2683390
A RDT-based interconnection network for scalable network-on-chip designs
The interconnection network plays an important role in the performance and energy consumption of a network-on-chip (NoC) system. In this paper, we propose a RDT(2,2,1)//spl alpha/-based interconnection network for NoC designs. RDT(2,2,1)//spl alpha/ is constructed by recursively overlaying 2D diagonal meshes (torus). The number of layers needed for routing the links in RDT(2,2,1)//spl alpha/ is shown to be bounded at 6, which is feasible to be implemented with current and future VLSI technologies. With the innovative diagonal structure and its simple rank assignment, RDT(2,2,1)//spl alpha/ possesses the following features: recursive structure, smaller diameter and average distance, embedded mesh/torus topology, a constant node degree of 8, and robust routing schemes. These features make RDT(2,2,1)//spl alpha/ a promising solution for the interconnection network of NoC designs satisfying the requirements for scalability, energy-efficiency, customizability, and fault-tolerance.
14595772
Performance analysis of practical RDT interconnection networks with SINOMP
RDT (recursive diagonal torus) consisting of recursively structured mesh/torus connections is a class of interconnection networks for massively parallel computers (MFCs). RDT(2,2,1)//spl alpha/ is one of its practical structure. It is suitable for the practical parallel computers due to its simple torus assignment and routing algorithm. In this paper, the method to compute its theoretical average distance, which is the performance index, is proposed. According to this method, the theoretical performance of RDT(2,2,1)//spl alpha/ is evaluated. The indices showing the performances of the practical communication process are obtained with an interconnection network simulator named SINOMP. After analyzing these performances, the suitable for the middle-size parallel computers is validated.
6183487
Practical routing and torus assignment for RDT
The connection topology of interconnection networks and the routing algorithm often dominate system performance in MPCs. RDT has already been proved to be one of the best interconnection networks used in such systems. It supports a smaller diameter and degree than most at the size of one thousand to tens of thousands nodes. The floating vector routing algorithm is very effective for transferring messages, which also shows good performance. In this paper, a descending vector routing algorithm is proposed. We also proposed a practical torus assignment named RDT(2,2,1)/a and the deadlock-free routing algorithm. RDT(2,2,1)/a mainly focuses on the MPC that has about one thousand nodes. With a simplified simulation and comparison, the results show that RDT(2,2,1)/a has a better performance at the size of one thousand nodes.
17384103
RDT Properties and Evaluations
Proposed for MPCs, RDT has already been proved to support better performances than most of the direct network, such as smaller diameter based on its vector routing algorithm, smaller degree, embedded mesh/torus topology, etc. It gives a network form method to form groups of networks with recursively structured torus/torus-like networks. A RDT structure can be formed with the method and its related parameters. After analyzing its performance by the average distance, the descending vector routing reducing redundant computations and the fault-tolerant routing algorithm are proposed. A simpler structure named RDT(2,2,1)/a are proposed for the parallel systems with no more than 5000 nodes and given its performance evaluation. Considering the structure features of the practical RDTs, they are suitable for the interconnection network of an NoC design. The design of laying out RDT(2,2, 1)/a is proposed and proved to be available
6740690
An integer programming approach for static mapping of paths onto heterogeneous real-time systems
In this paper, we study the problem of mapping a set of independent paths onto a heterogeneous real-time system. Each path is a pipeline of several stages where each stage consists of one application. Each path has latency and throughput requirements that have to be satisfied. The general goal of this problem is to find an initial static mapping of all applications onto available system resources to maximize the allowable increase in input load, until dynamic remapping is required to avoid Quality of Service (QoS) violations on any path. The objective function considered in this paper is to find a static mapping such that the sum of the latencies of all paths is minimized, while satisfying all latency and throughput requirements. The motivation behind it is to give more room for each path to accommodate additional load at run-time. We develop an integer programming (IP) formulation for modeling this mapping problem. By solving the formulation, a feasible mapping can be found that satisfies latency and throughput requirements of all paths and optimizes the objective function. Two heuristics are given along with the IP formulation to provide efficient solutions. Experimental results show the correctness of the IP formulation and the effectiveness of our heuristics.
14114624
A metric and mixed-integer-programming-based approach for resource allocation in dynamic real-time systems
Dynamic real-time systems such as embedded systems operate in environments in which several parameters vary at run time. These systems must satisfy several performance requirements. Resource allocation on these systems becomes challenging because variations of run-time parameters may cause violations of the performance requirements. Performance violations result in the need for dynamic re-allocation, which is a costly operation. A method for allocating resources such that the allocation can sustain the system in the light of a continuously changing environment is developed. We introduce a novel performance metric called MAIL (maximum allowable increase in load) to capture the effectiveness of a resource allocation. Given a resource allocation, MAIL quantifies the amount of additional load that can be sustained by the system without any performance violations. A mixed-integer-programming-based approach (MIP) is developed to determine a resource allocation that has the highest MAIL value. Using simulations, several sets of experiments are conducted to evaluate our heuristics in various scenarios of machine and task heterogeneities. The performance of MIP is compared with three other heuristics: integer-programming based, greedy, and classic min-min. Our results show that MIP performs significantly better when compared with the other heuristics.
15352374
Network-Aware State Update For Large Scale Mobile Games
In large scale mobile gaming environments, efficient mechanisms for state update is crucial to allow graceful real-time interaction of a large number of players, under limited wireless network bandwidth. By using the state updating threshold as a key parameter that bridges the resulting state inconsistency (or distortion) and the network traffic, we are able to model the fundamental traffic-distortion tradeoffs. Given the tradeoffs for all users, an optimal bandwidth allocation can be derived using well-known convex programming techniques. By exploring the temporal locality of gaming behavior, we also propose a prediction method to realize on-line bandwidth adaptation. Using real data trace from a multi-player driving game, the proposed network aware bandwidth allocation method, NABA, is able to achieve significant reduction in state distortion compared to two baselines: Uniform and Proportional policies. NABA is also adaptable to variations in system parameters, including bandwidth constraint and network delay.
14236359
Semi-naive Exploitation of One-Dependence Estimators
It is well known that the key of Bayesian classifier learning is to balance the two important issues, that is, the exploration of attribute dependencies in high orders for ensuring a sufficient flexibility in approximating the ground-truth dependencies, and the exploration of low orders for ensuring a stable probability estimate from limited training samples. By allowing one-order attribute dependencies, one-dependence estimators (ODEs) have been shown to be able to approximate the ground-truth attribute dependencies whilst keeping the effectiveness of probability estimation, and therefore leading to excellent performance. In previous studies, however, ODEs were exploited in simple ways, such as by averaging, for classification. In this paper, we propose a semi-naive exploitation of ODEs that fits a function of ODEs to pursue higher-order attribute dependencies. Extensive experiments show that the proposed SNODE approach can achieve better performance than many state-of-the-art Bayesian classifiers.
39238334
Information Processing and Routing in Wireless Sensor Networks
Introduction of Wireless Sensor Networks Background Energy Models Information Processing within a Collocated Cluster Information Transportation over a Tree Substrate Information Routing with Tunable Compression.