中国邮电高校学报(英文) ›› 2021, Vol. 28 ›› Issue (1): 78-86.doi: 10.19682/j.cnki.1005-8885.2021.0001

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Dynamic hierarchical collaborative caching scheme in ultra-dense networks 

陈嘉宁,李曦,纪红,张鹤立   

  1. 北京邮电大学
  • 收稿日期:2020-03-26 修回日期:2020-08-11 出版日期:2021-02-28 发布日期:2021-03-28
  • 通讯作者: 陈嘉宁 E-mail:chenjianing@bupt.edu.cn
  • 基金资助:

    This work was supported by the National Natural Science Foundation of China (61771070 and 61671088).

Dynamic hierarchical collaborative caching scheme in ultra-dense networks

  1. Key Laboratory of Universal Wireless Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China
  • Received:2020-03-26 Revised:2020-08-11 Online:2021-02-28 Published:2021-03-28
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (61771070 and 61671088).

摘要:


Pushing popular contents to the edge of the network can meet the growing demand for data traffic, reduce latency and relieve the pressure of the backhaul. However, considering the limited storage space of the base stations, it is impossible to cache all the contents, especially in ultra-dense network ( UDN). Furthermore, the uneven distribution of mobile users results in load imbalance among small base stations (SBSs) in both time and space, which also affects the caching strategy. To overcome these shortcoming, the impact of the changing load imbalance in UDN was investigated, and then a dynamic hierarchical collaborative caching (DHCC) scheme was proposed to optimize latency and caching hit rate. The storage of the SBS is logically divided into the independent caching layer and the collaborative caching layer. The independent caching layer caches the most popular contents for local users爷interest, and the collaborative caching layer caches contents as much as possible for the benefit of content diversity in the region. Different SBSs have respective storage space layer division ratios, according to their real-time traffic load. For SBSs with heavy load, the independent caching layers are allocated with more space. Otherwise, the collaborative caching layers could store more contents with larger space. The simulation results show that, DHCC improved both transmission latency and hit rate compared with existing caching schemes.


关键词: ultra-dense network (UDN), load imbalance, caching

Abstract:

Pushing popular contents to the edge of the network can meet the growing demand for data traffic, reduce latency and relieve the pressure of the backhaul. However, considering the limited storage space of the base stations, it is impossible to cache all the contents, especially in ultra-dense network ( UDN). Furthermore, the uneven distribution of mobile users results in load imbalance among small base stations (SBSs) in both time and space, which also affects the caching strategy. To overcome these shortcoming, the impact of the changing load imbalance in UDN was investigated, and then a dynamic hierarchical collaborative caching (DHCC) scheme was proposed to optimize latency and caching hit rate. The storage of the SBS is logically divided into the independent caching layer and the collaborative caching layer. The independent caching layer caches the most popular contents for local users爷interest, and the collaborative caching layer caches contents as much as possible for the benefit of content diversity in the region. Different SBSs have respective storage space layer division ratios, according to their real-time traffic load. For SBSs with heavy load, the independent caching layers are allocated with more space. Otherwise, the collaborative caching layers could store more contents with larger space. The simulation results show that, DHCC improved both transmission latency and hit rate compared with existing caching schemes.

Key words: ultra-dense network, load imbalance, caching

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