Environment-Adaptive Dynamic Caching for Vehicular Named Data Networks in Dynamic Network Environments

Caching plays a vital role in information exchanges in vehicular named data networks (VNDNs). However, current caching techniques cannot adapt to variable network environments. In this article, we propose an environment-adaptive dynamic caching (EADC) strategy for VNDNs to cope with the changing environments. This strategy consists of three factors: vehicle characteristic attributes, motion centrality attributes, and transmission cost attributes, which are used jointly to determine the cache probability. The vehicle characteristic attributes can reflect not only the social attributes but also the content popularity, and helps cache the most popular and desired contents. The motion centrality attributes reflect the contacting capacity and the control capacity of vehicles, and this enables vehicles with the most important locations to cache valuable contents. The transmission cost attributes focus on multiple performance metrics such as transmission delay and cache redundancy, which are used to reflect the content acquisition difficulty and reduce the hard events of long-distance content acquisition. The greatest characteristics and advantages of EADC are the strong adaptability to the content demand changing, network topology changing, and channel quality changing. Extensive simulation results illustrate the advantages of EADC in terms of average delay, cache utilization, cache hit ratio, and average hop count.