In September, in Cracow Poland , Gun Sirer gave a keynote talk titled "Network Positioning for Wide-Area and Wireless Networks" at LOCALITY 2005, associated with the International Symposium on Distributed Computing (DISC 2005).

In his keynote, Sirer explained that determining the location of nodes in a network is a basic building block operation that enables many interesting, location-aware applications. He described two techniques for determining node positions: the first is a comprehensive localization system for wireless networks and wide-area, and the second is a localization and routing framework for Internet-like wide-area networks.

Sirer believes the challenge is to efficiently pinpoint the location of nodes without having to use expensive and energy-consuming specialized hardware such as GPS receivers. His talk described a new framework for wireless localization in which we cast the problem as a constraint system, extract constraints aggressively from the MAC layer, and solve it with the aid of a few landmarks.

"In wide-area networks, I believe the challenge is to efficiently resolve geographic queries, for example where is the closest node to ? at high scale?" said Sirer.

Previous approaches relied on network coordinates; in this talk, Sirer outlined a scalable and efficient scheme for resolving geographic queries without computing network coordinates, and showed how this framework can be applied to three qualitatively different wide-area applications.

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