The paper presents a concept of the peer-to-peer related traffic optimization. The mechanism is based on the Oracle idea, where a peer is informed on closely located P2P nodes suggesting connection ...to them. The Oracle gains the relevant information on the basis of BGP databases, where the important extension is related to using a cooperation mechanism between different operators' domains.
Cost-Driven Peer Rating Algorithm Dulinski, Z.; Stankiewicz, R.; Wydrych, P. ...
2011 IEEE International Conference on Communications (ICC),
2011-June
Conference Proceeding
The paper presents a concept of a rating algorithm aiming at overall peer-to-peer traffic reduction (and locality awareness) and decrease of load on costly links, thus diminishing operator's costs. ...The rating algorithm is not only performed by a sole Oracle, as is typically proposed, but its operation is also supported by a similar entity located in other domains. Due to this concept, a usually omitted fact that the inter-domain routes are asymmetrical is properly dealt with. Simulations performed on a real topology show the usefulness of the presented approach.
One quarter of the Forward Ring Imaging Cherenkov (Forward RICH) detector has been installed and operated in the DELPHI experiment. The detector covers the forward-backward regions (15 degrees < ...theta <35 degrees ). Two radiator systems are used for particle identification in the momentum range up to 40 GeV/c, i.e., a liquid perfluorohexane and perfluorobutane gas. UV-photons with wavelengths from approximately 170 nm to approximately 200 nm (7.3-6.2 eV) are detected with high efficiency. The total active area of the photon detector is approximately 8 m/sup 2/.< >
The DELPHI detector installed in the LEP (Large Electron-Positron Collider) is equipped with RICH (ring imaging Cherenkov) counters. The barrel part incorporates a liquid (C/sub 6/F/sub 14/) and a ...gaseous (C/sub 5/F/sub 12/) radiator, providing particle identification up to 20 GeV/c. The Cherenkov photons of both radiators are detected by TPC (time projection chamber)-like photon detectors. The drift gas (75% CH/sub 4/+25% C/sub 2/H/sub 6/) is doped with TMAE (tetrakis-dimethylamine-ethylene) by which the ultraviolet Cherenkov photons are converted into single free photoelectrons. These are drifted towards multiwire proportional chambers at the end of the drift tubes, and the space coordinates of the conversion point are determined. One half of the barrel RICH is now equipped with drift tubes and has provided results from the liquid radiator since spring 1990. The gas radiator has been tested with C/sub 2/F/sub 6/ as a preliminary filling since August 1990. The data obtained demonstrate the good particle identification potential. For the liquid radiator, the number of detected photons per ring in hadron jets is N=8, whereas for muon pairs (single tracks) N=10 has been obtained. For the gas radiator, 2.1 photons per track were observed, which demonstrates good functioning of the focussing mirrors.< >
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