Distributed algorithm

About: Distributed algorithm is a research topic. Over the lifetime, 20416 publications have been published within this topic receiving 548109 citations.

Clustering algorithms for wireless ad hoc networks

Abstract: Efficient clustering algorithms play a very important role in the fast connection establishment of ad hoc networks. In this paper, we describe a communication model that is derived directly from that of Bluetooth, an emerging technology for pervasive computing; this technology is expected to play a major role in future personal area network applications. We further propose two new distributed algorithms for clustering in wireless ad hoc networks. The existing algorithms often become infeasible because they use models where the discovering devices broadcast their Ids and exchange substantial information in the initial stages of the algorithm.We propose a 2-stage distributed O(N) randomized algorithm for an N node complete network, that always finds the minimum number of star-shaped clusters, which have maximum size. We then present a completely deterministic O(N) distributed algorithm for the same model, which achieves the same purpose. We describe in detail how these algorithms can be applied to Bluetooth for efficient scatternet formation. Finally, we evaluate both algorithms using simulation experiments based on the Bluetooth communication model, and compare their performance.

MACEDON: methodology for automatically creating, evaluating, and designing overlay networks

Abstract: Currently, researchers designing and implementing large-scale overlay services employ disparate techniques at each stage in the production cycle: design, implementation, experimentation, and evaluation. As a result, complex and tedious tasks are often duplicated leading to ineffective resource use and difficulty in fairly comparing competing algorithms. In this paper, we present MACEDON, an infrastructure that provides facilities to: i) specify distributed algorithms in a concise domain-specific language; ii) generate code that executes in popular evaluation infrastructures and in live networks; iii) leverage an overlay-generic API to simplify the interoperability of algorithm implementations and applications; and iv) enable consistent experimental evaluation. We have used MACEDON to implement and evaluate a number of algorithms, including AMMO, Bullet, Chord, NICE, Overcast, Pastry, Scribe, and SplitStream, typically with only a few hundred lines of MACEDON code. Using our infrastructure, we are able to accurately reproduce or exceed published results and behavior demonstrated by current publicly available implementations.

A Distributed Algorithm for Maximum Lifetime Routing in Sensor Networks with Mobile Sink

Abstract: We consider a noise-limited wireless sensor network that consists of battery-operated nodes which can route information to a mobile sink in a multi-hop fashion. The problem of maximizing the network's lifetime, defined as the period of time during which the network can route a feasible flow to each sink location subject to power/energy constraints, is cast into a linear program, reduced into a simpler equivalent form and solved via dual decomposition. The unknowns are the sink sojourn times and the routing flow vector for each sink location. The presence of a mobile sink presents new challenges but the problem structure can still be exploited to find the optimal solution. A distributed algorithm based on the subgradient method and using the sink as leader is proposed and its performance is evaluated through simulation for random networks. The algorithm's requirements in memory are also provided.

Design Optimization of Time-and Cost-Constrained Fault-Tolerant Distributed Embedded Systems

Abstract: In this paper we present an approach to the design optimization of fault tolerant embedded systems for safety-critical applications. Processes are statically scheduled and communications are performed using the time-triggered protocol. We use process re-execution and replication for tolerating transient faults. Our design optimization approach decides the mapping of processes to processors and the assignment of fault-tolerant policies to processes such that transient faults are tolerated and the timing constraints of the application are satisfied. We present several heuristics which are able to find fault-tolerant implementations given a limited amount of resources. The developed algorithms are evaluated using extensive experiments, including a real-life example.