Design and analysis of collaborative EPC and RAN caching for LTE mobile networks
Design and analysis of collaborative EPC and RAN caching for LTE mobile networks
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DOI：
10.1016/j.comnet.2015.10.012
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发表时间：
2015-12
期刊：
影响因子：
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通讯作者：
Shoushou Ren;Tao Lin;W. An;Guoqiang Zhang;Dalei Wu;L. Bhuyan;Zhen Xu
中科院分区：
文献类型：
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作者：
Shoushou Ren;Tao Lin;W. An;Guoqiang Zhang;Dalei Wu;L. Bhuyan;Zhen Xu
移动视频流量的爆炸性增长给LTE移动网络带来了巨大的压力。在LTE移动网络中的演进分组核心(EPC)和无线接入网络(RAN)部署高速缓存可以通过减少重复的内容传输来有效地缓解这一压力。本文提出了一种LTE移动网络的协同缓存框架，将缓存部署在EPC和RAN上，以降低互联网接入的带宽成本，改善终端用户在延迟和拥塞方面的体验。基于该框架，我们将缓存问题分解为内容放置和请求路由两个子问题。我们利用拟阵和子模的性质，用贪婪的布局算法解决了内容放置的子问题。对于请求路由问题，我们将其转化为拟阵约束下子模函数极大化问题来求解，并提出了一种贪婪算法来调度短时隙的请求路由。在节省带宽成本方面，提出的CollaCach缓存方案可以获得至少1/2的最优解。实验结果表明，与其他方案相比，CollaCacheca方案可以节省更多的开销，支持更多的请求。
The explosive growth of mobile video traffic brings a great pressure on LTE mobile networks. Deploying caches at the evolved packet core (EPC) and radio access network (RAN) in LTE mobile networks can efficiently relieve this pressure by reducing duplicate content transmissions. In this paper, we propose a collaborative caching framework for the LTE mobile network with caches deployed at the EPC and RAN to reduce the bandwidth cost of Internet access and improve the end-user experience in terms of delay and congestion. Based on this framework, we decompose the caching problem into a content placement subproblem and a request routing subproblem. We solve the content placement subproblem with a greedy placement algorithm by utilizing the matroid and submodular properties. As for the request routing subproblem, we solve it by transforming it into the problem of maximizing a submodular function subject to a matroid constraint and present a greedy algorithm that schedules request routing with short time slot. The proposedCollaCachescheme can achieve at least 1/2 of the optimal solution in terms of bandwidth cost saving. Experimental results show thatCollaCachecan save more costs and support more requests compared with other schemes.