Traditional Caching Techniques Research Articles

Location-Aware Caching for Semantic-Based Image Queries in Mobile AD HOC Networks

Mobile image information retrieval, i.e., the processing of mobile image queries, has attracted research attention due to the recent technological advances in mobile and ubiquitous computing, network infrastructures, and multimedia streaming. The previous research focuses on data delivery, while few works have reported on content-based mobile information retrieval. Therefore, it is important to devise effective means to describe the semantics as well as content distribution of mobile data. Caching is an attractive solution that helps reveal semantic relationships among mobile data sources. However, traditional caching techniques rely on exact match of fixed values and are not efficient in dealing with imprecisely described image data. To address these issues, the authors propose a location-aware caching model which reflects the distribution of images based on the analysis of earlier queries. Through extensive simulations, the authors show that the proposed model can perform search with less cost for voluminous data.

Supporting User Mobility through Cache Relocation

Traffic and access delay can be reduced in a mobile network by caching data objects at network nodes near the clients. Traditional caching techniques, however, are unsuitable in this environment because they do not account for the changing location of the users. To deal with this problem, cache relocation techniques can be applied to dynamically relocate data objects so they remain close to the moving clients. Existing relocation techniques rely heavily on path prediction. Unfortunately, the inaccuracy of path prediction can lead to high relocation overhead and poor response time. This paper presents an analytical study of the effects of client mobility on network cache performance. Two new cache relocation techniques are proposed to deal with the issue of poor path prediction and reduce the overhead of existing cache relocation schemes. The first technique, 2PR, compensates for poor path prediction by temporarily moving data objects to a common parent node prior to a handover. Objects are moved to the correct destination once the client′s new location has been confirmed. The second technique, ROLP, reduces the traffic overhead associated with cache relocation by ensuring duplicate objects are not relocated and relocation of objects are performed only from the nearest node to the destination. Test results show that 2PR reduces the query delay experienced by mobile clients by 60 to 83% after handovers, while ROLP reduces the overhead of cache relocation by between 33 to 65% compared to existing schemes.