Design of a Satellite Cluster System in Distributed Simulation

This article presents the design and development of a satellite cluster system that supports an interfederation communication in High Level Architecture (HLA)-compliant distributed simulation. The interfederation communication enables the execution of a complex, large-scale cluster system of distributed satellites that share the dispersed data assets among satellite components collaboratively. After a brief review of the HLA bridge for interfederation communication, the authors discuss the design issues related to a satellite cluster system that provides cluster management, interfederation communication, and communication data management. They analyze system performance and scalability for centralized and decentralized configurations. The empirical results on the heterogeneous OS distributed system indicate that the satellite cluster system is effective and scalable due to the use of interfederation communication and the reduction of data transmission

Design of a Satellite Cluster System in Distributed Simulation

This article presents the design and development of a satellite cluster system that supports an interfederation communication in High Level Architecture (HLA)-compliant distributed simulation. The interfederation communication enables the execution of a complex, large-scale cluster system of distributed satellites that share the dispersed data assets among satellite components collaboratively. After a brief review of the HLA bridge for interfederation communication, the authors discuss the design issues related to a satellite cluster system that provides cluster management, interfederation communication, and communication data management. They analyze system performance and scalability for centralized and decentralized configurations. The empirical results on the heterogeneous OS distributed system indicate that the satellite cluster system is effective and scalable due to the use of interfederation communication and the reduction of data transmission

An Adaptive Scheme for Admission Control in ATM Networks

This paper presents a real time front-end admission control scheme for ATM networks. A call management scheme which uses the burstiness associated with traffic sources in a heterogeneous ATM environment to effect dynamic assignment of bandwidth is presented. In the proposed scheme, call acceptance is based on an on-line evaluation of the upper bound on cell loss probability which is derived from the estimated distribution of the number of calls arriving. Using this scheme, the negotiated quality of service will be assured when there is no estimation error. The control mechanism is effective when the number of calls is large, and tolerates loose bandwidth enforcement and loose policing control. The proposed approach is very effective in the connection oriented transport of ATM networks where the decision to admit new traffic is based on thea priori knowledge of the state of the route taken by the traffic

Simulation of a NASA LEO Satellite Hybrid Network

Various issues associated with "Simulation of a NASA LEO Satellite Hybrid Network" are presented in viewgraph form. Specific topics include: 1) Objective of the investigation; 2) Satellite orbit description and included nodes; 3) TCP and FTP simulation descriptions; 4) Simulation results; and 5) Derived conclusions

Asymmetric ATM Switch Modules With Imbalanced Traffic

This paper analyzes the performance of output channel grouped asymmetric packet switch modules in ATM networks, under geometrically bursty input traffic with input/output traffic imbalance. The switch module considered has n inputs and m outputs. A packet destined for a particular output address (out of g) needs to access only one of the r available physical output ports; m=gr. The motivation for the study of these switch modules is that they are the key building blocks in many large multistage switch architectures. A combination of exact derivation and numerical analysis yields the saturation throughput of input buffered switch modules for a wide range of traffic nonuniformity factors and burstiness. Results show a degradation in the maximum throughput, under input/output imbalance, as the average burst length increases. An interesting observation is that asymmetric switches tend to diminish the throughput advantage of the output-buffered switch module over the input buffered switch module under any traffic nonuniformity and burstiness. Our results also indicate that increasing the number of output ports per output address can significantly improve the switch performance, especially when traffic is highly nonuniform and burst

Asymmetric ATM Switch Modules With Imbalanced Traffic

This paper analyzes the performance of output channel grouped asymmetric packet switch modules in ATM networks, under geometrically bursty input traffic with input/output traffic imbalance. The switch module considered has n inputs and m outputs. A packet destined for a particular output address (out of g) needs to access only one of the r available physical output ports; m=gr. The motivation for the study of these switch modules is that they are the key building blocks in many large multistage switch architectures. A combination of exact derivation and numerical analysis yields the saturation throughput of input buffered switch modules for a wide range of traffic nonuniformity factors and burstiness. Results show a degradation in the maximum throughput, under input/output imbalance, as the average burst length increases. An interesting observation is that asymmetric switches tend to diminish the throughput advantage of the output-buffered switch module over the input buffered switch module under any traffic nonuniformity and burstiness. Our results also indicate that increasing the number of output ports per output address can significantly improve the switch performance, especially when traffic is highly nonuniform and burst

On the Multilevel Concentrator Location Problem for Local Access Networks

The multilevel concentrator location problem for a local access network is examined. A heuristic algorithm which is a modified version of the iterative self-organizing data analysis technique is presented. This algorithm clusters terminals and locates concentrators at the cluster centers. An a priori limit is not set on the number of levels of concentrators to be used. The cost-effectiveness of this algorithm for multilevel concentrator location is demonstrated in comparison to the one other algorithm for multilevel location currently available in the literature. Also, the proposed algorithm has significantly less computational space and time requirements