The Internet is a hierarchical architecture comprising heterogeneous entities of privately owned infrastructures, where higher level Internet service providers (ISPs) supply connectivity to the local ISPs and charge t...
详细信息
The Internet is a hierarchical architecture comprising heterogeneous entities of privately owned infrastructures, where higher level Internet service providers (ISPs) supply connectivity to the local ISPs and charge the local ISPs for the transit services. One of the challenging problems facing service providers today is how to increase the profitability while maintaining good service qualities. In this work, we seek to understand the fundamental issues on the "interplay" (or interaction) between ISPs at different tiers. While the local ISPs (which we term peers) can communicate with each other by purchasing the connectivity from transit ISPs, there stands an opportunity for them to set up private peering relationships. Under this competitive framework, we explore the issues on (a) impact of peering relationship, (b) resource distribution and (c) revenue maximization. Firstly, a generalized model is presented to characterize the behaviors of peers and the transit ISP, in which their economic interests are reflected. We study how a peer can distributively determine its optimal peering strategy. Furthermore, we show how a transit ISP is able to utilize the available information to infer its optimal pricing strategy, under which a revenue maximization is achieved. A distributed algorithm is proposed to help ISPs to provide a fair and efficient bandwidth allocation to peers, avoiding a resource monopolization of the market. Extensive simulations are carried out to support our claims.
We study a version of the beta-assignment problem (Chang and Lee, 1988) on asynchronous rings: consider a set of items and a set of m colors, where each item is associated to one color. Consider also n computational a...
详细信息
ISBN:
(纸本)9781424400546
We study a version of the beta-assignment problem (Chang and Lee, 1988) on asynchronous rings: consider a set of items and a set of m colors, where each item is associated to one color. Consider also n computational agents connected by an asynchronous ring. Each agent holds a subset of the items, where initially different agents might hold items associated to the same color. We analyze the problem of distributively assigning colors to agents in such a way that (a) each color is assigned to one agent and (b) the number of different colors assigned to each agent is minimum. Since any color assignment requires that the items be distributed according to it (e.g. all items of the same color are to be held by only one agent), we define the cost of a color assignment as the amount of items that need to be moved, given an initial allocation. We first show that any distributed algorithm for this problem on the ring requires a communication complexity of Omega(n middot m) and then we exhibit a polynomial time distributed algorithm with message complexity matching the bound, that determines a color assignment with cost at most (2 + epsi) times the optimal cost, for any 0 < epsi < 1
We propose two new distributed scheduling policies for ad hoc wireless networks that can achieve provable capacity regions. Known scheduling policies that guarantee comparable capacity regions are either centralized o...
详细信息
ISBN:
(纸本)1424401704
We propose two new distributed scheduling policies for ad hoc wireless networks that can achieve provable capacity regions. Known scheduling policies that guarantee comparable capacity regions are either centralized or need computation time that increases with the size of the network. In contrast, the unique feature of the proposed distributed scheduling policies is that they are constant-time policies, i.e., the time needed for computing a schedule is independent of the network size. Hence, they can be easily deployed in large networks
This paper presents an efficient distributed clustering technique capable of identifying embedded clusters over very large spatial datasets. The technique is based upon a client server approach, where the huge dataset...
详细信息
This paper presents an efficient distributed clustering technique capable of identifying embedded clusters over very large spatial datasets. The technique is based upon a client server approach, where the huge dataset stored in the server are partitioned into almost k equal partitions which are used by k clients to identify the embedded clusters in parallel for each partition sent by the server. Finally, the embedded clusters obtained from the k clients are merged at the Server for the ultimate results. Experimental results establish the superiority of the technique in terms of scale-up, speedup as well as cluster quality, in comparison to its other counterparts ([3], [6]).
In this paper we present a new distributed group mutual exclusion (DGME) based on clients/servers model, and uses a dynamic data structures. Several processes (clients) can access simultaneously to a same opened sessi...
详细信息
In this paper we present a new distributed group mutual exclusion (DGME) based on clients/servers model, and uses a dynamic data structures. Several processes (clients) can access simultaneously to a same opened session (server). The algorithm ensures that, at any time, at most one session is opened, and any requested session will be opened in a finite time. The number of messages is between 0 and m, where m is the number of session in the network. In the average case, O(Log(m)) messages are necessary to open a session. The maximum concurrency is n, where n is the number of processes in the network
This paper shows a new distributed algorithm for deadlock detection and resolution under the single-resource request model that highly improves the complexity measurements of previous proposals. The algorithm has a co...
