关键词: 上下文感知, 上下文缓存, 缓存置换算法, 上下文价值, 普适计算

Abstract: Due to the high dynamics of pervasive computing environment and the constraints of easy interruption and low transmission rate of wireless network, the overhead of context access is very huge. To solve these problems, a framework of context-aware system was proposed in this paper, and then a context caching replacement algorithm based on rules (RCRA) was introduced. The proposed algorithm determined whether to replace a context in the cache based on its access probability, timeliness and access history. When a new context was to get into the context cache, the algorithm was used to ensure that the latest and the most valuable context stayed in the cache. The experimental results show that the RCRA improves the hit rate and effectively reduces the overhead of context access. The RCRA is used in the rules-based context-aware system, and the algorithm has good utility.

Key words: context-aware, context cache, cache replacement algorism, context value, ubiquitous computing