In an ad hoc network, we cannot assume a trusted certificate authority and a centralized repository that are used in ordinary public-key infrastructure (PKI). Hence a PKI system of the Web-of-trust type in which each ...
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In an ad hoc network, we cannot assume a trusted certificate authority and a centralized repository that are used in ordinary public-key infrastructure (PKI). Hence a PKI system of the Web-of-trust type in which each node can issue certificates to others in a self-organizing manner has been studied. Although this system is useful for ad hoc networks whose topology can change, it has the problem that for authentication a node needs to find a certificate-chain to the destination node. In this paper, we formally model a web-of-trust-type PKI system, define the certificate-chain discovery problem, and propose a new distributed algorithm and its modifications that solve the problem. Furthermore, we propose a measure of communication cost, and according to the measure, we compare our algorithm with an existing method.
A wireless sensor network performing surveillance in time-critical missions involving event or target tracking demands accurate ground information be delivered within a delay guarantee. Present methods solve this by u...
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A wireless sensor network performing surveillance in time-critical missions involving event or target tracking demands accurate ground information be delivered within a delay guarantee. Present methods solve this by using in-network fusion across all packets to reduce network load in the hope of achieving the delay guarantee. In this paper, we aim to maximize data quality from sensor fusion, while still respecting delay guarantees. The proposed method makes admission control and routing decisions using a fully distributed algorithm based on constrained Markov Decision Processes (MDPs). Cooperation is enforced through well-defined rewards and leading nodes. Assessment of data quality is derived from likelihood ratio, which is a commonly used metric in sensor fusion. We study the performance of the proposed algorithm through extensive simulations, and show that it can achieve soft delay guarantees and good data quality compared to other schemes.
This paper proposes Local Conditioning as a truly distributed exact version of Belief Propagation for cyclic undirected graphical models. It is shown how to derive explicit recursive updates for messages and beliefs t...
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ISBN:
(纸本)9781509052943
This paper proposes Local Conditioning as a truly distributed exact version of Belief Propagation for cyclic undirected graphical models. It is shown how to derive explicit recursive updates for messages and beliefs that are truly distributed in the sense that messages are passed between individual nodes of the graph rather than between clustered nodes. Such a distributed algorithm is especially relevant for problems that require a distributed implementation, for example sensor networks. In order to compare its complexity and ease of implementation with a clustered version of Belief Propagation, we illustrate both in a Min-Sum block interpolation problem within the context of an Ising model.
We propose a new distributed algorithm for sparse variants of the network alignment problem, which occurs in a variety of data mining areas including systems biology, database matching, and computer vision. Our algori...
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We propose a new distributed algorithm for sparse variants of the network alignment problem, which occurs in a variety of data mining areas including systems biology, database matching, and computer vision. Our algorithm uses a belief propagation heuristic and provides near optimal solutions for this NP-hard combinatorial optimization problem. We show that our algorithm is faster and outperforms or ties existing algorithms on synthetic problems, a problem in bioinformatics, and a problem in ontology matching. We also provide a unified framework for studying and comparing all network alignment solvers.
This paper presents a non-convex optimization framework for the Network Utility Maximization problem in Wireless Networks, which incorporates the interference among links and introduces a power penalty term in the obj...
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This paper presents a non-convex optimization framework for the Network Utility Maximization problem in Wireless Networks, which incorporates the interference among links and introduces a power penalty term in the objective function to assure both convergence and energy efficiency of the method. Moreover, a distributed gradient based algorithm is proposed that converges to the optimal solution for problems with zero duality gap and a fair-allocation heuristic is presented to resolve user oscillations when they occur. Finally, numerical results regarding the performance of the heuristic and the distributed approach are presented.
This paper investigates the problems of the rotating consensus for a first-order multi-agent system under a directed graph. We propose the distributed algorithms for the agents so that agents can revolve around a comm...
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This paper investigates the problems of the rotating consensus for a first-order multi-agent system under a directed graph. We propose the distributed algorithms for the agents so that agents can revolve around a common center by using local relative information. Two kinds of rotating consensus problems are considered, namely, the rotating radius consensus probelm and the rotating displacement consensus problem. With the help of the graph theory and the Lyapunov theory, it is proved that the multi-agent system reaches relevant desired rotating consensus. Finally, simulation examples are provided to illustrate the correctness and effectiveness of proposed algorithms.
