Abstract: In recent years,mobile applications grow rapidly with the development of Android and iOS platforms.Most of applications on these smart phones are based on users,and these data are always generated by users.When users want relative data,it is not very realistic to request the data from a server every time.So a suitable cache technology is required.Traditional cache technologies pay much attention to the frequency or the last access time,but do not consider more about data generators’ relationship between data-generators.In mobile social network environment,data access is closely related to users’ relationships,so this factor should be suitable for use in cache technologies.In this paper,we proposed a user-relationship-based cache replacement algorithm,and combined users’ relationships with the classic cache algorithm LRU.Not only the access time of each data,but also the closeness value between the data requestors and the generator was taken into consideration.The experiment results show that our replacement strategy can improve cache hit ratio in mobile social environments.

Key words: Mobile social network,Mobile application,Least recently used,Closeness value,Cache size