, M2/S, the , /, /S and the , /M1, /S loss systems. The generalized loss system is a loss system with multi-class of batch arrival customers. In the system, a customer requires more than one server at the same time. The analyzing method makes use of the existence of a product form solution for a Markov process. This paper also presents a theorem for the , /M1, M2/S (PBAS) loss system. The theorem asserts that the steady-state probability of the total customers of the , /M1, M2/S (PBAS) loss system can be derived as that of the M x/M/S (PBAS) loss system with the same traffic intensity and batch size distribution. For the , /M1, M2/S (WBAS) loss system, two approximation analysis methods that assume the product form solution and use the theorem of the PBAS type system are propesed to obtain the blocking probability. The analysis for the generalized loss system and approximation analysis for the , , M2/S (WBAS) loss system are applied to the design and dimensioning of resource sharing systems in ISDN.

A highly reliable, operated efficiently, and scalable switching node is required for multivendor system management networks. This paper presents techniques for applying the Telecommunications Management Network (TMN) concept to a distributed switching node. First, we select the TMN protocol structures so as to minimize the command response time. To ensure efficient operation and flexible design of the operation, administration and maintenance (OA & M) software, we propose a command-message handling function for mapping managed objects (MOs) to the OA & M software. We have designed MO classes for switching-system-specific devices with a redundant configuration that ensures highly reliable system operation. The feasibility of these techniques have been confirmed on a prototype system.