We propose in this paper the centralized and distributed algorithms for rate maximization in wireless ad hoc networks with cochannel interference. The goal of the proposed algorithms is maximizing the data rate while ...
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We propose in this paper the centralized and distributed algorithms for rate maximization in wireless ad hoc networks with cochannel interference. The goal of the proposed algorithms is maximizing the data rate while minimizing the transmitting power on each hop. The distributed algorithm simulates the operation of the centralized algorithm in a distributed fashion and need not measure the link gains for all transmission links and interference links. We show that the distributed algorithm can find the maximal transmitting rate and the minimal transmitting power as the centralized algorithm does. Simulation results also show that the proposed distributed algorithm outperforms the previous distributed algorithm in the data rate achieved.
This paper focuses on the research of distributed rate control algorithms for the reverse link of 1times EV-DO systems. First, following the basic idea proposed by Kelly (1997), a utility maximization system model is ...
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This paper focuses on the research of distributed rate control algorithms for the reverse link of 1times EV-DO systems. First, following the basic idea proposed by Kelly (1997), a utility maximization system model is formulated. The objective of the rate control algorithms is to make the system converge to the optimal state of the system model. We investigate the performance of two distributed rate control algorithms: the conventional distributed rate control (CDRC) algorithm and the modified distributed rate control (MDRC) algorithm. The CDRC is based on the MAC algorithm in CDMA2000 1times EV-DO Standard (2005). With the CDRC, we give our conclusions as how to design the specific functions of the algorithm according to the utility functions to ensure the objective mentioned above. The MDRC is a new proposed algorithm based on the optimal solution of the system problem which can also ensure the objective. Our numerical simulation results give the performance comparisons between them and validate our deduction.
Verifying that each flow in the network satisfies its QoS requirements is one of the biggest scalability challenges in the current DiffServ architecture. This task is usually performed by a centralized allocation enti...
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Verifying that each flow in the network satisfies its QoS requirements is one of the biggest scalability challenges in the current DiffServ architecture. This task is usually performed by a centralized allocation entity that monitors the flows' QoS parameters. Efficient detection of problematic flows is even more challenging when considering aggregated information such as the end to end delay suffered by packets belonging to a specific flow. Known oblivious and reactive monitoring techniques do not scale well when the number of flows and the length of their paths increase, and when the network load increases. This is due both to load on the centralized bandwidth allocation entity and to the excessive number of monitoring and control messages needed. We propose a new monitoring paradigm termed autonomous monitoring, in which the network itself (i.e. the routers along the flow path) is responsible to discover when a violation of the SLA occurs (or is soon to occur). Only in such cases the centralized allocation entity is notified, and can take the required actions. We study the performance of this new distributed algorithm through theoretical analysis and extensive simulations. Our results indicate that in addition to dramatically reducing the load from the centralized allocation entity, the amount of network traffic needed is relatively small and thus the new monitoring scheme scales well.
5G Network architecture based on the ultra-dense deployment of millimeter-micro wave (mmW-μW) HetNets is a promising solution to maximize revenue and business potential of mobile network operators (MNOs). However, in...
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ISBN:
(纸本)9781538647288;9781538647271
5G Network architecture based on the ultra-dense deployment of millimeter-micro wave (mmW-μW) HetNets is a promising solution to maximize revenue and business potential of mobile network operators (MNOs). However, in the near future, MNOs are urged to manage these network architectures that will serve a large number of mobile subscribes with distinctive user profiles (Gold, Silver, Bronze or Best effort), and individual quality of service (QoS) requirements. In this paper, we provide a new user association scheme that take into consideration the profile and QoS requirements of each mobile user. Our association problem is formulated as a one-to-many matching game inspired from matching theory. Then, we propose two distributed differed acceptance algorithms executed successively to achieve two stables matching. The first one consists of assigning each gold mobile users to the most suitable mmW-μW base stations (BSs). Next, based on the first stable matching results, the second one consists of assigning each best effort user to the most suitable mmW-μW BSs without degrading the QoS of gold users. Simulation results corroborate our solution, and show its effectiveness by enhancing the average sum rate performance, while respecting the profile and QoS requirements of mobile users compared to the conventional Max-SINR and Max-RSSI association schemes.
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