Coded caching utilizes pre-fetching during off-peak hours and multi-casting for delivery in order to balance the traffic load in communication networks. Several works have studied the achievable peak and average rates under different conditions: variable file lengths or popularities, variable cache sizes, decentralized networks, etc. However, very few have considered the possibility of heterogeneous user profiles, despite modern content providers are investing heavily in categorizing users according to their habits and preferences. This paper proposes three coded caching schemes with uncoded pre-fetching for scenarios where end users are grouped into classes with different file demand sets (FDS). One scheme ignores the difference between the classes, another ignores the intersection between them and the third decouples the delivery of files common to all FDS from those unique to a single class. The transmission rates of the three schemes are compared with a lower bound to evaluate their gap to optimality, and with each other to show that each scheme can outperform the other two when certain conditions are met.
翻译:代码化的缓存利用了超高峰时段的预断和多投送,以平衡通信网络的交通负荷。一些工作研究了不同条件下可实现的峰值和平均速率:文件长度或广度可变、缓存规模可变、网络分散等等。然而,很少有人考虑了不同用户概况的可能性,尽管现代内容提供者正在根据用户的习惯和喜好大量投资于对用户进行分类。本文建议了三种编码化的缓存计划,对终端用户按不同文件需求组别(FDS)的情景进行未编码的预断。一个方案忽略了类别之间的差异,另一个方案忽略了类别与第三个类别之间的交叉点,将所有FDS通用文件的交付率从独有文件分解为单一类别。这三个方案的传输率与评估其差距与优化的较低约束值相比较,并互相表明,在满足某些条件时,每个方案都可优于其他两个方案。