Consider a wireless network consisting of a set of wireless nodes and a set of communication links, where each communication link corresponds to a pair of nodes that are within communication radius of each other. Unde...
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ISBN:
(数字)9781728152844
ISBN:
(纸本)9781728141305
Consider a wireless network consisting of a set of wireless nodes and a set of communication links, where each communication link corresponds to a pair of nodes that are within communication radius of each other. Under the primary interference model, two communication links cannot be active at the same time if they are incident to a common node. This model of interference arises in Bluetooth networks, where transmissions between a master node and slave nodes in a piconet are scheduled by time-division duplexing, and in CDMA systems when each node is equipped with a single transceiver. Each communication link has a certain minimum bandwidth quality-of-service requirement. The admission control problem is to determine whether the network has sufficient resources to satisfy the bandwidth requirements. In this work, distributed algorithms are proposed for this admission control problem, and performance guarantees of these distributed algorithms are given. If each node has knowledge of a certain global parameter, then a distributed algorithm for flow admission control is given which has the same performance as an optimal, centralized algorithm, i.e. the distributed algorithm gives a condition that is both necessary and sufficient for a set of flow rates to be feasible.
This paper presents a family of discrete-time distributed algorithms that enable nodes in an undirected, connected network to solve, in a fully decentralized fashion, a system of modular congruences whose residues and...
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ISBN:
(数字)9781538682661
ISBN:
(纸本)9781538682678
This paper presents a family of discrete-time distributed algorithms that enable nodes in an undirected, connected network to solve, in a fully decentralized fashion, a system of modular congruences whose residues and pairwise coprime moduli are locally known to the nodes. We show that each algorithm in the family is able to determine, in finite time, the congruence class of solutions whose existence and uniqueness is guaranteed by the Chinese remainder theorem. We also describe and analyze three specific algorithms from the family called Synchronous Updating (SU), Pairwise Equalizing (PE), and Groupwise Equalizing (GE), relating the convergence rate of SU to the network diameter and those of PE and GE to their asynchronous update patterns. Finally, we provide simulation results that illustrate their effectiveness.
For a connected graph , a set of edges(vertices) is a cyclic edge(vertex) cutset if-is not connected and at least two components contain a cycle respectively. The cyclic edge(vertex) connectivity (8((8) is the cardina...
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For a connected graph , a set of edges(vertices) is a cyclic edge(vertex) cutset if-is not connected and at least two components contain a cycle respectively. The cyclic edge(vertex) connectivity (8((8) is the cardinality of a minimum cyclic edge(vertex) cutset. In this paper, we gave distributed algorithms determining cyclic edge connectivity and cyclic vertex connectivity of cubic graphs. The experiment results showed that the distributed algorithms were significantly improved in time compared to the original algorithms when the graph was large. Time costs of the distributed algorithms separately for cyclic edge connectivity and cyclic vertex connectivity are correspondingly less than 33% and less than 40% that of the single machine algorithms when the graph was large enough.
Several efficient distributed algorithms have been developed for matrix-matrix multiplication: the 3D algorithm, the 2D SUMMA algorithm, and the 2.5D algorithm. Each of these algorithms was independently conceived and...
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ISBN:
(纸本)9781450380706
Several efficient distributed algorithms have been developed for matrix-matrix multiplication: the 3D algorithm, the 2D SUMMA algorithm, and the 2.5D algorithm. Each of these algorithms was independently conceived and they trade-off memory needed per node and the inter-node data communication volume. The convolutional neural network (CNN) computation may be viewed as a generalization of matrix-multiplication combined with neighborhood stencil computations. We develop communication-efficient distributed-memory algorithms for CNNs that are analogous to the 2D/2.5D/3D algorithms for matrix-matrix multiplication.
It is shown that the performance of the maximal scheduling algorithm in wireless ad hoc networks under the hypergraph interference model can be further away from optimal than previously known. The exact worst-case per...
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It is shown that the performance of the maximal scheduling algorithm in wireless ad hoc networks under the hypergraph interference model can be further away from optimal than previously known. The exact worst-case performance of this distributed, greedy scheduling algorithm is analyzed.
For a wide range of control engineering applications, the problem of solving a system of linear equations is often encountered and has been well studied. Traditionally, this problem has been mainly solved in a central...
