Affiliations: Department of Computer Science and Engineering, The
Pennsylvania State University, University Park, PA 16802-6106, USA
Note: [] Corresponding author: Bo Yang, 342 IST Building, Department of
Computer Science and Engineering, University Park, PA 16802-6106, USA. Tel.: +1
814 863 3646; Fax: +1 814 865 3176; E-mail: [email protected]
Abstract: Multimedia data are becoming popular in wireless ad hoc
environments. However, the traditional content-based retrieval techniques are
inefficient in ad hoc networks due to the multiple limitations such as node
mobility, computation capability, memory space, network bandwidth, and data
heterogeneity. To provide an efficient platform for multimedia retrieval, we
propose to cluster ad hoc multimedia databases based on their semantic
contents, and construct a virtual hierarchical indexing infrastructure overlaid
on the mobile databases. This content-aware clustering scheme uses a
semantic-aware framework as the theoretical foundation for data organization.
Several novel techniques are presented to facilitate the representation and
manipulation of multimedia data in ad hoc networks: 1) using concise
distribution expressions to represent the semantic similarity of multimedia
data, 2) constructing clusters based on the semantic relationships between
multimedia entities, 3) reducing the cost of content-based multimedia retrieval
through the restriction of semantic distances, and 4) employing a self-adaptive
mechanism that dynamically adjusts to the content and topology changes of the
ad hoc networks. The proposed scheme is scalable, fault-tolerant, and efficient
in performing content-based multimedia retrieval as demonstrated in our
combination of theoretical analysis and extensive experimental studies.
Keywords: Wireless ad hoc network, content-aware clustering, data content distribution, multimedia data, semantic-based retrieval
