Performance measurement of the hybrid prefetch scheme on vehicular telematics networks

Abstract

This paper measures and analyzes the performance of the hybrid prefetch scheme for gateways on the vehicular telematics network where every information is indexed by the link (street) ID, via simulation using a discrete event simulator. Combining the classic LRU and FAR techniques, the hybrid scheme groups links according to whether they are referenced during the given time interval or not, orders by the Euclidean distance in each group, and fetches the referenced set first. The exensive experiment results demonstrate that 1) the hybrid scheme can improve the request-level instant reply ratio by up to 20.3 %, overcoming 20 % loss of record-level hit ratio, compared with LRU, 2) this scheme outperforms other spatial-locality-based schemes at all satisfiability ranges and LRU when the satisfiability is above 0.8, also showing stable reply ratio for the practical time tolerance range, 3) it quickly stablizes after the prefetch memory initialization and is less affected by the hourly data access pattern change, maintaining steady instant reply ratio for the number of records in each request. © 2010 Springer-Verlag Berlin Heidelberg.