详细信息
This paper shows a new distributed algorithm for deadlock detection and resolution under the single-resource request model that highly improves the complexity measurements of previous proposals. The algorithm has a communication cost of 2n - 1 messages and a latency of n /spl middot/ T for a deadlock cycle of n processes, where T is the inter-site communication delay. The algorithm achieves this improvement even verifying the strongest correctness criteria considered in previous works: it resolves all deadlocks in finite time and does not resolve false deadlocks.
With the advance in technology, wireless sensor networks have been widely used in many application areas such as agricultural and environmental monitoring. Sensors distributed in these networks serve as good sources f...
详细信息
With the advance in technology, wireless sensor networks have been widely used in many application areas such as agricultural and environmental monitoring. Sensors distributed in these networks serve as good sources for data. This calls for distributed data mining, which searches for implicit, previously unknown, and potentially useful patterns that might be embedded in the distributed data. Many existing distributed data mining algorithms do not allow users to express the patterns to be mined according to their intension via the use of constraints. Consequently, these unconstrained mining algorithms can yield numerous patterns that are not interesting to users. In this paper, we propose an efficient tree-based system for mining patterns that satisfy user-defined constraints from a distributed environment such as a wireless sensor network. Experimental results show effectiveness of our proposed system
Camera networks are perhaps the most common type of sensor network and are deployed in a variety of real-world applications including surveillance, intelligent environments and scientific remote monitoring. A key prob...
详细信息
Camera networks are perhaps the most common type of sensor network and are deployed in a variety of real-world applications including surveillance, intelligent environments and scientific remote monitoring. A key problem in deploying a network of cameras is calibration, i.e., determining the location and orientation of each sensor so that observations in an image can be mapped to locations in the real world. This paper proposes a fully distributed approach for camera network calibration. The cameras collaborate to track an object that moves through the environment and reason probabilistically about which camera poses are consistent with the observed images. This reasoning employs sophisticated techniques for handling the difficult nonlinearities imposed by projective transformations, as well as the dense correlations that arise between distant cameras. Our method requires minimal overlap of the cameras' fields of view and makes very few assumptions about the motion of the object. In contrast to existing approaches, which are centralized, our distributed algorithm scales easily to very large camera networks. We evaluate the system on a real camera network with 25 nodes as well as simulated camera networks of up to 50 cameras and demonstrate that our approach performs well even when communication is lossy
This paper addresses the l—Exclusion problem for mobile ad hoc networks. The l—Exclusion problem, a generalization of distributed mutual exclusion problem, involves a group of processes, each of which intermittently...
详细信息
This paper addresses the l—Exclusion problem for mobile ad hoc networks. The l—Exclusion problem, a generalization of distributed mutual exclusion problem, involves a group of processes, each of which intermittently requires access to one of l identical resources or pieces of code called the critical section (CS). In literature, few token—based solutions to this l—Exclusion problem are available. Nevertheless, these solutions suffer from poor failure resiliency, as these do not consider failures associated with mobile ad hoc networks, such as loss or regeneration of tokens, crash or sudden recovery of nodes. This paper presents a consensus—based mobility—aware l—exclusion (LE) algorithm that operates asynchronously and copes explicitly with arbitrary (possibly concurrent) topology changes associated with such networks. The algorithm can tolerate link changes or failures, sudden crashes or recoveries of at most l—1 mobile nodes. The algorithm is based on collection enough consensuses for a mobile node intending to enter CS, and uses diffusing computations for this purpose. The algorithm requires nodes to communicate only with their current neighbors, making it well—suited for use in mobile ad hoc networks. This paper presents a simulation study to demonstrate that the proposed algorithm, as compared to the k—Reverse Link (KRL) algorithm, is quite effective to variety of operating conditions, and is highly adaptive to frequent and unpredictable topology changes due to link changes or failures or formations, sudden crashes or recoveries of at most l—1 mobile nodes, under different mobility settings.
暂无评论