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For a wide range of control engineering applications, the problem of solving a system of linear equations is often encountered and has been well studied. Traditionally, this problem has been mainly solved in a centralized manner. However, for applications related to large-scale complex networked systems, centralized algorithms are often subjected to some practical issues due to limited computational power and communication bandwidth. As a promising and viable alternative, distributed algorithms can effectively address the issues associated with centralized algorithms by solving the problem efficiently in a multi-agent setting that accords with the distributed nature of networked systems. distributed algorithms decompose the entire problem into many sub-problems that are solved by individual agents in a cooperative manner. In this survey paper, we provide a detailed overview of the state of the art relevant to distributed algorithms for solving a system of linear equations. We will first review basic distributed algorithms including both discrete-time and continuous-time algorithms. Then we will discuss the extended algorithms to achieve communication efficiency. Furthermore, we will also introduce distributed algorithms to obtain the minimum-norm solution for a system of linear equations with multiple solutions, as well as the least-squares solution when there is no solution. Finally, the relationship of distributed algorithms for solving a system of linear equations to the existing distributed optimization algorithms is discussed. (C) 2019 Elsevier Ltd. All rights reserved.
In cell-free Massive MIMO systems, a large number of distributed wireless access points (AP) are simultaneously serving a number of user equipments (UEs). This setup has the ability to offer a good quality of service,...
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ISBN:
(纸本)9781728176055
In cell-free Massive MIMO systems, a large number of distributed wireless access points (AP) are simultaneously serving a number of user equipments (UEs). This setup has the ability to offer a good quality of service, be it that there is still a need for low-complexity signal processing algorithms. In this paper, the problem of optimal uplink receive combining is tackled by providing an efficient distributed MMSE algorithm, with a minimal number of exchanged parameters between the APs and the network center. Scalable versions of this distributed MMSE algorithm are also proposed ensuring that the algorithm can be used in large networks with many UEs.
The verification of distributed algorithms is a challenge for formal techniques supported by tools, as model checkers and proof assistants. The difficulties, even for powerful tools, lie in the derivation of proofs of...
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ISBN:
(纸本)9783030325053;9783030325046
The verification of distributed algorithms is a challenge for formal techniques supported by tools, as model checkers and proof assistants. The difficulties, even for powerful tools, lie in the derivation of proofs of required properties, such as safety and eventuality, for distributed algorithms. Verification by construction can be achieved by using a formal framework in which models are constructed at different levels of abstraction;each level of abstraction is refined by the one below, and this refinement relationships is documented by an abstraction relation namely a gluing invariant. The highest levels of abstraction are used to express the required behavior in terms of the problem domain and the lowest level of abstraction corresponds to an implementation from which an efficient implementation can be derived automatically. In this paper, we describe a methodology based on the general concept of refinement and used for developing distributed algorithms satisfying a given list of safety and liveness properties. The modelling methodology is defined in the Event-B modelling language using the IDE Rodin.
Termination is an important non-functional property of distributed algorithms. In an event-driven setting, the interesting aspect of termination is the possibility of control flow loops through communication, which th...
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ISBN:
(纸本)9781450367943
Termination is an important non-functional property of distributed algorithms. In an event-driven setting, the interesting aspect of termination is the possibility of control flow loops through communication, which this paper aims to investigate. In practice, it is often difficult to spot the possible communication behaviour of an algorithm at a glance. With a static analysis, the design process can be supported by visualizing possible flow of messages and give hints on possible sources of non-termination. We propose a termination analysis for distributed algorithms formulated in an event-driven specification language. The idea is to construct a message flow graph describing the possible communication between components (input-action pairs). We show that acyclicity of that graph implies termination. While many interesting algorithms indeed contain cycles, we also suggest ways of detecting cycles which cannot lead to non-termination. As a practical evaluation, we describe a concrete programming language together with a tool for automated termination analysis.
In this brief announcement we summarize our results concerning distributed algorithms for LP-type problems in the well-known gossip model. LP-type problems include many important classes of problems such as (integer) ...
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ISBN:
(纸本)9781450361842
In this brief announcement we summarize our results concerning distributed algorithms for LP-type problems in the well-known gossip model. LP-type problems include many important classes of problems such as (integer) linear programming, geometric problems like smallest enclosing ball and polytope distance, and set problems like hitting set and set cover. In the gossip model, a node can only push information to or pull information from nodes chosen uniformly at random. Protocols for the gossip model are usually very practical due to their fast convergence, their simplicity, and their stability under stress and disruptions. Our algorithms are very efficient (logarithmic rounds or better with just polylogarithmic communication work per node per round) whenever the combinatorial dimension of the given LP-type problem is constant, even if the size of the given LP-type problem is polynomially large in the number of nodes.
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