10.07.2015 Views

In Network Processing and Data Aggregation in

In Network Processing and Data Aggregation in

In Network Processing and Data Aggregation in

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Benefits1. It is a completely distributed <strong>and</strong> localized solution for the periodic aggregationproblem <strong>and</strong> is not error prone to node failures (unlike the solutions that make use ofaggregation-trees) due to the broadcast nature of the communications that are performedbetween the nodes.2. Simulations showed that it achieves significant energy sav<strong>in</strong>gs for some thresholdparameters (Th).DrawbacksIt needs the exchange of big volumes of <strong>in</strong>formation between the nodes when thecomput<strong>in</strong>g aggregate is more complex than the cases of MAX/MIN (e.g. MEDIAN,HISTOGRAM etc.).Gossip-Based Computation of aggregates [9]<strong>In</strong> this paper [9], a new theoretical method is proposed for the computation ofaggregates (like sums, averages, r<strong>and</strong>om samples) with gossip-style protocols. But whyshould someone use a gossip based protocol? Here are some characteristics of them thatare enough to conv<strong>in</strong>ce someone about the benefits from us<strong>in</strong>g them:a) It is known that gossip-based algorithms perform well <strong>in</strong> terms of scalability.b) Each node communicates with one or a few nodes of its neighborhood, thus, onlylocal <strong>in</strong>formation is neededc) Simplicity of design <strong>and</strong> operation. Usually, gossip-style protocols do not requireerror recovery mechanisms, while often <strong>in</strong>curr<strong>in</strong>g only moderate overhead, compared tooptimal determ<strong>in</strong>istic protocols such as the construction of data dissem<strong>in</strong>ation treesd) They achieve high stability under stress <strong>and</strong> disruptions. <strong>In</strong> comparison,traditional techniques have absolute guarantees, but are unstable or fail to make progressdur<strong>in</strong>g periods of even modest disruption.It is po<strong>in</strong>ted out that the po<strong>in</strong>t-to-po<strong>in</strong>t Uniform Gossip protocol is not suitable forwireless sensor networks. <strong>In</strong>stead, an alternative distributed broadcast-based algorithm isproposed, namely flood<strong>in</strong>g. The convergence of the flood<strong>in</strong>g algorithm is analyzed by

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!