Abstract
========

Service discovery in Ubiquitous Computing is a task which has to be done
frequently due to dynamically changing environments. The limited battery
power of mobile devices requires us to optimize frequent and energy
costly tasks, especially the ones incurring in communication activities.
In this paper we present a novel service discovery algorithm based on
node clustering. Nodes within a cluster may sleep to save energy when
idle. A clusterhead node is always active and answers discovery requests
on behalf of other nodes to achieve low discovery latencies. Simulation
experiments show energy savings of up to 66% compared to an approach
where all nodes are permanently active while the discovery latencies
were not increased.