An Efficient Content Search Method Based on Local Link Replacement in Unstructured Peer-to-Peer Networks

Nagao OGINO  Takeshi KITAHARA  

IEICE TRANSACTIONS on Communications   Vol.E101-B   No.3   pp.740-749
Publication Date: 2018/03/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2017EBP3024
Type of Manuscript: PAPER
Category: Network
peer-to-peer network,  partial-match query,  interest-based locality,  small-world topology,  local link replacement,  

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Peer-to-peer overlay networks can easily achieve a large-scale content sharing system on the Internet. Although unstructured peer-to-peer networks are suitable for finding entire partial-match content, flooding-based search is an inefficient way to obtain target content. When the shared content is semantically specified by a great number of attributes, it is difficult to derive the semantic similarity of peers beforehand. This means that content search methods relying on interest-based locality are more advantageous than those based on the semantic similarity of peers. Existing search methods that exploit interest-based locality organize multiple peer groups, in each of which peers with common interests are densely connected using short-cut links. However, content searches among multiple peer groups are still inefficient when the number of incident links at each peer is limited due to the capacity of the peer. This paper proposes a novel content search method that exploits interest-based locality. The proposed method can organize an efficient peer-to-peer network similar to the semantic small-world random graph, which can be organized by the existing methods based on the semantic similarity of peers. In the proposed method, topology transformation based on local link replacement maintains the numbers of incident links at all the peers. Simulation results confirm that the proposed method can achieve a significantly higher ratio of obtainable partial-match content than existing methods that organize peer groups.